perf: arm_cspmu: nvidia: enable NVLINK-C2C port filtering

Enable NVLINK-C2C port filtering to distinguish traffic from
different GPUs connected to NVLINK-C2C.

Signed-off-by: Besar Wicaksono <bwicaksono@nvidia.com>
Link: https://lore.kernel.org/r/20241031142118.1865965-4-bwicaksono@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: bwicaksononv

Documentation/admin-guide/perf/nvidia-pmu.rst

@@ -86,6 +86,21 @@ Example usage:
 
    perf stat -a -e nvidia_nvlink_c2c0_pmu_3/event=0x0/
 
+The NVLink-C2C has two ports that can be connected to one GPU (occupying both
+ports) or to two GPUs (one GPU per port). The user can use "port" bitmap
+parameter to select the port(s) to monitor. Each bit represents the port number,
+e.g. "port=0x1" corresponds to port 0 and "port=0x3" is for port 0 and 1.
+
+Example for port filtering:
+
+* Count event id 0x0 from the GPU connected with socket 0 on port 0::
+
+   perf stat -a -e nvidia_nvlink_c2c0_pmu_0/event=0x0,port=0x1/
+
+* Count event id 0x0 from the GPUs connected with socket 0 on port 0 and port 1::
+
+   perf stat -a -e nvidia_nvlink_c2c0_pmu_0/event=0x0,port=0x3/
+
 NVLink-C2C1 PMU
 -------------------
 
@@ -116,6 +131,21 @@ Example usage:
 
    perf stat -a -e nvidia_nvlink_c2c1_pmu_3/event=0x0/
 
+The NVLink-C2C has two ports that can be connected to one GPU (occupying both
+ports) or to two GPUs (one GPU per port). The user can use "port" bitmap
+parameter to select the port(s) to monitor. Each bit represents the port number,
+e.g. "port=0x1" corresponds to port 0 and "port=0x3" is for port 0 and 1.
+
+Example for port filtering:
+
+* Count event id 0x0 from the GPU connected with socket 0 on port 0::
+
+   perf stat -a -e nvidia_nvlink_c2c1_pmu_0/event=0x0,port=0x1/
+
+* Count event id 0x0 from the GPUs connected with socket 0 on port 0 and port 1::
+
+   perf stat -a -e nvidia_nvlink_c2c1_pmu_0/event=0x0,port=0x3/
+
 CNVLink PMU
 ---------------
 

drivers/perf/arm_cspmu/nvidia_cspmu.c

@@ -130,6 +130,7 @@ static struct attribute *pcie_pmu_format_attrs[] = {
 
 static struct attribute *nvlink_c2c_pmu_format_attrs[] = {
 	ARM_CSPMU_FORMAT_EVENT_ATTR,
+	ARM_CSPMU_FORMAT_ATTR(port, "config1:0-1"),
 	NULL,
 };
 
@@ -210,7 +211,7 @@ static const struct nv_cspmu_match nv_cspmu_match[] = {
 	{
 	  .prodid = 0x104,
 	  .prodid_mask = NV_PRODID_MASK,
-	  .filter_mask = 0x0,
+	  .filter_mask = NV_NVL_C2C_FILTER_ID_MASK,
 	  .filter_default_val = NV_NVL_C2C_FILTER_ID_MASK,
 	  .name_pattern = "nvidia_nvlink_c2c1_pmu_%u",
 	  .name_fmt = NAME_FMT_SOCKET,
@@ -220,7 +221,7 @@ static const struct nv_cspmu_match nv_cspmu_match[] = {
 	{
 	  .prodid = 0x105,
 	  .prodid_mask = NV_PRODID_MASK,
-	  .filter_mask = 0x0,
+	  .filter_mask = NV_NVL_C2C_FILTER_ID_MASK,
 	  .filter_default_val = NV_NVL_C2C_FILTER_ID_MASK,
 	  .name_pattern = "nvidia_nvlink_c2c0_pmu_%u",
 	  .name_fmt = NAME_FMT_SOCKET,