Hi Gustavo, On Fri, Nov 11, 2016 at 02:16:09PM +0900, Gustavo Padovan wrote:
From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx> 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 fail in this case
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() Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx>
From an integration with writeback point of view, this looks fine to me - I can add writeback to this easily. A few comments below though:
--- drivers/gpu/drm/drm_atomic.c | 242 +++++++++++++++++++++++++++++++++++-------- drivers/gpu/drm/drm_crtc.c | 8 ++ include/drm/drm_atomic.h | 1 + include/drm/drm_crtc.h | 6 ++ 4 files changed, 212 insertions(+), 45 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 8e26ad1..cd39f13 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -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, u64 __user *fence_ptr) +{ + state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr; +} + +static u64 __user * get_out_fence_for_crtc(struct drm_atomic_state *state, + struct drm_crtc *crtc) +{ + u64 __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; +} +
You missed a couple of s/u64/s64/ in the two functions above.
/** * drm_atomic_set_mode_for_crtc - set mode for CRTC * @state: the CRTC whose incoming state to update @@ -491,6 +508,16 @@ 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 (!access_ok(VERIFY_WRITE, fence_ptr, sizeof(*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 @@ -533,6 +560,8 @@ 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 @@ -1659,11 +1688,9 @@ 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) @@ -1673,17 +1700,6 @@ 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; } @@ -1788,6 +1804,166 @@ 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; + + 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_ATOMIC_TEST_ONLY && fence_ptr) { + if (put_user(-1, fence_ptr)) + return -EFAULT; + + continue; + } + + 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; + + f[*num_fences].out_fence_ptr = fence_ptr; + + 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; + }
Looks to me that the cleanup path doesn't work here. If setup_out_fence fails, you bail out before incrementing num_fences, and so the cleanup loop will be an iteration short.
+ + (*num_fences)++; + + *fence_state = f;
I think this is problematic too. If I understand krealloc right, when you bail out before here and f != *fence_state, then the old *fence_state will have been already freed, and f is going to leak.
+ 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, int ret) +{ + struct drm_crtc *crtc; + struct drm_crtc_state *crtc_state; + int i; + + if (!ret) { + for (i = 0; i < num_fences; i++) + fd_install(fence_state[i].fd, + fence_state[i].sync_file->file); + return; + } + + if (!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); + }
I think this event cleanup needs to be before the !fence_state check; userspace can ask for events but no fences, and if that fails then the events need to be freed. Cheers, -Brian
+ + 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) { @@ -1800,11 +1976,10 @@ 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)) @@ -1919,20 +2094,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, 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) { /* @@ -1952,20 +2117,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, 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); diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 9b9881b..e8bc1ae 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -274,6 +274,8 @@ 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; @@ -434,6 +436,12 @@ 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) diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index 331bb10..c0eaec7 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -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 { diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 0870de1..44571bc 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -1264,6 +1264,12 @@ struct drm_mode_config { */ 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. */ -- 2.5.5
_______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel