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coresight: etb10: Refactor etb_drvdata::mode handling

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This patch moves the etb_drvdata::mode from a locat_t to a simple u32,
as it is for the ETF and ETR drivers.  This streamlines the code and adds
commonality with the other drivers when dealing with similar operations.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathieu Poirier 2018-09-20 13:17:58 -06:00 committed by Greg Kroah-Hartman
parent 22f429f19c
commit d43b8ec599
1 changed files with 35 additions and 29 deletions
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64
drivers/hwtracing/coresight/coresight-etb10.c
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@ -5,7 +5,6 @@
* Description: CoreSight Embedded Trace Buffer driver
*/
#include <asm/local.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
@ -72,8 +71,8 @@
* @miscdev: specifics to handle "/dev/xyz.etb" entry.
* @spinlock: only one at a time pls.
* @reading: synchronise user space access to etb buffer.
* @mode: this ETB is being used.
* @buf: area of memory where ETB buffer content gets sent.
* @mode: this ETB is being used.
* @buffer_depth: size of @buf.
* @trigger_cntr: amount of words to store after a trigger.
*/
@ -85,8 +84,8 @@ struct etb_drvdata {
struct miscdevice miscdev;
spinlock_t spinlock;
local_t reading;
local_t mode;
u8 *buf;
u32 mode;
u32 buffer_depth;
u32 trigger_cntr;
};
@ -138,10 +137,31 @@ static void etb_enable_hw(struct etb_drvdata *drvdata)
static int etb_enable(struct coresight_device *csdev, u32 mode, void *data)
{
int ret = 0;
u32 val;
unsigned long flags;
struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
/*
* When accessing from Perf, a HW buffer can be handled
* by a single trace entity. In sysFS mode many tracers
* can be logging to the same HW buffer.
*/
if (drvdata->mode == CS_MODE_PERF) {
ret = -EBUSY;
goto out;
}
/* Don't let perf disturb sysFS sessions */
if (drvdata->mode == CS_MODE_SYSFS && mode == CS_MODE_PERF) {
ret = -EBUSY;
goto out;
}
/* Nothing to do, the tracer is already enabled. */
if (drvdata->mode == CS_MODE_SYSFS && mode == CS_MODE_SYSFS)
goto out;
/*
* We don't have an internal state to clean up if we fail to setup
* the perf buffer. So we can perform the step before we turn the
@ -153,29 +173,12 @@ static int etb_enable(struct coresight_device *csdev, u32 mode, void *data)
goto out;
}
val = local_cmpxchg(&drvdata->mode,
CS_MODE_DISABLED, mode);
/*
* When accessing from Perf, a HW buffer can be handled
* by a single trace entity. In sysFS mode many tracers
* can be logging to the same HW buffer.
*/
if (val == CS_MODE_PERF)
return -EBUSY;
/* Don't let perf disturb sysFS sessions */
if (val == CS_MODE_SYSFS && mode == CS_MODE_PERF)
return -EBUSY;
/* Nothing to do, the tracer is already enabled. */
if (val == CS_MODE_SYSFS)
goto out;
spin_lock_irqsave(&drvdata->spinlock, flags);
drvdata->mode = mode;
etb_enable_hw(drvdata);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
if (!ret)
dev_dbg(drvdata->dev, "ETB enabled\n");
return ret;
@ -277,11 +280,14 @@ static void etb_disable(struct coresight_device *csdev)
unsigned long flags;
spin_lock_irqsave(&drvdata->spinlock, flags);
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
local_set(&drvdata->mode, CS_MODE_DISABLED);
/* Disable the ETB only if it needs to */
if (drvdata->mode != CS_MODE_DISABLED) {
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
drvdata->mode = CS_MODE_DISABLED;
}
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_dbg(drvdata->dev, "ETB disabled\n");
}
@ -488,7 +494,7 @@ static void etb_dump(struct etb_drvdata *drvdata)
unsigned long flags;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
if (drvdata->mode == CS_MODE_SYSFS) {
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
etb_enable_hw(drvdata);