drm/i915: advertise available metrics via sysfs

Each metric set is given a sysfs entry like:

/sys/class/drm/card0/metrics/<guid>/id

This allows userspace to enumerate the specific sets that are available
for the current system. The 'id' file contains an unsigned integer that
can be used to open the associated metric set via
DRM_IOCTL_I915_PERF_OPEN. The <guid> is a globally unique ID for a
specific OA unit register configuration that can be reliably used by
userspace as a key to lookup corresponding counter meta data and
normalization equations.

The guid registry is currently maintained as part of gputop along with
the XML metric set descriptions and code generation scripts, ref:

 https://github.com/rib/gputop
 > gputop-data/guids.xml
 > scripts/update-guids.py
 > gputop-data/oa-*.xml
 > scripts/i915-perf-kernelgen.py

 $ make -C gputop-data -f Makefile.xml SYSFS=1 WHITELIST=RenderBasic

Signed-off-by: Robert Bragg <robert@sixbynine.org>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Sourab Gupta <sourab.gupta@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161107194957.3385-8-robert@sixbynine.org

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 94a9fb0f7b39f658cfb6617c4582d0258a17268e..ff13503eae08d86ecfdd315ac256a5eda6cf05eb 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1129,6 +1129,9 @@ static void i915_driver_register(struct drm_i915_private *dev_priv)
                i915_debugfs_register(dev_priv);
                i915_guc_register(dev_priv);
                i915_setup_sysfs(dev_priv);
+
+               /* Depends on sysfs having been initialized */
+               i915_perf_register(dev_priv);
        } else
                DRM_ERROR("Failed to register driver for userspace access!\n");
 
@@ -1165,6 +1168,8 @@ static void i915_driver_unregister(struct drm_i915_private *dev_priv)
        acpi_video_unregister();
        intel_opregion_unregister(dev_priv);
 
+       i915_perf_unregister(dev_priv);
+
        i915_teardown_sysfs(dev_priv);
        i915_guc_unregister(dev_priv);
        i915_debugfs_unregister(dev_priv);

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3a69e219c7a2806827828ae190d89960ad509ae6..8da752304a9196cc815649eff125005aab920cc8 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2193,6 +2193,8 @@ struct drm_i915_private {
        struct {
                bool initialized;
 
+               struct kobject *metrics_kobj;
+
                struct mutex lock;
                struct list_head streams;
 
@@ -3533,6 +3535,8 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine,
 /* i915_perf.c */
 extern void i915_perf_init(struct drm_i915_private *dev_priv);
 extern void i915_perf_fini(struct drm_i915_private *dev_priv);
+extern void i915_perf_register(struct drm_i915_private *dev_priv);
+extern void i915_perf_unregister(struct drm_i915_private *dev_priv);
 
 /* i915_suspend.c */
 extern int i915_save_state(struct drm_device *dev);

diff --git a/drivers/gpu/drm/i915/i915_oa_hsw.c b/drivers/gpu/drm/i915/i915_oa_hsw.c
index 8906380d9177f518f61f276825f844e1630bbb34..6af25cfefc2227789e6c2f5ae45190f08fdd09fe 100644 (file)
--- a/drivers/gpu/drm/i915/i915_oa_hsw.c
+++ b/drivers/gpu/drm/i915/i915_oa_hsw.c
@@ -24,6 +24,8 @@
  *
  */
 
+#include <linux/sysfs.h>
+
 #include "i915_drv.h"
 #include "i915_oa_hsw.h"
 
@@ -142,3 +144,52 @@ int i915_oa_select_metric_set_hsw(struct drm_i915_private *dev_priv)
                return -ENODEV;
        }
 }
+
+static ssize_t
+show_render_basic_id(struct device *kdev, struct device_attribute *attr, char *buf)
+{
+       return sprintf(buf, "%d\n", METRIC_SET_ID_RENDER_BASIC);
+}
+
+static struct device_attribute dev_attr_render_basic_id = {
+       .attr = { .name = "id", .mode = 0444 },
+       .show = show_render_basic_id,
+       .store = NULL,
+};
+
+static struct attribute *attrs_render_basic[] = {
+       &dev_attr_render_basic_id.attr,
+       NULL,
+};
+
+static struct attribute_group group_render_basic = {
+       .name = "403d8832-1a27-4aa6-a64e-f5389ce7b212",
+       .attrs =  attrs_render_basic,
+};
+
+int
+i915_perf_register_sysfs_hsw(struct drm_i915_private *dev_priv)
+{
+       int mux_len;
+       int ret = 0;
+
+       if (get_render_basic_mux_config(dev_priv, &mux_len)) {
+               ret = sysfs_create_group(dev_priv->perf.metrics_kobj, &group_render_basic);
+               if (ret)
+                       goto error_render_basic;
+       }
+
+       return 0;
+
+error_render_basic:
+       return ret;
+}
+
+void
+i915_perf_unregister_sysfs_hsw(struct drm_i915_private *dev_priv)
+{
+       int mux_len;
+
+       if (get_render_basic_mux_config(dev_priv, &mux_len))
+               sysfs_remove_group(dev_priv->perf.metrics_kobj, &group_render_basic);
+}

diff --git a/drivers/gpu/drm/i915/i915_oa_hsw.h b/drivers/gpu/drm/i915/i915_oa_hsw.h
index b618a1f0aa94d7c25f79ca2df0cba67ba2b54942..429a229b5158e4e03990c89a0f6ac0a73cf260bf 100644 (file)
--- a/drivers/gpu/drm/i915/i915_oa_hsw.h
+++ b/drivers/gpu/drm/i915/i915_oa_hsw.h
@@ -31,4 +31,8 @@ extern int i915_oa_n_builtin_metric_sets_hsw;
 
 extern int i915_oa_select_metric_set_hsw(struct drm_i915_private *dev_priv);
 
+extern int i915_perf_register_sysfs_hsw(struct drm_i915_private *dev_priv);
+
+extern void i915_perf_unregister_sysfs_hsw(struct drm_i915_private *dev_priv);
+
 #endif

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 54653bcf0d7943772a49db97032b93cc839e1d22..c427cd8cbe1bdb1d6d002153ba0461b793c43f51 100644 (file)
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -812,6 +812,15 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
        int format_size;
        int ret;
 
+       /* If the sysfs metrics/ directory wasn't registered for some
+        * reason then don't let userspace try their luck with config
+        * IDs
+        */
+       if (!dev_priv->perf.metrics_kobj) {
+               DRM_ERROR("OA metrics weren't advertised via sysfs\n");
+               return -EINVAL;
+       }
+
        if (!(props->sample_flags & SAMPLE_OA_REPORT)) {
                DRM_ERROR("Only OA report sampling supported\n");
                return -EINVAL;
@@ -1408,6 +1417,49 @@ int i915_perf_open_ioctl(struct drm_device *dev, void *data,
        return ret;
 }
 
+void i915_perf_register(struct drm_i915_private *dev_priv)
+{
+       if (!IS_HASWELL(dev_priv))
+               return;
+
+       if (!dev_priv->perf.initialized)
+               return;
+
+       /* To be sure we're synchronized with an attempted
+        * i915_perf_open_ioctl(); considering that we register after
+        * being exposed to userspace.
+        */
+       mutex_lock(&dev_priv->perf.lock);
+
+       dev_priv->perf.metrics_kobj =
+               kobject_create_and_add("metrics",
+                                      &dev_priv->drm.primary->kdev->kobj);
+       if (!dev_priv->perf.metrics_kobj)
+               goto exit;
+
+       if (i915_perf_register_sysfs_hsw(dev_priv)) {
+               kobject_put(dev_priv->perf.metrics_kobj);
+               dev_priv->perf.metrics_kobj = NULL;
+       }
+
+exit:
+       mutex_unlock(&dev_priv->perf.lock);
+}
+
+void i915_perf_unregister(struct drm_i915_private *dev_priv)
+{
+       if (!IS_HASWELL(dev_priv))
+               return;
+
+       if (!dev_priv->perf.metrics_kobj)
+               return;
+
+       i915_perf_unregister_sysfs_hsw(dev_priv);
+
+       kobject_put(dev_priv->perf.metrics_kobj);
+       dev_priv->perf.metrics_kobj = NULL;
+}
+
 void i915_perf_init(struct drm_i915_private *dev_priv)
 {
        if (!IS_HASWELL(dev_priv))