Hi,
That fix sorts the problem on my board. However, be aware that the etmv4 PM code changes somewhat due to this patch [1] that is currently on the linux master branch and will appear in 5.8-rc6, and there are further new coresight patches in Mathieu's coresight/next and linux-next.
It may be better to rebase onto coresight/next for the next set.
Regards
Mike
[1] 9b6a3f3633a5 coresight: etmv4: Fix CPU power management setup in probe() function
On Sat, 18 Jul 2020 at 04:25, tingwei@codeaurora.org wrote:
Hi Mike,
Thanks for reporting this. This is a good catch.
I was testing on db845c but I didn't encounter this issue with multiple module load/unload test. I guess it's due to timing difference. The issue is etm4_cpu_pm_notify() is removed from cpu pm notification after last etm4 device is removed. There's racing condition when some etm4 device say etm0 is removed but etm4_cpu_pm_notify() is still called. I reproduced this issue by manually unbind etm4x device.
The fix is clean etmdrvdata[drvdata->cpu] in etm4_remove() so etm4_cpu_pm_notify() is gracefully returned. I've verified this on db845c with manually unbind etm4x device test. Do you mind test on your db410 as well? I'll put it into v4.
@@ -1542,6 +1543,7 @@ static int __exit etm4_remove(struct amba_device *adev)
etm_perf_symlink(drvdata->csdev, false);
etmdrvdata[drvdata->cpu] = NULL; if (--etm4_count == 0) { etm4_cpu_pm_unregister();On 2020-07-18 01:05, Mike Leach wrote:
Hi Tingwei,
Couldn't see 00/20 cover note for this set, so reporting this here as it relates to etmv4 in part.
The following sequence:- (There is a load dependency here of course, if I try to load ETMv4 without the coresight core, then I get a lot of missing symbol error messages - I assume this is expected behaviour?)
Coresight_etm4x module depends on coresight module, so it's expected behavior.
root@linaro-developer:/home/linaro/cs-mods# insmod coresight.ko root@linaro-developer:/home/linaro/cs-mods# insmod coresight-etm4x.ko
correctly loads the coresight core then ETMv4 module.
[ 1208.214674] coresight etm0: CPU0: ETM v4.0 initialized [ 1208.215534] coresight etm1: CPU1: ETM v4.0 initialized [ 1208.221020] coresight etm2: CPU2: ETM v4.0 initialized [ 1208.224757] coresight etm3: CPU3: ETM v4.0 initialized
However, if I then unload the ETMv4 module:-
root@linaro-developer:/home/linaro/cs-mods# rmmod coresight-etm4x.ko
I get a crash:-
[ 1215.963689] ------------[ cut here ]------------ [ 1215.963741] WARNING: CPU: 3 PID: 0 at drivers/hwtracing/coresight/coresight-etm4x-core.c:1364 etm4_cpu_pm_notify+0xad8/0xb48 [coresight_etm4x] [ 1215.967373] Modules linked in: coresight_etm4x(-) coresight [last unloaded: coresight] [ 1215.979960] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G W 5.8.0-rc5cs-modscs-mods-00020-gc03fe910680d #282 [ 1215.987856] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) [ 1215.998531] pstate: 80000085 (Nzcv daIf -PAN -UAO BTYPE=--) [ 1216.005396] pc : etm4_cpu_pm_notify+0xad8/0xb48 [coresight_etm4x] [ 1216.010687] lr : notifier_call_chain+0x5c/0xa0 [ 1216.016926] sp : ffff000009fe7d50 [ 1216.021265] x29: ffff000009fe7d50 x28: 0000000000000000 [ 1216.024653] x27: 0000011b1d1464b5 x26: 0000000000000001 [ 1216.030035] x25: ffff00003c79f888 x24: 0000000000000001 [ 1216.035330] x23: 0000000000000000 x22: 0000000000000000 [ 1216.040626] x21: 0000000000000000 x20: 0000000000000000 [ 1216.045921] x19: ffff000038396480 x18: 0000000000000000 [ 1216.051216] x17: 0000000000000000 x16: 0000000000000000 [ 1216.056510] x15: 0000000000000000 x14: ffffffffffffffff [ 1216.061806] x13: ffffffffffffffff x12: 0000000000000000 [ 1216.067101] x11: 0000000000000000 x10: 00000000000009b0 [ 1216.072396] x9 : ffff000009fe7e70 x8 : ffff000009fd4010 [ 1216.077690] x7 : 0000000000000000 x6 : 0000000023c2c562 [ 1216.082986] x5 : 00ffffffffffffff x4 : 0000000000000003 [ 1216.088281] x3 : ffff000038396880 x2 : ffff800008d8d280 [ 1216.093576] x1 : ffff80002b1aa000 x0 : 000000005f454c42 [ 1216.098873] Call trace: [ 1216.104178] etm4_cpu_pm_notify+0xad8/0xb48 [coresight_etm4x] [ 1216.106343] notifier_call_chain+0x5c/0xa0 [ 1216.112242] __atomic_notifier_call_chain+0x48/0x60 [ 1216.116236] cpu_pm_notify+0x44/0x70 [ 1216.121008] cpu_pm_enter+0x3c/0x80 [ 1216.124829] psci_enter_domain_idle_state+0x38/0xa8 [ 1216.128040] cpuidle_enter_state+0x88/0x478 [ 1216.132900] cpuidle_enter+0x44/0x58 [ 1216.137069] call_cpuidle+0x40/0x70 [ 1216.140888] do_idle+0x1e0/0x248 [ 1216.144099] cpu_startup_entry+0x28/0x98 [ 1216.147574] secondary_start_kernel+0x1a0/0x1f8 [ 1216.151476] ---[ end trace 97bcd7b8bdd7f9a7 ]---
This happens each time, though the CPU number can change. Test platform is Dragonboard DB410, linux 5.8-rc5 + this patch set.
Regards
Mike
On Fri, 17 Jul 2020 at 06:48, Tingwei Zhang tingwei@codeaurora.org wrote:
From: Kim Phillips kim.phillips@arm.com
Allow to build coresight-etm4x as a module, for ease of development.
- Kconfig becomes a tristate, to allow =m
- append -core to source file name to allow module to be called coresight-etm4x by the Makefile
- add an etm4_remove function, for module unload
- add a MODULE_DEVICE_TABLE for autoloading on boot
Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Leo Yan leo.yan@linaro.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Randy Dunlap rdunlap@infradead.org Cc: Suzuki K Poulose Suzuki.Poulose@arm.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Russell King linux@armlinux.org.uk Signed-off-by: Kim Phillips kim.phillips@arm.com Signed-off-by: Tingwei Zhang tingwei@codeaurora.org
drivers/hwtracing/coresight/Kconfig | 5 ++- drivers/hwtracing/coresight/Makefile | 4 +-- ...resight-etm4x.c => coresight-etm4x-core.c} | 31 ++++++++++++++++++- 3 files changed, 36 insertions(+), 4 deletions(-) rename drivers/hwtracing/coresight/{coresight-etm4x.c =>
coresight-etm4x-core.c} (98%)
diff --git a/drivers/hwtracing/coresight/Kconfig
b/drivers/hwtracing/coresight/Kconfig
index 8fd9fd139cf3..d6e107bbd30b 100644 --- a/drivers/hwtracing/coresight/Kconfig +++ b/drivers/hwtracing/coresight/Kconfig @@ -78,7 +78,7 @@ config CORESIGHT_SOURCE_ETM3X module will be called coresight-etm3x.
config CORESIGHT_SOURCE_ETM4X
bool "CoreSight Embedded Trace Macrocell 4.x driver"
tristate "CoreSight Embedded Trace Macrocell 4.x driver" depends on ARM64 select CORESIGHT_LINKS_AND_SINKS select PID_IN_CONTEXTIDR@@ -88,6 +88,9 @@ config CORESIGHT_SOURCE_ETM4X for instruction level tracing. Depending on the implemented
version
data tracing may also be available.
To compile this driver as a module, choose M here: themodule will be called coresight-etm4x.config CORESIGHT_STM tristate "CoreSight System Trace Macrocell driver" depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) ||
ARM64
diff --git a/drivers/hwtracing/coresight/Makefile
b/drivers/hwtracing/coresight/Makefile
index d619cfd0abd8..271dc255454f 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -14,8 +14,8 @@ obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) +=
coresight-funnel.o \
obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o coresight-etm3x-y := coresight-etm3x-core.o coresight-etm-cp14.o \ coresight-etm3x-sysfs.o -obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
coresight-etm4x-sysfs.o+obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o +coresight-etm4x-y := coresight-etm4x-core.o coresight-etm4x-sysfs.o obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o obj-$(CONFIG_CORESIGHT_CPU_DEBUG) += coresight-cpu-debug.o obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c
b/drivers/hwtracing/coresight/coresight-etm4x-core.c
similarity index 98% rename from drivers/hwtracing/coresight/coresight-etm4x.c rename to drivers/hwtracing/coresight/coresight-etm4x-core.c index 747afc875f91..b5945f62794c 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1536,6 +1536,26 @@ static struct amba_cs_uci_id uci_id_etm4[] = { } };
+static int __exit etm4_remove(struct amba_device *adev) +{
struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev);etm_perf_symlink(drvdata->csdev, false);if (--etm4_count == 0) {etm4_cpu_pm_unregister();cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
if (hp_online)cpuhp_remove_state_nocalls(hp_online);}coresight_unregister(drvdata->csdev);return 0;+}
static const struct amba_id etm4_ids[] = { CS_AMBA_ID(0x000bb95d), /* Cortex-A53 */ CS_AMBA_ID(0x000bb95e), /* Cortex-A57 */ @@ -1553,12 +1573,21 @@ static const struct amba_id etm4_ids[] = { {}, };
+MODULE_DEVICE_TABLE(amba, etm4_ids);
static struct amba_driver etm4x_driver = { .drv = { .name = "coresight-etm4x",
.owner = THIS_MODULE, .suppress_bind_attrs = true, }, .probe = etm4_probe,.remove = etm4_remove, .id_table = etm4_ids,}; -builtin_amba_driver(etm4x_driver); +module_amba_driver(etm4x_driver);
+MODULE_AUTHOR("Pratik Patel pratikp@codeaurora.org"); +MODULE_AUTHOR("Mathieu Poirier mathieu.poirier@linaro.org"); +MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace v4 driver");
+MODULE_LICENSE("GPL v2");
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