The ETM device can't keep up with the core pipeline when cpu core is at full speed. This may cause overflow within core and its ETM. This is a common phenomenon on ETM devices.

On HiSilicon Hip08 platform, a specific feature is added to set core pipeline. So commit rate can be reduced manually to avoid ETM overflow.

Signed-off-by: Qi Liu liuqi115@huawei.com --- Change since v1: - add CONFIG_ETM4X_IMPDEF_FEATURE and CONFIG_ETM4X_IMPDEF_HISILICON to keep specific feature off platforms which don't use it. Change since v2: - remove some unused variable. Change since v3: - use read/write_sysreg_s() to access register.

drivers/hwtracing/coresight/Kconfig | 9 +++ drivers/hwtracing/coresight/coresight-etm4x-core.c | 84 ++++++++++++++++++++++ drivers/hwtracing/coresight/coresight-etm4x.h | 12 ++++ 3 files changed, 105 insertions(+)

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig index c119824..1cc3601 100644 --- a/drivers/hwtracing/coresight/Kconfig +++ b/drivers/hwtracing/coresight/Kconfig @@ -110,6 +110,15 @@ config CORESIGHT_SOURCE_ETM4X To compile this driver as a module, choose M here: the module will be called coresight-etm4x.

+config ETM4X_IMPDEF_FEATURE + bool "Control overflow impdef support in CoreSight ETM 4.x driver " + depends on CORESIGHT_SOURCE_ETM4X + help + This control provides overflow implement define for CoreSight + ETM 4.x tracer module which could not reduce commit race + automatically, and could avoid overflow within ETM tracer module + and its cpu core. + config CORESIGHT_STM tristate "CoreSight System Trace Macrocell driver" depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) || ARM64 diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index abd706b..a1cf215 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -3,6 +3,7 @@ * Copyright (c) 2014, The Linux Foundation. All rights reserved. */

+#include <linux/bitops.h> #include <linux/kernel.h> #include <linux/moduleparam.h> #include <linux/init.h> @@ -28,7 +29,9 @@ #include <linux/perf_event.h> #include <linux/pm_runtime.h> #include <linux/property.h> + #include <asm/sections.h> +#include <asm/sysreg.h> #include <asm/local.h> #include <asm/virt.h>

@@ -103,6 +106,83 @@ struct etm4_enable_arg { int rc; };

+#ifdef CONFIG_ETM4X_IMPDEF_FEATURE + +#define HISI_HIP08_AMBA_ID 0x000b6d01 +#define ETM4_AMBA_MASK 0xfffff +#define HISI_HIP08_CORE_COMMIT_CLEAR 0x3000 +#define HISI_HIP08_CORE_COMMIT_SHIFT 12 +#define HISI_HIP08_CORE_COMMIT_REG sys_reg(3, 1, 15, 2, 5) + +bool etm4_hisi_match_pid(unsigned int id) +{ + return (id & ETM4_AMBA_MASK) == HISI_HIP08_AMBA_ID; +} + +static void etm4_hisi_config_core_commit(bool enable) +{ + u64 val; + + val = read_sysreg_s(HISI_HIP08_CORE_COMMIT_REG); + val &= ~HISI_HIP08_CORE_COMMIT_CLEAR; + val |= enable << HISI_HIP08_CORE_COMMIT_SHIFT; + write_sysreg_s(val, HISI_HIP08_CORE_COMMIT_REG); +} + +static struct etm4_arch_features etm4_features[] = { + [ETM4_IMPDEF_HISI_CORE_COMMIT] = { + .set_commit = etm4_hisi_config_core_commit, + }, + {}, +}; + +static void etm4_enable_arch_specific(struct etmv4_drvdata *drvdata) +{ + struct etm4_arch_features *ftr; + int bit; + + for_each_set_bit(bit, drvdata->arch_features, ETM4_IMPDEF_FEATURE_MAX) { + ftr = &etm4_features[bit]; + + if (ftr->set_commit) + ftr->set_commit(true); + } +} + +static void etm4_disable_arch_specific(struct etmv4_drvdata *drvdata) +{ + struct etm4_arch_features *ftr; + int bit; + + for_each_set_bit(bit, drvdata->arch_features, ETM4_IMPDEF_FEATURE_MAX) { + ftr = &etm4_features[bit]; + + if (ftr->set_commit) + ftr->set_commit(false); + } +} + +static void etm4x_check_arch_features(struct etmv4_drvdata *drvdata, + unsigned int id) +{ + if (etm4_hisi_match_pid(id)) + set_bit(ETM4_IMPDEF_HISI_CORE_COMMIT, drvdata->arch_features); +} +#else +static void etm4_enable_arch_specific(struct etmv4_drvdata *drvdata) +{ +} + +static void etm4_disable_arch_specific(struct etmv4_drvdata *drvdata) +{ +} + +static void etm4_check_arch_features(struct etmv4_drvdata drvdata, + unsigned int id) +{ +} +#endif /* CONFIG_ETM4X_IMPDEF_FEATURE */ + static int etm4_enable_hw(struct etmv4_drvdata *drvdata) { int i, rc; @@ -110,6 +190,7 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata) struct device *etm_dev = &drvdata->csdev->dev;

CS_UNLOCK(drvdata->base); + etm4_enable_arch_specific(drvdata);

etm4_os_unlock(drvdata);

@@ -476,6 +557,7 @@ static void etm4_disable_hw(void *info) int i;

CS_UNLOCK(drvdata->base); + etm4_disable_arch_specific(drvdata);

if (!drvdata->skip_power_up) { /* power can be removed from the trace unit now */ @@ -1547,6 +1629,8 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) drvdata->boot_enable = true; }

+ etm4x_check_arch_features(drvdata, id->id); + return 0; }

diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index eefc737..1784975 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -8,6 +8,7 @@

#include <asm/local.h> #include <linux/spinlock.h> +#include <linux/types.h> #include "coresight-priv.h"

/* @@ -203,6 +204,11 @@ /* Interpretation of resource numbers change at ETM v4.3 architecture */ #define ETM4X_ARCH_4V3 0x43

+enum etm_impdef_type { + ETM4_IMPDEF_HISI_CORE_COMMIT, + ETM4_IMPDEF_FEATURE_MAX, +}; + /** * struct etmv4_config - configuration information related to an ETMv4 * @mode: Controls various modes supported by this ETM. @@ -415,6 +421,7 @@ struct etmv4_save_state { * @state_needs_restore: True when there is context to restore after PM exit * @skip_power_up: Indicates if an implementation can skip powering up * the trace unit. + * @arch_features: Bitmap of arch features of etmv4 devices. */ struct etmv4_drvdata { void __iomem *base; @@ -463,6 +470,11 @@ struct etmv4_drvdata { struct etmv4_save_state *save_state; bool state_needs_restore; bool skip_power_up; + DECLARE_BITMAP(arch_features, ETM4_IMPDEF_FEATURE_MAX); +}; + +struct etm4_arch_features { + void (*set_commit)(bool enable); };

/* Address comparator access types */ -- 2.8.1