From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, coresight@lists.linaro.org,
mathieu.poirier@linaro.org, leo.yan@linaro.org,
mike.leach@linaro.org, anshuman.khandual@arm.com,
Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH v6 20/26] coresight: etm4x: Detect system instructions support
Date: Thu, 7 Jan 2021 12:38:53 +0000 [thread overview]
Message-ID: <20210107123859.674252-21-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20210107123859.674252-1-suzuki.poulose@arm.com>
ETM v4.4 onwards adds support for system instruction access
to the ETM. Detect the support on an ETM and switch to using the
mode when available.
Cc: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
.../coresight/coresight-etm4x-core.c | 39 +++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 9b00720e7a02..f5bbb6131d77 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -782,6 +782,37 @@ static const struct coresight_ops etm4_cs_ops = {
.source_ops = &etm4_source_ops,
};
+static inline bool cpu_supports_sysreg_trace(void)
+{
+ u64 dfr0 = read_sysreg_s(SYS_ID_AA64DFR0_EL1);
+
+ return ((dfr0 >> ID_AA64DFR0_TRACEVER_SHIFT) & 0xfUL) > 0;
+}
+
+static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata,
+ struct csdev_access *csa)
+{
+ u32 devarch;
+
+ if (!cpu_supports_sysreg_trace())
+ return false;
+
+ /*
+ * ETMs implementing sysreg access must implement TRCDEVARCH.
+ */
+ devarch = read_etm4x_sysreg_const_offset(TRCDEVARCH);
+ if ((devarch & ETM_DEVARCH_ID_MASK) != ETM_DEVARCH_ETMv4x_ARCH)
+ 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;
+}
+
static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata,
struct csdev_access *csa)
{
@@ -812,9 +843,17 @@ static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata,
static bool etm4_init_csdev_access(struct etmv4_drvdata *drvdata,
struct csdev_access *csa)
{
+ /*
+ * Always choose the memory mapped io, if there is
+ * a memory map to prevent sysreg access on broken
+ * systems.
+ */
if (drvdata->base)
return etm4_init_iomem_access(drvdata, csa);
+ if (etm4_init_sysreg_access(drvdata, csa))
+ return true;
+
return false;
}
--
2.24.1
next prev parent reply other threads:[~2021-01-07 12:42 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-07 12:38 [PATCH v6 00/26] coresight: etm4x: Support for system instructions Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 01/26] coresight: etm4x: Handle access to TRCSSPCICRn Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 02/26] coresight: etm4x: Skip accessing TRCPDCR in save/restore Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 03/26] coresight: Introduce device access abstraction Suzuki K Poulose
2021-01-07 23:38 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 04/26] coresight: tpiu: Prepare for using coresight " Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 05/26] coresight: Convert coresight_timeout to use " Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 06/26] coresight: Convert claim/disclaim operations to use access wrappers Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 07/26] coresight: etm4x: Always read the registers on the host CPU Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 08/26] coresight: etm4x: Convert all register accesses Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 09/26] coresight: etm4x: Add commentary on the registers Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 10/26] coresight: etm4x: Add sysreg access helpers Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 11/26] coresight: etm4x: Define DEVARCH register fields Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 12/26] coresight: etm4x: Check for Software Lock Suzuki K Poulose
2021-01-08 0:18 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 13/26] coresight: etm4x: Cleanup secure exception level masks Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 14/26] coresight: etm4x: Clean up " Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 15/26] coresight: etm4x: Handle ETM architecture version Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 16/26] coresight: etm4x: Detect access early on the target CPU Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 17/26] coresight: etm4x: Use TRCDEVARCH for component discovery Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 18/26] coresight: etm4x: Expose trcdevarch via sysfs Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 19/26] coresight: etm4x: Add necessary synchronization for sysreg access Suzuki K Poulose
2021-01-07 12:38 ` Suzuki K Poulose [this message]
2021-01-07 12:38 ` [PATCH v6 21/26] coresight: etm4x: Refactor probing routine Suzuki K Poulose
2021-01-08 0:38 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 22/26] coresight: etm4x: Run arch feature detection on the CPU Suzuki K Poulose
2021-01-08 0:49 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 23/26] coresight: etm4x: Add support for sysreg only devices Suzuki K Poulose
2021-01-08 0:55 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 24/26] dts: bindings: coresight: ETM system register access only units Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 25/26] arm64: Add TRFCR_ELx definitions Suzuki K Poulose
2021-01-08 1:01 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 26/26] coresight: Add support for v8.4 SelfHosted tracing Suzuki K Poulose
2021-01-08 1:02 ` Mathieu Poirier
2021-01-08 1:09 ` [PATCH v6 00/26] coresight: etm4x: Support for system instructions Mathieu Poirier
2021-01-08 9:08 ` Suzuki K Poulose
2021-01-08 14:15 ` Suzuki K Poulose
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