Re: [PATCH V3 05/14] coresight: ete: Add support for ETE tracing

Mike Leach
2021-02-15T13:22:32Z

HI,

On Tue, 2 Feb 2021 at 18:56, Mathieu Poirier <mathieu.poirier@linaro.org> wrote:
>
> On Wed, Jan 27, 2021 at 02:25:29PM +0530, Anshuman Khandual wrote:
> > From: Suzuki K Poulose <suzuki.poulose@arm.com>
> >
> > Add ETE as one of the supported device types we support
> > with ETM4x driver. The devices are named following the
> > existing convention as ete<N>.
> >
> > ETE mandates that the trace resource status register is programmed
> > before the tracing is turned on. For the moment simply write to
> > it indicating TraceActive.
> >
> > Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> > Cc: Mike Leach <mike.leach@linaro.org>
> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> > ---
> > drivers/hwtracing/coresight/Kconfig | 10 ++--
> > drivers/hwtracing/coresight/coresight-etm4x-core.c | 56 +++++++++++++++++-----
> > .../hwtracing/coresight/coresight-etm4x-sysfs.c | 19 ++++++--
> > drivers/hwtracing/coresight/coresight-etm4x.h | 16 ++++++-
> > 4 files changed, 79 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
> > index 7b44ba2..f154ae7 100644
> > --- a/drivers/hwtracing/coresight/Kconfig
> > +++ b/drivers/hwtracing/coresight/Kconfig
> > @@ -97,15 +97,15 @@ config CORESIGHT_SOURCE_ETM3X
> > module will be called coresight-etm3x.
> >
> > config CORESIGHT_SOURCE_ETM4X
> > - tristate "CoreSight Embedded Trace Macrocell 4.x driver"
> > + tristate "CoreSight ETMv4.x / ETE driver"
> > depends on ARM64
> > select CORESIGHT_LINKS_AND_SINKS
> > select PID_IN_CONTEXTIDR
> > help
> > - This driver provides support for the ETM4.x tracer module, tracing the
> > - instructions that a processor is executing. This is primarily useful
> > - for instruction level tracing. Depending on the implemented version
> > - data tracing may also be available.
> > + This driver provides support for the CoreSight Embedded Trace Macrocell
> > + version 4.x and the Embedded Trace Extensions (ETE). Both are CPU tracer
> > + modules, tracing the instructions that a processor is executing. This is
> > + primarily useful for instruction level tracing.
> >
> > To compile this driver as a module, choose M here: the
> > module will be called coresight-etm4x.
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > index 9e92d2a..b40e3c2 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > @@ -431,6 +431,13 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
> > etm4x_relaxed_write32(csa, trcpdcr | TRCPDCR_PU, TRCPDCR);
> > }
> >
> > + /*
> > + * ETE mandates that the TRCRSR is written to before
> > + * enabling it.
> > + */
> > + if (etm4x_is_ete(drvdata))
> > + etm4x_relaxed_write32(csa, TRCRSR_TA, TRCRSR);
> > +
> > /* Enable the trace unit */
> > etm4x_relaxed_write32(csa, 1, TRCPRGCTLR);
> >
> > @@ -864,13 +871,24 @@ static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata,
> > * ETMs implementing sysreg access must implement TRCDEVARCH.
> > */
> > devarch = read_etm4x_sysreg_const_offset(TRCDEVARCH);
> > - if ((devarch & ETM_DEVARCH_ID_MASK) != ETM_DEVARCH_ETMv4x_ARCH)
> > + switch (devarch & ETM_DEVARCH_ID_MASK) {
> > + case ETM_DEVARCH_ETMv4x_ARCH:
> > + *csa = (struct csdev_access) {
> > + .io_mem = false,
> > + .read = etm4x_sysreg_read,
> > + .write = etm4x_sysreg_write,
> > + };
> > + break;
> > + case ETM_DEVARCH_ETE_ARCH:
> > + *csa = (struct csdev_access) {
> > + .io_mem = false,
> > + .read = ete_sysreg_read,
> > + .write = ete_sysreg_write,
> > + };
> > + break;
> > + default:
> > return false;
> > - *csa = (struct csdev_access) {
> > - .io_mem = false,
> > - .read = etm4x_sysreg_read,
> > - .write = etm4x_sysreg_write,
> > - };
> > + }
> >
> > drvdata->arch = etm_devarch_to_arch(devarch);
> > return true;
> > @@ -1808,6 +1826,8 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
> > struct etmv4_drvdata *drvdata;
> > struct coresight_desc desc = { 0 };
> > struct etm4_init_arg init_arg = { 0 };
> > + u8 major, minor;
> > + char *type_name;
> >
> > drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> > if (!drvdata)
> > @@ -1834,10 +1854,6 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
> > if (drvdata->cpu < 0)
> > return drvdata->cpu;
> >
> > - desc.name = devm_kasprintf(dev, GFP_KERNEL, "etm%d", drvdata->cpu);
> > - if (!desc.name)
> > - return -ENOMEM;
> > -
> > init_arg.drvdata = drvdata;
> > init_arg.csa = &desc.access;
> > init_arg.pid = etm_pid;
> > @@ -1853,6 +1869,20 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
> > if (!desc.access.io_mem ||
> > fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
> > drvdata->skip_power_up = true;
>
> Add a space here...
>
> > + major = ETM_ARCH_MAJOR_VERSION(drvdata->arch);
> > + minor = ETM_ARCH_MINOR_VERSION(drvdata->arch);
>
> And here too. Othersiwe it makes a big blob in the middle of the function.
>
> > + if (etm4x_is_ete(drvdata)) {
> > + type_name = "ete";
> > + /* ETE v1 has major version == 5. Adjust this for logging.*/
> > + major -= 4;
>
> I don't have the documentation for the ETE but I would not adjust @major. I
> would simply leave it to what the HW gives us since regardless of the name, the
> major revision of the IP block is 5.
>

