Hi Gustavo,
On Thu, Oct 27, 2016 at 05:37:11PM -0200, Gustavo Padovan wrote:
>From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
>
>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 <gustavo.padovan at collabora.co.uk>
>---
> 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
>
