* [PATCH] coresight: tmc: Cleanup operation mode handling
@ 2016-09-14 13:53 ` Suzuki K Poulose
0 siblings, 0 replies; 10+ messages in thread
From: Suzuki K Poulose @ 2016-09-14 13:53 UTC (permalink / raw)
To: linux-arm-kernel
Cc: linux-kernel, venkatesh.vivekanandan, Suzuki K Poulose, Mathieu Poirier
The mode of operation of the TMC tracked in drvdata->mode is defined
as a local_t type. This is always checked and modified under the
drvdata->spinlock and hence we don't need local_t for it and the
unnecessary synchronisation instructions that comes with it. This
change makes the code a bit more cleaner.
Also fixes the order in which we update the drvdata->mode to
CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
which in turn depends on the mode to decide whether to dump the
trace to a buffer.
Applies on mathieu's coresight/next tree [1]
https://git.linaro.org/kernel/coresight.git next
Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 32 +++++++++++--------------
drivers/hwtracing/coresight/coresight-tmc-etr.c | 30 ++++++++++-------------
drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
3 files changed, 28 insertions(+), 36 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index d6941ea..c51ce45 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
* When operating in sysFS mode the content of the buffer needs to be
* read before the TMC is disabled.
*/
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etb_dump_hw(drvdata);
tmc_disable_hw(drvdata);
@@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
int ret = 0;
bool used = false;
char *buf = NULL;
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched.
*/
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
goto out;
/*
@@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
drvdata->buf = buf;
}
+ drvdata->mode = CS_MODE_SYSFS;
tmc_etb_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -180,7 +179,6 @@ out:
static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In Perf mode there can be only one writer per sink. There
* is also no need to continue if the ETB/ETR is already operated
* from sysFS.
*/
- if (val != CS_MODE_DISABLED) {
+ if (drvdata->mode != CS_MODE_DISABLED) {
ret = -EINVAL;
goto out;
}
+ drvdata->mode = mode;
tmc_etb_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
static void tmc_disable_etf_sink(struct coresight_device *csdev)
{
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
return;
}
- val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
/* Disable the TMC only if it needs to */
- if (val != CS_MODE_DISABLED)
+ if (drvdata->mode != CS_MODE_DISABLED) {
tmc_etb_disable_hw(drvdata);
+ drvdata->mode = CS_MODE_DISABLED;
+ }
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
}
tmc_etf_enable_hw(drvdata);
- local_set(&drvdata->mode, CS_MODE_SYSFS);
+ drvdata->mode = CS_MODE_SYSFS;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETF enabled\n");
@@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
return;
}
+ drvdata->mode = CS_MODE_DISABLED;
tmc_etf_disable_hw(drvdata);
- local_set(&drvdata->mode, CS_MODE_DISABLED);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC disabled\n");
@@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev,
return;
/* This shouldn't happen */
- if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF))
+ if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
return;
CS_UNLOCK(drvdata->base);
@@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = {
int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
{
- long val;
enum tmc_mode mode;
int ret = 0;
unsigned long flags;
@@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
goto out;
}
- val = local_read(&drvdata->mode);
/* Don't interfere if operated from Perf */
- if (val == CS_MODE_PERF) {
+ if (drvdata->mode == CS_MODE_PERF) {
ret = -EINVAL;
goto out;
}
@@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
}
/* Disable the TMC if need be */
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etb_disable_hw(drvdata);
drvdata->reading = true;
@@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
}
/* Re-enable the TMC if need be */
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
+ if (drvdata->mode == CS_MODE_SYSFS) {
/*
* The trace run will continue with the same allocated trace
* buffer. As such zero-out the buffer so that we don't end
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 886ea83..cf2bf60 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
* When operating in sysFS mode the content of the buffer needs to be
* read before the TMC is disabled.
*/
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_dump_hw(drvdata);
tmc_disable_hw(drvdata);
@@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
bool used = false;
- long val;
unsigned long flags;
void __iomem *vaddr = NULL;
dma_addr_t paddr;
@@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched.
*/
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
goto out;
/*
@@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
memset(drvdata->vaddr, 0, drvdata->size);
+ drvdata->mode = CS_MODE_SYSFS;
tmc_etr_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -174,7 +173,6 @@ out:
static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -188,18 +186,18 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In Perf mode there can be only one writer per sink. There
* is also no need to continue if the ETR is already operated
* from sysFS.
