drm/i915: Add i915 perf infrastructure
authorRobert Bragg <robert@sixbynine.org>
Mon, 7 Nov 2016 19:49:47 +0000 (19:49 +0000)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Tue, 22 Nov 2016 13:27:18 +0000 (14:27 +0100)
Adds base i915 perf infrastructure for Gen performance metrics.

This adds a DRM_IOCTL_I915_PERF_OPEN ioctl that takes an array of uint64
properties to configure a stream of metrics and returns a new fd usable
with standard VFS system calls including read() to read typed and sized
records; ioctl() to enable or disable capture and poll() to wait for
data.

A stream is opened something like:

  uint64_t properties[] = {
      /* Single context sampling */
      DRM_I915_PERF_PROP_CTX_HANDLE,        ctx_handle,

      /* Include OA reports in samples */
      DRM_I915_PERF_PROP_SAMPLE_OA,         true,

      /* OA unit configuration */
      DRM_I915_PERF_PROP_OA_METRICS_SET,    metrics_set_id,
      DRM_I915_PERF_PROP_OA_FORMAT,         report_format,
      DRM_I915_PERF_PROP_OA_EXPONENT,       period_exponent,
   };
   struct drm_i915_perf_open_param parm = {
      .flags = I915_PERF_FLAG_FD_CLOEXEC |
               I915_PERF_FLAG_FD_NONBLOCK |
               I915_PERF_FLAG_DISABLED,
      .properties_ptr = (uint64_t)properties,
      .num_properties = sizeof(properties) / 16,
   };
   int fd = drmIoctl(drm_fd, DRM_IOCTL_I915_PERF_OPEN, &param);

Records read all start with a common { type, size } header with
DRM_I915_PERF_RECORD_SAMPLE being of most interest. Sample records
contain an extensible number of fields and it's the
DRM_I915_PERF_PROP_SAMPLE_xyz properties given when opening that
determine what's included in every sample.

No specific streams are supported yet so any attempt to open a stream
will return an error.

v2:
    use i915_gem_context_get() - Chris Wilson
v3:
    update read() interface to avoid passing state struct - Chris Wilson
    fix some rebase fallout, with i915-perf init/deinit
v4:
    s/DRM_IORW/DRM_IOW/ - Emil Velikov

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/20161107194957.3385-2-robert@sixbynine.org
drivers/gpu/drm/i915/Makefile
drivers/gpu/drm/i915/i915_drv.c
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_perf.c [new file with mode: 0644]
include/uapi/drm/i915_drm.h

index 3dea46af9fe6785c5b5543a246b6ab43c9d39f6a..3e40d8f51f90fe4c60b7dfe5659325ce51f25520 100644 (file)
@@ -117,6 +117,9 @@ i915-$(CONFIG_DRM_I915_CAPTURE_ERROR) += i915_gpu_error.o
 # virtual gpu code
 i915-y += i915_vgpu.o
 
+# perf code
+i915-y += i915_perf.o
+
 ifeq ($(CONFIG_DRM_I915_GVT),y)
 i915-y += intel_gvt.o
 include $(src)/gvt/Makefile
index 445fec9c2841ad61282e538d4cfdbe1436e04fb3..94a9fb0f7b39f658cfb6617c4582d0258a17268e 100644 (file)
@@ -848,6 +848,8 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 
        intel_detect_preproduction_hw(dev_priv);
 
+       i915_perf_init(dev_priv);
+
        return 0;
 
 err_gvt:
@@ -863,6 +865,7 @@ err_workqueues:
  */
 static void i915_driver_cleanup_early(struct drm_i915_private *dev_priv)
 {
+       i915_perf_fini(dev_priv);
        i915_gem_load_cleanup(&dev_priv->drm);
        i915_workqueues_cleanup(dev_priv);
 }
@@ -2565,6 +2568,7 @@ static const struct drm_ioctl_desc i915_ioctls[] = {
        DRM_IOCTL_DEF_DRV(I915_GEM_USERPTR, i915_gem_userptr_ioctl, DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_GETPARAM, i915_gem_context_getparam_ioctl, DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_SETPARAM, i915_gem_context_setparam_ioctl, DRM_RENDER_ALLOW),
+       DRM_IOCTL_DEF_DRV(I915_PERF_OPEN, i915_perf_open_ioctl, DRM_RENDER_ALLOW),
 };
 
 static struct drm_driver driver = {
index c7d5f7a30fe80dda57de2d06b9a91629b5057761..b69f8445af7ed79ccf81625afb161e430df70b3c 100644 (file)
@@ -1797,6 +1797,84 @@ struct intel_wm_config {
        bool sprites_scaled;
 };
 
+struct i915_perf_stream;
+
+struct i915_perf_stream_ops {
+       /* Enables the collection of HW samples, either in response to
+        * I915_PERF_IOCTL_ENABLE or implicitly called when stream is
+        * opened without I915_PERF_FLAG_DISABLED.
+        */
+       void (*enable)(struct i915_perf_stream *stream);
+
+       /* Disables the collection of HW samples, either in response to
+        * I915_PERF_IOCTL_DISABLE or implicitly called before
+        * destroying the stream.
+        */
+       void (*disable)(struct i915_perf_stream *stream);
+
+       /* Return: true if any i915 perf records are ready to read()
+        * for this stream.
+        */
+       bool (*can_read)(struct i915_perf_stream *stream);
+
+       /* Call poll_wait, passing a wait queue that will be woken
+        * once there is something ready to read() for the stream
+        */
+       void (*poll_wait)(struct i915_perf_stream *stream,
+                         struct file *file,
+                         poll_table *wait);
+
+       /* For handling a blocking read, wait until there is something
+        * to ready to read() for the stream. E.g. wait on the same
+        * wait queue that would be passed to poll_wait() until
+        * ->can_read() returns true (if its safe to call ->can_read()
+        * without the i915 perf lock held).
+        */
+       int (*wait_unlocked)(struct i915_perf_stream *stream);
+
+       /* read - Copy buffered metrics as records to userspace
+        * @buf: the userspace, destination buffer
+        * @count: the number of bytes to copy, requested by userspace
+        * @offset: zero at the start of the read, updated as the read
+        *          proceeds, it represents how many bytes have been
+        *          copied so far and the buffer offset for copying the
+        *          next record.
+        *
+        * Copy as many buffered i915 perf samples and records for
+        * this stream to userspace as will fit in the given buffer.
+        *
+        * Only write complete records; returning -ENOSPC if there
+        * isn't room for a complete record.
+        *
+        * Return any error condition that results in a short read
+        * such as -ENOSPC or -EFAULT, even though these may be
+        * squashed before returning to userspace.
+        */
+       int (*read)(struct i915_perf_stream *stream,
+                   char __user *buf,
+                   size_t count,
+                   size_t *offset);
+
+       /* Cleanup any stream specific resources.
+        *
+        * The stream will always be disabled before this is called.
+        */
+       void (*destroy)(struct i915_perf_stream *stream);
+};
+
+struct i915_perf_stream {
+       struct drm_i915_private *dev_priv;
+
+       struct list_head link;
+
+       u32 sample_flags;
+
+       struct i915_gem_context *ctx;
+       bool enabled;
+
+       struct i915_perf_stream_ops *ops;
+};
+
 struct drm_i915_private {
        struct drm_device drm;
 
@@ -2092,6 +2170,12 @@ struct drm_i915_private {
 
        struct i915_runtime_pm pm;
 
+       struct {
+               bool initialized;
+               struct mutex lock;
+               struct list_head streams;
+       } perf;
+
        /* Abstract the submission mechanism (legacy ringbuffer or execlists) away */
        struct {
                void (*resume)(struct drm_i915_private *);
@@ -3253,6 +3337,9 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
 int i915_gem_context_reset_stats_ioctl(struct drm_device *dev, void *data,
                                       struct drm_file *file);
 
+int i915_perf_open_ioctl(struct drm_device *dev, void *data,
+                        struct drm_file *file);
+
 /* i915_gem_evict.c */
 int __must_check i915_gem_evict_something(struct i915_address_space *vm,
                                          u64 min_size, u64 alignment,
@@ -3383,6 +3470,10 @@ int intel_engine_cmd_parser(struct intel_engine_cs *engine,
                            u32 batch_len,
                            bool is_master);
 
+/* 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);
+
 /* i915_suspend.c */
 extern int i915_save_state(struct drm_device *dev);
 extern int i915_restore_state(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
new file mode 100644 (file)
index 0000000..777ce65
--- /dev/null
@@ -0,0 +1,449 @@
+/*
+ * Copyright © 2015-2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *   Robert Bragg <robert@sixbynine.org>
+ */
+
+#include <linux/anon_inodes.h>
+
+#include "i915_drv.h"
+
+struct perf_open_properties {
+       u32 sample_flags;
+
+       u64 single_context:1;
+       u64 ctx_handle;
+};
+
+static ssize_t i915_perf_read_locked(struct i915_perf_stream *stream,
+                                    struct file *file,
+                                    char __user *buf,
+                                    size_t count,
+                                    loff_t *ppos)
+{
+       /* Note we keep the offset (aka bytes read) separate from any
+        * error status so that the final check for whether we return
+        * the bytes read with a higher precedence than any error (see
+        * comment below) doesn't need to be handled/duplicated in
+        * stream->ops->read() implementations.
+        */
+       size_t offset = 0;
+       int ret = stream->ops->read(stream, buf, count, &offset);
+
+       /* If we've successfully copied any data then reporting that
+        * takes precedence over any internal error status, so the
+        * data isn't lost.
+        *
+        * For example ret will be -ENOSPC whenever there is more
+        * buffered data than can be copied to userspace, but that's
+        * only interesting if we weren't able to copy some data
+        * because it implies the userspace buffer is too small to
+        * receive a single record (and we never split records).
+        *
+        * Another case with ret == -EFAULT is more of a grey area
+        * since it would seem like bad form for userspace to ask us
+        * to overrun its buffer, but the user knows best:
+        *
+        *   http://yarchive.net/comp/linux/partial_reads_writes.html
+        */
+       return offset ?: (ret ?: -EAGAIN);
+}
+
+static ssize_t i915_perf_read(struct file *file,
+                             char __user *buf,
+                             size_t count,
+                             loff_t *ppos)
+{
+       struct i915_perf_stream *stream = file->private_data;
+       struct drm_i915_private *dev_priv = stream->dev_priv;
+       ssize_t ret;
+
+       if (!(file->f_flags & O_NONBLOCK)) {
+               /* Allow false positives from stream->ops->wait_unlocked.
+                */
+               do {
+                       ret = stream->ops->wait_unlocked(stream);
+                       if (ret)
+                               return ret;
+
+                       mutex_lock(&dev_priv->perf.lock);
+                       ret = i915_perf_read_locked(stream, file,
+                                                   buf, count, ppos);
+                       mutex_unlock(&dev_priv->perf.lock);
+               } while (ret == -EAGAIN);
+       } else {
+               mutex_lock(&dev_priv->perf.lock);
+               ret = i915_perf_read_locked(stream, file, buf, count, ppos);
+               mutex_unlock(&dev_priv->perf.lock);
+       }
+
+       return ret;
+}
+
+static unsigned int i915_perf_poll_locked(struct i915_perf_stream *stream,
+                                         struct file *file,
+                                         poll_table *wait)
+{
+       unsigned int streams = 0;
+
+       stream->ops->poll_wait(stream, file, wait);
+
+       if (stream->ops->can_read(stream))
+               streams |= POLLIN;
+
+       return streams;
+}
+
+static unsigned int i915_perf_poll(struct file *file, poll_table *wait)
+{
+       struct i915_perf_stream *stream = file->private_data;
+       struct drm_i915_private *dev_priv = stream->dev_priv;
+       int ret;
+
+       mutex_lock(&dev_priv->perf.lock);
+       ret = i915_perf_poll_locked(stream, file, wait);
+       mutex_unlock(&dev_priv->perf.lock);
+
+       return ret;
+}
+
+static void i915_perf_enable_locked(struct i915_perf_stream *stream)
+{
+       if (stream->enabled)
+               return;
+
+       /* Allow stream->ops->enable() to refer to this */
+       stream->enabled = true;
+
+       if (stream->ops->enable)
+               stream->ops->enable(stream);
+}
+
+static void i915_perf_disable_locked(struct i915_perf_stream *stream)
+{
+       if (!stream->enabled)
+               return;
+
+       /* Allow stream->ops->disable() to refer to this */
+       stream->enabled = false;
+
+       if (stream->ops->disable)
+               stream->ops->disable(stream);
+}
+
+static long i915_perf_ioctl_locked(struct i915_perf_stream *stream,
+                                  unsigned int cmd,
+                                  unsigned long arg)
+{
+       switch (cmd) {
+       case I915_PERF_IOCTL_ENABLE:
+               i915_perf_enable_locked(stream);
+               return 0;
+       case I915_PERF_IOCTL_DISABLE:
+               i915_perf_disable_locked(stream);
+               return 0;
+       }
+
+       return -EINVAL;
+}
+
+static long i915_perf_ioctl(struct file *file,
+                           unsigned int cmd,
+                           unsigned long arg)
+{
+       struct i915_perf_stream *stream = file->private_data;
+       struct drm_i915_private *dev_priv = stream->dev_priv;
+       long ret;
+
+       mutex_lock(&dev_priv->perf.lock);
+       ret = i915_perf_ioctl_locked(stream, cmd, arg);
+       mutex_unlock(&dev_priv->perf.lock);
+
+       return ret;
+}
+
+static void i915_perf_destroy_locked(struct i915_perf_stream *stream)
+{
+       struct drm_i915_private *dev_priv = stream->dev_priv;
+
+       if (stream->enabled)
+               i915_perf_disable_locked(stream);
+
+       if (stream->ops->destroy)
+               stream->ops->destroy(stream);
+
+       list_del(&stream->link);
+
+       if (stream->ctx) {
+               mutex_lock(&dev_priv->drm.struct_mutex);
+               i915_gem_context_put(stream->ctx);
+               mutex_unlock(&dev_priv->drm.struct_mutex);
+       }
+
+       kfree(stream);
+}
+
+static int i915_perf_release(struct inode *inode, struct file *file)
+{
+       struct i915_perf_stream *stream = file->private_data;
+       struct drm_i915_private *dev_priv = stream->dev_priv;
+
+       mutex_lock(&dev_priv->perf.lock);
+       i915_perf_destroy_locked(stream);
+       mutex_unlock(&dev_priv->perf.lock);
+
+       return 0;
+}
+
+
+static const struct file_operations fops = {
+       .owner          = THIS_MODULE,
+       .llseek         = no_llseek,
+       .release        = i915_perf_release,
+       .poll           = i915_perf_poll,
+       .read           = i915_perf_read,
+       .unlocked_ioctl = i915_perf_ioctl,
+};
+
+
+static struct i915_gem_context *
+lookup_context(struct drm_i915_private *dev_priv,
+              struct drm_i915_file_private *file_priv,
+              u32 ctx_user_handle)
+{
+       struct i915_gem_context *ctx;
+       int ret;
+
+       ret = i915_mutex_lock_interruptible(&dev_priv->drm);
+       if (ret)
+               return ERR_PTR(ret);
+
+       ctx = i915_gem_context_lookup(file_priv, ctx_user_handle);
+       if (!IS_ERR(ctx))
+               i915_gem_context_get(ctx);
+
+       mutex_unlock(&dev_priv->drm.struct_mutex);
+
+       return ctx;
+}
+
+static int
+i915_perf_open_ioctl_locked(struct drm_i915_private *dev_priv,
+                           struct drm_i915_perf_open_param *param,
+                           struct perf_open_properties *props,
+                           struct drm_file *file)
+{
+       struct i915_gem_context *specific_ctx = NULL;
+       struct i915_perf_stream *stream = NULL;
+       unsigned long f_flags = 0;
+       int stream_fd;
+       int ret;
+
+       if (props->single_context) {
+               u32 ctx_handle = props->ctx_handle;
+               struct drm_i915_file_private *file_priv = file->driver_priv;
+
+               specific_ctx = lookup_context(dev_priv, file_priv, ctx_handle);
+               if (IS_ERR(specific_ctx)) {
+                       ret = PTR_ERR(specific_ctx);
+                       if (ret != -EINTR)
+                               DRM_ERROR("Failed to look up context with ID %u for opening perf stream\n",
+                                         ctx_handle);
+                       goto err;
+               }
+       }
+
+       if (!specific_ctx && !capable(CAP_SYS_ADMIN)) {
+               DRM_ERROR("Insufficient privileges to open system-wide i915 perf stream\n");
+               ret = -EACCES;
+               goto err_ctx;
+       }
+
+       stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+       if (!stream) {
+               ret = -ENOMEM;
+               goto err_ctx;
+       }
+
+       stream->sample_flags = props->sample_flags;
+       stream->dev_priv = dev_priv;
+       stream->ctx = specific_ctx;
+
+       /*
+        * TODO: support sampling something
+        *
+        * For now this is as far as we can go.
+        */
+       DRM_ERROR("Unsupported i915 perf stream configuration\n");
+       ret = -EINVAL;
+       goto err_alloc;
+
+       list_add(&stream->link, &dev_priv->perf.streams);
+
+       if (param->flags & I915_PERF_FLAG_FD_CLOEXEC)
+               f_flags |= O_CLOEXEC;
+       if (param->flags & I915_PERF_FLAG_FD_NONBLOCK)
+               f_flags |= O_NONBLOCK;
+
+       stream_fd = anon_inode_getfd("[i915_perf]", &fops, stream, f_flags);
+       if (stream_fd < 0) {
+               ret = stream_fd;
+               goto err_open;
+       }
+
+       if (!(param->flags & I915_PERF_FLAG_DISABLED))
+               i915_perf_enable_locked(stream);
+
+       return stream_fd;
+
+err_open:
+       list_del(&stream->link);
+       if (stream->ops->destroy)
+               stream->ops->destroy(stream);
+err_alloc:
+       kfree(stream);
+err_ctx:
+       if (specific_ctx) {
+               mutex_lock(&dev_priv->drm.struct_mutex);
+               i915_gem_context_put(specific_ctx);
+               mutex_unlock(&dev_priv->drm.struct_mutex);
+       }
+err:
+       return ret;
+}
+
+/* Note we copy the properties from userspace outside of the i915 perf
+ * mutex to avoid an awkward lockdep with mmap_sem.
+ *
+ * Note this function only validates properties in isolation it doesn't
+ * validate that the combination of properties makes sense or that all
+ * properties necessary for a particular kind of stream have been set.
+ */
+static int read_properties_unlocked(struct drm_i915_private *dev_priv,
+                                   u64 __user *uprops,
+                                   u32 n_props,
+                                   struct perf_open_properties *props)
+{
+       u64 __user *uprop = uprops;
+       int i;
+
+       memset(props, 0, sizeof(struct perf_open_properties));
+
+       if (!n_props) {
+               DRM_ERROR("No i915 perf properties given");
+               return -EINVAL;
+       }
+
+       /* Considering that ID = 0 is reserved and assuming that we don't
+        * (currently) expect any configurations to ever specify duplicate
+        * values for a particular property ID then the last _PROP_MAX value is
+        * one greater than the maximum number of properties we expect to get
+        * from userspace.
+        */
+       if (n_props >= DRM_I915_PERF_PROP_MAX) {
+               DRM_ERROR("More i915 perf properties specified than exist");
+               return -EINVAL;
+       }
+
+       for (i = 0; i < n_props; i++) {
+               u64 id, value;
+               int ret;
+
+               ret = get_user(id, uprop);
+               if (ret)
+                       return ret;
+
+               ret = get_user(value, uprop + 1);
+               if (ret)
+                       return ret;
+
+               switch ((enum drm_i915_perf_property_id)id) {
+               case DRM_I915_PERF_PROP_CTX_HANDLE:
+                       props->single_context = 1;
+                       props->ctx_handle = value;
+                       break;
+               default:
+                       MISSING_CASE(id);
+                       DRM_ERROR("Unknown i915 perf property ID");
+                       return -EINVAL;
+               }
+
+               uprop += 2;
+       }
+
+       return 0;
+}
+
+int i915_perf_open_ioctl(struct drm_device *dev, void *data,
+                        struct drm_file *file)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       struct drm_i915_perf_open_param *param = data;
+       struct perf_open_properties props;
+       u32 known_open_flags;
+       int ret;
+
+       if (!dev_priv->perf.initialized) {
+               DRM_ERROR("i915 perf interface not available for this system");
+               return -ENOTSUPP;
+       }
+
+       known_open_flags = I915_PERF_FLAG_FD_CLOEXEC |
+                          I915_PERF_FLAG_FD_NONBLOCK |
+                          I915_PERF_FLAG_DISABLED;
+       if (param->flags & ~known_open_flags) {
+               DRM_ERROR("Unknown drm_i915_perf_open_param flag\n");
+               return -EINVAL;
+       }
+
+       ret = read_properties_unlocked(dev_priv,
+                                      u64_to_user_ptr(param->properties_ptr),
+                                      param->num_properties,
+                                      &props);
+       if (ret)
+               return ret;
+
+       mutex_lock(&dev_priv->perf.lock);
+       ret = i915_perf_open_ioctl_locked(dev_priv, param, &props, file);
+       mutex_unlock(&dev_priv->perf.lock);
+
+       return ret;
+}
+
+void i915_perf_init(struct drm_i915_private *dev_priv)
+{
+       INIT_LIST_HEAD(&dev_priv->perf.streams);
+       mutex_init(&dev_priv->perf.lock);
+
+       dev_priv->perf.initialized = true;
+}
+
+void i915_perf_fini(struct drm_i915_private *dev_priv)
+{
+       if (!dev_priv->perf.initialized)
+               return;
+
+       /* Currently nothing to clean up */
+
+       dev_priv->perf.initialized = false;
+}
index 12003f0d8c7f3dd9d19e5bc72a6f85696f0e9197..192dc1f8256b9722156b96c017d68289a4fe186e 100644 (file)
@@ -258,6 +258,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_GEM_USERPTR           0x33
 #define DRM_I915_GEM_CONTEXT_GETPARAM  0x34
 #define DRM_I915_GEM_CONTEXT_SETPARAM  0x35
+#define DRM_I915_PERF_OPEN             0x36
 
 #define DRM_IOCTL_I915_INIT            DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
 #define DRM_IOCTL_I915_FLUSH           DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -311,6 +312,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_GEM_USERPTR                     DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_USERPTR, struct drm_i915_gem_userptr)
 #define DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM    DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_GETPARAM, struct drm_i915_gem_context_param)
 #define DRM_IOCTL_I915_GEM_CONTEXT_SETPARAM    DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_CONTEXT_SETPARAM, struct drm_i915_gem_context_param)
+#define DRM_IOCTL_I915_PERF_OPEN       DRM_IOW(DRM_COMMAND_BASE + DRM_I915_PERF_OPEN, struct drm_i915_perf_open_param)
 
 /* Allow drivers to submit batchbuffers directly to hardware, relying
  * on the security mechanisms provided by hardware.
@@ -1228,6 +1230,71 @@ struct drm_i915_gem_context_param {
        __u64 value;
 };
 
+enum drm_i915_perf_property_id {
+       /**
+        * Open the stream for a specific context handle (as used with
+        * execbuffer2). A stream opened for a specific context this way
+        * won't typically require root privileges.
+        */
+       DRM_I915_PERF_PROP_CTX_HANDLE = 1,
+
+       DRM_I915_PERF_PROP_MAX /* non-ABI */
+};
+
+struct drm_i915_perf_open_param {
+       __u32 flags;
+#define I915_PERF_FLAG_FD_CLOEXEC      (1<<0)
+#define I915_PERF_FLAG_FD_NONBLOCK     (1<<1)
+#define I915_PERF_FLAG_DISABLED                (1<<2)
+
+       /** The number of u64 (id, value) pairs */
+       __u32 num_properties;
+
+       /**
+        * Pointer to array of u64 (id, value) pairs configuring the stream
+        * to open.
+        */
+       __u64 __user properties_ptr;
+};
+
+#define I915_PERF_IOCTL_ENABLE _IO('i', 0x0)
+#define I915_PERF_IOCTL_DISABLE        _IO('i', 0x1)
+
+/**
+ * Common to all i915 perf records
+ */
+struct drm_i915_perf_record_header {
+       __u32 type;
+       __u16 pad;
+       __u16 size;
+};
+
+enum drm_i915_perf_record_type {
+
+       /**
+        * Samples are the work horse record type whose contents are extensible
+        * and defined when opening an i915 perf stream based on the given
+        * properties.
+        *
+        * Boolean properties following the naming convention
+        * DRM_I915_PERF_SAMPLE_xyz_PROP request the inclusion of 'xyz' data in
+        * every sample.
+        *
+        * The order of these sample properties given by userspace has no
+        * affect on the ordering of data within a sample. The order will be
+        * documented here.
+        *
+        * struct {
+        *     struct drm_i915_perf_record_header header;
+        *
+        *     TODO: itemize extensible sample data here
+        * };
+        */
+       DRM_I915_PERF_RECORD_SAMPLE = 1,
+
+       DRM_I915_PERF_RECORD_MAX /* non-ABI */
+};
+
 #if defined(__cplusplus)
 }
 #endif