Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753077AbcD1PXz (ORCPT ); Thu, 28 Apr 2016 11:23:55 -0400 Received: from mail-yw0-f196.google.com ([209.85.161.196]:34817 "EHLO mail-yw0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752755AbcD1PXx (ORCPT ); Thu, 28 Apr 2016 11:23:53 -0400 Date: Thu, 28 Apr 2016 12:23:46 -0300 From: Gustavo Padovan To: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, dri-devel@lists.freedesktop.org, Daniel Stone , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Riley Andrews , Rob Clark , Greg Hackmann , John Harrison , Maarten Lankhorst , Sumit Semwal , Gustavo Padovan Subject: Re: [RFC v2 8/8] drm/fence: add out-fences support Message-ID: <20160428152346.GC3496@joana> Mail-Followup-To: Gustavo Padovan , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org, dri-devel@lists.freedesktop.org, Daniel Stone , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Riley Andrews , Rob Clark , Greg Hackmann , John Harrison , Maarten Lankhorst , Sumit Semwal , Gustavo Padovan References: <1461623608-29538-1-git-send-email-gustavo@padovan.org> <1461623608-29538-9-git-send-email-gustavo@padovan.org> <20160426145305.GY8291@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160426145305.GY8291@phenom.ffwll.local> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8117 Lines: 251 2016-04-26 Daniel Vetter : > On Mon, Apr 25, 2016 at 07:33:28PM -0300, Gustavo Padovan wrote: > > From: Gustavo Padovan > > > > Support DRM out-fences creating a sync_file with a fence for each crtc > > update with the DRM_MODE_ATOMIC_OUT_FENCE flag. > > > > We then send an struct drm_out_fences array with the out-fences fds back in > > the drm_atomic_ioctl() as an out arg in the out_fences_ptr field. > > > > struct drm_out_fences { > > __u32 crtc_id; > > __u32 fd; > > }; > > > > 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 > > > > Signed-off-by: Gustavo Padovan > > --- > > drivers/gpu/drm/drm_atomic.c | 163 +++++++++++++++++++++++++++++++++++++++++-- > > include/drm/drm_crtc.h | 10 +++ > > include/uapi/drm/drm_mode.h | 11 ++- > > 3 files changed, 179 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c > > index 5f9d434..06c6007 100644 > > --- a/drivers/gpu/drm/drm_atomic.c > > +++ b/drivers/gpu/drm/drm_atomic.c > > @@ -1566,6 +1566,133 @@ void drm_atomic_clean_old_fb(struct drm_device *dev, > > } > > EXPORT_SYMBOL(drm_atomic_clean_old_fb); > > > > +static struct drm_out_fence_state *get_out_fence(struct drm_device *dev, > > + struct drm_atomic_state *state, > > + uint32_t __user *out_fences_ptr, > > + uint64_t count_out_fences, > > + uint64_t user_data) > > +{ > > + struct drm_crtc *crtc; > > + struct drm_crtc_state *crtc_state; > > + struct drm_out_fences *out_fences; > > + struct drm_out_fence_state *fence_state; > > + int num_fences = 0; > > + int i, ret; > > + > > + if (count_out_fences > dev->mode_config.num_crtc) > > + return ERR_PTR(-EINVAL); > > + > > + out_fences = kcalloc(count_out_fences, sizeof(*out_fences), > > + GFP_KERNEL); > > + if (!out_fences) > > + return ERR_PTR(-ENOMEM); > > A bit tricky, but the above kcalloc is the only thing that catches integer > overflows in count_out_fences. Needs a comment imo since this could be a > security exploit if we accidentally screw it up. The check above makes sure that count_out_fences is not bigger than num_crtc. Don't that fix this? > > Also needs a testcase imo. > > > + > > + fence_state = kcalloc(count_out_fences, sizeof(*fence_state), > > + GFP_KERNEL); > > + if (!fence_state) { > > + kfree(out_fences); > > + return ERR_PTR(-ENOMEM); > > + } > > + > > + for (i = 0 ; i < count_out_fences ; i++) > > + fence_state[i].fd = -1; > > + > > + for_each_crtc_in_state(state, crtc, crtc_state, i) { > > + struct drm_pending_vblank_event *e; > > + struct fence *fence; > > + char name[32]; > > + > > + fence = kzalloc(sizeof(*fence), GFP_KERNEL); > > + if (!fence) { > > + ret = -ENOMEM; > > + goto out; > > + } > > + > > + fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock, > > + crtc->fence_context, crtc->fence_seqno); > > + > > + snprintf(name, sizeof(name), "crtc-%d_%lu", > > + drm_crtc_index(crtc), crtc->fence_seqno++); > > Hm ... fence_init_with_name? I'm kinda confused why we only name fences > that are exported though, and why not all of them. Debugging fence > deadlocks is real hard, so giving them all