This patch series is rebased on v6.8-rc4 from coresisght tree,[1], since latest changes are dependent on coresight_get/set_mode APIs.
Changelog from v6: * Added special device files for reading crashdata, so that read_prevboot mode flag is removed. * Added new sysfs TMC device attribute, stop_on_flush. Stop on flush trigger event is disabled by default. User need to explicitly enable this from sysfs for panic stop to work. * Address parameter for panicstop ETM configuration is chosen as kernel "panic" address by default. * Added missing tmc_wait_for_tmcready during panic handling * Few other misc code rearrangements.
Changelog from v5: * Fixed issues reported by CONFIG_DEBUG_ATOMIC_SLEEP * Fixed a memory leak while reading data from /dev/tmc_etrx in READ_PREVBOOT mode * Tested reading trace data from crashdump kernel
Changelog from v4: * Device tree binding - Description is made more explicit on the usage of reserved memory region - Mismatch in memory region names in dts binding and driver fixed - Removed "mem" suffix from the memory region names * Rename "struct tmc_register_snapshot" -> "struct tmc_crash_metadata", since it contains more than register snapshot. Related variables are named accordingly. * Rename struct tmc_drvdata members resrv_buf -> crash_tbuf metadata -> crash_mdata * Size field in metadata refers to RSZ register and hence indicates the size in 32 bit words. ETR metadata follows this convention, the same has been extended to ETF metadata as well. * Added crc32 for more robust metadata and tracedata validation. * Added/modified dev_dbg messages during metadata validation * Fixed a typo in patch 5 commit description
Changelog from v3: * Converted the Coresight ETM driver change to a named configuration. RFC tag has been removed with this change. * Fixed yaml issues reported by "make dt_binding_check" * Added names for reserved memory regions 0 and 1 * Added prevalidation checks for metadata processing * Fixed a regression introduced in RFC v3 - TMC Status register was getting saved wrongly * Reverted memremap attribute changes from _WB to _WC to match with the dma map attributes * Introduced reserved buffer mode specific .sync op. This fixes a possible crash when reserved buffer mode was used in normal trace capture, due to unwanted dma maintenance operations.
v6 is posted here: https://www.spinics.net/lists/kernel/msg5055812.html
Using Coresight for Kernel panic and Watchdog reset =================================================== This patch series is about extending Linux coresight driver support to address kernel panic and watchdog reset scenarios. This would help coresight users to debug kernel panic and watchdog reset using coresight trace data.
Coresight trace capture: Kernel panic ------------------------------------- From the coresight driver point of view, addressing the kernel panic situation has four main requirements.
a. Support for allocation of trace buffer pages from reserved memory area. Platform can advertise this using a new device tree property added to relevant coresight nodes.
b. Support for stopping coresight blocks at the time of panic
c. Saving required metadata in the specified format
d. Support for reading trace data captured at the time of panic
Allocation of trace buffer pages from reserved RAM ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A new optional device tree property "memory-region" is added to the ETR/ETF device nodes, that would give the base address and size of trace buffer.
Static allocation of trace buffers would ensure that both IOMMU enabled and disabled cases are handled. Also, platforms that support persistent RAM will allow users to read trace data in the subsequent boot without booting the crashdump kernel.
Note: For ETR sink devices, this reserved region will be used for both trace capture and trace data retrieval. For ETF sink devices, internal SRAM would be used for trace capture, and they would be synced to reserved region for retrieval.
Note: Patches 1 & 2 adds support for this.
Disabling coresight blocks at the time of panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In order to avoid the situation of losing relevant trace data after a kernel panic, it would be desirable to stop the coresight blocks at the time of panic.
This can be achieved by configuring the comparator, CTI and sink devices as below,
Comparator(triggers on kernel panic) --->External out --->CTI -- | ETR/ETF stop <------External In <-------------- Note:
* Patch 6 provides the necessary ETR configuration. * Patch 7 provides the necessary ETM configuration.
Saving metadata at the time of kernel panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Coresight metadata involves all additional data that are required for a successful trace decode in addition to the trace data. This involves ETR/ETF, ETE register snapshot etc.
A new optional device property "memory-region" is added to the ETR/ETF/ETE device nodes for this.
Note: Patches 3 & 4 adds support for this.
Reading trace data captured at the time of panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Trace data captured at the time of panic, can be read from rebooted kernel or from crashdump kernel using the below mentioned interface.
Note: Patch 5 adds support for this.
Steps for reading trace data captured in previous boot ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1. cd /sys/bus/coresight/devices/tmc_etrXX/
2. Dump trace buffer crashdata to a file,
#dd if=/dev/crash_tmc_etrXX of=~/cstrace.bin
General flow of trace capture and decode incase of kernel panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1. Enable source and sink on all the cores using the sysfs interface. ETR sink will have trace buffers allocated from reserved memory, by selecting "resrv" buffer mode from sysfs.
2. Run relevant tests.
3. On a kernel panic, all coresight blocks are disabled, necessary metadata is synced by kernel panic handler.
System would eventually reboot or boot a crashdump kernel.
4. For platforms that supports crashdump kernel, raw trace data can be dumped using the coresight sysfs interface from the crashdump kernel itself. Persistent RAM is not a requirement in this case.
5. For platforms that supports persistent RAM, trace data can be dumped using the coresight sysfs interface in the subsequent Linux boot. Crashdump kernel is not a requirement in this case. Persistent RAM ensures that trace data is intact across reboot.
Coresight trace capture: Watchdog reset --------------------------------------- The main difference between addressing the watchdog reset and kernel panic case are below,
a. Saving coresight metadata need to be taken care by the SCP(system control processor) firmware in the specified format, instead of kernel.
b. Reserved memory region given by firmware for trace buffer and metadata has to be in persistent RAM. Note: This is a requirement for watchdog reset case but optional in kernel panic case.
Watchdog reset can be supported only on platforms that meet the above two requirements.
Testing Kernel panic on Linux 6.8 --------------------------------- 1. Enable the preloaded ETM configuration
#echo 1 > /sys/kernel/config/cs-syscfg/configurations/panicstop/enable
2. Configure CTI using sysfs interface
#./cti_setup.sh
#cat cti_setup.sh
cd /sys/bus/coresight/devices/
ap_cti_config () { #ETM trig out[0] trigger to Channel 0 echo 0 4 > channels/trigin_attach }
etf_cti_config () { #ETF Flush in trigger from Channel 0 echo 0 1 > channels/trigout_attach echo 1 > channels/trig_filter_enable }
etr_cti_config () { #ETR Flush in from Channel 0 echo 0 1 > channels/trigout_attach echo 1 > channels/trig_filter_enable }
ctidevs=`find . -name "cti*"`
for i in $ctidevs do cd $i
connection=`find . -name "ete*"` if [ ! -z "$connection" ] then echo "AP CTI config for $i" ap_cti_config fi
connection=`find . -name "tmc_etf*"` if [ ! -z "$connection" ] then echo "ETF CTI config for $i" etf_cti_config fi
connection=`find . -name "tmc_etr*"` if [ ! -z "$connection" ] then echo "ETR CTI config for $i" etr_cti_config fi
cd .. done
Note: CTI connections are SOC specific and hence the above script is added just for reference.
3. Choose reserved buffer mode for ETR buffer #echo "resrv" > /sys/bus/coresight/devices/tmc_etr0/buf_mode_preferred
4. Enable stop on flush trigger configuration #echo 1 > /sys/bus/coresight/devices/tmc_etr0/stop_on_flush
4. Start Coresight tracing on cores 1 and 2 using sysfs interface
5. Run some application on core 1 #taskset -c 1 dd if=/dev/urandom of=/dev/null &
6. Invoke kernel panic on core 2 #echo 1 > /proc/sys/kernel/panic #taskset -c 2 echo c > /proc/sysrq-trigger
7. From rebooted kernel or crashdump kernel, read crashdata
Note: For crashdump kernel option, please make sure "crash_kexec_post_notifiers" is added to the kernel bootargs.
#dd if=/dev/crash_tmc_etr0 of=/trace/cstrace.bin
8. Run opencsd decoder tools/scripts to generate the instruction trace.
Sample Core 1 instruction trace dump: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A etm4_enable_hw: ffff800008ae1dd4 CONTEXT EL2 etm4_enable_hw: ffff800008ae1dd4 I etm4_enable_hw: ffff800008ae1dd4: d503201f nop I etm4_enable_hw: ffff800008ae1dd8: d503201f nop I etm4_enable_hw: ffff800008ae1ddc: d503201f nop I etm4_enable_hw: ffff800008ae1de0: d503201f nop I etm4_enable_hw: ffff800008ae1de4: d503201f nop I etm4_enable_hw: ffff800008ae1de8: d503233f paciasp I etm4_enable_hw: ffff800008ae1dec: a9be7bfd stp x29, x30, [sp, #-32]! I etm4_enable_hw: ffff800008ae1df0: 910003fd mov x29, sp I etm4_enable_hw: ffff800008ae1df4: a90153f3 stp x19, x20, [sp, #16] I etm4_enable_hw: ffff800008ae1df8: 2a0003f4 mov w20, w0 I etm4_enable_hw: ffff800008ae1dfc: 900085b3 adrp x19, ffff800009b95000 <reserved_mem+0xc48> I etm4_enable_hw: ffff800008ae1e00: 910f4273 add x19, x19, #0x3d0 I etm4_enable_hw: ffff800008ae1e04: f8747a60 ldr x0, [x19, x20, lsl #3] E etm4_enable_hw: ffff800008ae1e08: b4000140 cbz x0, ffff800008ae1e30 <etm4_starting_cpu+0x50> I 149.039572921 etm4_enable_hw: ffff800008ae1e30: a94153f3 ldp x19, x20, [sp, #16] I 149.039572921 etm4_enable_hw: ffff800008ae1e34: 52800000 mov w0, #0x0 // #0 I 149.039572921 etm4_enable_hw: ffff800008ae1e38: a8c27bfd ldp x29, x30, [sp], #32
..snip
149.052324811 chacha_block_generic: ffff800008642d80: 9100a3e0 add x0, I 149.052324811 chacha_block_generic: ffff800008642d84: b86178a2 ldr w2, [x5, x1, lsl #2] I 149.052324811 chacha_block_generic: ffff800008642d88: 8b010803 add x3, x0, x1, lsl #2 I 149.052324811 chacha_block_generic: ffff800008642d8c: b85fc063 ldur w3, [x3, #-4] I 149.052324811 chacha_block_generic: ffff800008642d90: 0b030042 add w2, w2, w3 I 149.052324811 chacha_block_generic: ffff800008642d94: b8217882 str w2, [x4, x1, lsl #2] I 149.052324811 chacha_block_generic: ffff800008642d98: 91000421 add x1, x1, #0x1 I 149.052324811 chacha_block_generic: ffff800008642d9c: f100443f cmp x1, #0x11
Sample Core 2 instruction trace dump(kernel panic triggered core): ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A etm4_enable_hw: ffff800008ae1dd4 CONTEXT EL2 etm4_enable_hw: ffff800008ae1dd4 I etm4_enable_hw: ffff800008ae1dd4: d503201f nop I etm4_enable_hw: ffff800008ae1dd8: d503201f nop I etm4_enable_hw: ffff800008ae1ddc: d503201f nop I etm4_enable_hw: ffff800008ae1de0: d503201f nop I etm4_enable_hw: ffff800008ae1de4: d503201f nop I etm4_enable_hw: ffff800008ae1de8: d503233f paciasp I etm4_enable_hw: ffff800008ae1dec: a9be7bfd stp x29, x30, [sp, #-32]! I etm4_enable_hw: ffff800008ae1df0: 910003fd mov x29, sp I etm4_enable_hw: ffff800008ae1df4: a90153f3 stp x19, x20, [sp, #16] I etm4_enable_hw: ffff800008ae1df8: 2a0003f4 mov w20, w0 I etm4_enable_hw: ffff800008ae1dfc: 900085b3 adrp x19, ffff800009b95000 <reserved_mem+0xc48> I etm4_enable_hw: ffff800008ae1e00: 910f4273 add x19, x19, #0x3d0 I etm4_enable_hw: ffff800008ae1e04: f8747a60 ldr x0, [x19, x20, lsl #3] E etm4_enable_hw: ffff800008ae1e08: b4000140 cbz x0, ffff800008ae1e30 <etm4_starting_cpu+0x50> I 149.046243445 etm4_enable_hw: ffff800008ae1e30: a94153f3 ldp x19, x20, [sp, #16] I 149.046243445 etm4_enable_hw: ffff800008ae1e34: 52800000 mov w0, #0x0 // #0 I 149.046243445 etm4_enable_hw: ffff800008ae1e38: a8c27bfd ldp x29, x30, [sp], #32 I 149.046243445 etm4_enable_hw: ffff800008ae1e3c: d50323bf autiasp E 149.046243445 etm4_enable_hw: ffff800008ae1e40: d65f03c0 ret A ete_sysreg_write: ffff800008adfa18
..snip
I 149.05422547 panic: ffff800008096300: a90363f7 stp x23, x24, [sp, #48] I 149.05422547 panic: ffff800008096304: 6b00003f cmp w1, w0 I 149.05422547 panic: ffff800008096308: 3a411804 ccmn w0, #0x1, #0x4, ne // ne = any N 149.05422547 panic: ffff80000809630c: 540001e0 b.eq ffff800008096348 <panic+0xe0> // b.none I 149.05422547 panic: ffff800008096310: f90023f9 str x25, [sp, #64] E 149.05422547 panic: ffff800008096314: 97fe44ef bl ffff8000080276d0 <panic_smp_self_stop> A panic: ffff80000809634c I 149.05422547 panic: ffff80000809634c: 910102d5 add x21, x22, #0x40 I 149.05422547 panic: ffff800008096350: 52800020 mov w0, #0x1 // #1 E 149.05422547 panic: ffff800008096354: 94166b8b bl ffff800008631180 <bust_spinlocks> N 149.054225518 bust_spinlocks: ffff800008631180: 340000c0 cbz w0, ffff800008631198 <bust_spinlocks+0x18> I 149.054225518 bust_spinlocks: ffff800008631184: f000a321 adrp x1, ffff800009a98000 <pbufs.0+0xbb8> I 149.054225518 bust_spinlocks: ffff800008631188: b9405c20 ldr w0, [x1, #92] I 149.054225518 bust_spinlocks: ffff80000863118c: 11000400 add w0, w0, #0x1 I 149.054225518 bust_spinlocks: ffff800008631190: b9005c20 str w0, [x1, #92] E 149.054225518 bust_spinlocks: ffff800008631194: d65f03c0 ret A panic: ffff800008096358
Future Improvements ------------------- * Explore changing CTI sysfs script to system configuration manager profile * Explore Perf based trace capture and decode
Links: 1. https://kernel.googlesource.com/pub/scm/linux/kernel/git/coresight/linux.git...
