Support for power reading

[loostrum]

I'm very much interested in measuring the energy efficiency of the Strix Point NPU I have available here, however I noticed that the driver does not support reading power data yet, it simply returns UINT32_MAX as the power value. Is there a timeline for adding support for this to the xdna driver?

[csbnw]

To support this, it seems that this TODO item needs to be addressed:

xdna-driver/src/driver/amdxdna/aie2_pci.c

Line 907 in e3fbe6e

sensor->input = __UINT32_MAX__; /* TODO: query the device and get the power data */

This program should then be able to report power usage:

// query-sensor.c

#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>

#include <amdxdna_accel.h>

int main() {
  int fd = open("/dev/accel/accel0", O_RDWR);
  if (fd < 0) {
    perror("open");
    return 1;
  }

  struct amdxdna_drm_query_sensor sensor;
  struct amdxdna_drm_get_info args;

  memset(&sensor, 0, sizeof(sensor));
  memset(&args, 0, sizeof(args));
  args.param = DRM_AMDXDNA_QUERY_SENSORS;

  args.buffer = (uintptr_t)&sensor;
  args.buffer_size = sizeof(sensor);

  int ret = ioctl(fd, DRM_IOCTL_AMDXDNA_GET_INFO, &args);
  if (ret) {
    perror("ioctl DRM_IOCTL_AMDXDNA_GET_INFO");
    close(fd);
    return 1;
  }

  printf("Sensor label: %s\n", sensor.label);
  printf("Sensor value: %ue%d %s\n", sensor.input, sensor.unitm, sensor.units);

  close(fd);
  return 0;
}

Compilation using gcc query-sensor.c -I $XDNA_DRIVER_ROOT/src/include/uapi/drm_local

With the current version (e9d2788a884784e3531e95d65b923c2252a1132e) this indeed reports UINT32_MAX:

Sensor label: Total Power
Sensor value: 4294967295e-3 mW