overlay: Read frequency from perf

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/overlay/gpu-freq.c b/overlay/gpu-freq.c
index 0a400be..f6bc67a 100644 (file)
--- a/overlay/gpu-freq.c
+++ b/overlay/gpu-freq.c
@@ -30,6 +30,38 @@
 
 #include "gpu-freq.h"
 #include "debugfs.h"
+#include "perf.h"
+
+static int perf_i915_open(int config, int group)
+{
+       struct perf_event_attr attr;
+
+       memset(&attr, 0, sizeof (attr));
+
+       attr.type = i915_type_id();
+       if (attr.type == 0)
+               return -ENOENT;
+       attr.config = config;
+
+       attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED;
+       if (group == -1)
+               attr.read_format |= PERF_FORMAT_GROUP;
+
+       return perf_event_open(&attr, -1, 0, group, 0);
+}
+
+static int perf_open(void)
+{
+       int fd;
+
+       fd = perf_i915_open(I915_PERF_ACTUAL_FREQUENCY, -1);
+       if (perf_i915_open(I915_PERF_REQUESTED_FREQUENCY, fd) < 0) {
+               close(fd);
+               fd = -1;
+       }
+
+       return fd;
+}
 
 int gpu_freq_init(struct gpu_freq *gf)
 {
@@ -38,6 +70,8 @@ int gpu_freq_init(struct gpu_freq *gf)
 
        memset(gf, 0, sizeof(*gf));
 
+       gf->fd = perf_open();
+
        sprintf(buf, "%s/i915_cur_delayinfo", debugfs_dri_path);
        fd = open(buf, 0);
        if (fd < 0)
@@ -79,31 +113,58 @@ err:
 
 int gpu_freq_update(struct gpu_freq *gf)
 {
-       char buf[4096], *s;
-       int fd, len = -1;
-
        if (gf->error)
                return gf->error;
 
-       sprintf(buf, "%s/i915_cur_delayinfo", debugfs_dri_path);
-       fd = open(buf, 0);
-       if (fd < 0)
-               return gf->error = errno;
-
-       len = read(fd, buf, sizeof(buf)-1);
-       close(fd);
-       if (len < 0)
-               return gf->error = EIO;
-
-       buf[len] = '\0';
-
-       s = strstr(buf, "RPNSWREQ:");
-       if (s)
-               sscanf(s, "RPNSWREQ: %dMHz", &gf->request);
-
-       s = strstr(buf, "CAGF:");
-       if (s)
-               sscanf(s, "CAGF: %dMHz", &gf->current);
+       if (gf->fd < 0) {
+               char buf[4096], *s;
+               int fd, len = -1;
+
+               sprintf(buf, "%s/i915_cur_delayinfo", debugfs_dri_path);
+               fd = open(buf, 0);
+               if (fd < 0)
+                       return gf->error = errno;
+
+               len = read(fd, buf, sizeof(buf)-1);
+               close(fd);
+               if (len < 0)
+                       return gf->error = EIO;
+
+               buf[len] = '\0';
+
+               s = strstr(buf, "RPNSWREQ:");
+               if (s)
+                       sscanf(s, "RPNSWREQ: %dMHz", &gf->request);
+
+               s = strstr(buf, "CAGF:");
+               if (s)
+                       sscanf(s, "CAGF: %dMHz", &gf->current);
+       } else {
+               struct gpu_freq_stat *s = &gf->stat[gf->count++&1];
+               struct gpu_freq_stat *d = &gf->stat[gf->count&1];
+               uint64_t data[4], d_time;
+               int len;
+
+               len = read(gf->fd, data, sizeof(data));
+               if (len < 0)
+                       return gf->error = errno;
+
+               s->timestamp = data[1];
+               s->act = data[2];
+               s->req = data[3];
+
+               if (gf->count == 1)
+                       return EAGAIN;
+
+               d_time = s->timestamp - d->timestamp;
+               if (d_time == 0) {
+                       gf->count--;
+                       return EAGAIN;
+               }
+
+               gf->current = (s->act - d->act) / d_time;
+               gf->request = (s->req - d->req) / d_time;
+       }
 
        return 0;
 }

diff --git a/overlay/gpu-freq.h b/overlay/gpu-freq.h
index d78aa1b..cdd2bb6 100644 (file)
--- a/overlay/gpu-freq.h
+++ b/overlay/gpu-freq.h
@@ -25,7 +25,15 @@
 #ifndef GPU_FREQ_H
 #define GPU_FREQ_H
 
+#include <stdint.h>
+
 struct gpu_freq {
+       struct gpu_freq_stat {
+               uint64_t act, req;
+               uint64_t timestamp;
+       } stat[2];
+       int fd;
+       int count;
        int min, max;
        int rpn, rp1, rp0;
        int request;