*/
- if (val != CS_MODE_DISABLED) {
+ if (drvdata->mode == CS_MODE_DISABLED) {
+ drvdata->mode = CS_MODE_PERF;
+ tmc_etr_enable_hw(drvdata);
+ } else {
ret = -EINVAL;
- goto out;
}
- tmc_etr_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
static void tmc_disable_etr_sink(struct coresight_device *csdev)
{
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
return;
}
- val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
/* Disable the TMC only if it needs to */
- if (val != CS_MODE_DISABLED)
+ if (drvdata->mode != CS_MODE_DISABLED) {
tmc_etr_disable_hw(drvdata);
+ drvdata->mode = CS_MODE_DISABLED;
+ }
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = {
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
{
int ret = 0;
- long val;
unsigned long flags;
/* config types are set a boot time and never change */
@@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
goto out;
}
- val = local_read(&drvdata->mode);
/* Don't interfere if operated from Perf */
- if (val == CS_MODE_PERF) {
+ if (drvdata->mode == CS_MODE_PERF) {
ret = -EINVAL;
goto out;
}
@@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
}
/* Disable the TMC if need be */
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_disable_hw(drvdata);
drvdata->reading = true;
@@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
/* RE-enable the TMC if need be */
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
+ if (drvdata->mode == CS_MODE_SYSFS) {
/*
* The trace run will continue with the same allocated trace
* buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 44b3ae3..51c0185 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -117,7 +117,7 @@ struct tmc_drvdata {
void __iomem *vaddr;
u32 size;
u32 len;
- local_t mode;
+ u32 mode;
enum tmc_config_type config_type;
enum tmc_mem_intf_width memwidth;
u32 trigger_cntr;
--
2.7.4
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH] coresight: tmc: Cleanup operation mode handling
@ 2016-09-14 13:53 ` Suzuki K Poulose
0 siblings, 0 replies; 10+ messages in thread
From: Suzuki K Poulose @ 2016-09-14 13:53 UTC (permalink / raw)
To: linux-arm-kernel
The mode of operation of the TMC tracked in drvdata->mode is defined
as a local_t type. This is always checked and modified under the
drvdata->spinlock and hence we don't need local_t for it and the
unnecessary synchronisation instructions that comes with it. This
change makes the code a bit more cleaner.
Also fixes the order in which we update the drvdata->mode to
CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
which in turn depends on the mode to decide whether to dump the
trace to a buffer.
Applies on mathieu's coresight/next tree [1]
https://git.linaro.org/kernel/coresight.git next
Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 32 +++++++++++--------------
drivers/hwtracing/coresight/coresight-tmc-etr.c | 30 ++++++++++-------------
drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
3 files changed, 28 insertions(+), 36 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index d6941ea..c51ce45 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
* When operating in sysFS mode the content of the buffer needs to be
* read before the TMC is disabled.
*/
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etb_dump_hw(drvdata);
tmc_disable_hw(drvdata);
@@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
int ret = 0;
bool used = false;
char *buf = NULL;
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched.
*/
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
goto out;
/*
@@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
drvdata->buf = buf;
}
+ drvdata->mode = CS_MODE_SYSFS;
tmc_etb_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -180,7 +179,6 @@ out:
static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In Perf mode there can be only one writer per sink. There
* is also no need to continue if the ETB/ETR is already operated
* from sysFS.
*/
- if (val != CS_MODE_DISABLED) {
+ if (drvdata->mode != CS_MODE_DISABLED) {
ret = -EINVAL;
goto out;
}
+ drvdata->mode = mode;
tmc_etb_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
static void tmc_disable_etf_sink(struct coresight_device *csdev)
{
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
return;
}
- val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
/* Disable the TMC only if it needs to */
- if (val != CS_MODE_DISABLED)
+ if (drvdata->mode != CS_MODE_DISABLED) {
tmc_etb_disable_hw(drvdata);
+ drvdata->mode = CS_MODE_DISABLED;
+ }
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
}
tmc_etf_enable_hw(drvdata);
- local_set(&drvdata->mode, CS_MODE_SYSFS);
+ drvdata->mode = CS_MODE_SYSFS;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETF enabled\n");
@@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
return;
}
+ drvdata->mode = CS_MODE_DISABLED;
tmc_etf_disable_hw(drvdata);
- local_set(&drvdata->mode, CS_MODE_DISABLED);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC disabled\n");
@@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev,
return;
/* This shouldn't happen */
- if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF))
+ if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
return;
CS_UNLOCK(drvdata->base);
@@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = {
int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
{
- long val;
enum tmc_mode mode;
int ret = 0;
unsigned long flags;
@@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
goto out;
}
- val = local_read(&drvdata->mode);
/* Don't interfere if operated from Perf */
- if (val == CS_MODE_PERF) {
+ if (drvdata->mode == CS_MODE_PERF) {
ret = -EINVAL;
goto out;
}
@@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
}
/* Disable the TMC if need be */
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etb_disable_hw(drvdata);
drvdata->reading = true;
@@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
}
/* Re-enable the TMC if need be */
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
+ if (drvdata->mode == CS_MODE_SYSFS) {
/*
* The trace run will continue with the same allocated trace
* buffer. As such zero-out the buffer so that we don't end
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 886ea83..cf2bf60 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
* When operating in sysFS mode the content of the buffer needs to be
* read before the TMC is disabled.
*/
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_dump_hw(drvdata);
tmc_disable_hw(drvdata);
@@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
bool used = false;
- long val;
unsigned long flags;
void __iomem *vaddr = NULL;
dma_addr_t paddr;
@@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched.
*/
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
goto out;
/*
@@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
memset(drvdata->vaddr, 0, drvdata->size);
+ drvdata->mode = CS_MODE_SYSFS;
tmc_etr_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -174,7 +173,6 @@ out:
static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -188,18 +186,18 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
goto out;
}
- val = local_xchg(&drvdata->mode, mode);
/*
* In Perf mode there can be only one writer per sink. There
* is also no need to continue if the ETR is already operated
* from sysFS.
*/
- if (val != CS_MODE_DISABLED) {
+ if (drvdata->mode == CS_MODE_DISABLED) {
+ drvdata->mode = CS_MODE_PERF;
+ tmc_etr_enable_hw(drvdata);
+ } else {
ret = -EINVAL;
- goto out;
}
- tmc_etr_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
static void tmc_disable_etr_sink(struct coresight_device *csdev)
{
- long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
return;
}
- val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
/* Disable the TMC only if it needs to */
- if (val != CS_MODE_DISABLED)
+ if (drvdata->mode != CS_MODE_DISABLED) {
tmc_etr_disable_hw(drvdata);
+ drvdata->mode = CS_MODE_DISABLED;
+ }
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = {
int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
{
int ret = 0;
- long val;
unsigned long flags;
/* config types are set a boot time and never change */
@@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
goto out;
}
- val = local_read(&drvdata->mode);
/* Don't interfere if operated from Perf */
- if (val == CS_MODE_PERF) {
+ if (drvdata->mode == CS_MODE_PERF) {
ret = -EINVAL;
goto out;
}
@@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
}
/* Disable the TMC if need be */
- if (val == CS_MODE_SYSFS)
+ if (drvdata->mode == CS_MODE_SYSFS)
tmc_etr_disable_hw(drvdata);
drvdata->reading = true;
@@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
/* RE-enable the TMC if need be */
- if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
+ if (drvdata->mode == CS_MODE_SYSFS) {
/*
* The trace run will continue with the same allocated trace
* buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 44b3ae3..51c0185 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -117,7 +117,7 @@ struct tmc_drvdata {
void __iomem *vaddr;
u32 size;
u32 len;
- local_t mode;
+ u32 mode;
enum tmc_config_type config_type;
enum tmc_mem_intf_width memwidth;
u32 trigger_cntr;
--
2.7.4
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] coresight: tmc: Cleanup operation mode handling
2016-09-14 13:53 ` Suzuki K Poulose
@ 2016-09-15 11:21 ` Venkatesh Vivekanandan
-1 siblings, 0 replies; 10+ messages in thread
From: Venkatesh Vivekanandan @ 2016-09-15 11:21 UTC (permalink / raw)
To: Suzuki K Poulose; +Cc: linux-arm-kernel, linux-kernel, Mathieu Poirier
On Wed, Sep 14, 2016 at 7:23 PM, Suzuki K Poulose
<suzuki.poulose@arm.com> wrote:
> The mode of operation of the TMC tracked in drvdata->mode is defined
> as a local_t type. This is always checked and modified under the
> drvdata->spinlock and hence we don't need local_t for it and the
> unnecessary synchronisation instructions that comes with it. This
> change makes the code a bit more cleaner.
>
> Also fixes the order in which we update the drvdata->mode to
> CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
> mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
> which in turn depends on the mode to decide whether to dump the
> trace to a buffer.
