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From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: mathieu.poirier@linaro.org, mike.leach@linaro.org,
	linux-kernel@vger.kernel.org, anshuman.khandual@arm.com,
	jonathan.zhouwen@huawei.com, coresight@lists.linaro.org,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH v4 20/25] coresight: etm4x: Detect system instructions support
Date: Thu, 19 Nov 2020 16:45:42 +0000	[thread overview]
Message-ID: <20201119164547.2982871-21-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20201119164547.2982871-1-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 7ac0a185c146..5cbea9c27f58 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -684,6 +684,37 @@ 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)
 {
@@ -714,9 +745,17 @@ 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


  parent reply	other threads:[~2020-11-19 16:46 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-19 16:45 [PATCH v4 00/26] coresight: etm4x: Support for system instructions Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 01/25] coresight: etm4x: Handle access to TRCSSPCICRn Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 02/25] coresight: etm4x: Skip accessing TRCPDCR in save/restore Suzuki K Poulose
2020-11-20  5:40   ` Sai Prakash Ranjan
2020-11-27 18:55   ` Mathieu Poirier
2020-11-30  9:37     ` Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 03/25] coresight: Introduce device access abstraction Suzuki K Poulose
2020-11-27 19:11   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 04/25] coresight: tpiu: Prepare for using coresight " Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 05/25] coresight: Convert coresight_timeout to use " Suzuki K Poulose
2020-11-30 20:55   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 06/25] coresight: Convert claim/disclaim operations to use access wrappers Suzuki K Poulose
2020-11-30 21:04   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 07/25] coresight: etm4x: Always read the registers on the host CPU Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 08/25] coresight: etm4x: Convert all register accesses Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 09/25] coresight: etm4x: Add commentary on the registers Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 10/25] coresight: etm4x: Add sysreg access helpers Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 11/25] coresight: etm4x: Define DEVARCH register fields Suzuki K Poulose
2020-11-30 21:19   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 12/25] coresight: etm4x: Check for Software Lock Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 13/25] coresight: etm4x: Cleanup secure exception level masks Suzuki K Poulose
2020-11-30 21:25   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 14/25] coresight: etm4x: Clean up " Suzuki K Poulose
2020-11-30 21:45   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 15/25] coresight: etm4x: Handle ETM architecture version Suzuki K Poulose
2020-11-30 21:48   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 16/25] coresight: etm4x: Detect access early on the target CPU Suzuki K Poulose
2020-11-30 21:53   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 17/25] coresight: etm4x: Use TRCDEVARCH for component discovery Suzuki K Poulose
2020-11-27 18:28   ` Mathieu Poirier
2020-11-30  9:30     ` Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 18/25] coresight: etm4x: Expose trcdevarch via trcidr Suzuki K Poulose
2020-11-30 22:42   ` Mathieu Poirier
2020-11-19 16:45 ` [PATCH v4 19/25] coresight: etm4x: Add necessary synchronization for sysreg access Suzuki K Poulose
2020-11-19 16:45 ` Suzuki K Poulose [this message]
2020-11-23  7:58   ` [PATCH v4 20/25] coresight: etm4x: Detect system instructions support Tingwei Zhang
2020-11-23  9:39     ` Suzuki K Poulose
2020-11-24  0:41       ` Tingwei Zhang
2020-11-24 11:38         ` Suzuki K Poulose
2020-11-25  4:57           ` Tingwei Zhang
2020-11-19 16:45 ` [PATCH v4 21/25] coresight: etm4x: Refactor probing routine Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 22/25] coresight: etm4x: Add support for sysreg only devices Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 23/25] dts: bindings: coresight: ETM system register access only units Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 24/25] arm64: Add TRFCR_ELx definitions Suzuki K Poulose
2020-11-19 17:18   ` Catalin Marinas
2020-11-20 10:03     ` Suzuki K Poulose
2020-11-19 16:45 ` [PATCH v4 25/25] coresight: Add support for v8.4 SelfHosted tracing Suzuki K Poulose
2020-11-19 17:22   ` Catalin Marinas
2020-11-20 10:03     ` Suzuki K Poulose

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