On Mon, 16 Dec 2024 at 11:50, Yeoreum Yun yeoreum.yun@arm.com wrote:
In coresight-tmc drivers, tmc_drvdata->spinlock can be held during __schedule() by perf_event_task_sched_out()/in().
Since tmc_drvdata->spinlock type is spinlock_t and perf_event_task_sched_out()/in() is called after acquiring rq_lock, which is raw_spinlock_t (an unsleepable lock), this poses an issue in PREEMPT_RT kernel where spinlock_t is sleepable.
To address this, change type tmc_drvdata->spinlock in coresight-tmc drivers, which can be called by perf_event_task_sched_out()/in(), from spinlock_t to raw_spinlock_t.
Signed-off-by: Yeoreum Yun yeoreum.yun@arm.com
.../hwtracing/coresight/coresight-tmc-core.c | 6 +-- .../hwtracing/coresight/coresight-tmc-etf.c | 48 +++++++++---------- .../hwtracing/coresight/coresight-tmc-etr.c | 40 ++++++++-------- drivers/hwtracing/coresight/coresight-tmc.h | 2 +- 4 files changed, 48 insertions(+), 48 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index e9876252a789..4e9925300931 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -492,7 +492,7 @@ static int __tmc_probe(struct device *dev, struct resource *res) drvdata->base = base; desc.access = CSDEV_ACCESS_IOMEM(base);
spin_lock_init(&drvdata->spinlock);
raw_spin_lock_init(&drvdata->spinlock); devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID); drvdata->config_type = BMVAL(devid, 6, 7);@@ -596,7 +596,7 @@ static void tmc_shutdown(struct amba_device *adev) unsigned long flags; struct tmc_drvdata *drvdata = amba_get_drvdata(adev);
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (coresight_get_mode(drvdata->csdev) == CS_MODE_DISABLED) goto out;@@ -610,7 +610,7 @@ static void tmc_shutdown(struct amba_device *adev) * the system is going down after this. */ out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);}
static void __tmc_remove(struct device *dev) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index d4f641cd9de6..fca8e9ffb3cf 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -182,9 +182,9 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev) * If we don't have a buffer release the lock and allocate memory. * Otherwise keep the lock and move along. */
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (!drvdata->buf) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); /* Allocating the memory here while outside of the spinlock */ buf = kzalloc(drvdata->size, GFP_KERNEL);@@ -192,7 +192,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev) return -ENOMEM;
/* Let's try again */
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); } if (drvdata->reading) {@@ -235,7 +235,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev) used = false; } out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); /* Free memory outside the spinlock if need be */ if (!used)@@ -253,7 +253,7 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data) struct perf_output_handle *handle = data; struct cs_buffers *buf = etm_perf_sink_config(handle);
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); do { ret = -EINVAL; if (drvdata->reading)@@ -296,7 +296,7 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data) csdev->refcnt++; } } while (0);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret;} @@ -331,16 +331,16 @@ static int tmc_disable_etf_sink(struct coresight_device *csdev) unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; } csdev->refcnt--; if (csdev->refcnt) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; }@@ -351,7 +351,7 @@ static int tmc_disable_etf_sink(struct coresight_device *csdev) drvdata->pid = -1; coresight_set_mode(csdev, CS_MODE_DISABLED);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); dev_dbg(&csdev->dev, "TMC-ETB/ETF disabled\n"); return 0;@@ -366,9 +366,9 @@ static int tmc_enable_etf_link(struct coresight_device *csdev, struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); bool first_enable = false;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; }@@ -381,7 +381,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev, } if (!ret) csdev->refcnt++;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); if (first_enable) dev_dbg(&csdev->dev, "TMC-ETF enabled\n");@@ -396,9 +396,9 @@ static void tmc_disable_etf_link(struct coresight_device *csdev, struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); bool last_disable = false;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return; }@@ -408,7 +408,7 @@ static void tmc_disable_etf_link(struct coresight_device *csdev, coresight_set_mode(csdev, CS_MODE_DISABLED); last_disable = true; }
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); if (last_disable) dev_dbg(&csdev->dev, "TMC-ETF disabled\n");@@ -488,7 +488,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, if (WARN_ON_ONCE(coresight_get_mode(csdev) != CS_MODE_PERF)) return 0;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); /* Don't do anything if another tracer is using this sink */ if (csdev->refcnt != 1)@@ -585,7 +585,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev, */ CS_LOCK(drvdata->base); out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return to_read;} @@ -623,7 +623,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) drvdata->config_type != TMC_CONFIG_TYPE_ETF)) return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->reading) { ret = -EBUSY;@@ -655,7 +655,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