For consistency this adjustment should be retained. All the prior
drivers reported the protocol version related to this.
For ETM3.x this value was 0x2 - logging printed "ETMv3.x", for PTM
this value was 0x3 - logging printed "PTM 1.x".
Only for ETMv4 is this value the same as the protocol version.

Mike

> > + } else {
> > + type_name = "etm";
> > + }
> > +
> > + desc.name = devm_kasprintf(dev, GFP_KERNEL,
> > + "%s%d", type_name, drvdata->cpu);
> > + if (!desc.name)
> > + return -ENOMEM;
> >
> > etm4_init_trace_id(drvdata);
> > etm4_set_default(&drvdata->config);
> > @@ -1881,9 +1911,8 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
> >
> > etmdrvdata[drvdata->cpu] = drvdata;
> >
> > - dev_info(&drvdata->csdev->dev, "CPU%d: ETM v%d.%d initialized\n",
> > - drvdata->cpu, ETM_ARCH_MAJOR_VERSION(drvdata->arch),
> > - ETM_ARCH_MINOR_VERSION(drvdata->arch));
> > + dev_info(&drvdata->csdev->dev, "CPU%d: %s v%d.%d initialized\n",
> > + drvdata->cpu, type_name, major, minor);
> >
> > if (boot_enable) {
> > coresight_enable(drvdata->csdev);
> > @@ -2027,6 +2056,7 @@ static struct amba_driver etm4x_amba_driver = {
> >
> > static const struct of_device_id etm4_sysreg_match[] = {
> > { .compatible = "arm,coresight-etm4x-sysreg" },
> > + { .compatible = "arm,embedded-trace-extension" },
> > {}
> > };
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> > index b646d53..1c490bc 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> > @@ -2374,12 +2374,20 @@ static inline bool
> > etm4x_register_implemented(struct etmv4_drvdata *drvdata, u32 offset)
> > {
> > switch (offset) {
> > - ETM4x_SYSREG_LIST_CASES
> > + ETM_COMMON_SYSREG_LIST_CASES
> > /*
> > - * Registers accessible via system instructions are always
> > - * implemented.
> > + * Common registers to ETE & ETM4x accessible via system
> > + * instructions are always implemented.
> > */
> > return true;
> > +
> > + ETM4x_ONLY_SYSREG_LIST_CASES
> > + /*
> > + * We only support etm4x and ete. So if the device is not
> > + * ETE, it must be ETMv4x.
> > + */
> > + return !etm4x_is_ete(drvdata);
> > +
> > ETM4x_MMAP_LIST_CASES
> > /*
> > * Registers accessible only via memory-mapped registers
> > @@ -2389,8 +2397,13 @@ etm4x_register_implemented(struct etmv4_drvdata *drvdata, u32 offset)
> > * coresight_register() and the csdev is not initialized
> > * until that is done. So rely on the drvdata->base to
> > * detect if we have a memory mapped access.
> > + * Also ETE doesn't implement memory mapped access, thus
> > + * it is sufficient to check that we are using mmio.
> > */
> > return !!drvdata->base;
