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 Reviewed-by: James Clark james.clark@arm.com --- .../hwtracing/coresight/coresight-tmc-core.c | 50 ++++++++++++ .../hwtracing/coresight/coresight-tmc-etr.c | 79 +++++++++++++++++++ drivers/hwtracing/coresight/coresight-tmc.h | 25 ++++++ 3 files changed, 154 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index 3a482fd2cb22..248989833b20 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -23,6 +23,7 @@ #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> #include <linux/platform_device.h> @@ -398,6 +399,53 @@ static inline bool tmc_etr_has_non_secure_access(struct tmc_drvdata *drvdata)
static const struct amba_id tmc_ids[];
+static int of_tmc_get_reserved_resource_by_name(struct device *dev, + const char *name, + struct resource *res) +{ + int index, rc = -ENODEV; + struct device_node *node; + + if (!is_of_node(dev->fwnode)) + return -ENODEV; + + index = of_property_match_string(dev->of_node, "memory-region-names", + name); + if (index < 0) + return rc; + + node = of_parse_phandle(dev->of_node, "memory-region", index); + if (!node) + return rc; + + if (!of_address_to_resource(node, 0, res) && + res->start != 0 && resource_size(res) != 0) + rc = 0; + of_node_put(node); + + return rc; +} + +static void tmc_get_reserved_region(struct device *parent) +{ + struct tmc_drvdata *drvdata = dev_get_drvdata(parent); + struct resource res; + + if (of_tmc_get_reserved_resource_by_name(parent, "tracedata", &res)) + return; + + drvdata->resrv_buf.vaddr = memremap(res.start, + resource_size(&res), + MEMREMAP_WC); + if (IS_ERR_OR_NULL(drvdata->resrv_buf.vaddr)) { + dev_err(parent, "Reserved trace buffer mapping failed\n"); + return; + } + + drvdata->resrv_buf.paddr = res.start; + drvdata->resrv_buf.size = resource_size(&res); +} + /* Detect and initialise the capabilities of a TMC ETR */ static int tmc_etr_setup_caps(struct device *parent, u32 devid, struct csdev_access *access) @@ -508,6 +556,8 @@ static int __tmc_probe(struct device *dev, struct resource *res) 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 a48bb85d0e7f..8bca5b36334a 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; };
/* @@ -695,6 +696,75 @@ 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->resrv_buf.paddr, + drvdata->resrv_buf.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->resrv_buf.vaddr; + resrv_buf->size = etr_buf->size = drvdata->resrv_buf.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. @@ -801,6 +871,7 @@ 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) @@ -826,6 +897,7 @@ 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); @@ -844,6 +916,7 @@ 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 = tmc_has_reserved_buffer(drvdata); }
static bool etr_can_use_flat_mode(struct etr_buf_hw *buf_hw, ssize_t etr_buf_size) @@ -1831,6 +1904,7 @@ 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", };
@@ -1849,6 +1923,9 @@ 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; } @@ -1876,6 +1953,8 @@ 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 2671926be62a..d2261eddab71 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 * @pclk: APB clock if present, otherwise NULL @@ -189,6 +201,10 @@ struct etr_buf { * @idr_mutex: Access serialisation for idr. * @sysfs_buf: SYSFS buffer for ETR. * @perf_buf: PERF buffer for ETR. + * @resrv_buf: 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 { struct clk *pclk; @@ -214,6 +230,7 @@ struct tmc_drvdata { struct mutex idr_mutex; struct etr_buf *sysfs_buf; struct etr_buf *perf_buf; + struct tmc_resrv_buf resrv_buf; };
struct etr_buf_operations { @@ -331,6 +348,14 @@ 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 tmc_has_reserved_buffer(struct tmc_drvdata *drvdata) +{ + if (drvdata->resrv_buf.vaddr && + drvdata->resrv_buf.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);