drvdata->reading = true;out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret;} @@ -672,14 +672,14 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) drvdata->config_type != TMC_CONFIG_TYPE_ETF)) return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); /* Re-enable the TMC if need be */ if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) { /* There is no point in reading a TMC in HW FIFO mode */ mode = readl_relaxed(drvdata->base + TMC_MODE); if (mode != TMC_MODE_CIRCULAR_BUFFER) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EINVAL; } /*@@ -693,7 +693,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) memset(drvdata->buf, 0, drvdata->size); rc = __tmc_etb_enable_hw(drvdata); if (rc) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return rc; } } else {@@ -706,7 +706,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) }
drvdata->reading = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); /* * Free allocated memory outside of the spinlock. There is no needdiff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index a48bb85d0e7f..a0a90ce7333e 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1176,10 +1176,10 @@ static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev) * buffer, provided the size matches. Any allocation has to be done * with the lock released. */
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); sysfs_buf = READ_ONCE(drvdata->sysfs_buf); if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); /* Allocate memory with the locks released */ free_buf = new_buf = tmc_etr_setup_sysfs_buf(drvdata);@@ -1187,7 +1187,7 @@ static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev) return new_buf;
/* Let's try again */
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); } if (drvdata->reading || coresight_get_mode(csdev) == CS_MODE_PERF) {@@ -1206,7 +1206,7 @@ static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev) }
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); /* Free memory outside the spinlock if need be */ if (free_buf)@@ -1224,7 +1224,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) if (IS_ERR(sysfs_buf)) return PTR_ERR(sysfs_buf);
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); /* * In sysFS mode we can have multiple writers per sink. Since this@@ -1243,7 +1243,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) }
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); if (!ret) dev_dbg(&csdev->dev, "TMC-ETR enabled\n");@@ -1562,17 +1562,17 @@ tmc_update_etr_buffer(struct coresight_device *csdev, struct etr_perf_buffer *etr_perf = config; struct etr_buf *etr_buf = etr_perf->etr_buf;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); /* Don't do anything if another tracer is using this sink */ if (csdev->refcnt != 1) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); goto out; } if (WARN_ON(drvdata->perf_buf != etr_buf)) { lost = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); goto out; }@@ -1582,7 +1582,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev, tmc_sync_etr_buf(drvdata);
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); lost = etr_buf->full; offset = etr_buf->offset;@@ -1651,7 +1651,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data) struct perf_output_handle *handle = data; struct etr_perf_buffer *etr_perf = etm_perf_sink_config(handle);
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); /* Don't use this sink if it is already claimed by sysFS */ if (coresight_get_mode(csdev) == CS_MODE_SYSFS) { rc = -EBUSY;@@ -1691,7 +1691,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data) }
unlock_out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return rc;}
@@ -1713,16 +1713,16 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev) unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; } csdev->refcnt--; if (csdev->refcnt) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; }@@ -1735,7 +1735,7 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev) /* Reset perf specific data */ drvdata->perf_buf = NULL;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); dev_dbg(&csdev->dev, "TMC-ETR disabled\n"); return 0;@@ -1762,7 +1762,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR)) return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (drvdata->reading) { ret = -EBUSY; goto out;@@ -1784,7 +1784,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
drvdata->reading = true;out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret;} @@ -1798,7 +1798,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR)) return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
raw_spin_lock_irqsave(&drvdata->spinlock, flags); /* RE-enable the TMC if need be */ if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) {@@ -1818,7 +1818,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) }
drvdata->reading = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); /* Free allocated memory out side of the spinlock */ if (sysfs_buf)diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 2671926be62a..60b395025bc4 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -195,7 +195,7 @@ struct tmc_drvdata { void __iomem *base; struct coresight_device *csdev; struct miscdevice miscdev;
spinlock_t spinlock;
raw_spinlock_t spinlock; pid_t pid; bool reading; union {-- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
Reviewed-by: Mike Leach mike.leach@linaro.org
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Mike Leach