Linu Cherian (7): dt-bindings: arm: coresight-tmc: Add "memory-region" property coresight: tmc-etr: Add support to use reserved trace memory coresight: core: Add provision for panic callbacks coresight: tmc: Enable panic sync handling coresight: tmc: Add support for reading crash data coresight: tmc: Stop trace capture on FlIn coresight: config: Add preloaded configuration
.../bindings/arm/arm,coresight-tmc.yaml | 26 ++ drivers/hwtracing/coresight/Makefile | 2 +- .../coresight/coresight-cfg-preload.c | 2 + .../coresight/coresight-cfg-preload.h | 2 + .../hwtracing/coresight/coresight-cfg-pstop.c | 83 +++++ drivers/hwtracing/coresight/coresight-core.c | 37 ++ .../coresight/coresight-etm4x-core.c | 1 + .../hwtracing/coresight/coresight-tmc-core.c | 248 +++++++++++++- .../hwtracing/coresight/coresight-tmc-etf.c | 161 ++++++++- .../hwtracing/coresight/coresight-tmc-etr.c | 322 +++++++++++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 83 +++++ include/linux/coresight.h | 25 ++ 12 files changed, 972 insertions(+), 20 deletions(-) create mode 100644 drivers/hwtracing/coresight/coresight-cfg-pstop.c
memory-region 0: Reserved trace buffer memory
TMC ETR: When available, use this reserved memory region for trace data capture. Same region is used for trace data retention after a panic or watchdog reset.
TMC ETF: When available, use this reserved memory region for trace data retention synced from internal SRAM after a panic or watchdog reset.
memory-region 1: Reserved meta data memory
TMC ETR, ETF: When available, use this memory for register snapshot retention synced from hardware registers after a panic or watchdog reset.
Reviewed-by: Rob Herring robh@kernel.org Signed-off-by: Linu Cherian lcherian@marvell.com --- Changelog from v6: * Added new line after memory-region description - suggested by Rob Herring
.../bindings/arm/arm,coresight-tmc.yaml | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml b/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml index cb8dceaca70e..4787d7c6bac2 100644 --- a/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml +++ b/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml @@ -101,6 +101,29 @@ properties: and ETF configurations. $ref: /schemas/graph.yaml#/properties/port
+ memory-region: + items: + - description: Reserved trace buffer memory for ETR and ETF sinks. + For ETR, this reserved memory region is used for trace data capture. + Same region is used for trace data retention as well after a panic + or watchdog reset. + This reserved memory region is used as trace buffer or used for trace + data retention only if specifically selected by the user in sysfs + interface. + The default memory usage models for ETR in sysfs/perf modes are + otherwise unaltered. + + For ETF, this reserved memory region is used by default for + retention of trace data synced from internal SRAM after a panic + or watchdog reset. + - description: Reserved meta data memory. Used for ETR and ETF sinks + for storing metadata. + + memory-region-names: + items: + - const: tracedata + - const: metadata + required: - compatible - reg @@ -115,6 +138,9 @@ examples: etr@20070000 { compatible = "arm,coresight-tmc", "arm,primecell"; reg = <0x20070000 0x1000>; + memory-region = <&etr_trace_mem_reserved>, + <&etr_mdata_mem_reserved>; + memory-region-names = "tracedata", "metadata";
clocks = <&oscclk6a>; clock-names = "apb_pclk";
Add support to use reserved memory for coresight ETR trace buffer.
Introduce a new ETR buffer mode called ETR_MODE_RESRV, which becomes available when ETR device tree node is supplied with a valid reserved memory region.
ETR_MODE_RESRV can be selected only by explicit user request.
$ echo resrv >/sys/bus/coresight/devices/tmc_etr<N>/buf_mode_preferred
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com --- Changelog from v6: * Removed redundant goto statements * Setting of etr_buf->size to the reserved memory size is done after successful dma map inside the alloc function * Removed the special casing for ETR_MODE_RESRV * Fixed the tab spacing in struct tmc_drvdata
.../hwtracing/coresight/coresight-tmc-core.c | 47 +++++++++++ .../hwtracing/coresight/coresight-tmc-etr.c | 82 ++++++++++++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 27 ++++++ 3 files changed, 153 insertions(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 72005b0c633e..1325387d6257 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -22,6 +22,7 @@ #include <linux/spinlock.h> #include <linux/pm_runtime.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/coresight.h> #include <linux/amba/bus.h>
@@ -370,6 +371,50 @@ static inline bool tmc_etr_has_non_secure_access(struct tmc_drvdata *drvdata) return (auth & TMC_AUTH_NSID_MASK) == 0x3; }
+static struct device_node *tmc_get_region_byname(struct device_node *node, + char *name) +{ + int index; + + index = of_property_match_string(node, "memory-region-names", name); + if (index < 0) + return ERR_PTR(-ENODEV); + + return of_parse_phandle(node, "memory-region", index); +} + +static void tmc_get_reserved_region(struct device *parent) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(parent); + struct device_node *node; + struct resource res; + int rc; + + node = tmc_get_region_byname(parent->of_node, "tracedata"); + if (IS_ERR_OR_NULL(node)) { + dev_dbg(parent, "No reserved trace buffer specified\n"); + return; + } + + rc = of_address_to_resource(node, 0, &res); + of_node_put(node); + if (rc || res.start == 0 || resource_size(&res) == 0) { + dev_err(parent, "Reserved trace buffer memory is invalid\n"); + return; + } + + drvdata->crash_tbuf.vaddr = memremap(res.start, + resource_size(&res), + MEMREMAP_WC); + if (IS_ERR_OR_NULL(drvdata->crash_tbuf.vaddr)) { + dev_err(parent, "Reserved trace buffer mapping failed\n"); + return; + } + + drvdata->crash_tbuf.paddr = res.start; + drvdata->crash_tbuf.size = resource_size(&res); +} + /* Detect and initialise the capabilities of a TMC ETR */ static int tmc_etr_setup_caps(struct device *parent, u32 devid, void *dev_caps) { @@ -482,6 +527,8 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) drvdata->size = readl_relaxed(drvdata->base + TMC_RSZ) * 4; }
+ tmc_get_reserved_region(dev); + desc.dev = dev;
switch (drvdata->config_type) { diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index e75428fa1592..2bbf53480c66 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -30,6 +30,7 @@ struct etr_buf_hw { bool has_iommu; bool has_etr_sg; bool has_catu; + bool has_resrv; };
/* @@ -694,6 +695,75 @@ static const struct etr_buf_operations etr_flat_buf_ops = { .get_data = tmc_etr_get_data_flat_buf, };
+/* + * tmc_etr_alloc_resrv_buf: Allocate a contiguous DMA buffer from reserved region. + */ +static int tmc_etr_alloc_resrv_buf(struct tmc_drvdata *drvdata, + struct etr_buf *etr_buf, int node, + void **pages) +{ + struct etr_flat_buf *resrv_buf; + struct device *real_dev = drvdata->csdev->dev.parent; + + /* We cannot reuse existing pages for resrv buf */ + if (pages) + return -EINVAL; + + resrv_buf = kzalloc(sizeof(*resrv_buf), GFP_KERNEL); + if (!resrv_buf) + return -ENOMEM; + + resrv_buf->daddr = dma_map_resource(real_dev, drvdata->crash_tbuf.paddr, + drvdata->crash_tbuf.size, + DMA_FROM_DEVICE, 0); + if (dma_mapping_error(real_dev, resrv_buf->daddr)) { + dev_err(real_dev, "failed to map source buffer address\n"); + kfree(resrv_buf); + return -ENOMEM; + } + + resrv_buf->vaddr = drvdata->crash_tbuf.vaddr; + resrv_buf->size = etr_buf->size = drvdata->crash_tbuf.size; + resrv_buf->dev = &drvdata->csdev->dev; + etr_buf->hwaddr = resrv_buf->daddr; + etr_buf->mode = ETR_MODE_RESRV; + etr_buf->private = resrv_buf; + return 0; +} + +static void tmc_etr_free_resrv_buf(struct etr_buf *etr_buf) +{ + struct etr_flat_buf *resrv_buf = etr_buf->private; + + if (resrv_buf && resrv_buf->daddr) { + struct device *real_dev = resrv_buf->dev->parent; + + dma_unmap_resource(real_dev, resrv_buf->daddr, + resrv_buf->size, DMA_FROM_DEVICE, 0); + } + kfree(resrv_buf); +} + +static void tmc_etr_sync_resrv_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp) +{ + /* + * Adjust the buffer to point to the beginning of the trace data + * and update the available trace data. + */ + etr_buf->offset = rrp - etr_buf->hwaddr; + if (etr_buf->full) + etr_buf->len = etr_buf->size; + else + etr_buf->len = rwp - rrp; +} + +static const struct etr_buf_operations etr_resrv_buf_ops = { + .alloc = tmc_etr_alloc_resrv_buf, + .free = tmc_etr_free_resrv_buf, + .sync = tmc_etr_sync_resrv_buf, + .get_data = tmc_etr_get_data_flat_buf, +}; + /* * tmc_etr_alloc_sg_buf: Allocate an SG buf @etr_buf. Setup the parameters * appropriately. @@ -800,6 +870,7 @@ static const struct etr_buf_operations *etr_buf_ops[] = { [ETR_MODE_FLAT] = &etr_flat_buf_ops, [ETR_MODE_ETR_SG] = &etr_sg_buf_ops, [ETR_MODE_CATU] = NULL, + [ETR_MODE_RESRV] = &etr_resrv_buf_ops };
void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu) @@ -825,6 +896,7 @@ static inline int tmc_etr_mode_alloc_buf(int mode, case ETR_MODE_FLAT: case ETR_MODE_ETR_SG: case ETR_MODE_CATU: + case ETR_MODE_RESRV: if (etr_buf_ops[mode] && etr_buf_ops[mode]->alloc) rc = etr_buf_ops[mode]->alloc(drvdata, etr_buf, node, pages); @@ -843,6 +915,7 @@ static void get_etr_buf_hw(struct device *dev, struct etr_buf_hw *buf_hw) buf_hw->has_iommu = iommu_get_domain_for_dev(dev->parent); buf_hw->has_etr_sg = tmc_etr_has_cap(drvdata, TMC_ETR_SG); buf_hw->has_catu = !!tmc_etr_get_catu_device(drvdata); + buf_hw->has_resrv = is_tmc_reserved_region_valid(dev->parent); }
static bool etr_can_use_flat_mode(struct etr_buf_hw *buf_hw, ssize_t etr_buf_size) @@ -874,13 +947,10 @@ static struct etr_buf *tmc_alloc_etr_buf(struct tmc_drvdata *drvdata, if (!etr_buf) return ERR_PTR(-ENOMEM);
- etr_buf->size = size; - /* If there is user directive for buffer mode, try that first */ if (drvdata->etr_mode != ETR_MODE_AUTO) rc = tmc_etr_mode_alloc_buf(drvdata->etr_mode, drvdata, etr_buf, node, pages); - /* * If we have to use an existing list of pages, we cannot reliably * use a contiguous DMA memory (even if we have an IOMMU). Otherwise, @@ -1830,6 +1900,7 @@ static const char *const buf_modes_str[] = { [ETR_MODE_FLAT] = "flat", [ETR_MODE_ETR_SG] = "tmc-sg", [ETR_MODE_CATU] = "catu", + [ETR_MODE_RESRV] = "resrv", [ETR_MODE_AUTO] = "auto", };
@@ -1848,6 +1919,9 @@ static ssize_t buf_modes_available_show(struct device *dev, if (buf_hw.has_catu) size += sysfs_emit_at(buf, size, "%s ", buf_modes_str[ETR_MODE_CATU]);
+ if (buf_hw.has_resrv) + size += sysfs_emit_at(buf, size, "%s ", buf_modes_str[ETR_MODE_RESRV]); + size += sysfs_emit_at(buf, size, "\n"); return size; } @@ -1875,6 +1949,8 @@ static ssize_t buf_mode_preferred_store(struct device *dev, drvdata->etr_mode = ETR_MODE_ETR_SG; else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_CATU]) && buf_hw.has_catu) drvdata->etr_mode = ETR_MODE_CATU; + else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_RESRV]) && buf_hw.has_resrv) + drvdata->etr_mode = ETR_MODE_RESRV; else if (sysfs_streq(buf, buf_modes_str[ETR_MODE_AUTO])) drvdata->etr_mode = ETR_MODE_AUTO; else diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index cef979c897e6..2abc5387cdf7 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -135,6 +135,7 @@ enum etr_mode { ETR_MODE_FLAT, /* Uses contiguous flat buffer */ ETR_MODE_ETR_SG, /* Uses in-built TMC ETR SG mechanism */ ETR_MODE_CATU, /* Use SG mechanism in CATU */ + ETR_MODE_RESRV, /* Use reserved region contiguous buffer */ ETR_MODE_AUTO, /* Use the default mechanism */ };
@@ -164,6 +165,17 @@ struct etr_buf { void *private; };
+/** + * @paddr : Start address of reserved memory region. + * @vaddr : Corresponding CPU virtual address. + * @size : Size of reserved memory region. + */ +struct tmc_resrv_buf { + phys_addr_t paddr; + void *vaddr; + size_t size; +}; + /** * struct tmc_drvdata - specifics associated to an TMC component * @base: memory mapped base address for this component. @@ -187,6 +199,10 @@ struct etr_buf { * @idr_mutex: Access serialisation for idr. * @sysfs_buf: SYSFS buffer for ETR. * @perf_buf: PERF buffer for ETR. + * @crash_tbuf: Used by ETR as hardware trace buffer and for trace data + * retention (after crash) only when ETR_MODE_RESRV buffer + * mode is enabled. Used by ETF for trace data retention + * (after crash) by default. */ struct tmc_drvdata { void __iomem *base; @@ -211,6 +227,7 @@ struct tmc_drvdata { struct mutex idr_mutex; struct etr_buf *sysfs_buf; struct etr_buf *perf_buf; + struct tmc_resrv_buf crash_tbuf; };
struct etr_buf_operations { @@ -328,6 +345,16 @@ tmc_sg_table_buf_size(struct tmc_sg_table *sg_table) return (unsigned long)sg_table->data_pages.nr_pages << PAGE_SHIFT; }
+static inline bool is_tmc_reserved_region_valid(struct device *dev) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(dev); + + if (drvdata->crash_tbuf.paddr && + drvdata->crash_tbuf.size) + return true; + return false; +} + struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);
void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu);
Panic callback handlers allows coresight device drivers to sync relevant trace data and trace metadata to reserved memory regions so that they can be retrieved later in the subsequent boot or in the crashdump kernel.
