4 files changed, 99 insertions, 8 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index f47adb4aa59a..250999cdf814 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1616,6 +1616,7 @@ struct drm_ioctl_desc i915_ioctls[] = {
         DRM_IOCTL_DEF(DRM_I915_GEM_GET_TILING, i915_gem_get_tiling, 0),
         DRM_IOCTL_DEF(DRM_I915_GEM_GET_APERTURE, i915_gem_get_aperture_ioctl, 0),
         DRM_IOCTL_DEF(DRM_I915_GET_PIPE_FROM_CRTC_ID, intel_get_pipe_from_crtc_id, 0),
+        DRM_IOCTL_DEF(DRM_I915_GEM_MADVISE, i915_gem_madvise_ioctl, 0),
 };
 
 int i915_max_ioctl = DRM_ARRAY_SIZE(i915_ioctls);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index bbcf5fc72666..2f89c2136be9 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -566,6 +566,11 @@ struct drm_i915_gem_object {
          * in an execbuffer object list.
          */
         int in_execbuffer;
+
+        /**
+         * Advice: are the backing pages purgeable?
+         */
+        int madv;
 };
 
 /**
@@ -705,6 +710,8 @@ int i915_gem_busy_ioctl(struct drm_device *dev, void *data,
                         struct drm_file *file_priv);
 int i915_gem_throttle_ioctl(struct drm_device *dev, void *data,
                             struct drm_file *file_priv);
+int i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
+                           struct drm_file *file_priv);
 int i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
                            struct drm_file *file_priv);
 int i915_gem_leavevt_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 2fff2e0a976e..2ab30f251943 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1436,13 +1436,21 @@ i915_gem_object_put_pages(struct drm_gem_object *obj)
         if (obj_priv->tiling_mode != I915_TILING_NONE)
                 i915_gem_object_save_bit_17_swizzle(obj);
 
-        for (i = 0; i < page_count; i++)
-                if (obj_priv->pages[i] != NULL) {
-                        if (obj_priv->dirty)
-                                set_page_dirty(obj_priv->pages[i]);
-                        mark_page_accessed(obj_priv->pages[i]);
-                        page_cache_release(obj_priv->pages[i]);
-                }
+        if (obj_priv->madv == I915_MADV_DONTNEED)
+            obj_priv->dirty = 0;
+
+        for (i = 0; i < page_count; i++) {
+                if (obj_priv->pages[i] == NULL)
+                        break;
+
+                if (obj_priv->dirty)
+                        set_page_dirty(obj_priv->pages[i]);
+
+                if (obj_priv->madv == I915_MADV_WILLNEED)
+                    mark_page_accessed(obj_priv->pages[i]);
+
+                page_cache_release(obj_priv->pages[i]);
+        }
         obj_priv->dirty = 0;
 
         drm_free_large(obj_priv->pages);
@@ -2412,6 +2420,12 @@ i915_gem_object_bind_to_gtt(struct drm_gem_object *obj, unsigned alignment)
 
         if (dev_priv->mm.suspended)
                 return -EBUSY;
+
+        if (obj_priv->madv == I915_MADV_DONTNEED) {
+                DRM_ERROR("Attempting to bind a purgeable object\n");
+                return -EINVAL;
+        }
+
         if (alignment == 0)
                 alignment = i915_gem_get_gtt_alignment(obj);
         if (alignment & (i915_gem_get_gtt_alignment(obj) - 1)) {
@@ -3679,6 +3693,13 @@ i915_gem_pin_ioctl(struct drm_device *dev, void *data,
         }
         obj_priv = obj->driver_private;
 
+        if (obj_priv->madv == I915_MADV_DONTNEED) {
+                DRM_ERROR("Attempting to pin a I915_MADV_DONTNEED buffer\n");
+                drm_gem_object_unreference(obj);
+                mutex_unlock(&dev->struct_mutex);
+                return -EINVAL;
+        }
+
         if (obj_priv->pin_filp != NULL && obj_priv->pin_filp != file_priv) {
                 DRM_ERROR("Already pinned in i915_gem_pin_ioctl(): %d\n",
                           args->handle);
@@ -3791,6 +3812,49 @@ i915_gem_throttle_ioctl(struct drm_device *dev, void *data,
     return i915_gem_ring_throttle(dev, file_priv);
 }
 
+int
+i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
+                       struct drm_file *file_priv)
+{
+        struct drm_i915_gem_madvise *args = data;
+        struct drm_gem_object *obj;
+        struct drm_i915_gem_object *obj_priv;
+
+        switch (args->madv) {
+        case I915_MADV_DONTNEED:
+        case I915_MADV_WILLNEED:
+            break;
+        default:
+            return -EINVAL;
+        }
+
+        obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+        if (obj == NULL) {
+                DRM_ERROR("Bad handle in i915_gem_madvise_ioctl(): %d\n",
+                          args->handle);
+                return -EBADF;
+        }
+
+        mutex_lock(&dev->struct_mutex);
+        obj_priv = obj->driver_private;
+
+        if (obj_priv->pin_count) {
+                drm_gem_object_unreference(obj);
+                mutex_unlock(&dev->struct_mutex);
+
+                DRM_ERROR("Attempted i915_gem_madvise_ioctl() on a pinned object\n");
+                return -EINVAL;
+        }
+
+        obj_priv->madv = args->madv;
+        args->retained = obj_priv->gtt_space != NULL;
+
+        drm_gem_object_unreference(obj);
+        mutex_unlock(&dev->struct_mutex);
+
+        return 0;
+}
+
 int i915_gem_init_object(struct drm_gem_object *obj)
 {
         struct drm_i915_gem_object *obj_priv;
@@ -3815,6 +3879,7 @@ int i915_gem_init_object(struct drm_gem_object *obj)
         obj_priv->fence_reg = I915_FENCE_REG_NONE;
         INIT_LIST_HEAD(&obj_priv->list);
         INIT_LIST_HEAD(&obj_priv->fence_list);
+        obj_priv->madv = I915_MADV_WILLNEED;
 
         return 0;
 }
@@ -4506,7 +4571,7 @@ i915_gem_object_truncate(struct drm_gem_object *obj)
 static inline int
 i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj_priv)
 {
-        return !obj_priv->dirty;
+        return !obj_priv->dirty || obj_priv->madv == I915_MADV_DONTNEED;
 }
 
 static int
diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
index 8e1e92583fbc..607c9da061e8 100644
--- a/include/drm/i915_drm.h
+++ b/include/drm/i915_drm.h
@@ -185,6 +185,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_GEM_GET_APERTURE 0x23
 #define DRM_I915_GEM_MMAP_GTT   0x24
 #define DRM_I915_GET_PIPE_FROM_CRTC_ID  0x25
+#define DRM_I915_GEM_MADVISE    0x26
 
 #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)
@@ -221,6 +222,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_GEM_GET_TILING   DRM_IOWR (DRM_COMMAND_BASE + DRM_I915_GEM_GET_TILING, struct drm_i915_gem_get_tiling)
 #define DRM_IOCTL_I915_GEM_GET_APERTURE DRM_IOR  (DRM_COMMAND_BASE + DRM_I915_GEM_GET_APERTURE, struct drm_i915_gem_get_aperture)
 #define DRM_IOCTL_I915_GET_PIPE_FROM_CRTC_ID DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GET_PIPE_FROM_CRTC_ID, struct drm_intel_get_pipe_from_crtc_id)
+#define DRM_IOCTL_I915_GEM_MADVISE      DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_MADVISE, struct drm_i915_gem_madvise)
 
 /* Allow drivers to submit batchbuffers directly to hardware, relying
  * on the security mechanisms provided by hardware.
@@ -667,4 +669,20 @@ struct drm_i915_get_pipe_from_crtc_id {
         __u32 pipe;
 };
 
+#define I915_MADV_WILLNEED 0
+#define I915_MADV_DONTNEED 1
+
+struct drm_i915_gem_madvise {
+        /** Handle of the buffer to change the backing store advice */
+        __u32 handle;
+
+        /* Advice: either the buffer will be needed again in the near future,
+         *         or wont be and could be discarded under memory pressure.
+         */
+        __u32 madv;
+
+        /** Whether the backing store still exists. */
+        __u32 retained;
+};
+
 #endif                          /* _I915_DRM_H_ */