Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759981AbcJ1JX4 (ORCPT ); Fri, 28 Oct 2016 05:23:56 -0400 Received: from foss.arm.com ([217.140.101.70]:54478 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757234AbcJ1JXy (ORCPT ); Fri, 28 Oct 2016 05:23:54 -0400 Date: Fri, 28 Oct 2016 10:23:45 +0100 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, Sumit Semwal , Maarten Lankhorst , Gustavo Padovan Subject: Re: [PATCH v6 6/6] drm/fence: add out-fences support Message-ID: <20161028092344.GB29507@e106950-lin.cambridge.arm.com> References: <1477597031-5139-1-git-send-email-gustavo@padovan.org> <1477597031-5139-7-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: <1477597031-5139-7-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: 13518 Lines: 436 Hi Gustavo, On Thu, Oct 27, 2016 at 05:37:11PM -0200, 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 > >Signed-off-by: Gustavo Padovan >--- > drivers/gpu/drm/drm_atomic.c | 199 ++++++++++++++++++++++++++++++++++++------- > drivers/gpu/drm/drm_crtc.c | 8 ++ > include/drm/drm_atomic.h | 1 + > include/drm/drm_crtc.h | 17 ++++ > 4 files changed, 196 insertions(+), 29 deletions(-) > >diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c >index 28d9366..9b70a27 100644 >--- a/drivers/gpu/drm/drm_atomic.c >+++ b/drivers/gpu/drm/drm_atomic.c >@@ -290,6 +290,46 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state, > EXPORT_SYMBOL(drm_atomic_get_crtc_state); > > /** >+ * drm_atomic_set_out_fence_for_crtc - set CRTC out fence pointer >+ * @state: global atomic state object >+ * @crtc: crtc to set the out fence pointer >+ * @fence_ptr: the userspace pointer to user >+ * >+ * This function stores the out fence pointer in the atomic state. >+ */ >+static void >+drm_atomic_set_out_fence_for_crtc(struct drm_atomic_state *state, >+ struct drm_crtc *crtc, u64 __user *fence_ptr) bikeshed: I'd rather these were called set/get_out_fence_ptr_for_crtc, as they don't involve struct drm_fence at all. >+{ >+ state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr; >+} >+ >+/** >+ * drm_atomic_get_out_fence_for_crtc - get CRTC out fence pointer >+ * @state: global atomic state object >+ * @crtc: crtc to set the out fence pointer >+ * >+ * Get the user pointer that should be used for to store the out fence fd. >+ * This function should be called only once per atomic state as it clears >+ * the out_fence_ptr store there to prevent drivers to access them. >+ * >+ * Returns: >+ * >+ * The out fence user pointer. >+ */ >+static u64 __user * >+drm_atomic_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; >+} >+ >+/** > * drm_atomic_set_mode_for_crtc - set mode for CRTC > * @state: the CRTC whose incoming state to update > * @mode: kernel-internal mode to use for the CRTC, or NULL to disable >@@ -490,6 +530,12 @@ 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) { >+ uint64_t __user *fence_ptr = u64_to_user_ptr(val); >+ if (!access_ok(VERIFY_WRITE, fence_ptr, sizeof(*fence_ptr))) >+ return -EFAULT; >+ >+ drm_atomic_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 >@@ -532,6 +578,8 @@ 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 >@@ -1506,11 +1554,9 @@ EXPORT_SYMBOL(drm_atomic_nonblocking_commit); > */ > > 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) >@@ -1520,17 +1566,6 @@ 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; > } > >@@ -1635,6 +1670,38 @@ void drm_atomic_clean_old_fb(struct drm_device *dev, > } > EXPORT_SYMBOL(drm_atomic_clean_old_fb); > >+struct dma_fence *get_crtc_fence(struct drm_crtc *crtc, >+ struct drm_crtc_state *crtc_state) >+{ >+ 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; >+} >+ >+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; >+} >+ > int drm_mode_atomic_ioctl(struct drm_device *dev, > void *data, struct drm_file *file_priv) > { >@@ -1649,9 +1716,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, > 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, fence_idx = 0; > > /* disallow for drivers not supporting atomic: */ > if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) >@@ -1766,13 +1834,33 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, > drm_mode_object_unreference(obj); > } > >+ fence_state = kcalloc(dev->mode_config.num_crtc, sizeof(*fence_state), >+ GFP_KERNEL); >+ if (!fence_state) { >+ ret = -ENOMEM; >+ goto out; >+ } > >- if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) { >- for_each_crtc_in_state(state, crtc, crtc_state, i) { >+ for_each_crtc_in_state(state, crtc, crtc_state, i) { >+ >+ fence_state->out_fence_ptr = >+ drm_atomic_get_out_fence_for_crtc(crtc_state->state, crtc); I think you're missing some subscripting on fence_state in this loop. Here you set fence_state->out_fence_ptr directly, whereas I guess it should be fence_state[fence_idx].out_fence_ptr; >+ >+ if (fence_state->out_fence_ptr && >+ (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY)) { >+ if (put_user(-1, fence_state->out_fence_ptr)) { >+ ret = -EFAULT; >+ goto out; >+ } >+ >+ continue; >+ } >+ >+ if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || >+ fence_state->out_fence_ptr) { > struct drm_pending_vblank_event *e; > >- e = create_vblank_event(dev, file_priv, NULL, >- arg->user_data); >+ e = create_vblank_event(dev, arg->user_data); > if (!e) { > ret = -ENOMEM; > goto out; >@@ -1780,6 +1868,39 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, > > 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; >+ goto out; >+ } >+ } >+ >+ if (fence_state->out_fence_ptr) { >+ struct dma_fence *fence; >+ >+ fence = get_crtc_fence(crtc, crtc_state); >+ if (!fence) { >+ ret = -ENOMEM; >+ goto out; >+ } >+ >+ ret = setup_out_fence(&fence_state[fence_idx++], fence); Related to above, I think if you're going to manipulate the fence_state array outside of setup_out_fence you should drop the inline increment here, as it will be easy for a refactor to miss it and add bugs. >+ if (ret) { >+ dma_fence_put(fence); >+ goto out; >+ } >+ >+ crtc_state->event->base.fence = fence; >+ } > } > > if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) { >@@ -1794,24 +1915,44 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, > ret = drm_atomic_commit(state); > } > >+ if (ret) >+ goto out; >+ >+ for (i = 0; i < fence_idx; i++) >+ fd_install(fence_state[i].fd, fence_state[i].sync_file->file); >+ > 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. >- */ >- >+ if (ret) { > for_each_crtc_in_state(state, crtc, crtc_state, i) { >- if (!crtc_state->event) >- continue; >+ /* >+ * 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); >+ } > >- drm_event_cancel_free(dev, &crtc_state->event->base); >+ if (fence_state) { >+ for (i = 0; i < fence_idx; 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_INFO("Couldn't clear out_fence_ptr\n"); >+ } > } > } > >+ kfree(fence_state); >+ > if (ret == -EDEADLK) { > drm_atomic_state_clear(state); > drm_modeset_backoff(&ctx); >diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c >index e2a06c8..a18d81b 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 2d1e9c9..ebde60e 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; >+ u64 __user *out_fence_ptr; > }; > > struct __drm_connnectors_state { >diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h >index 278dbdd..2539394 100644 >--- a/include/drm/drm_crtc.h >+++ b/include/drm/drm_crtc.h >@@ -768,6 +768,18 @@ static inline struct drm_crtc *fence_to_crtc(struct dma_fence *fence) > } > > /** >+ * struct drm_out_fence_state - store out_fence data for install and clean up >+ * @out_fence_ptr: user pointer to store the fence fd in. >+ * @sync_file: sync_file related to the out_fence >+ * @fd: file descriptor to installed on the sync_file. >+ */ >+struct drm_out_fence_state { >+ u64 __user *out_fence_ptr; >+ struct sync_file *sync_file; >+ int fd; >+}; >+ >+/* > * struct drm_mode_set - new values for a CRTC config change > * @fb: framebuffer to use for new config > * @crtc: CRTC whose configuration we're about to change >@@ -1245,6 +1257,11 @@ 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. >+ */ Is it worth noting that userspace should provide a pointer to a u64 and not a plain int? Either here or in some more detailed kernel-doc for the OUT_FENCE_PTR property. Cheers, Brian >+ struct drm_property *prop_out_fence_ptr; >+ /** > * @prop_crtc_id: Default atomic plane property to specify the > * &drm_crtc. > */ >-- >2.5.5 >