> > +
> > + ETE_ONLY_SYSREG_LIST_CASES
> > + return etm4x_is_ete(drvdata);
> > }
> >
> > return false;
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> > index ca24ac5..8b90de5 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> > @@ -128,6 +128,8 @@
> > #define TRCCIDR2 0xFF8
> > #define TRCCIDR3 0xFFC
> >
> > +#define TRCRSR_TA BIT(12)
> > +
> > /*
> > * System instructions to access ETM registers.
> > * See ETMv4.4 spec ARM IHI0064F section 4.3.6 System instructions
> > @@ -390,6 +392,9 @@
> > #define ETM_COMMON_SYSREG_LIST_CASES \
> > ETM_COMMON_SYSREG_LIST(NOP, __unused)
> >
> > +#define ETM4x_ONLY_SYSREG_LIST_CASES \
> > + ETM4x_ONLY_SYSREG_LIST(NOP, __unused)
> > +
> > #define ETM4x_SYSREG_LIST_CASES \
> > ETM_COMMON_SYSREG_LIST_CASES \
> > ETM4x_ONLY_SYSREG_LIST(NOP, __unused)
> > @@ -406,7 +411,6 @@
> > ETE_ONLY_SYSREG_LIST(WRITE, (val))
> >
> > #define ETE_ONLY_SYSREG_LIST_CASES \
> > - ETM_COMMON_SYSREG_LIST_CASES \
>
> This goes in patch 04.
>
> With the above:
>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>
> > ETE_ONLY_SYSREG_LIST(NOP, __unused)
> >
> > #define read_etm4x_sysreg_offset(offset, _64bit) \
> > @@ -589,11 +593,14 @@
> > ((ETM_DEVARCH_MAKE_ARCHID_ARCH_VER(major)) | ETM_DEVARCH_ARCHID_ARCH_PART(0xA13))
> >
> > #define ETM_DEVARCH_ARCHID_ETMv4x ETM_DEVARCH_MAKE_ARCHID(0x4)
> > +#define ETM_DEVARCH_ARCHID_ETE ETM_DEVARCH_MAKE_ARCHID(0x5)
> >
> > #define ETM_DEVARCH_ID_MASK \
> > (ETM_DEVARCH_ARCHITECT_MASK | ETM_DEVARCH_ARCHID_MASK | ETM_DEVARCH_PRESENT)
> > #define ETM_DEVARCH_ETMv4x_ARCH \
> > (ETM_DEVARCH_ARCHITECT_ARM | ETM_DEVARCH_ARCHID_ETMv4x | ETM_DEVARCH_PRESENT)
> > +#define ETM_DEVARCH_ETE_ARCH \
> > + (ETM_DEVARCH_ARCHITECT_ARM | ETM_DEVARCH_ARCHID_ETE | ETM_DEVARCH_PRESENT)
> >
> > #define TRCSTATR_IDLE_BIT 0
> > #define TRCSTATR_PMSTABLE_BIT 1
> > @@ -683,6 +690,8 @@
> > #define ETM_ARCH_MINOR_VERSION(arch) ((arch) & 0xfU)
> >
> > #define ETM_ARCH_V4 ETM_ARCH_VERSION(4, 0)
> > +#define ETM_ARCH_ETE ETM_ARCH_VERSION(5, 0)
> > +
> > /* Interpretation of resource numbers change at ETM v4.3 architecture */
> > #define ETM_ARCH_V4_3 ETM_ARCH_VERSION(4, 3)
> >
> > @@ -989,4 +998,9 @@ void etm4_config_trace_mode(struct etmv4_config *config);
> >
> > u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit);
> > void etm4x_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit);
> > +
> > +static inline bool etm4x_is_ete(struct etmv4_drvdata *drvdata)
> > +{
> > + return drvdata->arch >= ETM_ARCH_ETE;
> > +}
> > #endif
> > --
> > 2.7.4
> >

--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK