[PATCH v4 13/13] coresight-etm4x: Read only access to the tracer's ID registers

From: Mathieu Poirier
Date: Wed May 13 2015 - 12:36:42 EST


ETM ID registers contain valuable information about the capabilities
of the implementation and are very useful when configuring the device for
various trace scenarios.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-coresight-devices-etm4x | 90 ++++++++++++++++++++++
drivers/hwtracing/coresight/coresight-etm4x.c | 37 +++++++++
2 files changed, 127 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
index bde788dfd3f7..2fe2e3dae487 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
@@ -358,3 +358,93 @@ KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Description: (R) Print the content of the Peripheral ID3 Register
(0xFEC). The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr0
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the tracing capabilities of the trace unit (0x1E0).
+ The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr1
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the tracing capabilities of the trace unit (0x1E4).
+ The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr2
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the maximum size of the data value, data address,
+ VMID, context ID and instuction address in the trace unit
+ (0x1E8). The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr3
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the value associated with various resources
+ available to the trace unit. See the Trace Macrocell
+ architecture specification for more details (0x1E8).
+ The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr4
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns how many resources the trace unit supports (0x1F0).
+ The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr5
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns how many resources the trace unit supports (0x1F4).
+ The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr8
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the maximum speculation depth of the instruction
+ trace stream. (0x180). The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr9
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the number of P0 right-hand keys that the trace unit
+ can use (0x184). The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr10
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the number of P1 right-hand keys that the trace unit
+ can use (0x188). The value is taken directly from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr11
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the number of special P1 right-hand keys that the
+ trace unit can use (0x18C). The value is taken directly from
+ the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr12
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the number of conditional P1 right-hand keys that
+ the trace unit can use (0x190). The value is taken directly
+ from the HW.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr13
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
+Description: (R) Returns the number of special conditional P1 right-hand keys
+ that the trace unit can use (0x194). The value is taken
+ directly from the HW.
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index 0568e4413411..f0b50af4fc30 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -2238,6 +2238,37 @@ static struct attribute *coresight_etmv4_mgmt_attrs[] = {
NULL,
};

+coresight_simple_func(trcidr0, TRCIDR0);
+coresight_simple_func(trcidr1, TRCIDR1);
+coresight_simple_func(trcidr2, TRCIDR2);
+coresight_simple_func(trcidr3, TRCIDR3);
+coresight_simple_func(trcidr4, TRCIDR4);
+coresight_simple_func(trcidr5, TRCIDR5);
+/* trcidr[6,7] are reserved */
+coresight_simple_func(trcidr8, TRCIDR8);
+coresight_simple_func(trcidr9, TRCIDR9);
+coresight_simple_func(trcidr10, TRCIDR10);
+coresight_simple_func(trcidr11, TRCIDR11);
+coresight_simple_func(trcidr12, TRCIDR12);
+coresight_simple_func(trcidr13, TRCIDR13);
+
+static struct attribute *coresight_etmv4_trcidr_attrs[] = {
+ &dev_attr_trcidr0.attr,
+ &dev_attr_trcidr1.attr,
+ &dev_attr_trcidr2.attr,
+ &dev_attr_trcidr3.attr,
+ &dev_attr_trcidr4.attr,
+ &dev_attr_trcidr5.attr,
+ /* trcidr[6,7] are reserved */
+ &dev_attr_trcidr8.attr,
+ &dev_attr_trcidr9.attr,
+ &dev_attr_trcidr10.attr,
+ &dev_attr_trcidr11.attr,
+ &dev_attr_trcidr12.attr,
+ &dev_attr_trcidr13.attr,
+ NULL,
+};
+
static const struct attribute_group coresight_etmv4_group = {
.attrs = coresight_etmv4_attrs,
};
@@ -2247,9 +2278,15 @@ static const struct attribute_group coresight_etmv4_mgmt_group = {
.name = "mgmt",
};

+static const struct attribute_group coresight_etmv4_trcidr_group = {
+ .attrs = coresight_etmv4_trcidr_attrs,
+ .name = "trcidr",
+};
+
static const struct attribute_group *coresight_etmv4_groups[] = {
&coresight_etmv4_group,
&coresight_etmv4_mgmt_group,
+ &coresight_etmv4_trcidr_group,
NULL,
};

--
1.9.1

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