Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756093AbcKKLlW (ORCPT ); Fri, 11 Nov 2016 06:41:22 -0500 Received: from foss.arm.com ([217.140.101.70]:41006 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751606AbcKKLlU (ORCPT ); Fri, 11 Nov 2016 06:41:20 -0500 Date: Fri, 11 Nov 2016 11:41:16 +0000 From: Brian Starkey To: Gustavo Padovan Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Daniel Stone , Daniel Vetter , Rob Clark , Greg Hackmann , John Harrison , laurent.pinchart@ideasonboard.com, seanpaul@google.com, marcheu@google.com, m.chehab@samsung.com, Maarten Lankhorst , Gustavo Padovan Subject: Re: [PATCH v8 3/3] drm/fence: add out-fences support Message-ID: <20161111114115.GB26660@e106950-lin.cambridge.arm.com> References: <1478841369-20826-1-git-send-email-gustavo@padovan.org> <1478841369-20826-4-git-send-email-gustavo@padovan.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <1478841369-20826-4-git-send-email-gustavo@padovan.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13969 Lines: 473 Hi Gustavo, On Fri, Nov 11, 2016 at 02:16:09PM +0900, Gustavo Padovan wrote: >From: Gustavo Padovan > >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 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 >