On Thu, Jan 07, 2021 at 12:38:59PM +0000, Suzuki K Poulose wrote:
> From: Jonathan Zhou <jonathan.zhou...@huawei.com>
>
> v8.4 tracing extensions added support for trace filtering controlled
> by TRFCR_ELx. This must be programmed to allow tracing at EL1/EL2 and
> EL0. The timestamp used is the virtual time. Also enable CONTEXIDR_EL2
> tracing if we are running the kernel at EL2.
>
> Cc: Catalin Marinas <catalin.mari...@arm.com>
> Cc: Mathieu Poirier <mathieu.poir...@linaro.org>
> Cc: Mike Leach <mike.le...@linaro.org>
> Cc: Will Deacon <w...@kernel.org>
> Signed-off-by: Jonathan Zhou <jonathan.zhou...@huawei.com>
> [ Move the trace filtering setup etm_init_arch_data() and
> clean ups]
> Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
Reviewed-by: Mathieu Poirier <mathieu.poir...@linaro.org>
> ---
> .../coresight/coresight-etm4x-core.c | 25 +++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 34a6cdff75e7..6d96f4226bca 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -859,6 +859,30 @@ static bool etm4_init_csdev_access(struct etmv4_drvdata
> *drvdata,
> return false;
> }
>
> +static void cpu_enable_tracing(void)
> +{
> + u64 dfr0 = read_sysreg(id_aa64dfr0_el1);
> + u64 trfcr;
> +
> + if (!cpuid_feature_extract_unsigned_field(dfr0,
> ID_AA64DFR0_TRACE_FILT_SHIFT))
> + return;
> +
> + /*
> + * If the CPU supports v8.4 SelfHosted Tracing, enable
> + * tracing at the kernel EL and EL0, forcing to use the
> + * virtual time as the timestamp.
> + */
> + trfcr = (TRFCR_ELx_TS_VIRTUAL |
> + TRFCR_ELx_ExTRE |
> + TRFCR_ELx_E0TRE);
> +
> + /* If we are running at EL2, allow tracing the CONTEXTIDR_EL2. */
> + if (is_kernel_in_hyp_mode())
> + trfcr |= TRFCR_EL2_CX;
> +
> + write_sysreg_s(trfcr, SYS_TRFCR_EL1);
> +}
> +
> static void etm4_init_arch_data(void *info)
> {
> u32 etmidr0;
> @@ -1044,6 +1068,7 @@ static void etm4_init_arch_data(void *info)
> /* NUMCNTR, bits[30:28] number of counters available for tracing */
> drvdata->nr_cntr = BMVAL(etmidr5, 28, 30);
> etm4_cs_lock(drvdata, csa);
> + cpu_enable_tracing();
> }
>
> static inline u32 etm4_get_victlr_access_type(struct etmv4_config *config)
> --
> 2.24.1
>