Signed-off-by: Linu Cherian lcherian@marvell.com
--- Changelog from v6: * Rebase changes w.r.t struct coresight_device
drivers/hwtracing/coresight/coresight-core.c | 37 ++++++++++++++++++++ include/linux/coresight.h | 12 +++++++ 2 files changed, 49 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index b83613e34289..61d75aad476b 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -19,6 +19,7 @@ #include <linux/property.h> #include <linux/delay.h> #include <linux/pm_runtime.h> +#include <linux/panic_notifier.h>
#include "coresight-etm-perf.h" #include "coresight-priv.h" @@ -1365,6 +1366,36 @@ const struct bus_type coresight_bustype = { .name = "coresight", };
+static int coresight_panic_sync(struct device *dev, void *data) +{ + int mode; + struct coresight_device *csdev; + + /* Run through panic sync handlers for all enabled devices */ + csdev = container_of(dev, struct coresight_device, dev); + mode = coresight_get_mode(csdev); + + if ((mode == CS_MODE_SYSFS) || (mode == CS_MODE_PERF)) { + if (panic_ops(csdev)) + panic_ops(csdev)->sync(csdev); + } + + return 0; +} + +static int coresight_panic_cb(struct notifier_block *self, + unsigned long v, void *p) +{ + bus_for_each_dev(&coresight_bustype, NULL, NULL, + coresight_panic_sync); + + return 0; +} + +static struct notifier_block coresight_notifier = { + .notifier_call = coresight_panic_cb, +}; + static int __init coresight_init(void) { int ret; @@ -1377,6 +1408,10 @@ static int __init coresight_init(void) if (ret) goto exit_bus_unregister;
+ /* Register function to be called for panic */ + ret = atomic_notifier_chain_register(&panic_notifier_list, + &coresight_notifier); + /* initialise the coresight syscfg API */ ret = cscfg_init(); if (!ret) @@ -1391,6 +1426,8 @@ static int __init coresight_init(void) static void __exit coresight_exit(void) { cscfg_exit(); + atomic_notifier_chain_unregister(&panic_notifier_list, + &coresight_notifier); etm_perf_exit(); bus_unregister(&coresight_bustype); } diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 5f288d475490..b156467c9baa 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -315,6 +315,7 @@ enum cs_mode { #define link_ops(csdev) csdev->ops->link_ops #define helper_ops(csdev) csdev->ops->helper_ops #define ect_ops(csdev) csdev->ops->ect_ops +#define panic_ops(csdev) csdev->ops->panic_ops
/** * struct coresight_ops_sink - basic operations for a sink @@ -384,11 +385,22 @@ struct coresight_ops_helper { int (*disable)(struct coresight_device *csdev, void *data); };
+ +/** + * struct coresight_ops_panic - Generic device ops for panic handing + * + * @sync : Sync the device register state/trace data + */ +struct coresight_ops_panic { + int (*sync)(struct coresight_device *csdev); +}; + struct coresight_ops { const struct coresight_ops_sink *sink_ops; const struct coresight_ops_link *link_ops; const struct coresight_ops_source *source_ops; const struct coresight_ops_helper *helper_ops; + const struct coresight_ops_panic *panic_ops; };
static inline u32 csdev_access_relaxed_read32(struct csdev_access *csa,
- Get reserved region from device tree node for metadata - Define metadata format for TMC - Add TMC ETR panic sync handler that syncs register snapshot to metadata region - Add TMC ETF panic sync handler that syncs register snapshot to metadata region and internal SRAM to reserved trace buffer region.
Signed-off-by: Linu Cherian lcherian@marvell.com --- Changelog from v6: * Moved the changes specific to stop on flush event that are part of panic sync handler, from patch 6 to here. * Added missing tmc_wait_for_tmcready(drvdata);
.../hwtracing/coresight/coresight-tmc-core.c | 25 +++++++ .../hwtracing/coresight/coresight-tmc-etf.c | 72 +++++++++++++++++++ .../hwtracing/coresight/coresight-tmc-etr.c | 70 ++++++++++++++++++ drivers/hwtracing/coresight/coresight-tmc.h | 45 +++++++++++- 4 files changed, 211 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 1325387d6257..7170416c3e1a 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -413,6 +413,31 @@ static void tmc_get_reserved_region(struct device *parent)
drvdata->crash_tbuf.paddr = res.start; drvdata->crash_tbuf.size = resource_size(&res); + + /* Metadata region */ + node = tmc_get_region_byname(parent->of_node, "metadata"); + if (IS_ERR_OR_NULL(node)) { + dev_dbg(parent, "No metadata memory-region specified\n"); + return; + } + + rc = of_address_to_resource(node, 0, &res); + of_node_put(node); + if (rc || res.start == 0 || resource_size(&res) == 0) { + dev_err(parent, "Metadata memory is invalid\n"); + return; + } + + drvdata->crash_mdata.vaddr = memremap(res.start, + resource_size(&res), + MEMREMAP_WC); + if (IS_ERR_OR_NULL(drvdata->crash_mdata.vaddr)) { + dev_err(parent, "Metadata memory mapping failed\n"); + return; + } + + drvdata->crash_mdata.paddr = res.start; + drvdata->crash_mdata.size = resource_size(&res); }
/* Detect and initialise the capabilities of a TMC ETR */ diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index d4f641cd9de6..e396716da4f3 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -590,6 +590,73 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, return to_read; }
+static int tmc_panic_sync_etf(struct coresight_device *csdev) +{ + u32 val; + struct csdev_access *csa; + struct tmc_crash_metadata *mdata; + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + csa = &drvdata->csdev->access; + + /* Make sure we have valid reserved memory */ + if (!is_tmc_reserved_region_valid(csdev->dev.parent)) + return 0; + + mdata = (struct tmc_crash_metadata *)drvdata->crash_mdata.vaddr; + mdata->valid = false; + + CS_UNLOCK(drvdata->base); + + /* Proceed only if ETF is enabled or configured as sink */ + val = readl(drvdata->base + TMC_CTL); + if (!(val & TMC_CTL_CAPT_EN)) + goto out; + + val = readl(drvdata->base + TMC_MODE); + if (val != TMC_MODE_CIRCULAR_BUFFER) + goto out; + + val = readl(drvdata->base + TMC_FFSR); + /* Do manual flush and stop only if its not auto-stopped */ + if (!(val & TMC_FFSR_FT_STOPPED)) { + dev_info(&csdev->dev, + "%s: Triggering manual flush\n", __func__); + tmc_flush_and_stop(drvdata); + } else + tmc_wait_for_tmcready(drvdata); + + /* Sync registers from hardware to metadata region */ + mdata->sts = csdev_access_relaxed_read32(csa, TMC_STS); + mdata->trc_paddr = drvdata->crash_tbuf.paddr; + + /* Sync Internal SRAM to reserved trace buffer region */ + tmc_etb_dump_hw(drvdata); + memcpy(drvdata->crash_tbuf.vaddr, drvdata->buf, drvdata->len); + /* Store as per RSZ register convention */ + mdata->size = drvdata->len >> 2; + + /* + * Make sure all previous writes are completed, + * before we mark valid + */ + dsb(sy); + mdata->valid = true; + /* + * Below order need to maintained, since crc of metadata + * is dependent on first + */ + mdata->crc32_tdata = find_crash_tracedata_crc(drvdata, mdata); + mdata->crc32_mdata = find_crash_metadata_crc(mdata); + + tmc_disable_hw(drvdata); + + dev_info(&csdev->dev, "%s: success\n", __func__); +out: + CS_UNLOCK(drvdata->base); + return 0; +} + static const struct coresight_ops_sink tmc_etf_sink_ops = { .enable = tmc_enable_etf_sink, .disable = tmc_disable_etf_sink, @@ -603,6 +670,10 @@ static const struct coresight_ops_link tmc_etf_link_ops = { .disable = tmc_disable_etf_link, };
+static const struct coresight_ops_panic tmc_etf_sync_ops = { + .sync = tmc_panic_sync_etf, +}; + const struct coresight_ops tmc_etb_cs_ops = { .sink_ops = &tmc_etf_sink_ops, }; @@ -610,6 +681,7 @@ const struct coresight_ops tmc_etb_cs_ops = { const struct coresight_ops tmc_etf_cs_ops = { .sink_ops = &tmc_etf_sink_ops, .link_ops = &tmc_etf_link_ops, + .panic_ops = &tmc_etf_sync_ops, };
int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 2bbf53480c66..b268de6af9a3 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1810,6 +1810,71 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev) return 0; }
+static int tmc_panic_sync_etr(struct coresight_device *csdev) +{ + u32 val; + struct csdev_access *csa; + struct tmc_crash_metadata *mdata; + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + csa = &drvdata->csdev->access; + + if (!drvdata->etr_buf) + return 0; + + /* Being in RESRV mode implies valid reserved memory as well */ + if (drvdata->etr_buf->mode != ETR_MODE_RESRV) + return 0; + + mdata = (struct tmc_crash_metadata *)drvdata->crash_mdata.vaddr; + mdata->valid = false; + + CS_UNLOCK(drvdata->base); + + /* Proceed only if ETR is enabled */ + val = readl(drvdata->base + TMC_CTL); + if (!(val & TMC_CTL_CAPT_EN)) + goto out; + + val = readl(drvdata->base + TMC_FFSR); + /* Do manual flush and stop only if its not auto-stopped */ + if (!(val & TMC_FFSR_FT_STOPPED)) { + dev_info(&csdev->dev, + "%s: Triggering manual flush\n", __func__); + tmc_flush_and_stop(drvdata); + } else + tmc_wait_for_tmcready(drvdata); + + /* Sync registers from hardware to metadata region */ + mdata->size = csdev_access_relaxed_read32(csa, TMC_RSZ); + mdata->sts = csdev_access_relaxed_read32(csa, TMC_STS); + mdata->rrp = tmc_read_rrp(drvdata); + mdata->rwp = tmc_read_rwp(drvdata); + mdata->dba = tmc_read_dba(drvdata); + mdata->trc_paddr = drvdata->crash_tbuf.paddr; + + /* + * Make sure all previous writes are completed, + * before we mark valid + */ + dsb(sy); + mdata->valid = true; + /* + * Below order need to maintained, since crc of metadata + * is dependent on first + */ + mdata->crc32_tdata = find_crash_tracedata_crc(drvdata, mdata); + mdata->crc32_mdata = find_crash_metadata_crc(mdata); + + tmc_disable_hw(drvdata); + + dev_info(&csdev->dev, "%s: success\n", __func__); +out: + CS_UNLOCK(drvdata->base); + + return 0; +} + static const struct coresight_ops_sink tmc_etr_sink_ops = { .enable = tmc_enable_etr_sink, .disable = tmc_disable_etr_sink, @@ -1818,8 +1883,13 @@ static const struct coresight_ops_sink tmc_etr_sink_ops = { .free_buffer = tmc_free_etr_buffer, };
+static const struct coresight_ops_panic tmc_etr_sync_ops = { + .sync = tmc_panic_sync_etr, +}; + const struct coresight_ops tmc_etr_cs_ops = { .sink_ops = &tmc_etr_sink_ops, + .panic_ops = &tmc_etr_sync_ops, };
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 2abc5387cdf7..875d4129da7c 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -12,6 +12,7 @@ #include <linux/miscdevice.h> #include <linux/mutex.h> #include <linux/refcount.h> +#include <linux/crc32.h>
#define TMC_RSZ 0x004 #define TMC_STS 0x00c @@ -76,6 +77,9 @@ #define TMC_AXICTL_AXCACHE_OS (0xf << 2) #define TMC_AXICTL_ARCACHE_OS (0xf << 16)
+/* TMC_FFSR - 0x300 */ +#define TMC_FFSR_FT_STOPPED BIT(1) + /* TMC_FFCR - 0x304 */ #define TMC_FFCR_FLUSHMAN_BIT 6 #define TMC_FFCR_EN_FMT BIT(0) @@ -131,6 +135,21 @@ enum tmc_mem_intf_width { #define CORESIGHT_SOC_600_ETR_CAPS \ (TMC_ETR_SAVE_RESTORE | TMC_ETR_AXI_ARCACHE)
+/* TMC metadata region for ETR and ETF configurations */ +struct tmc_crash_metadata { + uint32_t crc32_mdata; /* crc of metadata */ + uint32_t crc32_tdata; /* crc of tracedata */ + uint32_t valid; /* Indicate if this ETF/ETR was enabled */ + uint32_t size; /* Ram Size register */ + uint32_t sts; /* Status register */ + uint32_t reserved32[3]; + uint64_t rrp; /* Ram Read pointer register */ + uint64_t rwp; /* Ram Write pointer register */ + uint64_t dba; /* Data buffer address register */ + uint64_t trc_paddr; /* Phys address of trace buffer */ + uint64_t reserved64[3]; +}; + enum etr_mode { ETR_MODE_FLAT, /* Uses contiguous flat buffer */ ETR_MODE_ETR_SG, /* Uses in-built TMC ETR SG mechanism */ @@ -203,6 +222,8 @@ struct tmc_resrv_buf { * retention (after crash) only when ETR_MODE_RESRV buffer * mode is enabled. Used by ETF for trace data retention * (after crash) by default. + * @crash_mdata: Reserved memory for storing tmc crash metadata. + * Used by ETR/ETF. */ struct tmc_drvdata { void __iomem *base; @@ -228,6 +249,7 @@ struct tmc_drvdata { struct etr_buf *sysfs_buf; struct etr_buf *perf_buf; struct tmc_resrv_buf crash_tbuf; + struct tmc_resrv_buf crash_mdata; };
struct etr_buf_operations { @@ -350,11 +372,32 @@ static inline bool is_tmc_reserved_region_valid(struct device *dev) struct tmc_drvdata *drvdata = dev_get_drvdata(dev);
if (drvdata->crash_tbuf.paddr && - drvdata->crash_tbuf.size) + drvdata->crash_tbuf.size && + drvdata->crash_mdata.paddr && + drvdata->crash_mdata.size) return true; return false; }
+static inline uint32_t find_crash_metadata_crc(struct tmc_crash_metadata *md) +{ + unsigned long crc_size; + + crc_size = sizeof(struct tmc_crash_metadata) - + offsetof(struct tmc_crash_metadata, crc32_tdata); + return crc32_le(0, (void *)&md->crc32_tdata, crc_size); +} + +static inline uint32_t find_crash_tracedata_crc(struct tmc_drvdata *drvdata, + struct tmc_crash_metadata *md) +{ + unsigned long crc_size; + + /* Take CRC of configured buffer size to keep it simple */ + crc_size = md->size << 2; + return crc32_le(0, (void *)drvdata->crash_tbuf.vaddr, crc_size); +} + struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);
void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu);
* Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace captured in previous crash/watchdog reset.
* Add special device files for reading ETR/ETF crash data.
* User can read the crash data as below
For example, for reading crash data from tmc_etf sink
#dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Tanmay Jagdale tanmay@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com --- Changelog from v6: * Removed read_prevboot flag in sysfs * Added special device files for reading crashdata * Renamed CS mode READ_PREVBOOT to READ_CRASHDATA * Setting the READ_CRASHDATA mode is done as part of file open.
.../coresight/coresight-etm4x-core.c | 1 + .../hwtracing/coresight/coresight-tmc-core.c | 145 ++++++++++++++++- .../hwtracing/coresight/coresight-tmc-etf.c | 73 +++++++++ .../hwtracing/coresight/coresight-tmc-etr.c | 154 +++++++++++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 11 +- include/linux/coresight.h | 13 ++ 6 files changed, 390 insertions(+), 7 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index c2ca4a02dfce..5eb411e39b01 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1011,6 +1011,7 @@ static void etm4_disable(struct coresight_device *csdev,
switch (mode) { case CS_MODE_DISABLED: + case CS_MODE_READ_CRASHDATA: break; case CS_MODE_SYSFS: etm4_disable_sysfs(csdev); diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 7170416c3e1a..b6bc37159527 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -103,6 +103,60 @@ u32 tmc_get_memwidth_mask(struct tmc_drvdata *drvdata) return mask; }
+int tmc_read_prepare_crashdata(struct tmc_drvdata *drvdata) +{ + int ret = 0; + struct tmc_crash_metadata *mdata; + struct coresight_device *csdev = drvdata->csdev; + + if (!drvdata->crash_mdata.vaddr) { + ret = -ENOMEM; + goto out; + } + + mdata = drvdata->crash_mdata.vaddr; + /* Check data integrity of metadata */ + if (mdata->crc32_mdata != find_crash_metadata_crc(mdata)) { + dev_dbg(&drvdata->csdev->dev, + "CRC mismatch in tmc crash metadata\n"); + ret = -EINVAL; + goto out; + } + /* Check data integrity of tracedata */ + if (mdata->crc32_tdata != find_crash_tracedata_crc(drvdata, mdata)) { + dev_dbg(&drvdata->csdev->dev, + "CRC mismatch in tmc crash tracedata\n"); + ret = -EINVAL; + goto out; + } + /* Check for valid metadata */ + if (!mdata->valid) { + dev_dbg(&drvdata->csdev->dev, + "Data invalid in tmc crash metadata\n"); + ret = -EINVAL; + goto out; + } + + /* Sink specific crashdata mode preparation */ + ret = crashdata_ops(csdev)->prepare(csdev); + if (ret) + goto out; + + if (mdata->sts & 0x1) + coresight_insert_barrier_packet(drvdata->buf); + +out: + return ret; +} + +int tmc_read_unprepare_crashdata(struct tmc_drvdata *drvdata) +{ + struct coresight_device *csdev = drvdata->csdev; + + /* Sink specific crashdata mode preparation */ + return crashdata_ops(csdev)->unprepare(csdev); +} + static int tmc_read_prepare(struct tmc_drvdata *drvdata) { int ret = 0; @@ -153,6 +207,9 @@ static int tmc_open(struct inode *inode, struct file *file) struct tmc_drvdata *drvdata = container_of(file->private_data, struct tmc_drvdata, miscdev);
+ if (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA) + return -EBUSY; + ret = tmc_read_prepare(drvdata); if (ret) return ret; @@ -177,13 +234,12 @@ static inline ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata, return -EINVAL; }
-static ssize_t tmc_read(struct file *file, char __user *data, size_t len, - loff_t *ppos) +static ssize_t tmc_read_common(struct tmc_drvdata *drvdata, char __user *data, + size_t len, loff_t *ppos) { char *bufp; ssize_t actual; - struct tmc_drvdata *drvdata = container_of(file->private_data, - struct tmc_drvdata, miscdev); + actual = tmc_get_sysfs_trace(drvdata, *ppos, len, &bufp); if (actual <= 0) return 0; @@ -200,6 +256,16 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len, return actual; }
+static ssize_t tmc_read(struct file *file, char __user *data, size_t len, + loff_t *ppos) +{ + struct tmc_drvdata *drvdata = container_of(file->private_data, + struct tmc_drvdata, miscdev); + + return tmc_read_common(drvdata, data, len, ppos); +} + + static int tmc_release(struct inode *inode, struct file *file) { int ret; @@ -222,6 +288,61 @@ static const struct file_operations tmc_fops = { .llseek = no_llseek, };
+static int tmc_crashdata_open(struct inode *inode, struct file *file) +{ + int ret; + struct tmc_drvdata *drvdata = container_of(file->private_data, + struct tmc_drvdata, + crashdev); + + if (!coresight_take_mode(drvdata->csdev, CS_MODE_READ_CRASHDATA)) + return -EBUSY; + + ret = tmc_read_prepare(drvdata); + if (ret) { + coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED); + return ret; + } + + nonseekable_open(inode, file); + + dev_dbg(&drvdata->csdev->dev, "%s: successfully opened\n", __func__); + return 0; +} + +static ssize_t tmc_crashdata_read(struct file *file, char __user *data, + size_t len, loff_t *ppos) +{ + struct tmc_drvdata *drvdata = container_of(file->private_data, + struct tmc_drvdata, + crashdev); + + return tmc_read_common(drvdata, data, len, ppos); +} + +static int tmc_crashdata_release(struct inode *inode, struct file *file) +{ + int ret = 0; + struct tmc_drvdata *drvdata = container_of(file->private_data, + struct tmc_drvdata, + crashdev); + + ret = tmc_read_unprepare(drvdata); + + coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED); + + dev_dbg(&drvdata->csdev->dev, "%s: released\n", __func__); + return ret; +} + +static const struct file_operations tmc_crashdata_fops = { + .owner = THIS_MODULE, + .open = tmc_crashdata_open, + .read = tmc_crashdata_read, + .release = tmc_crashdata_release, + .llseek = no_llseek, +}; + static enum tmc_mem_intf_width tmc_get_memwidth(u32 devid) { enum tmc_mem_intf_width memwidth; @@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) coresight_unregister(drvdata->csdev); else pm_runtime_put(&adev->dev); + + if (!is_tmc_reserved_region_valid(dev)) + goto out; + + drvdata->crashdev.name = + devm_kasprintf(dev, GFP_KERNEL, "%s_%s", "crash", desc.name); + drvdata->crashdev.minor = MISC_DYNAMIC_MINOR; + drvdata->crashdev.fops = &tmc_crashdata_fops; + ret = misc_register(&drvdata->crashdev); + if (ret) + pr_err("%s: Failed to setup dev interface for crashdata\n", + desc.name); + out: return ret; } @@ -630,7 +764,8 @@ static void tmc_shutdown(struct amba_device *adev)
spin_lock_irqsave(&drvdata->spinlock, flags);
- if (coresight_get_mode(drvdata->csdev) == CS_MODE_DISABLED) + if ((coresight_get_mode(drvdata->csdev) == CS_MODE_DISABLED) || + (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA)) goto out;
if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index e396716da4f3..6c3bc7907c58 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -657,6 +657,56 @@ static int tmc_panic_sync_etf(struct coresight_device *csdev) return 0; }
+static int tmc_etb_setup_crashdata_buf(struct tmc_drvdata *drvdata) +{ + unsigned long size; + struct tmc_crash_metadata *mdata; + struct device *dev = &drvdata->csdev->dev; + + mdata = drvdata->crash_mdata.vaddr; + size = mdata->size << 2; + + /* + * Buffer address given by metadata for retrieval of trace data + * from previous boot is expected to be same as the reserved + * trace buffer memory region provided through DTS + */ + if (is_tmc_reserved_region_valid(dev->parent) + && (drvdata->crash_tbuf.paddr == mdata->trc_paddr)) + drvdata->buf = drvdata->crash_tbuf.vaddr; + else { + dev_dbg(dev, "Trace buffer address of previous boot invalid\n"); + return -EINVAL; + } + + drvdata->len = size; + return 0; +} + +static void tmc_etb_free_crashdata_buf(struct tmc_drvdata *drvdata) +{ + void *buf = drvdata->buf; + + if (!buf) + return; + drvdata->buf = NULL; +} + +static int tmc_etb_prepare_crashdata(struct coresight_device *csdev) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + return tmc_etb_setup_crashdata_buf(drvdata); +} + +static int tmc_etb_unprepare_crashdata(struct coresight_device *csdev) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + tmc_etb_free_crashdata_buf(drvdata); + return 0; +} + static const struct coresight_ops_sink tmc_etf_sink_ops = { .enable = tmc_enable_etf_sink, .disable = tmc_disable_etf_sink, @@ -674,6 +724,11 @@ static const struct coresight_ops_panic tmc_etf_sync_ops = { .sync = tmc_panic_sync_etf, };
+static const struct coresight_ops_crashdata tmc_etf_crashdata_ops = { + .prepare = tmc_etb_prepare_crashdata, + .unprepare = tmc_etb_unprepare_crashdata, +}; + const struct coresight_ops tmc_etb_cs_ops = { .sink_ops = &tmc_etf_sink_ops, }; @@ -682,6 +737,7 @@ const struct coresight_ops tmc_etf_cs_ops = { .sink_ops = &tmc_etf_sink_ops, .link_ops = &tmc_etf_link_ops, .panic_ops = &tmc_etf_sync_ops, + .crashdata_ops = &tmc_etf_crashdata_ops, };
int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) @@ -702,6 +758,14 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) goto out; }
+ if (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA) { + ret = tmc_read_prepare_crashdata(drvdata); + if (ret) + goto out; + else + goto mode_valid; + } + /* Don't interfere if operated from Perf */ if (coresight_get_mode(drvdata->csdev) == CS_MODE_PERF) { ret = -EINVAL; @@ -725,6 +789,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) __tmc_etb_disable_hw(drvdata); }
+mode_valid: drvdata->reading = true; out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -744,8 +809,16 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) drvdata->config_type != TMC_CONFIG_TYPE_ETF)) return -EINVAL;
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA) { + tmc_read_unprepare_crashdata(drvdata); + drvdata->reading = false; + spin_unlock_irqrestore(&drvdata->spinlock, flags); + return 0; + } + /* Re-enable the TMC if need be */ if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) { /* There is no point in reading a TMC in HW FIFO mode */ diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index b268de6af9a3..6fb9b7659f52 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1157,7 +1157,12 @@ ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata, { s64 offset; ssize_t actual = len; - struct etr_buf *etr_buf = drvdata->sysfs_buf; + struct etr_buf *etr_buf; + + if (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA) + etr_buf = drvdata->sysfs_crash_buf; + else + etr_buf = drvdata->sysfs_buf;
if (pos + actual > etr_buf->len) actual = etr_buf->len - pos; @@ -1875,6 +1880,130 @@ static int tmc_panic_sync_etr(struct coresight_device *csdev) return 0; }
+static int tmc_etr_setup_crashdata_buf(struct tmc_drvdata *drvdata) +{ + int rc = 0; + u64 trace_addr; + struct etr_buf *etr_buf; + struct etr_flat_buf *resrv_buf; + struct tmc_crash_metadata *mdata; + struct device *dev = &drvdata->csdev->dev; + + mdata = drvdata->crash_mdata.vaddr; + + etr_buf = kzalloc(sizeof(*etr_buf), GFP_ATOMIC); + if (!etr_buf) { + rc = -ENOMEM; + goto out; + } + etr_buf->size = drvdata->crash_tbuf.size; + + resrv_buf = kzalloc(sizeof(*resrv_buf), GFP_ATOMIC); + if (!resrv_buf) { + rc = -ENOMEM; + goto rmem_err; + } + + /* + * Buffer address given by metadata for retrieval of trace data + * from previous boot is expected to be same as the reserved + * trace buffer memory region provided through DTS + */ + if (is_tmc_reserved_region_valid(dev->parent) + && (drvdata->crash_tbuf.paddr == mdata->trc_paddr)) + resrv_buf->vaddr = drvdata->crash_tbuf.vaddr; + else { + dev_dbg(dev, "Trace buffer address of previous boot invalid\n"); + rc = -EINVAL; + goto map_err; + } + + resrv_buf->size = etr_buf->size; + resrv_buf->dev = &drvdata->csdev->dev; + etr_buf->hwaddr = trace_addr; + etr_buf->mode = ETR_MODE_RESRV; + etr_buf->private = resrv_buf; + etr_buf->ops = etr_buf_ops[ETR_MODE_RESRV]; + + drvdata->sysfs_crash_buf = etr_buf; + + return 0; + +map_err: + kfree(resrv_buf); + +rmem_err: + kfree(etr_buf); + +out: + return rc; +} + +static int tmc_etr_sync_crashdata_buf(struct tmc_drvdata *drvdata) +{ + u32 status; + u64 rrp, rwp, dba; + struct tmc_crash_metadata *mdata; + struct etr_buf *etr_buf = drvdata->sysfs_crash_buf; + + mdata = drvdata->crash_mdata.vaddr; + + rrp = mdata->rrp; + rwp = mdata->rwp; + dba = mdata->dba; + status = mdata->sts; + + etr_buf->full = !!(status & TMC_STS_FULL); + + /* Sync the buffer pointers */ + etr_buf->offset = rrp - dba; + if (etr_buf->full) + etr_buf->len = etr_buf->size; + else + etr_buf->len = rwp - rrp; + + /* Additional sanity checks for validating metadata */ + if ((etr_buf->offset > etr_buf->size) || + (etr_buf->len > etr_buf->size)) { + dev_dbg(&drvdata->csdev->dev, + "Offset and length invalid in tmc crash metadata\n"); + return -EINVAL; + } + + return 0; +} + +static void tmc_etr_free_crashdata_buf(struct tmc_drvdata *drvdata) +{ + struct etr_buf *etr_buf = drvdata->sysfs_crash_buf; + + if (!etr_buf) + return; + drvdata->sysfs_crash_buf = NULL; +} + +static int tmc_etr_prepare_crashdata(struct coresight_device *csdev) +{ + int ret = 0; + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + ret = tmc_etr_setup_crashdata_buf(drvdata); + if (ret) + goto out; + ret = tmc_etr_sync_crashdata_buf(drvdata); + +out: + return ret; +} + +static int tmc_etr_unprepare_crashdata(struct coresight_device *csdev) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + tmc_etr_free_crashdata_buf(drvdata); + return 0; +} + static const struct coresight_ops_sink tmc_etr_sink_ops = { .enable = tmc_enable_etr_sink, .disable = tmc_disable_etr_sink, @@ -1887,9 +2016,15 @@ static const struct coresight_ops_panic tmc_etr_sync_ops = { .sync = tmc_panic_sync_etr, };
+static const struct coresight_ops_crashdata tmc_etr_crashdata_ops = { + .prepare = tmc_etr_prepare_crashdata, + .unprepare = tmc_etr_unprepare_crashdata, +}; + const struct coresight_ops tmc_etr_cs_ops = { .sink_ops = &tmc_etr_sink_ops, .panic_ops = &tmc_etr_sync_ops, + .crashdata_ops = &tmc_etr_crashdata_ops, };
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) @@ -1901,12 +2036,21 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR)) return -EINVAL;
+ spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->reading) { ret = -EBUSY; goto out; }
+ if (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA) { + ret = tmc_read_prepare_crashdata(drvdata); + if (ret) + goto out; + else + goto mode_valid; + } + /* * We can safely allow reads even if the ETR is operating in PERF mode, * since the sysfs session is captured in mode specific data. @@ -1921,6 +2065,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) __tmc_etr_disable_hw(drvdata);
+mode_valid: drvdata->reading = true; out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -1939,6 +2084,12 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
+ if (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA) { + sysfs_buf = drvdata->sysfs_crash_buf; + tmc_read_unprepare_crashdata(drvdata); + goto out; + } + /* RE-enable the TMC if need be */ if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) { /* @@ -1956,6 +2107,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) drvdata->sysfs_buf = NULL; }
+out: drvdata->reading = false; spin_unlock_irqrestore(&drvdata->spinlock, flags);
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 875d4129da7c..528174283ecc 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -200,6 +200,8 @@ struct tmc_resrv_buf { * @base: memory mapped base address for this component. * @csdev: component vitals needed by the framework. * @miscdev: specifics to handle "/dev/xyz.tmc" entry. + * @crashdev: specifics to handle "/dev/crash_tmc_xyz" entry for reading + * crash tracedata. * @spinlock: only one at a time pls. * @pid: Process ID of the process being monitored by the session * that is using this component. @@ -218,7 +220,10 @@ struct tmc_resrv_buf { * @idr_mutex: Access serialisation for idr. * @sysfs_buf: SYSFS buffer for ETR. * @perf_buf: PERF buffer for ETR. - * @crash_tbuf: Used by ETR as hardware trace buffer and for trace data + * @sysfs_crash_buf: Sysfs crashdata buffer for ETR. This is a special purpose + * buffer that is used only for mapping the trace buffer from + * previous crash and not for capturing trace. + * @crash_tbuf: Used by ETR as hardware trace buffer and for trace data * retention (after crash) only when ETR_MODE_RESRV buffer * mode is enabled. Used by ETF for trace data retention * (after crash) by default. @@ -229,6 +234,7 @@ struct tmc_drvdata { void __iomem *base; struct coresight_device *csdev; struct miscdevice miscdev; + struct miscdevice crashdev; spinlock_t spinlock; pid_t pid; bool reading; @@ -248,6 +254,7 @@ struct tmc_drvdata { struct mutex idr_mutex; struct etr_buf *sysfs_buf; struct etr_buf *perf_buf; + struct etr_buf *sysfs_crash_buf; struct tmc_resrv_buf crash_tbuf; struct tmc_resrv_buf crash_mdata; }; @@ -299,6 +306,8 @@ void tmc_flush_and_stop(struct tmc_drvdata *drvdata); void tmc_enable_hw(struct tmc_drvdata *drvdata); void tmc_disable_hw(struct tmc_drvdata *drvdata); u32 tmc_get_memwidth_mask(struct tmc_drvdata *drvdata); +int tmc_read_prepare_crashdata(struct tmc_drvdata *drvdata); +int tmc_read_unprepare_crashdata(struct tmc_drvdata *drvdata);
/* ETB/ETF functions */ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata); diff --git a/include/linux/coresight.h b/include/linux/coresight.h index b156467c9baa..b5e825b25e9d 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -308,6 +308,7 @@ enum cs_mode { CS_MODE_DISABLED, CS_MODE_SYSFS, CS_MODE_PERF, + CS_MODE_READ_CRASHDATA, /* Trace data from previous crash */ };
#define source_ops(csdev) csdev->ops->source_ops @@ -316,6 +317,7 @@ enum cs_mode { #define helper_ops(csdev) csdev->ops->helper_ops #define ect_ops(csdev) csdev->ops->ect_ops #define panic_ops(csdev) csdev->ops->panic_ops +#define crashdata_ops(csdev) csdev->ops->crashdata_ops
/** * struct coresight_ops_sink - basic operations for a sink @@ -395,12 +397,23 @@ struct coresight_ops_panic { int (*sync)(struct coresight_device *csdev); };
+/** + * struct coresight_ops_crashdata - Generic device ops for crashdata mode + * + * @prepare : Preparation for reading crashdata mode + */ +struct coresight_ops_crashdata { + int (*prepare)(struct coresight_device *csdev); + int (*unprepare)(struct coresight_device *csdev); +}; + struct coresight_ops { const struct coresight_ops_sink *sink_ops; const struct coresight_ops_link *link_ops; const struct coresight_ops_source *source_ops; const struct coresight_ops_helper *helper_ops; const struct coresight_ops_panic *panic_ops; + const struct coresight_ops_crashdata *crashdata_ops; };
static inline u32 csdev_access_relaxed_read32(struct csdev_access *csa,
Configure TMC ETR and ETF to flush and stop trace capture on FlIn event based on sysfs attribute, /sys/bus/coresight/devices/tmc_etXn/stop_on_flush.
Signed-off-by: Linu Cherian lcherian@marvell.com --- Changelog from v6: * Added new sysfs attribute stop_on_flush * stop_on_flush event is enabled on TMC only upon user request for sysfs modes
.../hwtracing/coresight/coresight-tmc-core.c | 31 +++++++++++++++++++ .../hwtracing/coresight/coresight-tmc-etf.c | 16 +++++++--- .../hwtracing/coresight/coresight-tmc-etr.c | 16 +++++++--- drivers/hwtracing/coresight/coresight-tmc.h | 4 +++ 4 files changed, 57 insertions(+), 10 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index b6bc37159527..701952ce9e87 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -452,9 +452,40 @@ static ssize_t buffer_size_store(struct device *dev,
static DEVICE_ATTR_RW(buffer_size);
+static ssize_t stop_on_flush_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(dev->parent); + + return sprintf(buf, "%#x\n", drvdata->stop_on_flush); +} + +static ssize_t stop_on_flush_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + int ret; + u8 val; + struct tmc_drvdata *drvdata = dev_get_drvdata(dev->parent); + + ret = kstrtou8(buf, 0, &val); + if (ret) + return ret; + if (val) + drvdata->stop_on_flush = true; + else + drvdata->stop_on_flush = false; + + return size; +} + +static DEVICE_ATTR_RW(stop_on_flush); + + static struct attribute *coresight_tmc_attrs[] = { &dev_attr_trigger_cntr.attr, &dev_attr_buffer_size.attr, + &dev_attr_stop_on_flush.attr, NULL, };
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 6c3bc7907c58..d3bbadc76bcd 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -19,6 +19,7 @@ static int tmc_set_etf_buffer(struct coresight_device *csdev, static int __tmc_etb_enable_hw(struct tmc_drvdata *drvdata) { int rc = 0; + u32 ffcr;
CS_UNLOCK(drvdata->base);
@@ -32,10 +33,12 @@ static int __tmc_etb_enable_hw(struct tmc_drvdata *drvdata) }
writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE); - writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI | - TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT | - TMC_FFCR_TRIGON_TRIGIN, - drvdata->base + TMC_FFCR); + + ffcr = TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI | TMC_FFCR_FON_FLIN | + TMC_FFCR_FON_TRIG_EVT | TMC_FFCR_TRIGON_TRIGIN; + if (drvdata->stop_on_flush_en) + ffcr |= TMC_FFCR_STOP_ON_FLUSH; + writel_relaxed(ffcr, drvdata->base + TMC_FFCR);
writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG); tmc_enable_hw(drvdata); @@ -225,7 +228,8 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev) used = true; drvdata->buf = buf; } - + if (drvdata->stop_on_flush) + drvdata->stop_on_flush_en = true; ret = tmc_etb_enable_hw(drvdata); if (!ret) { coresight_set_mode(csdev, CS_MODE_SYSFS); @@ -349,6 +353,8 @@ static int tmc_disable_etf_sink(struct coresight_device *csdev) tmc_etb_disable_hw(drvdata); /* Dissociate from monitored process. */ drvdata->pid = -1; + /* Reset stop on flush */ + drvdata->stop_on_flush_en = false; coresight_set_mode(csdev, CS_MODE_DISABLED);
spin_unlock_irqrestore(&drvdata->spinlock, flags); diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 6fb9b7659f52..161f31f8bb3d 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1056,7 +1056,7 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata)
static int __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) { - u32 axictl, sts; + u32 axictl, sts, ffcr; struct etr_buf *etr_buf = drvdata->etr_buf; int rc = 0;
@@ -1102,10 +1102,12 @@ static int __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) writel_relaxed(sts, drvdata->base + TMC_STS); }
- writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI | - TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT | - TMC_FFCR_TRIGON_TRIGIN, - drvdata->base + TMC_FFCR); + ffcr = TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI | TMC_FFCR_FON_FLIN | + TMC_FFCR_FON_TRIG_EVT | TMC_FFCR_TRIGON_TRIGIN; + if (drvdata->stop_on_flush_en) + ffcr |= TMC_FFCR_STOP_ON_FLUSH; + writel_relaxed(ffcr, drvdata->base + TMC_FFCR); + writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG); tmc_enable_hw(drvdata);
@@ -1310,6 +1312,8 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) goto out; }
+ if (drvdata->stop_on_flush) + drvdata->stop_on_flush_en = true; ret = tmc_etr_enable_hw(drvdata, sysfs_buf); if (!ret) { coresight_set_mode(csdev, CS_MODE_SYSFS); @@ -1805,6 +1809,8 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev) tmc_etr_disable_hw(drvdata); /* Dissociate from monitored process. */ drvdata->pid = -1; + /* Reset stop on flush */ + drvdata->stop_on_flush_en = false; coresight_set_mode(csdev, CS_MODE_DISABLED); /* Reset perf specific data */ drvdata->perf_buf = NULL; diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 528174283ecc..81eadb384b83 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -205,6 +205,8 @@ struct tmc_resrv_buf { * @spinlock: only one at a time pls. * @pid: Process ID of the process being monitored by the session * that is using this component. + * @stop_on_flush: Stop on flush trigger user configuration. + * @stop_on_flush_en: Stop on flush enable flag * @buf: Snapshot of the trace data for ETF/ETB. * @etr_buf: details of buffer used in TMC-ETR * @len: size of the available trace for ETF/ETB. @@ -238,6 +240,8 @@ struct tmc_drvdata { spinlock_t spinlock; pid_t pid; bool reading; + bool stop_on_flush; + bool stop_on_flush_en; union { char *buf; /* TMC ETB */ struct etr_buf *etr_buf; /* TMC ETR */
Add a preloaded configuration for generating external trigger on address match. This can be used by CTI and ETR blocks to stop trace capture on kernel panic.
Kernel address for "panic" function is used as the default trigger address.
This new configuration is available as, /sys/kernel/config/cs-syscfg/configurations/panicstop
Signed-off-by: Linu Cherian lcherian@marvell.com --- Changelog from v6: * By default address value is set to kernel "panic"
drivers/hwtracing/coresight/Makefile | 2 +- .../coresight/coresight-cfg-preload.c | 2 + .../coresight/coresight-cfg-preload.h | 2 + .../hwtracing/coresight/coresight-cfg-pstop.c | 83 +++++++++++++++++++ 4 files changed, 88 insertions(+), 1 deletion(-) create mode 100644 drivers/hwtracing/coresight/coresight-cfg-pstop.c
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index 4ba478211b31..46ce7f39d05f 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -25,7 +25,7 @@ subdir-ccflags-y += $(condflags) obj-$(CONFIG_CORESIGHT) += coresight.o coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \ coresight-sysfs.o coresight-syscfg.o coresight-config.o \ - coresight-cfg-preload.o coresight-cfg-afdo.o \ + coresight-cfg-preload.o coresight-cfg-afdo.o coresight-cfg-pstop.o \ coresight-syscfg-configfs.o coresight-trace-id.o obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \ diff --git a/drivers/hwtracing/coresight/coresight-cfg-preload.c b/drivers/hwtracing/coresight/coresight-cfg-preload.c index e237a4edfa09..4980e68483c5 100644 --- a/drivers/hwtracing/coresight/coresight-cfg-preload.c +++ b/drivers/hwtracing/coresight/coresight-cfg-preload.c @@ -13,6 +13,7 @@ static struct cscfg_feature_desc *preload_feats[] = { #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) &strobe_etm4x, + &gen_etrig_etm4x, #endif NULL }; @@ -20,6 +21,7 @@ static struct cscfg_feature_desc *preload_feats[] = { static struct cscfg_config_desc *preload_cfgs[] = { #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) &afdo_etm4x, + &pstop_etm4x, #endif NULL }; diff --git a/drivers/hwtracing/coresight/coresight-cfg-preload.h b/drivers/hwtracing/coresight/coresight-cfg-preload.h index 21299e175477..291ba530a6a5 100644 --- a/drivers/hwtracing/coresight/coresight-cfg-preload.h +++ b/drivers/hwtracing/coresight/coresight-cfg-preload.h @@ -10,4 +10,6 @@ #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) extern struct cscfg_feature_desc strobe_etm4x; extern struct cscfg_config_desc afdo_etm4x; +extern struct cscfg_feature_desc gen_etrig_etm4x; +extern struct cscfg_config_desc pstop_etm4x; #endif diff --git a/drivers/hwtracing/coresight/coresight-cfg-pstop.c b/drivers/hwtracing/coresight/coresight-cfg-pstop.c new file mode 100644 index 000000000000..c2bfbd07bfaf --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-cfg-pstop.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright(C) 2023 Marvell. + * Based on coresight-cfg-afdo.c + */ + +#include "coresight-config.h" + +/* ETMv4 includes and features */ +#if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) +#include "coresight-etm4x-cfg.h" + +/* preload configurations and features */ + +/* preload in features for ETMv4 */ + +/* panic_stop feature */ +static struct cscfg_parameter_desc gen_etrig_params[] = { + { + .name = "address", + .value = (u64)panic, + }, +}; + +static struct cscfg_regval_desc gen_etrig_regs[] = { + /* resource selector */ + { + .type = CS_CFG_REG_TYPE_RESOURCE, + .offset = TRCRSCTLRn(2), + .hw_info = ETM4_CFG_RES_SEL, + .val32 = 0x40001, + }, + /* single address comparator */ + { + .type = CS_CFG_REG_TYPE_RESOURCE | CS_CFG_REG_TYPE_VAL_64BIT | + CS_CFG_REG_TYPE_VAL_PARAM, + .offset = TRCACVRn(0), + .val32 = 0x0, + }, + { + .type = CS_CFG_REG_TYPE_RESOURCE, + .offset = TRCACATRn(0), + .val64 = 0xf00, + }, + /* Driver external output[0] with comparator out */ + { + .type = CS_CFG_REG_TYPE_RESOURCE, + .offset = TRCEVENTCTL0R, + .val32 = 0x2, + }, + /* end of regs */ +}; + +struct cscfg_feature_desc gen_etrig_etm4x = { + .name = "gen_etrig", + .description = "Generate external trigger on address match\n" + "parameter 'address': address of kernel address\n", + .match_flags = CS_CFG_MATCH_CLASS_SRC_ETM4, + .nr_params = ARRAY_SIZE(gen_etrig_params), + .params_desc = gen_etrig_params, + .nr_regs = ARRAY_SIZE(gen_etrig_regs), + .regs_desc = gen_etrig_regs, +}; + +/* create a panic stop configuration */ + +/* the total number of parameters in used features */ +#define PSTOP_NR_PARAMS ARRAY_SIZE(gen_etrig_params) + +static const char *pstop_ref_names[] = { + "gen_etrig", +}; + +struct cscfg_config_desc pstop_etm4x = { + .name = "panicstop", + .description = "Stop ETM on kernel panic\n", + .nr_feat_refs = ARRAY_SIZE(pstop_ref_names), + .feat_ref_names = pstop_ref_names, + .nr_total_params = PSTOP_NR_PARAMS, +}; + +/* end of ETM4x configurations */ +#endif /* IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X) */
Hi Suzuki/James,
-----Original Message----- From: Linu Cherian lcherian@marvell.com Sent: Thursday, March 7, 2024 9:06 AM To: suzuki.poulose@arm.com; mike.leach@linaro.org; james.clark@arm.com; leo.yan@linaro.org Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Linu Cherian lcherian@marvell.com Subject: [PATCH v7 0/7] Coresight for Kernel panic and watchdog reset
This patch series is rebased on v6.8-rc4 from coresisght tree,[1], since latest changes are dependent on coresight_get/set_mode APIs.
Do you have any feedback on this version ?
Thanks.
On 09/04/2024 01:10, Linu Cherian wrote:
Hi Suzuki/James,
-----Original Message----- From: Linu Cherian lcherian@marvell.com Sent: Thursday, March 7, 2024 9:06 AM To: suzuki.poulose@arm.com; mike.leach@linaro.org; james.clark@arm.com; leo.yan@linaro.org Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Linu Cherian lcherian@marvell.com Subject: [PATCH v7 0/7] Coresight for Kernel panic and watchdog reset
This patch series is rebased on v6.8-rc4 from coresisght tree,[1], since latest changes are dependent on coresight_get/set_mode APIs.
Do you have any feedback on this version ?
Thanks.
Hi Linu,
Sorry it was on my list, I'll take a look this week.
On 07/03/2024 03:36, Linu Cherian wrote:
Add support to use reserved memory for coresight ETR trace buffer.
Introduce a new ETR buffer mode called ETR_MODE_RESRV, which becomes available when ETR device tree node is supplied with a valid reserved memory region.
ETR_MODE_RESRV can be selected only by explicit user request.
$ echo resrv >/sys/bus/coresight/devices/tmc_etr<N>/buf_mode_preferred
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed redundant goto statements
- Setting of etr_buf->size to the reserved memory size is done after successful dma map inside the alloc function
- Removed the special casing for ETR_MODE_RESRV
- Fixed the tab spacing in struct tmc_drvdata
.../hwtracing/coresight/coresight-tmc-core.c | 47 +++++++++++ .../hwtracing/coresight/coresight-tmc-etr.c | 82 ++++++++++++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 27 ++++++ 3 files changed, 153 insertions(+), 3 deletions(-)
[...]
static bool etr_can_use_flat_mode(struct etr_buf_hw *buf_hw, ssize_t etr_buf_size) @@ -874,13 +947,10 @@ static struct etr_buf *tmc_alloc_etr_buf(struct tmc_drvdata *drvdata, if (!etr_buf) return ERR_PTR(-ENOMEM);
- etr_buf->size = size;
Hi Linu,
Not sure if this was left in by mistake? It's not mentioned in the commit message and it doesn't seem to match the description.
Please make sure the current tests pass both with and without a reserved buffer defined in the DT. I get lots of failures with this patchset applied on N1SDP. ETF seems to work but ETR doesn't:
$ sudo perf test -vvv "arm coresight"
Recording trace (only user mode) with path: CPU1 => tmc_etf0 CoreSight path testing (CPU1 -> tmc_etf0): PASS
Recording trace (only user mode) with path: CPU1 => tmc_etr0 CoreSight path testing (CPU1 -> tmc_etr0): FAIL ...
Dmesg: [ 1938.622091] coresight tmc_etr0: Unable to allocate ETR buffer
/* If there is user directive for buffer mode, try that first */ if (drvdata->etr_mode != ETR_MODE_AUTO) rc = tmc_etr_mode_alloc_buf(drvdata->etr_mode, drvdata, etr_buf, node, pages);
Whitespace change.
On 07/03/2024 03:36, Linu Cherian wrote:
Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace captured in previous crash/watchdog reset.
Add special device files for reading ETR/ETF crash data.
User can read the crash data as below
For example, for reading crash data from tmc_etf sink
#dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Tanmay Jagdale tanmay@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed read_prevboot flag in sysfs
- Added special device files for reading crashdata
- Renamed CS mode READ_PREVBOOT to READ_CRASHDATA
- Setting the READ_CRASHDATA mode is done as part of file open.
[...]
@@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) coresight_unregister(drvdata->csdev); else pm_runtime_put(&adev->dev);
- if (!is_tmc_reserved_region_valid(dev))
goto out;- drvdata->crashdev.name =
devm_kasprintf(dev, GFP_KERNEL, "%s_%s", "crash", desc.name);- drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
- drvdata->crashdev.fops = &tmc_crashdata_fops;
- ret = misc_register(&drvdata->crashdev);
- if (ret)
pr_err("%s: Failed to setup dev interface for crashdata\n",desc.name);
Is this all optional after the is_tmc_reserved_region_valid()? Skipping to out seems to be more like an error condition, but in this case it's not? Having it like this makes it more difficult to add extra steps to the probe function. You could move it to a function and flip the condition which would be clearer:
if (is_tmc_reserved_region_valid(dev)) register_crash_dev_interface(drvdata);
out: return ret; }
[...]
+static int tmc_etr_setup_crashdata_buf(struct tmc_drvdata *drvdata) +{
- int rc = 0;
- u64 trace_addr;
- struct etr_buf *etr_buf;
- struct etr_flat_buf *resrv_buf;
- struct tmc_crash_metadata *mdata;
- struct device *dev = &drvdata->csdev->dev;
- mdata = drvdata->crash_mdata.vaddr;
- etr_buf = kzalloc(sizeof(*etr_buf), GFP_ATOMIC);
- if (!etr_buf) {
rc = -ENOMEM;goto out;- }
- etr_buf->size = drvdata->crash_tbuf.size;
- resrv_buf = kzalloc(sizeof(*resrv_buf), GFP_ATOMIC);
- if (!resrv_buf) {
rc = -ENOMEM;goto rmem_err;- }
- /*
* Buffer address given by metadata for retrieval of trace data* from previous boot is expected to be same as the reserved* trace buffer memory region provided through DTS*/- if (is_tmc_reserved_region_valid(dev->parent)
&& (drvdata->crash_tbuf.paddr == mdata->trc_paddr))resrv_buf->vaddr = drvdata->crash_tbuf.vaddr;- else {
dev_dbg(dev, "Trace buffer address of previous boot invalid\n");rc = -EINVAL;goto map_err;- }
- resrv_buf->size = etr_buf->size;
- resrv_buf->dev = &drvdata->csdev->dev;
- etr_buf->hwaddr = trace_addr;
trace_addr is uninitialised at this point. If you pull the latest coresight branch we enabled some extra compiler warnings which catch this.
I assume it's supposed to be mdata->trc_paddr?
Is there some kind of test that could be added that could have caught this? Maybe skip the full reboot flow but just enable the feature and see if we can read from the buffer.
Or even just toggling the mode on and off via sysfs. We're running the Perf and kselftests on Juno internally so I can add a reserved region to the Juno DT and make sure this stays working.
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Friday, April 12, 2024 3:27 PM To: Linu Cherian lcherian@marvell.com; suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Anil Kumar Reddy H areddy3@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 2/7] coresight: tmc-etr: Add support to use reserved trace memory
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
On 07/03/2024 03:36, Linu Cherian wrote:
Add support to use reserved memory for coresight ETR trace buffer.
Introduce a new ETR buffer mode called ETR_MODE_RESRV, which becomes available when ETR device tree node is supplied with a valid reserved memory region.
ETR_MODE_RESRV can be selected only by explicit user request.
$ echo resrv /sys/bus/coresight/devices/tmc_etr<N>/buf_mode_preferred
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed redundant goto statements
- Setting of etr_buf->size to the reserved memory size is done after successful dma map inside the alloc function
- Removed the special casing for ETR_MODE_RESRV
- Fixed the tab spacing in struct tmc_drvdata
.../hwtracing/coresight/coresight-tmc-core.c | 47 +++++++++++ .../hwtracing/coresight/coresight-tmc-etr.c | 82 ++++++++++++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 27 ++++++ 3 files changed, 153 insertions(+), 3 deletions(-)
[...]
static bool etr_can_use_flat_mode(struct etr_buf_hw *buf_hw, ssize_t etr_buf_size) @@ -874,13 +947,10 @@ static struct etr_buf
*tmc_alloc_etr_buf(struct tmc_drvdata *drvdata,
if (!etr_buf) return ERR_PTR(-ENOMEM);
- etr_buf->size = size;
Hi Linu,
Not sure if this was left in by mistake? It's not mentioned in the commit message and it doesn't seem to match the description.
Yeah, that change was by mistake. Sorry about that.
Please make sure the current tests pass both with and without a reserved buffer defined in the DT. I get lots of failures with this patchset applied on N1SDP. ETF seems to work but ETR doesn't:
Ack.
$ sudo perf test -vvv "arm coresight"
Recording trace (only user mode) with path: CPU1 => tmc_etf0 CoreSight path testing (CPU1 -> tmc_etf0): PASS
Recording trace (only user mode) with path: CPU1 => tmc_etr0 CoreSight path testing (CPU1 -> tmc_etr0): FAIL ...
Dmesg: [ 1938.622091] coresight tmc_etr0: Unable to allocate ETR buffer
/* If there is user directive for buffer mode, try that first */ if (drvdata->etr_mode != ETR_MODE_AUTO) rc = tmc_etr_mode_alloc_buf(drvdata->etr_mode, drvdata, etr_buf, node, pages);
Whitespace change.
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Friday, April 12, 2024 3:36 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Anil Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
On 07/03/2024 03:36, Linu Cherian wrote:
Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace captured in previous crash/watchdog reset.
Add special device files for reading ETR/ETF crash data.
User can read the crash data as below
For example, for reading crash data from tmc_etf sink
#dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Tanmay Jagdale tanmay@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed read_prevboot flag in sysfs
- Added special device files for reading crashdata
- Renamed CS mode READ_PREVBOOT to READ_CRASHDATA
- Setting the READ_CRASHDATA mode is done as part of file open.
[...]
@@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device *adev,
const struct amba_id *id)
coresight_unregister(drvdata->csdev);else pm_runtime_put(&adev->dev);
- if (!is_tmc_reserved_region_valid(dev))
goto out;- drvdata->crashdev.name =
devm_kasprintf(dev, GFP_KERNEL, "%s_%s", "crash",desc.name);
- drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
- drvdata->crashdev.fops = &tmc_crashdata_fops;
- ret = misc_register(&drvdata->crashdev);
- if (ret)
pr_err("%s: Failed to setup dev interface for crashdata\n",desc.name);Is this all optional after the is_tmc_reserved_region_valid()? Skipping to out seems to be more like an error condition, but in this case it's not? Having it like this makes it more difficult to add extra steps to the probe function. You could move it to a function and flip the condition which would be clearer:
Ack.
if (is_tmc_reserved_region_valid(dev)) register_crash_dev_interface(drvdata);
out: return ret; }
[...]
+static int tmc_etr_setup_crashdata_buf(struct tmc_drvdata *drvdata) {
- int rc = 0;
- u64 trace_addr;
- struct etr_buf *etr_buf;
- struct etr_flat_buf *resrv_buf;
- struct tmc_crash_metadata *mdata;
- struct device *dev = &drvdata->csdev->dev;
- mdata = drvdata->crash_mdata.vaddr;
- etr_buf = kzalloc(sizeof(*etr_buf), GFP_ATOMIC);
- if (!etr_buf) {
rc = -ENOMEM;goto out;- }
- etr_buf->size = drvdata->crash_tbuf.size;
- resrv_buf = kzalloc(sizeof(*resrv_buf), GFP_ATOMIC);
- if (!resrv_buf) {
rc = -ENOMEM;goto rmem_err;- }
- /*
* Buffer address given by metadata for retrieval of trace data* from previous boot is expected to be same as the reserved* trace buffer memory region provided through DTS*/- if (is_tmc_reserved_region_valid(dev->parent)
&& (drvdata->crash_tbuf.paddr == mdata->trc_paddr))resrv_buf->vaddr = drvdata->crash_tbuf.vaddr;- else {
dev_dbg(dev, "Trace buffer address of previous bootinvalid\n");
rc = -EINVAL;goto map_err;- }
- resrv_buf->size = etr_buf->size;
- resrv_buf->dev = &drvdata->csdev->dev;
- etr_buf->hwaddr = trace_addr;
trace_addr is uninitialised at this point. If you pull the latest coresight branch we enabled some extra compiler warnings which catch this.
I assume it's supposed to be mdata->trc_paddr?
Since no DMA operation happens here, its supposed to be kept NULL. Since it was redundant for crash data read operation, missed catching this. Will fix this.
Is there some kind of test that could be added that could have caught this? Maybe skip the full reboot flow but just enable the feature and see if we can read from the buffer.
As pointed above this field is redundant for crashdata read mode. So its not a functionality breakage as such.
Or even just toggling the mode on and off via sysfs. We're running the Perf and kselftests on Juno internally so I can add a reserved region to the Juno DT and make sure this stays working.
Did you meant adding a kselftest for tracing and reading back tracedata in sysfs mode using the reserved region ?
Thanks Linu Cherian.
On 15/04/2024 05:01, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Friday, April 12, 2024 3:36 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Anil Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
On 07/03/2024 03:36, Linu Cherian wrote:
Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace captured in previous crash/watchdog reset.
Add special device files for reading ETR/ETF crash data.
User can read the crash data as below
For example, for reading crash data from tmc_etf sink
#dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Tanmay Jagdale tanmay@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed read_prevboot flag in sysfs
- Added special device files for reading crashdata
- Renamed CS mode READ_PREVBOOT to READ_CRASHDATA
- Setting the READ_CRASHDATA mode is done as part of file open.
[...]
@@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device *adev,
const struct amba_id *id)
coresight_unregister(drvdata->csdev);else pm_runtime_put(&adev->dev);
- if (!is_tmc_reserved_region_valid(dev))
goto out;- drvdata->crashdev.name =
devm_kasprintf(dev, GFP_KERNEL, "%s_%s", "crash",desc.name);
- drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
- drvdata->crashdev.fops = &tmc_crashdata_fops;
- ret = misc_register(&drvdata->crashdev);
- if (ret)
pr_err("%s: Failed to setup dev interface for crashdata\n",desc.name);Is this all optional after the is_tmc_reserved_region_valid()? Skipping to out seems to be more like an error condition, but in this case it's not? Having it like this makes it more difficult to add extra steps to the probe function. You could move it to a function and flip the condition which would be clearer:
Ack.
if (is_tmc_reserved_region_valid(dev)) register_crash_dev_interface(drvdata);
out: return ret; }
[...]
+static int tmc_etr_setup_crashdata_buf(struct tmc_drvdata *drvdata) {
- int rc = 0;
- u64 trace_addr;
- struct etr_buf *etr_buf;
- struct etr_flat_buf *resrv_buf;
- struct tmc_crash_metadata *mdata;
- struct device *dev = &drvdata->csdev->dev;
- mdata = drvdata->crash_mdata.vaddr;
- etr_buf = kzalloc(sizeof(*etr_buf), GFP_ATOMIC);
- if (!etr_buf) {
rc = -ENOMEM;goto out;- }
- etr_buf->size = drvdata->crash_tbuf.size;
- resrv_buf = kzalloc(sizeof(*resrv_buf), GFP_ATOMIC);
- if (!resrv_buf) {
rc = -ENOMEM;goto rmem_err;- }
- /*
* Buffer address given by metadata for retrieval of trace data* from previous boot is expected to be same as the reserved* trace buffer memory region provided through DTS*/- if (is_tmc_reserved_region_valid(dev->parent)
&& (drvdata->crash_tbuf.paddr == mdata->trc_paddr))resrv_buf->vaddr = drvdata->crash_tbuf.vaddr;- else {
dev_dbg(dev, "Trace buffer address of previous bootinvalid\n");
rc = -EINVAL;goto map_err;- }
- resrv_buf->size = etr_buf->size;
- resrv_buf->dev = &drvdata->csdev->dev;
- etr_buf->hwaddr = trace_addr;
trace_addr is uninitialised at this point. If you pull the latest coresight branch we enabled some extra compiler warnings which catch this.
I assume it's supposed to be mdata->trc_paddr?
Since no DMA operation happens here, its supposed to be kept NULL. Since it was redundant for crash data read operation, missed catching this. Will fix this.
Is there some kind of test that could be added that could have caught this? Maybe skip the full reboot flow but just enable the feature and see if we can read from the buffer.
As pointed above this field is redundant for crashdata read mode. So its not a functionality breakage as such.
Ah ok that's not as bad as I thought then. I went back to version 4 or 5 and thought I saw it was assigned so assumed there was a mistake.
Or even just toggling the mode on and off via sysfs. We're running the Perf and kselftests on Juno internally so I can add a reserved region to the Juno DT and make sure this stays working.
Did you meant adding a kselftest for tracing and reading back tracedata in sysfs mode using the reserved region ?
Yes just enable, disable then read back. I don't think we need to do a decode, but make sure a non zero size is read. And the test can be skipped if the reserved region doesn't exist.
Thanks Linu Cherian.
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Monday, April 15, 2024 2:59 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Anil Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: Re: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
On 15/04/2024 05:01, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Friday, April 12, 2024 3:36 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com;
Anil
Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
On 07/03/2024 03:36, Linu Cherian wrote:
Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace captured in previous crash/watchdog reset.
Add special device files for reading ETR/ETF crash data.
User can read the crash data as below
For example, for reading crash data from tmc_etf sink
#dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Tanmay Jagdale tanmay@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed read_prevboot flag in sysfs
- Added special device files for reading crashdata
- Renamed CS mode READ_PREVBOOT to READ_CRASHDATA
- Setting the READ_CRASHDATA mode is done as part of file open.
[...]