>
> Applies on mathieu's coresight/next tree [1]
>
> https://git.linaro.org/kernel/coresight.git next
>
> Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
> drivers/hwtracing/coresight/coresight-tmc-etf.c | 32 +++++++++++--------------
> drivers/hwtracing/coresight/coresight-tmc-etr.c | 30 ++++++++++-------------
> drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
> 3 files changed, 28 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index d6941ea..c51ce45 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> int ret = 0;
> bool used = false;
> char *buf = NULL;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> drvdata->buf = buf;
> }
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -180,7 +179,6 @@ out:
> static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETB/ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode != CS_MODE_DISABLED) {
> ret = -EINVAL;
> goto out;
> }
>
> + drvdata->mode = mode;
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etf_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etb_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
> }
>
> tmc_etf_enable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_SYSFS);
> + drvdata->mode = CS_MODE_SYSFS;
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC-ETF enabled\n");
> @@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
> return;
> }
>
> + drvdata->mode = CS_MODE_DISABLED;
> tmc_etf_disable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_DISABLED);
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC disabled\n");
> @@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev,
> return;
>
> /* This shouldn't happen */
> - if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF))
> + if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
> return;
>
> CS_UNLOCK(drvdata->base);
> @@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = {
>
> int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> {
> - long val;
> enum tmc_mode mode;
> int ret = 0;
> unsigned long flags;
> @@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Re-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. As such zero-out the buffer so that we don't end
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index 886ea83..cf2bf60 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> bool used = false;
> - long val;
> unsigned long flags;
> void __iomem *vaddr = NULL;
> dma_addr_t paddr;
> @@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
>
> memset(drvdata->vaddr, 0, drvdata->size);
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etr_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -174,7 +173,6 @@ out:
> static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -188,18 +186,18 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode == CS_MODE_DISABLED) {
> + drvdata->mode = CS_MODE_PERF;
> + tmc_etr_enable_hw(drvdata);
> + } else {
> ret = -EINVAL;
> - goto out;
> }
>
> - tmc_etr_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etr_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etr_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = {
> int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
>
> /* config types are set a boot time and never change */
> @@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
> spin_lock_irqsave(&drvdata->spinlock, flags);
>
> /* RE-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
> index 44b3ae3..51c0185 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc.h
> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
> @@ -117,7 +117,7 @@ struct tmc_drvdata {
> void __iomem *vaddr;
> u32 size;
> u32 len;
> - local_t mode;
> + u32 mode;
> enum tmc_config_type config_type;
> enum tmc_mem_intf_width memwidth;
> u32 trigger_cntr;
> --
> 2.7.4
>
tmc_etb_dump_hw is called to dump trace from hardware in ETF mode.
Tested-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH] coresight: tmc: Cleanup operation mode handling
@ 2016-09-15 11:21 ` Venkatesh Vivekanandan
0 siblings, 0 replies; 10+ messages in thread
From: Venkatesh Vivekanandan @ 2016-09-15 11:21 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Sep 14, 2016 at 7:23 PM, Suzuki K Poulose
<suzuki.poulose@arm.com> wrote:
> The mode of operation of the TMC tracked in drvdata->mode is defined
> as a local_t type. This is always checked and modified under the
> drvdata->spinlock and hence we don't need local_t for it and the
> unnecessary synchronisation instructions that comes with it. This
> change makes the code a bit more cleaner.
>
> Also fixes the order in which we update the drvdata->mode to
> CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
> mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
> which in turn depends on the mode to decide whether to dump the
> trace to a buffer.
>
> Applies on mathieu's coresight/next tree [1]
>
> https://git.linaro.org/kernel/coresight.git next
>
> Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
> drivers/hwtracing/coresight/coresight-tmc-etf.c | 32 +++++++++++--------------
> drivers/hwtracing/coresight/coresight-tmc-etr.c | 30 ++++++++++-------------
> drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
> 3 files changed, 28 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index d6941ea..c51ce45 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> int ret = 0;
> bool used = false;
> char *buf = NULL;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> drvdata->buf = buf;
> }
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -180,7 +179,6 @@ out:
> static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETB/ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode != CS_MODE_DISABLED) {
> ret = -EINVAL;
> goto out;
> }
>
> + drvdata->mode = mode;
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etf_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etb_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
> }
>
> tmc_etf_enable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_SYSFS);
> + drvdata->mode = CS_MODE_SYSFS;
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC-ETF enabled\n");
> @@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
> return;
> }
>
> + drvdata->mode = CS_MODE_DISABLED;
> tmc_etf_disable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_DISABLED);
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC disabled\n");
> @@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev,
> return;
>
> /* This shouldn't happen */
> - if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF))
> + if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
> return;
>
> CS_UNLOCK(drvdata->base);
> @@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = {
>
> int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> {
> - long val;
> enum tmc_mode mode;
> int ret = 0;
> unsigned long flags;
> @@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Re-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. As such zero-out the buffer so that we don't end
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index 886ea83..cf2bf60 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> bool used = false;
> - long val;
> unsigned long flags;
> void __iomem *vaddr = NULL;
> dma_addr_t paddr;
> @@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
>
> memset(drvdata->vaddr, 0, drvdata->size);
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etr_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -174,7 +173,6 @@ out:
> static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -188,18 +186,18 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode == CS_MODE_DISABLED) {
> + drvdata->mode = CS_MODE_PERF;
> + tmc_etr_enable_hw(drvdata);
> + } else {
> ret = -EINVAL;
> - goto out;
> }
>
> - tmc_etr_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etr_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etr_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = {
> int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
>
> /* config types are set a boot time and never change */
> @@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
> spin_lock_irqsave(&drvdata->spinlock, flags);
>
> /* RE-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
> index 44b3ae3..51c0185 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc.h
> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
> @@ -117,7 +117,7 @@ struct tmc_drvdata {
> void __iomem *vaddr;
> u32 size;
> u32 len;
> - local_t mode;
> + u32 mode;
> enum tmc_config_type config_type;
> enum tmc_mem_intf_width memwidth;
> u32 trigger_cntr;
> --
> 2.7.4
>
tmc_etb_dump_hw is called to dump trace from hardware in ETF mode.
