On Thu, Nov 26, 2020 at 09:34:30PM +0800, Qi Liu wrote: > 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 <liuqi...@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. > Change since v4: > - rename the call back function to a more generic name, and fix some > compile warnings. > > drivers/hwtracing/coresight/Kconfig | 9 +++ > drivers/hwtracing/coresight/coresight-etm4x-core.c | 88 > ++++++++++++++++++++++ > drivers/hwtracing/coresight/coresight-etm4x.h | 8 ++ > 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..fcee27a 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 +106,87 @@ 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
Here bit 12 and 13 are cleared but in etm4_hisi_config_core_commit() only bit 12 is set - is this intentional? What is bit 13 for? > +#define HISI_HIP08_CORE_COMMIT_SHIFT 12 > +#define HISI_HIP08_CORE_COMMIT_REG sys_reg(3, 1, 15, 2, 5) > + > +struct etm4_arch_features { > + void (*arch_callback)(bool enable); > +}; > + > +static 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] = { > + .arch_callback = 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->arch_callback) > + ftr->arch_callback(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->arch_callback) > + ftr->arch_callback(false); > + } > +} > + > +static void etm4_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 +194,7 @@ 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 +561,7 @@ 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 +1633,8 @@ static int etm4_probe(struct amba_device *adev, const > struct amba_id *id) > drvdata->boot_enable = true; > } > > + etm4_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..3dd3e06 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 +470,7 @@ 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); > }; > > /* Address comparator access types */ > -- > 2.8.1 >