names might be a good idea. > > Anyway, seems like more room for a bit more sync_file/struct fence > merging. We just removed name from sync_file_create() so snprintf() is not even necessary here anymore. > > > + > > + fence_state[i].fd = get_unused_fd_flags(O_CLOEXEC); > > + if (fence_state[i].fd < 0) { > > + fence_put(fence); > > + ret = fence_state[i].fd; > > + goto out; > > + } > > + > > + fence_state[i].sync_file = sync_file_create(name, fence); > > + if(!fence_state[i].sync_file) { > > + fence_put(fence); > > + ret = -ENOMEM; > > + goto out; > > + } > > + > > + if (crtc_state->event) { > > + crtc_state->event->base.fence = fence; > > + } else { > > This looks a bit funny - I'd change the create event logic to create an > event either if we have the either drm event or out-fence flag set. Ok. > > > + e = create_vblank_event(dev, NULL, fence, user_data); > > + if (!e) { > > + ret = -ENOMEM; > > + goto out; > > + } > > + > > + crtc_state->event = e; > > + } > > + > > + out_fences[num_fences].crtc_id = crtc->base.id; > > + out_fences[num_fences].fd = fence_state[i].fd; > > + num_fences++; > > + } > > + > > + if (copy_to_user(out_fences_ptr, out_fences, > > + num_fences * sizeof(*out_fences))) { > > + ret = -EFAULT; > > + goto out; > > + } > > + > > + kfree(out_fences); > > + > > + return fence_state; > > + > > +out: > > + for (i = 0 ; i < count_out_fences ; i++) { > > + if (fence_state[i].sync_file) > > + sync_file_put(fence_state[i].sync_file); > > + if (fence_state[i].fd >= 0) > > + put_unused_fd(fence_state[i].fd); > > + } > > + > > + kfree(fence_state); > > + kfree(out_fences); > > + > > + return ERR_PTR(ret); > > +} > > + > > +static void install_out_fence(uint64_t count_out_fences, > > + struct drm_out_fence_state *state) > > +{ > > + int i; > > + > > + for (i = 0 ; i < count_out_fences ; i++) { > > + if (state[i].sync_file) > > + sync_file_install(state[i].sync_file, state[i].fd); > > Is sync_file_install anything more than fd_install? Imo a wrapper for > just that function is overkill and just hides stuff. I'd nuke it (another > sync_file patch though). In dma-buf we also don't wrap it, we only have a > convenience wrapper for users who want to combine the > get_unused_flags+fd_install in one go. And maybe even that is silly. > > Ok, I unlazied and it's indeed just a silly wrapper. Please nuke it. already fixed in the sync file de-stage patches. > > > + } > > +} > > + > > +static void release_out_fence(uint64_t count_out_fences, > > + struct drm_out_fence_state *state) > > +{ > > + int i; > > + > > + for (i = 0 ; i < count_out_fences ; i++) { > > + if (state->sync_file) > > + sync_file_put(state->sync_file); > > + if (state->fd >= 0) > > + put_unused_fd(state->fd); > > + } > > +} > > + > > int drm_mode_atomic_ioctl(struct drm_device *dev, > > void *data, struct drm_file *file_priv) > > { > > @@ -1574,12 +1701,14 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, > > uint32_t __user *count_props_ptr = (uint32_t __user *)(unsigned long)(arg->count_props_ptr); > > uint32_t __user *props_ptr = (uint32_t __user *)(unsigned long)(arg->props_ptr); > > uint64_t __user *prop_values_ptr = (uint64_t __user *)(unsigned long)(arg->prop_values_ptr); > > + uint32_t __user *out_fences_ptr = (uint32_t __user *)(unsigned long)(arg->out_fences_ptr); > > unsigned int copied_objs, copied_props; > > 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; > > @@ -1605,9 +1734,13 @@ int drm_mode_atomic_ioctl(struct drm_device *dev, > > !dev->mode_config.async_page_flip) > > return -EINVAL; > > > > + if ((arg->flags & DRM_MODE_ATOMIC_OUT_FENCE) && !arg->count_out_fences) > > + return -EINVAL; > > We need testcases which check that arg->count_out_fences and > arg->out_fences are 0 when the OUT_FENCE flag is not set. > > Definitely needs an igt testcase for this invalid input case. Ofc we also > need tests that give the kernel nonsens in count_out_fences and out_fences > with the flag set. > > > + > > /* can't test and expect an event at the same time. */ > > if ((arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) && > > - (arg->flags & DRM_MODE_PAGE_FLIP_EVENT)) > > + (arg->flags & (DRM_MODE_PAGE_FLIP_EVENT > > + | DRM_MODE_ATOMIC_OUT_FENCE))) > > If you go with my suggestion above to create the event if either is set, > maybe a DRM_MODE_ATOMIC_EVENT_MASK with both? Would read easier. Ok. Gustavo