Tested-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] coresight: tmc: Cleanup operation mode handling
2016-09-14 13:53 ` Suzuki K Poulose
@ 2016-09-16 17:07 ` Mathieu Poirier
-1 siblings, 0 replies; 10+ messages in thread
From: Mathieu Poirier @ 2016-09-16 17:07 UTC (permalink / raw)
To: Suzuki K Poulose; +Cc: linux-arm-kernel, linux-kernel, Venkatesh Vivekanandan
On 14 September 2016 at 07:53, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
> The mode of operation of the TMC tracked in drvdata->mode is defined
> as a local_t type. This is always checked and modified under the
> drvdata->spinlock and hence we don't need local_t for it and the
> unnecessary synchronisation instructions that comes with it. This
> change makes the code a bit more cleaner.
>
> Also fixes the order in which we update the drvdata->mode to
> CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
> mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
> which in turn depends on the mode to decide whether to dump the
> trace to a buffer.
Thank you for the patch - just a few comments below.
Regards,
Mathieu
>
> Applies on mathieu's coresight/next tree [1]
>
> https://git.linaro.org/kernel/coresight.git next
>
> Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
> drivers/hwtracing/coresight/coresight-tmc-etf.c | 32 +++++++++++--------------
> drivers/hwtracing/coresight/coresight-tmc-etr.c | 30 ++++++++++-------------
> drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
> 3 files changed, 28 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index d6941ea..c51ce45 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> int ret = 0;
> bool used = false;
> char *buf = NULL;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> drvdata->buf = buf;
> }
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -180,7 +179,6 @@ out:
> static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETB/ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode != CS_MODE_DISABLED) {
> ret = -EINVAL;
> goto out;
> }
>
> + drvdata->mode = mode;
Given the way tmc_enable_etf_sink_perf() is called in
tmc_enable_etf_sink(), I think it is time to get rid of the 'mode'
parameter - it doesn't do anything nowadays. Same thing for
tmc_enable_etf_sink_sysfs() and ETR.
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etf_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etb_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
> }
>
> tmc_etf_enable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_SYSFS);
> + drvdata->mode = CS_MODE_SYSFS;
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC-ETF enabled\n");
> @@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
> return;
> }
>
> + drvdata->mode = CS_MODE_DISABLED;
> tmc_etf_disable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_DISABLED);
I think setting the mode should come after tmc_etf_disable_hw(), as it
was before.
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC disabled\n");
> @@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev,
> return;
>
> /* This shouldn't happen */
> - if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF))
> + if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
> return;
>
> CS_UNLOCK(drvdata->base);
> @@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = {
>
> int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> {
> - long val;
> enum tmc_mode mode;
> int ret = 0;
> unsigned long flags;
> @@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Re-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. As such zero-out the buffer so that we don't end
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index 886ea83..cf2bf60 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> bool used = false;
> - long val;
> unsigned long flags;
> void __iomem *vaddr = NULL;
> dma_addr_t paddr;
> @@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
>
> memset(drvdata->vaddr, 0, drvdata->size);
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etr_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -174,7 +173,6 @@ out:
> static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -188,18 +186,18 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode == CS_MODE_DISABLED) {
> + drvdata->mode = CS_MODE_PERF;
> + tmc_etr_enable_hw(drvdata);
> + } else {
> ret = -EINVAL;
> - goto out;
> }
>
> - tmc_etr_enable_hw(drvdata);
Is there a reason for not proceeding the same way as in
tmc_enable_etr_sink_perf()? I thought that was a better approach.
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etr_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etr_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = {
> int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
>
> /* config types are set a boot time and never change */
> @@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
> spin_lock_irqsave(&drvdata->spinlock, flags);
>
> /* RE-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
> index 44b3ae3..51c0185 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc.h
> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
> @@ -117,7 +117,7 @@ struct tmc_drvdata {
> void __iomem *vaddr;
> u32 size;
> u32 len;
> - local_t mode;
> + u32 mode;
> enum tmc_config_type config_type;
> enum tmc_mem_intf_width memwidth;
> u32 trigger_cntr;
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH] coresight: tmc: Cleanup operation mode handling
@ 2016-09-16 17:07 ` Mathieu Poirier
0 siblings, 0 replies; 10+ messages in thread
From: Mathieu Poirier @ 2016-09-16 17:07 UTC (permalink / raw)
To: linux-arm-kernel
On 14 September 2016 at 07:53, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
> The mode of operation of the TMC tracked in drvdata->mode is defined
> as a local_t type. This is always checked and modified under the
> drvdata->spinlock and hence we don't need local_t for it and the
> unnecessary synchronisation instructions that comes with it. This
> change makes the code a bit more cleaner.
>
> Also fixes the order in which we update the drvdata->mode to
> CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
> mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
> which in turn depends on the mode to decide whether to dump the
> trace to a buffer.
Thank you for the patch - just a few comments below.
Regards,
Mathieu
>
> Applies on mathieu's coresight/next tree [1]
>
> https://git.linaro.org/kernel/coresight.git next
>
> Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanandan@broadcom.com>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
> drivers/hwtracing/coresight/coresight-tmc-etf.c | 32 +++++++++++--------------
> drivers/hwtracing/coresight/coresight-tmc-etr.c | 30 ++++++++++-------------
> drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
> 3 files changed, 28 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index d6941ea..c51ce45 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> int ret = 0;
> bool used = false;
> char *buf = NULL;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
> drvdata->buf = buf;
> }
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -180,7 +179,6 @@ out:
> static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETB/ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode != CS_MODE_DISABLED) {
> ret = -EINVAL;
> goto out;
> }
>
> + drvdata->mode = mode;
Given the way tmc_enable_etf_sink_perf() is called in
tmc_enable_etf_sink(), I think it is time to get rid of the 'mode'
parameter - it doesn't do anything nowadays. Same thing for
tmc_enable_etf_sink_sysfs() and ETR.
> tmc_etb_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etf_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etb_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
> }
>
> tmc_etf_enable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_SYSFS);
> + drvdata->mode = CS_MODE_SYSFS;
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC-ETF enabled\n");
> @@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
> return;
> }
>
> + drvdata->mode = CS_MODE_DISABLED;
> tmc_etf_disable_hw(drvdata);
> - local_set(&drvdata->mode, CS_MODE_DISABLED);
I think setting the mode should come after tmc_etf_disable_hw(), as it
was before.
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> dev_info(drvdata->dev, "TMC disabled\n");
> @@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev,
> return;
>
> /* This shouldn't happen */
> - if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF))
> + if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
> return;
>
> CS_UNLOCK(drvdata->base);
> @@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = {
>
> int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> {
> - long val;
> enum tmc_mode mode;
> int ret = 0;
> unsigned long flags;
> @@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etb_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
> }
>
> /* Re-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. As such zero-out the buffer so that we don't end
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index 886ea83..cf2bf60 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
> * When operating in sysFS mode the content of the buffer needs to be
> * read before the TMC is disabled.
> */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_dump_hw(drvdata);
> tmc_disable_hw(drvdata);
>
> @@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> bool used = false;
> - long val;
> unsigned long flags;
> void __iomem *vaddr = NULL;
> dma_addr_t paddr;
> @@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In sysFS mode we can have multiple writers per sink. Since this
> * sink is already enabled no memory is needed and the HW need not be
> * touched.
> */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> goto out;
>
> /*
> @@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
>
> memset(drvdata->vaddr, 0, drvdata->size);
>
> + drvdata->mode = CS_MODE_SYSFS;
> tmc_etr_enable_hw(drvdata);
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -174,7 +173,6 @@ out:
> static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -188,18 +186,18 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode)
> goto out;
> }
>
> - val = local_xchg(&drvdata->mode, mode);
> /*
> * In Perf mode there can be only one writer per sink. There
> * is also no need to continue if the ETR is already operated
> * from sysFS.
> */
> - if (val != CS_MODE_DISABLED) {
> + if (drvdata->mode == CS_MODE_DISABLED) {
> + drvdata->mode = CS_MODE_PERF;
> + tmc_etr_enable_hw(drvdata);
> + } else {
> ret = -EINVAL;
> - goto out;
> }
>
> - tmc_etr_enable_hw(drvdata);
Is there a reason for not proceeding the same way as in
tmc_enable_etr_sink_perf()? I thought that was a better approach.
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
>
> static void tmc_disable_etr_sink(struct coresight_device *csdev)
> {
> - long val;
> unsigned long flags;
> struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>
> @@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
> return;
> }
>
> - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
> /* Disable the TMC only if it needs to */
> - if (val != CS_MODE_DISABLED)
> + if (drvdata->mode != CS_MODE_DISABLED) {
> tmc_etr_disable_hw(drvdata);
> + drvdata->mode = CS_MODE_DISABLED;
> + }
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>
> @@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = {
> int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> {
> int ret = 0;
> - long val;
> unsigned long flags;
>
> /* config types are set a boot time and never change */
> @@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> goto out;
> }
>
> - val = local_read(&drvdata->mode);
> /* Don't interfere if operated from Perf */
> - if (val == CS_MODE_PERF) {
> + if (drvdata->mode == CS_MODE_PERF) {
> ret = -EINVAL;
> goto out;
> }
> @@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
> }
>
> /* Disable the TMC if need be */
> - if (val == CS_MODE_SYSFS)
> + if (drvdata->mode == CS_MODE_SYSFS)
> tmc_etr_disable_hw(drvdata);
>
> drvdata->reading = true;
> @@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
> spin_lock_irqsave(&drvdata->spinlock, flags);
>
> /* RE-enable the TMC if need be */
> - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
> + if (drvdata->mode == CS_MODE_SYSFS) {
> /*
> * The trace run will continue with the same allocated trace
> * buffer. The trace buffer is cleared in tmc_etr_enable_hw(),
> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
> index 44b3ae3..51c0185 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc.h
> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
> @@ -117,7 +117,7 @@ struct tmc_drvdata {
> void __iomem *vaddr;
> u32 size;
> u32 len;
> - local_t mode;
> + u32 mode;
> enum tmc_config_type config_type;
> enum tmc_mem_intf_width memwidth;
> u32 trigger_cntr;
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] coresight: tmc: Cleanup operation mode handling
2016-09-16 17:07 ` Mathieu Poirier
@ 2016-09-19 16:59 ` Suzuki K Poulose
-1 siblings, 0 replies; 10+ messages in thread
From: Suzuki K Poulose @ 2016-09-19 16:59 UTC (permalink / raw)
To: Mathieu Poirier; +Cc: linux-arm-kernel, linux-kernel, Venkatesh Vivekanandan
On 16/09/16 18:07, Mathieu Poirier wrote:
> On 14 September 2016 at 07:53, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
>> The mode of operation of the TMC tracked in drvdata->mode is defined
>> as a local_t type. This is always checked and modified under the
>> drvdata->spinlock and hence we don't need local_t for it and the
>> unnecessary synchronisation instructions that comes with it. This
>> change makes the code a bit more cleaner.
>>
>> Also fixes the order in which we update the drvdata->mode to
>> CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
>> mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
>> which in turn depends on the mode to decide whether to dump the
>> trace to a buffer.
>
> Thank you for the patch - just a few comments below.
>
>> @@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
>> goto out;
>> }
>>
>> - val = local_xchg(&drvdata->mode, mode);
>> /*
>> * In Perf mode there can be only one writer per sink. There
>> * is also no need to continue if the ETB/ETR is already operated
>> * from sysFS.
>> */
>> - if (val != CS_MODE_DISABLED) {
>> + if (drvdata->mode != CS_MODE_DISABLED) {
>> ret = -EINVAL;
>> goto out;
>> }
>>
>> + drvdata->mode = mode;
>
> Given the way tmc_enable_etf_sink_perf() is called in
> tmc_enable_etf_sink(), I think it is time to get rid of the 'mode'
> parameter - it doesn't do anything nowadays. Same thing for
> tmc_enable_etf_sink_sysfs() and ETR.
Sure, makes sense. I will clean it up.
>> @@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
>> return;
>> }
>>
>> + drvdata->mode = CS_MODE_DISABLED;
>> tmc_etf_disable_hw(drvdata);
>> - local_set(&drvdata->mode, CS_MODE_DISABLED);
>
> I think setting the mode should come after tmc_etf_disable_hw(), as it
> was before.
You're right, I will change it.
Thanks for the review. Will send the updated series soon.
Cheers
Suzuki
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH] coresight: tmc: Cleanup operation mode handling
@ 2016-09-19 16:59 ` Suzuki K Poulose
0 siblings, 0 replies; 10+ messages in thread
From: Suzuki K Poulose @ 2016-09-19 16:59 UTC (permalink / raw)
To: linux-arm-kernel
On 16/09/16 18:07, Mathieu Poirier wrote:
> On 14 September 2016 at 07:53, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
>> The mode of operation of the TMC tracked in drvdata->mode is defined
>> as a local_t type. This is always checked and modified under the
>> drvdata->spinlock and hence we don't need local_t for it and the
>> unnecessary synchronisation instructions that comes with it. This
>> change makes the code a bit more cleaner.
>>
>> Also fixes the order in which we update the drvdata->mode to
>> CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the
>> mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw()
>> which in turn depends on the mode to decide whether to dump the
>> trace to a buffer.
>
> Thank you for the patch - just a few comments below.
>
>> @@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
>> goto out;
>> }
>>
>> - val = local_xchg(&drvdata->mode, mode);
>> /*
>> * In Perf mode there can be only one writer per sink. There
>> * is also no need to continue if the ETB/ETR is already operated
>> * from sysFS.
>> */
>> - if (val != CS_MODE_DISABLED) {
>> + if (drvdata->mode != CS_MODE_DISABLED) {
>> ret = -EINVAL;
>> goto out;
>> }
>>
>> + drvdata->mode = mode;
>
> Given the way tmc_enable_etf_sink_perf() is called in
> tmc_enable_etf_sink(), I think it is time to get rid of the 'mode'
> parameter - it doesn't do anything nowadays. Same thing for
> tmc_enable_etf_sink_sysfs() and ETR.
Sure, makes sense. I will clean it up.
>> @@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
>> return;
>> }
>>
>> + drvdata->mode = CS_MODE_DISABLED;
>> tmc_etf_disable_hw(drvdata);
>> - local_set(&drvdata->mode, CS_MODE_DISABLED);
>
> I think setting the mode should come after tmc_etf_disable_hw(), as it
> was before.
You're right, I will change it.
Thanks for the review. Will send the updated series soon.
Cheers
Suzuki
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] coresight: tmc: Cleanup operation mode handling
2016-09-19 16:59 ` Suzuki K Poulose
@ 2016-09-19 17:07 ` Suzuki K Poulose
-1 siblings, 0 replies; 10+ messages in thread
From: Suzuki K Poulose @ 2016-09-19 17:07 UTC (permalink / raw)
To: Mathieu Poirier; +Cc: linux-arm-kernel, linux-kernel, Venkatesh Vivekanandan
On 19/09/16 17:59, Suzuki K Poulose wrote:
> On 16/09/16 18:07, Mathieu Poirier wrote:
>> On 14 September 2016 at 07:53, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
> Cheers
> Suzuki
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
>
Bah, sorry about that. You are fine. This email is intended for the public list discussions.
Suzuki
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH] coresight: tmc: Cleanup operation mode handling
@ 2016-09-19 17:07 ` Suzuki K Poulose
0 siblings, 0 replies; 10+ messages in thread
From: Suzuki K Poulose @ 2016-09-19 17:07 UTC (permalink / raw)
To: linux-arm-kernel
On 19/09/16 17:59, Suzuki K Poulose wrote:
> On 16/09/16 18:07, Mathieu Poirier wrote:
>> On 14 September 2016 at 07:53, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
> Cheers
> Suzuki
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
>
Bah, sorry about that. You are fine. This email is intended for the public list discussions.
Suzuki
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2016-09-19 17:07 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-14 13:53 [PATCH] coresight: tmc: Cleanup operation mode handling Suzuki K Poulose
2016-09-14 13:53 ` Suzuki K Poulose
2016-09-15 11:21 ` Venkatesh Vivekanandan
2016-09-15 11:21 ` Venkatesh Vivekanandan
2016-09-16 17:07 ` Mathieu Poirier
2016-09-16 17:07 ` Mathieu Poirier
2016-09-19 16:59 ` Suzuki K Poulose
2016-09-19 16:59 ` Suzuki K Poulose
2016-09-19 17:07 ` Suzuki K Poulose
2016-09-19 17:07 ` Suzuki K Poulose
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