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-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etf.c90
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etr.c93
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc.c14
3 files changed, 170 insertions, 27 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 91e43572ce9f..6eb1665cfc9c 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -16,14 +16,12 @@
*/
#include <linux/coresight.h>
+#include <linux/slab.h>
#include "coresight-priv.h"
#include "coresight-tmc.h"
void tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
{
- /* Zero out the memory to help with debug */
- memset(drvdata->buf, 0, drvdata->size);
-
CS_UNLOCK(drvdata->base);
/* Wait for TMCSReady bit to be set */
@@ -110,21 +108,67 @@ static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata)
static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
{
+ int ret = 0;
+ bool used = false;
+ char *buf = NULL;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ /* This shouldn't be happening */
+ if (WARN_ON(mode != CS_MODE_SYSFS))
+ return -EINVAL;
+
+ /*
+ * If we don't have a buffer release the lock and allocate memory.
+ * Otherwise keep the lock and move along.
+ */
spin_lock_irqsave(&drvdata->spinlock, flags);
- if (drvdata->reading) {
+ if (!drvdata->buf) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- return -EBUSY;
+
+ /* Allocating the memory here while outside of the spinlock */
+ buf = kzalloc(drvdata->size, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ /* Let's try again */
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ }
+
+ if (drvdata->reading) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /*
+ * If drvdata::buf isn't NULL, memory was allocated for a previous
+ * trace run but wasn't read. If so simply zero-out the memory.
+ * Otherwise use the memory allocated above.
+ *
+ * The memory is freed when users read the buffer using the
+ * /dev/xyz.{etf|etb} interface. See tmc_read_unprepare_etf() for
+ * details.
+ */
+ if (drvdata->buf) {
+ memset(drvdata->buf, 0, drvdata->size);
+ } else {
+ used = true;
+ drvdata->buf = buf;
}
tmc_etb_enable_hw(drvdata);
drvdata->enable = true;
+out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- dev_info(drvdata->dev, "TMC-ETB/ETF enabled\n");
- return 0;
+ /* Free memory outside the spinlock if need be */
+ if (!used && buf)
+ kfree(buf);
+
+ if (!ret)
+ dev_info(drvdata->dev, "TMC-ETB/ETF enabled\n");
+
+ return ret;
}
static void tmc_disable_etf_sink(struct coresight_device *csdev)
@@ -223,6 +267,12 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
goto out;
}
+ /* If drvdata::buf is NULL the trace data has been read already */
+ if (drvdata->buf == NULL) {
+ ret = -EINVAL;
+ goto out;
+ }
+
/* Disable the TMC if need be */
if (drvdata->enable)
tmc_etb_disable_hw(drvdata);
@@ -236,6 +286,7 @@ out:
int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
{
+ char *buf = NULL;
enum tmc_mode mode;
unsigned long flags;
@@ -254,11 +305,34 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
}
/* Re-enable the TMC if need be */
- if (drvdata->enable)
+ if (drvdata->enable) {
+ /*
+ * The trace run will continue with the same allocated trace
+ * buffer. As such zero-out the buffer so that we don't end
+ * up with stale data.
+ *
+ * Since the tracer is still enabled drvdata::buf
+ * can't be NULL.
+ */
+ memset(drvdata->buf, 0, drvdata->size);
tmc_etb_enable_hw(drvdata);
+ } else {
+ /*
+ * The ETB/ETF is not tracing and the buffer was just read.
+ * As such prepare to free the trace buffer.
+ */
+ buf = drvdata->buf;
+ drvdata->buf = NULL;
+ }
drvdata->reading = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ /*
+ * Free allocated memory outside of the spinlock. There is no need
+ * to assert the validity of 'buf' since calling kfree(NULL) is safe.
+ */
+ kfree(buf);
+
return 0;
}
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 3483d139a4ac..ac37bf904fb7 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -16,6 +16,7 @@
*/
#include <linux/coresight.h>
+#include <linux/dma-mapping.h>
#include "coresight-priv.h"
#include "coresight-tmc.h"
@@ -83,21 +84,71 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
{
+ int ret = 0;
+ bool used = false;
unsigned long flags;
+ void __iomem *vaddr = NULL;
+ dma_addr_t paddr;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ /* This shouldn't be happening */
+ if (WARN_ON(mode != CS_MODE_SYSFS))
+ return -EINVAL;
+
+ /*
+ * If we don't have a buffer release the lock and allocate memory.
