The mode of operation of the TMC tracked in drvdata->mode is defined as a local_t type. This is always checked and modified under the drvdata->spinlock and hence we don't need local_t for it and the unnecessary synchronisation instructions that comes with it. This change makes the code a bit more cleaner.
Also fixes the order in which we update the drvdata->mode to CS_MODE_DISABLED. i.e, in tmc_disable_etX_sink we change the mode to CS_MODE_DISABLED before invoking tmc_disable_etX_hw() which in turn depends on the mode to decide whether to dump the trace to a buffer. Applies on mathieu's coresight/next tree [1] https://git.linaro.org/kernel/coresight.git next Reported-by: Venkatesh Vivekanandan <venkatesh.vivekanan...@broadcom.com> Cc: Mathieu Poirier <mathieu.poir...@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com> --- drivers/hwtracing/coresight/coresight-tmc-etf.c | 32 +++++++++++-------------- drivers/hwtracing/coresight/coresight-tmc-etr.c | 30 ++++++++++------------- drivers/hwtracing/coresight/coresight-tmc.h | 2 +- 3 files changed, 28 insertions(+), 36 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index d6941ea..c51ce45 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -70,7 +70,7 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata) * When operating in sysFS mode the content of the buffer needs to be * read before the TMC is disabled. */ - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) + if (drvdata->mode == CS_MODE_SYSFS) tmc_etb_dump_hw(drvdata); tmc_disable_hw(drvdata); @@ -108,7 +108,6 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode) int ret = 0; bool used = false; char *buf = NULL; - long val; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -138,13 +137,12 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode) goto out; } - val = local_xchg(&drvdata->mode, 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) + if (drvdata->mode == CS_MODE_SYSFS) goto out; /* @@ -163,6 +161,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode) drvdata->buf = buf; } + drvdata->mode = CS_MODE_SYSFS; tmc_etb_enable_hw(drvdata); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -180,7 +179,6 @@ out: static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode) { int ret = 0; - long val; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -194,17 +192,17 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode) goto out; } - val = local_xchg(&drvdata->mode, mode); /* * In Perf mode there can be only one writer per sink. There * is also no need to continue if the ETB/ETR is already operated * from sysFS. */ - if (val != CS_MODE_DISABLED) { + if (drvdata->mode != CS_MODE_DISABLED) { ret = -EINVAL; goto out; } + drvdata->mode = mode; tmc_etb_enable_hw(drvdata); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -227,7 +225,6 @@ static int tmc_enable_etf_sink(struct coresight_device *csdev, u32 mode) static void tmc_disable_etf_sink(struct coresight_device *csdev) { - long val; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -237,10 +234,11 @@ static void tmc_disable_etf_sink(struct coresight_device *csdev) return; } - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED); /* Disable the TMC only if it needs to */ - if (val != CS_MODE_DISABLED) + if (drvdata->mode != CS_MODE_DISABLED) { tmc_etb_disable_hw(drvdata); + drvdata->mode = CS_MODE_DISABLED; + } spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -260,7 +258,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev, } tmc_etf_enable_hw(drvdata); - local_set(&drvdata->mode, CS_MODE_SYSFS); + drvdata->mode = CS_MODE_SYSFS; spin_unlock_irqrestore(&drvdata->spinlock, flags); dev_info(drvdata->dev, "TMC-ETF enabled\n"); @@ -279,8 +277,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev, return; } + drvdata->mode = CS_MODE_DISABLED; tmc_etf_disable_hw(drvdata); - local_set(&drvdata->mode, CS_MODE_DISABLED); spin_unlock_irqrestore(&drvdata->spinlock, flags); dev_info(drvdata->dev, "TMC disabled\n"); @@ -383,7 +381,7 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev, return; /* This shouldn't happen */ - if (WARN_ON_ONCE(local_read(&drvdata->mode) != CS_MODE_PERF)) + if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF)) return; CS_UNLOCK(drvdata->base); @@ -504,7 +502,6 @@ const struct coresight_ops tmc_etf_cs_ops = { int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) { - long val; enum tmc_mode mode; int ret = 0; unsigned long flags; @@ -528,9 +525,8 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) goto out; } - val = local_read(&drvdata->mode); /* Don't interfere if operated from Perf */ - if (val == CS_MODE_PERF) { + if (drvdata->mode == CS_MODE_PERF) { ret = -EINVAL; goto out; } @@ -542,7 +538,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) } /* Disable the TMC if need be */ - if (val == CS_MODE_SYSFS) + if (drvdata->mode == CS_MODE_SYSFS) tmc_etb_disable_hw(drvdata); drvdata->reading = true; @@ -573,7 +569,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) } /* Re-enable the TMC if need be */ - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) { + if (drvdata->mode == CS_MODE_SYSFS) { /* * The trace run will continue with the same allocated trace * buffer. As such zero-out the buffer so that we don't end diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 886ea83..cf2bf60 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -86,7 +86,7 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) * When operating in sysFS mode the content of the buffer needs to be * read before the TMC is disabled. */ - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) + if (drvdata->mode == CS_MODE_SYSFS) tmc_etr_dump_hw(drvdata); tmc_disable_hw(drvdata); @@ -97,7 +97,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode) { int ret = 0; bool used = false; - long val; unsigned long flags; void __iomem *vaddr = NULL; dma_addr_t paddr; @@ -134,13 +133,12 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode) goto out; } - val = local_xchg(&drvdata->mode, 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) + if (drvdata->mode == CS_MODE_SYSFS) goto out; /* @@ -157,6 +155,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode) memset(drvdata->vaddr, 0, drvdata->size); + drvdata->mode = CS_MODE_SYSFS; tmc_etr_enable_hw(drvdata); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -174,7 +173,6 @@ out: static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode) { int ret = 0; - long val; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -188,18 +186,18 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, u32 mode) goto out; } - val = local_xchg(&drvdata->mode, mode); /* * In Perf mode there can be only one writer per sink. There * is also no need to continue if the ETR is already operated * from sysFS. */ - if (val != CS_MODE_DISABLED) { + if (drvdata->mode == CS_MODE_DISABLED) { + drvdata->mode = CS_MODE_PERF; + tmc_etr_enable_hw(drvdata); + } else { ret = -EINVAL; - goto out; } - tmc_etr_enable_hw(drvdata); out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -221,7 +219,6 @@ static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode) static void tmc_disable_etr_sink(struct coresight_device *csdev) { - long val; unsigned long flags; struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); @@ -231,10 +228,11 @@ static void tmc_disable_etr_sink(struct coresight_device *csdev) return; } - val = local_xchg(&drvdata->mode, CS_MODE_DISABLED); /* Disable the TMC only if it needs to */ - if (val != CS_MODE_DISABLED) + if (drvdata->mode != CS_MODE_DISABLED) { tmc_etr_disable_hw(drvdata); + drvdata->mode = CS_MODE_DISABLED; + } spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -253,7 +251,6 @@ const struct coresight_ops tmc_etr_cs_ops = { int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) { int ret = 0; - long val; unsigned long flags; /* config types are set a boot time and never change */ @@ -266,9 +263,8 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) goto out; } - val = local_read(&drvdata->mode); /* Don't interfere if operated from Perf */ - if (val == CS_MODE_PERF) { + if (drvdata->mode == CS_MODE_PERF) { ret = -EINVAL; goto out; } @@ -280,7 +276,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) } /* Disable the TMC if need be */ - if (val == CS_MODE_SYSFS) + if (drvdata->mode == CS_MODE_SYSFS) tmc_etr_disable_hw(drvdata); drvdata->reading = true; @@ -303,7 +299,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) spin_lock_irqsave(&drvdata->spinlock, flags); /* RE-enable the TMC if need be */ - if (local_read(&drvdata->mode) == CS_MODE_SYSFS) { + if (drvdata->mode == CS_MODE_SYSFS) { /* * The trace run will continue with the same allocated trace * buffer. The trace buffer is cleared in tmc_etr_enable_hw(), diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 44b3ae3..51c0185 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -117,7 +117,7 @@ struct tmc_drvdata { void __iomem *vaddr; u32 size; u32 len; - local_t mode; + u32 mode; enum tmc_config_type config_type; enum tmc_mem_intf_width memwidth; u32 trigger_cntr; -- 2.7.4
