coresight-etm4x: Read only access to the tracer's ID registers

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@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
index bde788dfd3f72c3205e3d8d38abe7ee26e33803b..2fe2e3dae487a094c7e6aba3def141ee3544ffca 100644 (file)
--- 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@linaro.org>
 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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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@linaro.org>
+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 0568e4413411bb14053d832f544c25ba31c102a2..f0b50af4fc30c9b94a126983a308662c1e62d5cf 100644 (file)
--- 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,
 };