drm/fence: add out-fences support
authorGustavo Padovan <gustavo.padovan@collabora.co.uk>
Wed, 16 Nov 2016 13:00:21 +0000 (22:00 +0900)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Wed, 16 Nov 2016 13:36:27 +0000 (14:36 +0100)
Support DRM out-fences by creating a sync_file with a fence for each CRTC
that sets the OUT_FENCE_PTR property.

We use the out_fence pointer received in the OUT_FENCE_PTR prop to send
the sync_file fd back to userspace.

The sync_file and fd are allocated/created before commit, but the
fd_install operation only happens after we know that commit succeed.

v2: Comment by Rob Clark:
- Squash commit that adds DRM_MODE_ATOMIC_OUT_FENCE flag here.

    Comment by Daniel Vetter:
- Add clean up code for out_fences

v3: Comments by Daniel Vetter:
- create DRM_MODE_ATOMIC_EVENT_MASK
- userspace should fill out_fences_ptr with the crtc_ids for which
it wants fences back.

v4: Create OUT_FENCE_PTR properties and remove old approach.

v5: Comments by Brian Starkey:
- Remove extra fence_get() in atomic_ioctl()
- Check ret before iterating on the crtc_state
- check ret before fd_install
- set fence_state to NULL at the beginning
- check fence_state->out_fence_ptr before put_user()
- change order of fput() and put_unused_fd() on failure

     - Add access_ok() check to the out_fence_ptr received
     - Rebase after fence -> dma_fence rename
     - Store out_fence_ptr in the drm_atomic_state
     - Split crtc_setup_out_fence()
     - return -1 as out_fence with TEST_ONLY flag

v6: Comments by Daniel Vetter
- Add prepare/unprepare_crtc_signaling()
- move struct drm_out_fence_state to drm_atomic.c
- mark get_crtc_fence() as static

    Comments by Brian Starkey
- proper set fence_ptr fence_state array
- isolate fence_idx increment

    - improve error handling

v7: Comments by Daniel Vetter
- remove prefix from internal functions
- make out_fence_ptr an s64 pointer
- degrade DRM_INFO to DRM_DEBUG_ATOMIC when put_user fail
- fix doc issues
- filter out OUT_FENCE_PTR == NULL and do not fail in this case
- add complete_crtc_signalling()
- krealloc fence_state on demand

    Comment by Brian Starkey
- remove unused crtc_state arg from get_out_fence()

v8: Comment by Brian Starkey
- cancel events before check for !fence_state
- convert a few lefovers u64 types for out_fence_ptr
- fix memleak by assign fence_state earlier after realloc
- proper accout num_fences in case of error

v9: Comment by Brian Starkey
- memset last position of fence_state after krealloc
    Comments by Sean Paul
- pass install_fds in complete_crtc_signaling() instead of ret

     - put_user(-1, fence_ptr) when decoding props

v10: Comment by Brian Starkey
- remove unneeded num_fences increment on error path
- kfree fence_state after installing fences fd

v11: rebase against latest drm-misc

v12: rebase again against latest drm-misc

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Brian Starkey <brian.starkey@arm.com> (v10)
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Robert Foss <robert.foss@collabora.com> (v10)
[danvet: Appease checkpatch.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1479301221-13056-1-git-send-email-gustavo@padovan.org
drivers/gpu/drm/drm_atomic.c
drivers/gpu/drm/drm_crtc.c
drivers/gpu/drm/drm_mode_config.c
include/drm/drm_atomic.h
include/drm/drm_mode_config.h

index 3ad780a..b476ec5 100644 (file)
@@ -290,6 +290,23 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state,
 }
 EXPORT_SYMBOL(drm_atomic_get_crtc_state);
 
+static void set_out_fence_for_crtc(struct drm_atomic_state *state,
+                                  struct drm_crtc *crtc, s64 __user *fence_ptr)
+{
+       state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr;
+}
+
+static s64 __user *get_out_fence_for_crtc(struct drm_atomic_state *state,
+                                         struct drm_crtc *crtc)
+{
+       s64 __user *fence_ptr;
+
+       fence_ptr = state->crtcs[drm_crtc_index(crtc)].out_fence_ptr;
+       state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = NULL;
+
+       return fence_ptr;
+}
+
 /**
  * drm_atomic_set_mode_for_crtc - set mode for CRTC
  * @state: the CRTC whose incoming state to update
@@ -494,6 +511,16 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
                                        &replaced);
                state->color_mgmt_changed |= replaced;
                return ret;
+       } else if (property == config->prop_out_fence_ptr) {
+               s64 __user *fence_ptr = u64_to_user_ptr(val);
+
+               if (!fence_ptr)
+                       return 0;
+
+               if (put_user(-1, fence_ptr))
+                       return -EFAULT;
+
+               set_out_fence_for_crtc(state->state, crtc, fence_ptr);
        } else if (crtc->funcs->atomic_set_property)
                return crtc->funcs->atomic_set_property(crtc, state, property, val);
        else
@@ -536,6 +563,8 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc,
                *val = (state->ctm) ? state->ctm->base.id : 0;
        else if (property == config->gamma_lut_property)
                *val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
+       else if (property == config->prop_out_fence_ptr)
+               *val = 0;
        else if (crtc->funcs->atomic_get_property)
                return crtc->funcs->atomic_get_property(crtc, state, property, val);
        else
@@ -1664,11 +1693,9 @@ int drm_atomic_debugfs_init(struct drm_minor *minor)
  */
 
 static struct drm_pending_vblank_event *create_vblank_event(
-               struct drm_device *dev, struct drm_file *file_priv,
-               struct dma_fence *fence, uint64_t user_data)
+               struct drm_device *dev, uint64_t user_data)
 {
        struct drm_pending_vblank_event *e = NULL;
-       int ret;
 
        e = kzalloc(sizeof *e, GFP_KERNEL);
        if (!e)
@@ -1678,17 +1705,6 @@ static struct drm_pending_vblank_event *create_vblank_event(
        e->event.base.length = sizeof(e->event);
        e->event.user_data = user_data;
 
-       if (file_priv) {
-               ret = drm_event_reserve_init(dev, file_priv, &e->base,
-                                            &e->event.base);
-               if (ret) {
-                       kfree(e);
-                       return NULL;
-               }
-       }
-
-       e->base.fence = fence;
-
        return e;
 }
 
@@ -1793,6 +1809,165 @@ void drm_atomic_clean_old_fb(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_atomic_clean_old_fb);
 
+static struct dma_fence *get_crtc_fence(struct drm_crtc *crtc)
+{
+       struct dma_fence *fence;
+
+       fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+       if (!fence)
+               return NULL;
+
+       dma_fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock,
+                      crtc->fence_context, ++crtc->fence_seqno);
+
+       return fence;
+}
+
+struct drm_out_fence_state {
+       s64 __user *out_fence_ptr;
+       struct sync_file *sync_file;
+       int fd;
+};
+
+static int setup_out_fence(struct drm_out_fence_state *fence_state,
+                          struct dma_fence *fence)
+{
+       fence_state->fd = get_unused_fd_flags(O_CLOEXEC);
+       if (fence_state->fd < 0)
+               return fence_state->fd;
+
+       if (put_user(fence_state->fd, fence_state->out_fence_ptr))
+               return -EFAULT;
+
+       fence_state->sync_file = sync_file_create(fence);
+       if (!fence_state->sync_file)
+               return -ENOMEM;
+
+       return 0;
+}
+
+static int prepare_crtc_signaling(struct drm_device *dev,
+                                 struct drm_atomic_state *state,
+                                 struct drm_mode_atomic *arg,
+                                 struct drm_file *file_priv,
+                                 struct drm_out_fence_state **fence_state,
+                                 unsigned int *num_fences)
+{
+       struct drm_crtc *crtc;
+       struct drm_crtc_state *crtc_state;
+       int i, ret;
+
+       if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY)
+               return 0;
+
+       for_each_crtc_in_state(state, crtc, crtc_state, i) {
+               u64 __user *fence_ptr;
+
+               fence_ptr = get_out_fence_for_crtc(crtc_state->state, crtc);
+
+               if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) {
+                       struct drm_pending_vblank_event *e;
+
+                       e = create_vblank_event(dev, arg->user_data);
+                       if (!e)
+                               return -ENOMEM;
+
+                       crtc_state->event = e;
+               }
+
+               if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
+                       struct drm_pending_vblank_event *e = crtc_state->event;
+
+                       if (!file_priv)
+                               continue;
+
+                       ret = drm_event_reserve_init(dev, file_priv, &e->base,
+                                                    &e->event.base);
+                       if (ret) {
+                               kfree(e);
+                               crtc_state->event = NULL;
+                               return ret;
+                       }
+               }
+
+               if (fence_ptr) {
+                       struct dma_fence *fence;
+                       struct drm_out_fence_state *f;
+
+                       f = krealloc(*fence_state, sizeof(**fence_state) *
+                                    (*num_fences + 1), GFP_KERNEL);
+                       if (!f)
+                               return -ENOMEM;
+
+                       memset(&f[*num_fences], 0, sizeof(*f));
+
+                       f[*num_fences].out_fence_ptr = fence_ptr;
+                       *fence_state = f;
+
+                       fence = get_crtc_fence(crtc);
+                       if (!fence)
+                               return -ENOMEM;
+
+                       ret = setup_out_fence(&f[(*num_fences)++], fence);
+                       if (ret) {
+                               dma_fence_put(fence);
+                               return ret;
+                       }
+
+                       crtc_state->event->base.fence = fence;
+               }
+       }
+
+       return 0;
+}
+
+static void complete_crtc_signaling(struct drm_device *dev,
+                                   struct drm_atomic_state *state,
+                                   struct drm_out_fence_state *fence_state,
+                                   unsigned int num_fences,
+                                   bool install_fds)
+{
+       struct drm_crtc *crtc;
+       struct drm_crtc_state *crtc_state;
+       int i;
+
+       if (install_fds) {
+               for (i = 0; i < num_fences; i++)
+                       fd_install(fence_state[i].fd,
+                                  fence_state[i].sync_file->file);
+
+               kfree(fence_state);
+               return;
+       }
+
+       for_each_crtc_in_state(state, crtc, crtc_state, i) {
+               /*
+                * TEST_ONLY and PAGE_FLIP_EVENT are mutually
+                * exclusive, if they weren't, this code should be
+                * called on success for TEST_ONLY too.
+                */
+               if (crtc_state->event)
+                       drm_event_cancel_free(dev, &crtc_state->event->base);
+       }
+
+       if (!fence_state)
+               return;
+
+       for (i = 0; i < num_fences; i++) {
+               if (fence_state[i].sync_file)
+                       fput(fence_state[i].sync_file->file);
+               if (fence_state[i].fd >= 0)
+                       put_unused_fd(fence_state[i].fd);
+
+               /* If this fails log error to the user */
+               if (fence_state[i].out_fence_ptr &&
+                   put_user(-1, fence_state[i].out_fence_ptr))
+                       DRM_DEBUG_ATOMIC("Couldn't clear out_fence_ptr\n");
+       }
+
+       kfree(fence_state);
+}
+
 int drm_mode_atomic_ioctl(struct drm_device *dev,
                          void *data, struct drm_file *file_priv)
 {
@@ -1805,11 +1980,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
        struct drm_atomic_state *state;
        struct drm_modeset_acquire_ctx ctx;
        struct drm_plane *plane;
-       struct drm_crtc *crtc;
-       struct drm_crtc_state *crtc_state;
+       struct drm_out_fence_state *fence_state = NULL;
        unsigned plane_mask;
        int ret = 0;
-       unsigned int i, j;
+       unsigned int i, j, num_fences = 0;
 
        /* disallow for drivers not supporting atomic: */
        if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
@@ -1924,20 +2098,10 @@ retry:
                drm_mode_object_unreference(obj);
        }
 
-       if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
-               for_each_crtc_in_state(state, crtc, crtc_state, i) {
-                       struct drm_pending_vblank_event *e;
-
-                       e = create_vblank_event(dev, file_priv, NULL,
-                                               arg->user_data);
-                       if (!e) {
-                               ret = -ENOMEM;
-                               goto out;
-                       }
-
-                       crtc_state->event = e;
-               }
-       }
+       ret = prepare_crtc_signaling(dev, state, arg, file_priv, &fence_state,
+                                    &num_fences);
+       if (ret)
+               goto out;
 
        if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
                /*
@@ -1957,20 +2121,7 @@ retry:
 out:
        drm_atomic_clean_old_fb(dev, plane_mask, ret);
 
-       if (ret && arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
-               /*
-                * TEST_ONLY and PAGE_FLIP_EVENT are mutually exclusive,
-                * if they weren't, this code should be called on success
-                * for TEST_ONLY too.
-                */
-
-               for_each_crtc_in_state(state, crtc, crtc_state, i) {
-                       if (!crtc_state->event)
-                               continue;
-
-                       drm_event_cancel_free(dev, &crtc_state->event->base);
-               }
-       }
+       complete_crtc_signaling(dev, state, fence_state, num_fences, !ret);
 
        if (ret == -EDEADLK) {
                drm_atomic_state_clear(state);
index dbfae42..90931e0 100644 (file)
@@ -267,6 +267,8 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
        if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
                drm_object_attach_property(&crtc->base, config->prop_active, 0);
                drm_object_attach_property(&crtc->base, config->prop_mode_id, 0);
+               drm_object_attach_property(&crtc->base,
+                                          config->prop_out_fence_ptr, 0);
        }
 
        return 0;
index 8bee2ad..2735a58 100644 (file)
@@ -314,6 +314,12 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
                return -ENOMEM;
        dev->mode_config.prop_in_fence_fd = prop;
 
+       prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
+                       "OUT_FENCE_PTR", 0, U64_MAX);
+       if (!prop)
+               return -ENOMEM;
+       dev->mode_config.prop_out_fence_ptr = prop;
+
        prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
                        "CRTC_ID", DRM_MODE_OBJECT_CRTC);
        if (!prop)
index 331bb10..c0eaec7 100644 (file)
@@ -144,6 +144,7 @@ struct __drm_crtcs_state {
        struct drm_crtc *ptr;
        struct drm_crtc_state *state;
        struct drm_crtc_commit *commit;
+       s64 __user *out_fence_ptr;
 };
 
 struct __drm_connnectors_state {
index c6754cc..bf9991b 100644 (file)
@@ -485,6 +485,12 @@ struct drm_mode_config {
         * for a Plane.
         */
        struct drm_property *prop_in_fence_fd;
+       /**
+        * @prop_out_fence_ptr: Sync File fd pointer representing the
+        * outgoing fences for a CRTC. Userspace should provide a pointer to a
+        * value of type s64, and then cast that pointer to u64.
+        */
+       struct drm_property *prop_out_fence_ptr;
        /**
         * @prop_crtc_id: Default atomic plane property to specify the
         * &drm_crtc.