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

diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 07abf28..c106d14 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -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)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 4c4cbd1..0ab1f73 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -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.

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 867ad8b..918d461 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -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;

diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 6695955..01c0382 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -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);