+ * Otherwise keep the lock and move along.
+ */
spin_lock_irqsave(&drvdata->spinlock, flags);
- if (drvdata->reading) {
+ if (!drvdata->vaddr) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- return -EBUSY;
+
+ /*
+ * Contiguous memory can't be allocated while a spinlock is
+ * held. As such allocate memory here and free it if a buffer
+ * has already been allocated (from a previous session).
+ */
+ vaddr = dma_alloc_coherent(drvdata->dev, drvdata->size,
+ &paddr, GFP_KERNEL);
+ if (!vaddr)
+ return -ENOMEM;
+
+ /* Let's try again */
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+ }
+
+ if (drvdata->reading) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ /*
+ * If drvdata::buf == NULL, use the memory allocated above.
+ * Otherwise a buffer still exists from a previous session, so
+ * simply use that.
+ */
+ if (drvdata->buf == NULL) {
+ used = true;
+ drvdata->vaddr = vaddr;
+ drvdata->paddr = paddr;
+ drvdata->buf = drvdata->vaddr;
}
+ memset(drvdata->vaddr, 0, drvdata->size);
+
tmc_etr_enable_hw(drvdata);
drvdata->enable = true;
+out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
- dev_info(drvdata->dev, "TMC-ETR enabled\n");
- return 0;
+ /* Free memory outside the spinlock if need be */
+ if (!used && vaddr)
+ dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
+
+ if (!ret)
+ dev_info(drvdata->dev, "TMC-ETR enabled\n");
+
+ return ret;
}
static void tmc_disable_etr_sink(struct coresight_device *csdev)
@@ -129,6 +180,7 @@ const struct coresight_ops tmc_etr_cs_ops = {
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
{
+ int ret = 0;
unsigned long flags;
/* config types are set a boot time and never change */
@@ -137,11 +189,18 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
+ /* If drvdata::buf is NULL the trace data has been read already */
+ if (drvdata->buf == NULL) {
+ ret = -EINVAL;
+ goto out;
+ }
+
/* Disable the TMC if need be */
if (drvdata->enable)
tmc_etr_disable_hw(drvdata);
drvdata->reading = true;
+out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return 0;
@@ -150,6 +209,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
{
unsigned long flags;
+ dma_addr_t paddr;
+ void __iomem *vaddr = NULL;
/* config types are set a boot time and never change */
if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
@@ -158,11 +219,33 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
/* RE-enable the TMC if need be */
- if (drvdata->enable)
+ if (drvdata->enable) {
+ /*
+ * The trace run will continue with the same allocated trace
+ * buffer. As such zero-out the buffer so that we don't end
+ * up with stale data.
+ *
+ * Since the tracer is still enabled drvdata::buf
+ * can't be NULL.
+ */
+ memset(drvdata->buf, 0, drvdata->size);
tmc_etr_enable_hw(drvdata);
+ } else {
+ /*
+ * The ETR is not tracing and the buffer was just read.
+ * As such prepare to free the trace buffer.
+ */
+ vaddr = drvdata->vaddr;
+ paddr = drvdata->paddr;
+ drvdata->buf = NULL;
+ }
drvdata->reading = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+ /* Free allocated memory out side of the spinlock */
+ if (vaddr)
+ dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
+
return 0;
}
diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c
index 63f8e55116a6..e8e12a9b917a 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.c
+++ b/drivers/hwtracing/coresight/coresight-tmc.c
@@ -319,20 +319,6 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
pm_runtime_put(&adev->dev);
- if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) {
- drvdata->vaddr = dma_alloc_coherent(dev, drvdata->size,
- &drvdata->paddr, GFP_KERNEL);
- if (!drvdata->vaddr)
- return -ENOMEM;
-
- memset(drvdata->vaddr, 0, drvdata->size);
- drvdata->buf = drvdata->vaddr;
- } else {
- drvdata->buf = devm_kzalloc(dev, drvdata->size, GFP_KERNEL);
- if (!drvdata->buf)
- return -ENOMEM;
- }
-
desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
if (!desc) {
ret = -ENOMEM;
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-03 15:14:44 +0000