@@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device *adev,
const struct amba_id *id)
coresight_unregister(drvdata->csdev);else pm_runtime_put(&adev->dev);
- if (!is_tmc_reserved_region_valid(dev))
goto out;- drvdata->crashdev.name =
devm_kasprintf(dev, GFP_KERNEL, "%s_%s", "crash",desc.name);
- drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
- drvdata->crashdev.fops = &tmc_crashdata_fops;
- ret = misc_register(&drvdata->crashdev);
- if (ret)
pr_err("%s: Failed to setup dev interface for crashdata\n",desc.name);Is this all optional after the is_tmc_reserved_region_valid()? Skipping to out seems to be more like an error condition, but in this case it's not? Having it like this makes it more difficult to add extra steps to the probe function. You could move it to a function and flip
the condition which would be clearer:
Ack.
if (is_tmc_reserved_region_valid(dev)) register_crash_dev_interface(drvdata);
Did you meant changing the condition of "is_tmc_reserved_region_valid" by "flip the condition". If yes, that’s not required IMHO, since the reserved region is still valid.
IIUC, the idea here is to not to fail the tmc_probe due to an error condition in register_crash_dev_interface, so that the normal condition is not affected. Also the error condition can be notified to the user using a pr_dbg / pr_err.
Thanks.
On 21/04/2024 03:49, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Monday, April 15, 2024 2:59 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Anil Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: Re: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
On 15/04/2024 05:01, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Friday, April 12, 2024 3:36 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com;
Anil
Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
On 07/03/2024 03:36, Linu Cherian wrote:
Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace captured in previous crash/watchdog reset.
Add special device files for reading ETR/ETF crash data.
User can read the crash data as below
For example, for reading crash data from tmc_etf sink
#dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Tanmay Jagdale tanmay@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed read_prevboot flag in sysfs
- Added special device files for reading crashdata
- Renamed CS mode READ_PREVBOOT to READ_CRASHDATA
- Setting the READ_CRASHDATA mode is done as part of file open.
[...]
@@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device *adev,
const struct amba_id *id)
coresight_unregister(drvdata->csdev);else pm_runtime_put(&adev->dev);
- if (!is_tmc_reserved_region_valid(dev))
goto out;- drvdata->crashdev.name =
devm_kasprintf(dev, GFP_KERNEL, "%s_%s", "crash",desc.name);
- drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
- drvdata->crashdev.fops = &tmc_crashdata_fops;
- ret = misc_register(&drvdata->crashdev);
- if (ret)
pr_err("%s: Failed to setup dev interface for crashdata\n",desc.name);Is this all optional after the is_tmc_reserved_region_valid()? Skipping to out seems to be more like an error condition, but in this case it's not? Having it like this makes it more difficult to add extra steps to the probe function. You could move it to a function and flip
the condition which would be clearer:
Ack.
if (is_tmc_reserved_region_valid(dev)) register_crash_dev_interface(drvdata);
Did you meant changing the condition of "is_tmc_reserved_region_valid" by "flip the condition". If yes, that’s not required IMHO, since the reserved region is still valid.
By flip I mean remove the !. You had this:
if (!is_tmc_reserved_region_valid(dev)) goto out;
But instead you should put your registration code in a function, remove the ! and replace the goto with a function:
if (is_tmc_reserved_region_valid(dev)) ret = register_crash_dev_interface(drvdata);
Where register_crash_dev_interface() is everything you added in between the goto and the out: label. The reason is that you've made it impossible to extend the probe function with new behavior without having to understand that this new bit must always come last. Otherwise new behavior would also be skipped over if the reserved region doesn't exist.
IIUC, the idea here is to not to fail the tmc_probe due to an error condition in register_crash_dev_interface, so that the normal condition is not affected. Also the error condition can be notified to the user using a pr_dbg / pr_err.
Thanks.
I'm not sure I follow exactly what you mean here, but for the one error condition you are checking for on the call to misc_register() you can still return that from the new function and check it in the probe.
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Monday, April 22, 2024 1:48 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Anil Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
On 21/04/2024 03:49, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Monday, April 15, 2024 2:59 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com;
Anil
Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: Re: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
On 15/04/2024 05:01, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Friday, April 12, 2024 3:36 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com;
Anil
Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
--
On 07/03/2024 03:36, Linu Cherian wrote:
- Introduce a new mode CS_MODE_READ_CRASHDATA for reading
trace
captured in previous crash/watchdog reset.
Add special device files for reading ETR/ETF crash data.
User can read the crash data as below
For example, for reading crash data from tmc_etf sink
#dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
Signed-off-by: Anil Kumar Reddy areddy3@marvell.com Signed-off-by: Tanmay Jagdale tanmay@marvell.com Signed-off-by: Linu Cherian lcherian@marvell.com
Changelog from v6:
- Removed read_prevboot flag in sysfs
- Added special device files for reading crashdata
- Renamed CS mode READ_PREVBOOT to READ_CRASHDATA
- Setting the READ_CRASHDATA mode is done as part of file open.
[...]
@@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device *adev,
const struct amba_id *id)
coresight_unregister(drvdata->csdev);else pm_runtime_put(&adev->dev);
- if (!is_tmc_reserved_region_valid(dev))
goto out;- drvdata->crashdev.name =
devm_kasprintf(dev, GFP_KERNEL, "%s_%s","crash",
desc.name);
- drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
- drvdata->crashdev.fops = &tmc_crashdata_fops;
- ret = misc_register(&drvdata->crashdev);
- if (ret)
pr_err("%s: Failed to setup dev interface forcrashdata\n",
desc.name);Is this all optional after the is_tmc_reserved_region_valid()? Skipping to out seems to be more like an error condition, but in this case it's not? Having it like this makes it more difficult to add extra steps to the probe function. You could move it to a function and flip
the condition which would be clearer:
Ack.
if (is_tmc_reserved_region_valid(dev)) register_crash_dev_interface(drvdata);
Did you meant changing the condition of "is_tmc_reserved_region_valid"
by "flip the condition".
If yes, that’s not required IMHO, since the reserved region is still valid.
By flip I mean remove the !. You had this:
if (!is_tmc_reserved_region_valid(dev)) goto out;
But instead you should put your registration code in a function, remove the ! and replace the goto with a function:
if (is_tmc_reserved_region_valid(dev)) ret = register_crash_dev_interface(drvdata);Where register_crash_dev_interface() is everything you added in between the goto and the out: label. The reason is that you've made it impossible to extend the probe function with new behavior without having to understand that this new bit must always come last. Otherwise new behavior would also be skipped over if the reserved region doesn't exist.
Thanks. That’s clear to me.
IIUC, the idea here is to not to fail the tmc_probe due to an error condition in register_crash_dev_interface, so that the normal condition is
not affected. Also the error condition can be notified to the user using a pr_dbg / pr_err.
Thanks.
I'm not sure I follow exactly what you mean here, but for the one error condition you are checking for on the call to misc_register() you can still return that from the new function and check it in the probe.
Actually was trying to clarify that we may not want to fail the probe due to a failure in the register_crash_dev_interface, since the normal trace operations could continue without crash_dev interface.(Tracing with or without the reserved region doesn’t get affected as well). Please see the changes below. That way the changes are simpler.
@@ -507,6 +628,18 @@ static u32 tmc_etr_get_max_burst_size(struct device *dev) return burst_size; }
+static void register_crash_dev_interface(struct tmc_drvdata * drvdata, + const char *name) +{ + drvdata->crashdev.name = + devm_kasprintf(&drvdata->csdev->dev, GFP_KERNEL, "%s_%s", "crash", name); + drvdata->crashdev.minor = MISC_DYNAMIC_MINOR; + drvdata->crashdev.fops = &tmc_crashdata_fops; + if (misc_register(&drvdata->crashdev)) + dev_dbg(&drvdata->csdev->dev, + "Failed to setup user interface for crashdata\n"); +} + static int tmc_probe(struct amba_device *adev, const struct amba_id *id) { int ret = 0; @@ -619,6 +752,10 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) coresight_unregister(drvdata->csdev); else pm_runtime_put(&adev->dev); + + if (is_tmc_reserved_region_valid(dev)) + register_crash_dev_interface(drvdata, desc.name); + out: return ret; }
Thanks. Linu Cherian.
On 25/04/2024 03:07, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Monday, April 22, 2024 1:48 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com; Anil Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
On 21/04/2024 03:49, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Monday, April 15, 2024 2:59 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com;
Anil
Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: Re: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
On 15/04/2024 05:01, Linu Cherian wrote:
Hi James,
-----Original Message----- From: James Clark james.clark@arm.com Sent: Friday, April 12, 2024 3:36 PM To: Linu Cherian lcherian@marvell.com; Suzuki K Poulose suzuki.poulose@arm.com Cc: linux-arm-kernel@lists.infradead.org; coresight@lists.linaro.org; linux- kernel@vger.kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org; conor+dt@kernel.org; devicetree@vger.kernel.org; Sunil Kovvuri Goutham sgoutham@marvell.com; George Cherian gcherian@marvell.com;
Anil
Kumar Reddy H areddy3@marvell.com; Tanmay Jagdale tanmay@marvell.com; mike.leach@linaro.org; leo.yan@linaro.org Subject: [EXTERNAL] Re: [PATCH v7 5/7] coresight: tmc: Add support for reading crash data
Prioritize security for external emails: Confirm sender and content safety before clicking links or opening attachments
--
On 07/03/2024 03:36, Linu Cherian wrote: > * Introduce a new mode CS_MODE_READ_CRASHDATA for reading
trace
> captured in previous crash/watchdog reset. > > * Add special device files for reading ETR/ETF crash data. > > * User can read the crash data as below > > For example, for reading crash data from tmc_etf sink > > #dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin > > Signed-off-by: Anil Kumar Reddy areddy3@marvell.com > Signed-off-by: Tanmay Jagdale tanmay@marvell.com > Signed-off-by: Linu Cherian lcherian@marvell.com > --- > Changelog from v6: > * Removed read_prevboot flag in sysfs > * Added special device files for reading crashdata > * Renamed CS mode READ_PREVBOOT to READ_CRASHDATA > * Setting the READ_CRASHDATA mode is done as part of file open. >
[...]
> @@ -619,6 +740,19 @@ static int tmc_probe(struct amba_device > *adev, const struct amba_id *id) > coresight_unregister(drvdata->csdev); > else > pm_runtime_put(&adev->dev); > + > + if (!is_tmc_reserved_region_valid(dev)) > + goto out; > + > + drvdata->crashdev.name = > + devm_kasprintf(dev, GFP_KERNEL, "%s_%s",
"crash",
desc.name); > + drvdata->crashdev.minor = MISC_DYNAMIC_MINOR; > + drvdata->crashdev.fops = &tmc_crashdata_fops; > + ret = misc_register(&drvdata->crashdev); > + if (ret) > + pr_err("%s: Failed to setup dev interface for
crashdata\n",
> + desc.name); > +
Is this all optional after the is_tmc_reserved_region_valid()? Skipping to out seems to be more like an error condition, but in this case it's not? Having it like this makes it more difficult to add extra steps to the probe function. You could move it to a function and flip
the condition which would be clearer:
Ack.
if (is_tmc_reserved_region_valid(dev)) register_crash_dev_interface(drvdata);
Did you meant changing the condition of "is_tmc_reserved_region_valid"
by "flip the condition".
If yes, that’s not required IMHO, since the reserved region is still valid.
By flip I mean remove the !. You had this:
if (!is_tmc_reserved_region_valid(dev)) goto out;
But instead you should put your registration code in a function, remove the ! and replace the goto with a function:
if (is_tmc_reserved_region_valid(dev)) ret = register_crash_dev_interface(drvdata);Where register_crash_dev_interface() is everything you added in between the goto and the out: label. The reason is that you've made it impossible to extend the probe function with new behavior without having to understand that this new bit must always come last. Otherwise new behavior would also be skipped over if the reserved region doesn't exist.
Thanks. That’s clear to me.
IIUC, the idea here is to not to fail the tmc_probe due to an error condition in register_crash_dev_interface, so that the normal condition is
not affected. Also the error condition can be notified to the user using a pr_dbg / pr_err.
Thanks.
I'm not sure I follow exactly what you mean here, but for the one error condition you are checking for on the call to misc_register() you can still return that from the new function and check it in the probe.
Actually was trying to clarify that we may not want to fail the probe due to a failure in the register_crash_dev_interface, since the normal trace operations could continue without crash_dev interface.(Tracing with or without the reserved region doesn’t get affected as well). Please see the changes below. That way the changes are simpler.
@@ -507,6 +628,18 @@ static u32 tmc_etr_get_max_burst_size(struct device *dev) return burst_size; }
+static void register_crash_dev_interface(struct tmc_drvdata * drvdata,
const char *name)+{
drvdata->crashdev.name =devm_kasprintf(&drvdata->csdev->dev, GFP_KERNEL, "%s_%s", "crash", name);drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;drvdata->crashdev.fops = &tmc_crashdata_fops;if (misc_register(&drvdata->crashdev))dev_dbg(&drvdata->csdev->dev,"Failed to setup user interface for crashdata\n");+}
static int tmc_probe(struct amba_device *adev, const struct amba_id *id) { int ret = 0; @@ -619,6 +752,10 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) coresight_unregister(drvdata->csdev); else pm_runtime_put(&adev->dev);
if (is_tmc_reserved_region_valid(dev))register_crash_dev_interface(drvdata, desc.name);out: return ret; }
Thanks. Linu Cherian.
Looks good to me!
-
James Clark -
Linu Cherian