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Message-Id: <1458678202-3447-10-git-send-email-mathieu.poirier@linaro.org>
Date: Tue, 22 Mar 2016 14:23:17 -0600
From: Mathieu Poirier <mathieu.poirier@...aro.org>
To: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH 09/14] coresight: tmc: adding mode of operation for link/sinks
Moving tmc_drvdata::enable to a local_t mode. That way the
sink interface is aware of it's orgin and the foundation for
mutual exclusion between the sysFS and Perf interface can be
laid out.
Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 29 ++++++++++++++++++++-----
drivers/hwtracing/coresight/coresight-tmc-etr.c | 25 +++++++++++++++++----
drivers/hwtracing/coresight/coresight-tmc.h | 5 +++--
3 files changed, 47 insertions(+), 12 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index e5d67e01409c..a88c76d7f473 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -108,6 +108,7 @@ static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata)
static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
{
+ u32 val;
bool allocated = false;
char *buf = NULL;
unsigned long flags;
@@ -125,6 +126,15 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
return -EBUSY;
}
+ val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, 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)
+ 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.
@@ -141,9 +151,9 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
}
tmc_etb_enable_hw(drvdata);
- drvdata->enable = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+out:
/* Free memory outside the spinlock if need be */
if (!allocated)
kfree(buf);
@@ -154,6 +164,7 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode)
static void tmc_disable_etf_sink(struct coresight_device *csdev)
{
+ u32 val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -163,9 +174,15 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev)
return;
}
+ val = local_cmpxchg(&drvdata->mode, CS_MODE_SYSFS, CS_MODE_DISABLED);
+ /* Nothing to do, the TMC was already disabled */
+ if (val == CS_MODE_DISABLED)
+ goto out;
+
tmc_etb_disable_hw(drvdata);
tmc_etb_dump_hw(drvdata);
- drvdata->enable = false;
+
+out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETB/ETF disabled\n");
@@ -184,7 +201,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
}
tmc_etf_enable_hw(drvdata);
- drvdata->enable = true;
+ local_set(&drvdata->mode, CS_MODE_SYSFS);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETF enabled\n");
@@ -204,7 +221,7 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
}
tmc_etf_disable_hw(drvdata);
- drvdata->enable = false;
+ local_set(&drvdata->mode, CS_MODE_DISABLED);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC disabled\n");
@@ -237,7 +254,7 @@ int tmc_read_prepare_etf(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
/* The TMC isn't enabled, so there is no need to disable it */
- if (!drvdata->enable) {
+ if (local_read(&drvdata->mode) == CS_MODE_DISABLED) {
/*
* The ETB/ETF is disabled already. If drvdata::buf is NULL
* trace data has been harvested.
@@ -288,7 +305,7 @@ int tmc_read_unprepare_etf(struct tmc_drvdata *drvdata)
}
/* The TMC isn't enabled, so there is no need to enable it */
- if (!drvdata->enable) {
+ if (local_read(&drvdata->mode) == CS_MODE_DISABLED) {
/*
* The ETB/ETF is not tracing and the buffer was just read.
* As such prepare to free the trace buffer.
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index c4962568276e..540d0b96a958 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -84,6 +84,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
{
+ u32 val;
bool allocated = false;
unsigned long flags;
void __iomem *vaddr;
@@ -107,6 +108,15 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
return -EBUSY;
}
+ val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, 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)
+ goto out;
+
/*
* If drvdata::buf == NULL, use the memory allocated above.
* Otherwise a buffer still exists from a previous session, so
@@ -122,9 +132,9 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
memset(drvdata->vaddr, 0, drvdata->size);
tmc_etr_enable_hw(drvdata);
- drvdata->enable = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
+out:
/* Free memory outside the spinlock if need be */
if (!allocated)
dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
@@ -135,6 +145,7 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
static void tmc_disable_etr_sink(struct coresight_device *csdev)
{
+ u32 val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -144,9 +155,15 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev)
return;
}
+ val = local_cmpxchg(&drvdata->mode, CS_MODE_SYSFS, CS_MODE_DISABLED);
+ /* Nothing to do, the TMC was already disabled */
+ if (val == CS_MODE_DISABLED)
+ goto out;
+
tmc_etr_disable_hw(drvdata);
tmc_etr_dump_hw(drvdata);
- drvdata->enable = false;
+
+out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETR disabled\n");
@@ -168,7 +185,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
spin_lock_irqsave(&drvdata->spinlock, flags);
/* The TMC isn't enabled, so there is no need to disable it */
- if (!drvdata->enable) {
+ if (local_read(&drvdata->mode) == CS_MODE_DISABLED) {
/*
* The ETR is disabled already. If drvdata::buf is NULL
* trace data has been harvested.
@@ -210,7 +227,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
}
/* The TMC isn't enabled, so there is no need to enable it */
- if (!drvdata->enable) {
+ if (local_read(&drvdata->mode) == CS_MODE_DISABLED) {
/*
* The ETR is not tracing and trace data was just read. As
* such prepare to free the trace buffer.
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 6b11caf77ad1..6dbd70861b17 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -18,6 +18,7 @@
#ifndef _CORESIGHT_TMC_H
#define _CORESIGHT_TMC_H
+#include <linux/io.h>
#include <linux/miscdevice.h>
#define TMC_RSZ 0x004
@@ -100,7 +101,7 @@ enum tmc_mem_intf_width {
* @paddr: DMA start location in RAM.
* @vaddr: virtual representation of @paddr.
* @size: @buf size.
- * @enable: this TMC is being used.
+ * @mode: how this TMC is being used.
* @config_type: TMC variant, must be of type @tmc_config_type.
* @trigger_cntr: amount of words to store after a trigger.
*/
@@ -116,7 +117,7 @@ struct tmc_drvdata {
dma_addr_t paddr;
void __iomem *vaddr;
u32 size;
- bool enable;
+ local_t mode;
enum tmc_config_type config_type;
u32 trigger_cntr;
};
--
2.1.4
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