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

On 2/2/21 6:56 PM, Mathieu Poirier wrote:

On Wed, Jan 27, 2021 at 02:25:29PM +0530, Anshuman Khandual wrote:

quoted

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 <redacted>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <redacted>
---

...

quoted

@@ -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...

quoted

+	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.

quoted

+	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.

At the moment only register definitions are public and can be found here :

https://developer.arm.com/docs/ddi0601/g/aarch64-system-registers/trcdevarch

The ETE is natural extension of the ETM architecture to support future
architecture changes and is designed in a way that the same software
can driver both ETM and ETE without much changes.

quoted

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.

Sure, will move it.

With the above:

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Thanks for the review

Suzuki

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel