Commit 669c4614 authored by Yabin Cui's avatar Yabin Cui Committed by Suzuki K Poulose
Browse files

coresight: tmc: Don't enable TMC when it's not ready. 



If TMC ETR is enabled without being ready, in later use we may
see AXI bus errors caused by accessing invalid addresses.

Signed-off-by: default avatarYabin Cui <yabinc@google.com>
[ Tweak error message ]
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230127231001.1920947-1-yabinc@google.com
parent c88a15d9

drivers/hwtracing/coresight/coresight-tmc-core.c

+3 −1
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ DEFINE_CORESIGHT_DEVLIST(etb_devs, "tmc_etb"); 
DEFINE_CORESIGHT_DEVLIST(etf_devs, "tmc_etf");

DEFINE_CORESIGHT_DEVLIST(etr_devs, "tmc_etr");



void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata)

int tmc_wait_for_tmcready(struct tmc_drvdata *drvdata)

{

	struct coresight_device *csdev = drvdata->csdev;

	struct csdev_access *csa = &csdev->access;
@@ -40,7 +40,9 @@ void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata) 
	if (coresight_timeout(csa, TMC_STS, TMC_STS_TMCREADY_BIT, 1)) {

		dev_err(&csdev->dev,

			"timeout while waiting for TMC to be Ready\n");

		return -EBUSY;

	}

	return 0;

}



void tmc_flush_and_stop(struct tmc_drvdata *drvdata)

drivers/hwtracing/coresight/coresight-tmc-etf.c

+36 −9
Original line number Diff line number Diff line
@@ -16,12 +16,20 @@ 
static int tmc_set_etf_buffer(struct coresight_device *csdev,

			      struct perf_output_handle *handle);



static void __tmc_etb_enable_hw(struct tmc_drvdata *drvdata)

static int __tmc_etb_enable_hw(struct tmc_drvdata *drvdata)

{

	int rc = 0;



	CS_UNLOCK(drvdata->base);



	/* Wait for TMCSReady bit to be set */

	tmc_wait_for_tmcready(drvdata);

	rc = tmc_wait_for_tmcready(drvdata);

	if (rc) {

		dev_err(&drvdata->csdev->dev,

			"Failed to enable: TMC not ready\n");

		CS_LOCK(drvdata->base);

		return rc;

	}



	writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);

	writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
@@ -33,6 +41,7 @@ static void __tmc_etb_enable_hw(struct tmc_drvdata *drvdata) 
	tmc_enable_hw(drvdata);



	CS_LOCK(drvdata->base);

	return rc;

}



static int tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
@@ -42,8 +51,10 @@ static int tmc_etb_enable_hw(struct tmc_drvdata *drvdata) 
	if (rc)

		return rc;



	__tmc_etb_enable_hw(drvdata);

	return 0;

	rc = __tmc_etb_enable_hw(drvdata);

	if (rc)

		coresight_disclaim_device(drvdata->csdev);

	return rc;

}



static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata)
@@ -91,12 +102,20 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata) 
	coresight_disclaim_device(drvdata->csdev);

}



static void __tmc_etf_enable_hw(struct tmc_drvdata *drvdata)

static int __tmc_etf_enable_hw(struct tmc_drvdata *drvdata)

{

	int rc = 0;



	CS_UNLOCK(drvdata->base);



	/* Wait for TMCSReady bit to be set */

	tmc_wait_for_tmcready(drvdata);

	rc = tmc_wait_for_tmcready(drvdata);

	if (rc) {

		dev_err(&drvdata->csdev->dev,

			"Failed to enable : TMC is not ready\n");

		CS_LOCK(drvdata->base);

		return rc;

	}



	writel_relaxed(TMC_MODE_HARDWARE_FIFO, drvdata->base + TMC_MODE);

	writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI,
@@ -105,6 +124,7 @@ static void __tmc_etf_enable_hw(struct tmc_drvdata *drvdata) 
	tmc_enable_hw(drvdata);



	CS_LOCK(drvdata->base);

	return rc;

}



static int tmc_etf_enable_hw(struct tmc_drvdata *drvdata)
@@ -114,8 +134,10 @@ static int tmc_etf_enable_hw(struct tmc_drvdata *drvdata) 
	if (rc)

		return rc;



	__tmc_etf_enable_hw(drvdata);

	return 0;

	rc = __tmc_etf_enable_hw(drvdata);

	if (rc)

		coresight_disclaim_device(drvdata->csdev);

	return rc;

}



static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata)
@@ -639,6 +661,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) 
	char *buf = NULL;

	enum tmc_mode mode;

	unsigned long flags;

	int rc = 0;



	/* config types are set a boot time and never change */

	if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB &&
@@ -664,7 +687,11 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) 
		 * can't be NULL.

		 */

		memset(drvdata->buf, 0, drvdata->size);

		__tmc_etb_enable_hw(drvdata);

		rc = __tmc_etb_enable_hw(drvdata);

		if (rc) {

			spin_unlock_irqrestore(&drvdata->spinlock, flags);

			return rc;

		}

	} else {

		/*

		 * The ETB/ETF is not tracing and the buffer was just read.

drivers/hwtracing/coresight/coresight-tmc-etr.c

+16 −3
Original line number Diff line number Diff line
@@ -983,15 +983,22 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata) 
	etr_buf->ops->sync(etr_buf, rrp, rwp);

}



static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata)

static int __tmc_etr_enable_hw(struct tmc_drvdata *drvdata)

{

	u32 axictl, sts;

	struct etr_buf *etr_buf = drvdata->etr_buf;

	int rc = 0;



	CS_UNLOCK(drvdata->base);



	/* Wait for TMCSReady bit to be set */

	tmc_wait_for_tmcready(drvdata);

	rc = tmc_wait_for_tmcready(drvdata);

	if (rc) {

		dev_err(&drvdata->csdev->dev,

			"Failed to enable : TMC not ready\n");

		CS_LOCK(drvdata->base);

		return rc;

	}



	writel_relaxed(etr_buf->size / 4, drvdata->base + TMC_RSZ);

	writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
@@ -1032,6 +1039,7 @@ static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) 
	tmc_enable_hw(drvdata);



	CS_LOCK(drvdata->base);

	return rc;

}



static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata,
@@ -1060,7 +1068,12 @@ static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata, 
	rc = coresight_claim_device(drvdata->csdev);

	if (!rc) {

		drvdata->etr_buf = etr_buf;

		__tmc_etr_enable_hw(drvdata);

		rc = __tmc_etr_enable_hw(drvdata);

		if (rc) {

			drvdata->etr_buf = NULL;

			coresight_disclaim_device(drvdata->csdev);

			tmc_etr_disable_catu(drvdata);

		}

	}



	return rc;

drivers/hwtracing/coresight/coresight-tmc.h

+1 −1
Original line number Diff line number Diff line
@@ -255,7 +255,7 @@ struct tmc_sg_table { 
};



/* Generic functions */

void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata);

int tmc_wait_for_tmcready(struct tmc_drvdata *drvdata);

void tmc_flush_and_stop(struct tmc_drvdata *drvdata);

void tmc_enable_hw(struct tmc_drvdata *drvdata);

void tmc_disable_hw(struct tmc_drvdata *drvdata);