coresight: ete: Add support for ETE tracing

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: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20210405164307.1720226-14-suzuki.poulose@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

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.

drivers/hwtracing/coresight/coresight-etm4x-core.c

@@ -433,6 +433,13 @@ 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);
 
@@ -894,13 +901,24 @@ 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;
@@ -1841,6 +1859,8 @@ 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)
@@ -1867,10 +1887,6 @@ 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;
@@ -1887,6 +1903,22 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
 	    fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
 		drvdata->skip_power_up = true;
 
+	major = ETM_ARCH_MAJOR_VERSION(drvdata->arch);
+	minor = ETM_ARCH_MINOR_VERSION(drvdata->arch);
+
+	if (etm4x_is_ete(drvdata)) {
+		type_name = "ete";
+		/* ETE v1 has major version == 0b101. Adjust this for logging.*/
+		major -= 4;
+	} 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);
 
@@ -1914,9 +1946,8 @@ 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);
@@ -2059,6 +2090,7 @@ 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" },
 	{}
 };
 

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;

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
@@ -591,11 +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
@@ -685,6 +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)
 
@@ -993,4 +1000,9 @@ 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