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authorBrian Starkey <brian.starkey@arm.com>2017-03-29 19:42:33 +0300
committerLiviu Dudau <Liviu.Dudau@arm.com>2018-06-20 17:29:18 +0300
commitb13cc8dd588434e2aec781e6d12224e4c408ac18 (patch)
treec202a3e17b01d1db38cebd680dd7d5cdc0f641cf /drivers
parent935774cd71fe604cc8ed24adcb507d7784255672 (diff)
downloadlinux-b13cc8dd588434e2aec781e6d12224e4c408ac18.tar.xz
drm: writeback: Add out-fences for writeback connectors
Add the WRITEBACK_OUT_FENCE_PTR property to writeback connectors, to enable userspace to get a fence which will signal once the writeback is complete. It is not allowed to request an out-fence without a framebuffer attached to the connector. A timeline is added to drm_writeback_connector for use by the writeback out-fences. In the case of a commit failure or DRM_MODE_ATOMIC_TEST_ONLY, the fence is set to -1. Changes from v2: - Rebase onto Gustavo Padovan's v9 explicit sync series - Change out_fence_ptr type to s32 __user * - Set *out_fence_ptr to -1 in drm_atomic_connector_set_property - Store fence in drm_writeback_job Gustavo Padovan: - Move out_fence_ptr out of connector_state - Signal fence from drm_writeback_signal_completion instead of in driver directly Changes from v3: - Rebase onto commit 7e9081c5aac7 ("drm/fence: fix memory overwrite when setting out_fence fd") (change out_fence_ptr to s32 __user *, for real this time.) - Update documentation around WRITEBACK_OUT_FENCE_PTR Signed-off-by: Brian Starkey <brian.starkey@arm.com> [rebased and fixed conflicts] Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com> Signed-off-by: Liviu Dudau <liviu.dudau@arm.com> Reviewed-by: Eric Anholt <eric@anholt.net> Reviewed-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/229036/
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/drm_atomic.c99
-rw-r--r--drivers/gpu/drm/drm_writeback.c109
2 files changed, 197 insertions, 11 deletions
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 3e53d6e5c340..115719059434 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -318,6 +318,35 @@ static s32 __user *get_out_fence_for_crtc(struct drm_atomic_state *state,
return fence_ptr;
}
+static int set_out_fence_for_connector(struct drm_atomic_state *state,
+ struct drm_connector *connector,
+ s32 __user *fence_ptr)
+{
+ unsigned int index = drm_connector_index(connector);
+
+ if (!fence_ptr)
+ return 0;
+
+ if (put_user(-1, fence_ptr))
+ return -EFAULT;
+
+ state->connectors[index].out_fence_ptr = fence_ptr;
+
+ return 0;
+}
+
+static s32 __user *get_out_fence_for_connector(struct drm_atomic_state *state,
+ struct drm_connector *connector)
+{
+ unsigned int index = drm_connector_index(connector);
+ s32 __user *fence_ptr;
+
+ fence_ptr = state->connectors[index].out_fence_ptr;
+ state->connectors[index].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
@@ -727,6 +756,12 @@ static int drm_atomic_connector_check(struct drm_connector *connector,
return -EINVAL;
}
+ if (writeback_job->out_fence && !writeback_job->fb) {
+ DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] requesting out-fence without framebuffer\n",
+ connector->base.id, connector->name);
+ return -EINVAL;
+ }
+
return 0;
}
@@ -1367,6 +1402,11 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
if (fb)
drm_framebuffer_put(fb);
return ret;
+ } else if (property == config->writeback_out_fence_ptr_property) {
+ s32 __user *fence_ptr = u64_to_user_ptr(val);
+
+ return set_out_fence_for_connector(state->state, connector,
+ fence_ptr);
} else if (connector->funcs->atomic_set_property) {
return connector->funcs->atomic_set_property(connector,
state, property, val);
@@ -1456,6 +1496,8 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
} else if (property == config->writeback_fb_id_property) {
/* Writeback framebuffer is one-shot, write and forget */
*val = 0;
+ } else if (property == config->writeback_out_fence_ptr_property) {
+ *val = 0;
} else if (connector->funcs->atomic_get_property) {
return connector->funcs->atomic_get_property(connector,
state, property, val);
@@ -2292,7 +2334,7 @@ static int setup_out_fence(struct drm_out_fence_state *fence_state,
return 0;
}
-static int prepare_crtc_signaling(struct drm_device *dev,
+static int prepare_signaling(struct drm_device *dev,
struct drm_atomic_state *state,
struct drm_mode_atomic *arg,
struct drm_file *file_priv,
@@ -2301,6 +2343,8 @@ static int prepare_crtc_signaling(struct drm_device *dev,
{
struct drm_crtc *crtc;
struct drm_crtc_state *crtc_state;
+ struct drm_connector *conn;
+ struct drm_connector_state *conn_state;
int i, c = 0, ret;
if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY)
@@ -2366,6 +2410,43 @@ static int prepare_crtc_signaling(struct drm_device *dev,
c++;
}
+ for_each_new_connector_in_state(state, conn, conn_state, i) {
+ struct drm_writeback_job *job;
+ struct drm_out_fence_state *f;
+ struct dma_fence *fence;
+ s32 __user *fence_ptr;
+
+ fence_ptr = get_out_fence_for_connector(state, conn);
+ if (!fence_ptr)
+ continue;
+
+ job = drm_atomic_get_writeback_job(conn_state);
+ if (!job)
+ return -ENOMEM;
+
+ f = krealloc(*fence_state, sizeof(**fence_state) *
+ (*num_fences + 1), GFP_KERNEL);
+ if (!f)
+ return -ENOMEM;
+
+ memset(&f[*num_fences], 0, sizeof(*f));
+
+ f[*num_fences].out_fence_ptr = fence_ptr;
+ *fence_state = f;
+
+ fence = drm_writeback_get_out_fence((struct drm_writeback_connector *)conn);
+ if (!fence)
+ return -ENOMEM;
+
+ ret = setup_out_fence(&f[(*num_fences)++], fence);
+ if (ret) {
+ dma_fence_put(fence);
+ return ret;
+ }
+
+ job->out_fence = fence;
+ }
+
/*
* Having this flag means user mode pends on event which will never
* reach due to lack of at least one CRTC for signaling
@@ -2376,11 +2457,11 @@ static int prepare_crtc_signaling(struct drm_device *dev,
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,
- bool install_fds)
+static void complete_signaling(struct drm_device *dev,
+ struct drm_atomic_state *state,
+ struct drm_out_fence_state *fence_state,
+ unsigned int num_fences,
+ bool install_fds)
{
struct drm_crtc *crtc;
struct drm_crtc_state *crtc_state;
@@ -2550,8 +2631,8 @@ retry:
drm_mode_object_put(obj);
}
- ret = prepare_crtc_signaling(dev, state, arg, file_priv, &fence_state,
- &num_fences);
+ ret = prepare_signaling(dev, state, arg, file_priv, &fence_state,
+ &num_fences);
if (ret)
goto out;
@@ -2567,7 +2648,7 @@ retry:
}
out:
- complete_crtc_signaling(dev, state, fence_state, num_fences, !ret);
+ complete_signaling(dev, state, fence_state, num_fences, !ret);
if (ret == -EDEADLK) {
drm_atomic_state_clear(state);
diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index e5b8a4b79724..827395071f0b 100644
--- a/drivers/gpu/drm/drm_writeback.c
+++ b/drivers/gpu/drm/drm_writeback.c
@@ -14,6 +14,7 @@
#include <drm/drm_property.h>
#include <drm/drm_writeback.h>
#include <drm/drmP.h>
+#include <linux/dma-fence.h>
/**
* DOC: overview
@@ -31,6 +32,16 @@
* framebuffer applies only to a single commit (see below). A framebuffer may
* not be attached while the CRTC is off.
*
+ * Unlike with planes, when a writeback framebuffer is removed by userspace DRM
+ * makes no attempt to remove it from active use by the connector. This is
+ * because no method is provided to abort a writeback operation, and in any
+ * case making a new commit whilst a writeback is ongoing is undefined (see
+ * WRITEBACK_OUT_FENCE_PTR below). As soon as the current writeback is finished,
+ * the framebuffer will automatically no longer be in active use. As it will
+ * also have already been removed from the framebuffer list, there will be no
+ * way for any userspace application to retrieve a reference to it in the
+ * intervening period.
+ *
* Writeback connectors have some additional properties, which userspace
* can use to query and control them:
*
@@ -47,8 +58,54 @@
* data is an array of u32 DRM_FORMAT_* fourcc values.
* Userspace can use this blob to find out what pixel formats are supported
* by the connector's writeback engine.
+ *
+ * "WRITEBACK_OUT_FENCE_PTR":
+ * Userspace can use this property to provide a pointer for the kernel to
+ * fill with a sync_file file descriptor, which will signal once the
+ * writeback is finished. The value should be the address of a 32-bit
+ * signed integer, cast to a u64.
+ * Userspace should wait for this fence to signal before making another
+ * commit affecting any of the same CRTCs, Planes or Connectors.
+ * **Failure to do so will result in undefined behaviour.**
+ * For this reason it is strongly recommended that all userspace
+ * applications making use of writeback connectors *always* retrieve an
+ * out-fence for the commit and use it appropriately.
+ * From userspace, this property will always read as zero.
*/
+#define fence_to_wb_connector(x) container_of(x->lock, \
+ struct drm_writeback_connector, \
+ fence_lock)
+
+static const char *drm_writeback_fence_get_driver_name(struct dma_fence *fence)
+{
+ struct drm_writeback_connector *wb_connector =
+ fence_to_wb_connector(fence);
+
+ return wb_connector->base.dev->driver->name;
+}
+
+static const char *
+drm_writeback_fence_get_timeline_name(struct dma_fence *fence)
+{
+ struct drm_writeback_connector *wb_connector =
+ fence_to_wb_connector(fence);
+
+ return wb_connector->timeline_name;
+}
+
+static bool drm_writeback_fence_enable_signaling(struct dma_fence *fence)
+{
+ return true;
+}
+
+static const struct dma_fence_ops drm_writeback_fence_ops = {
+ .get_driver_name = drm_writeback_fence_get_driver_name,
+ .get_timeline_name = drm_writeback_fence_get_timeline_name,
+ .enable_signaling = drm_writeback_fence_enable_signaling,
+ .wait = dma_fence_default_wait,
+};
+
static int create_writeback_properties(struct drm_device *dev)
{
struct drm_property *prop;
@@ -72,6 +129,15 @@ static int create_writeback_properties(struct drm_device *dev)
dev->mode_config.writeback_pixel_formats_property = prop;
}
+ if (!dev->mode_config.writeback_out_fence_ptr_property) {
+ prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
+ "WRITEBACK_OUT_FENCE_PTR", 0,
+ U64_MAX);
+ if (!prop)
+ return -ENOMEM;
+ dev->mode_config.writeback_out_fence_ptr_property = prop;
+ }
+
return 0;
}
@@ -141,6 +207,15 @@ int drm_writeback_connector_init(struct drm_device *dev,
INIT_LIST_HEAD(&wb_connector->job_queue);
spin_lock_init(&wb_connector->job_lock);
+ wb_connector->fence_context = dma_fence_context_alloc(1);
+ spin_lock_init(&wb_connector->fence_lock);
+ snprintf(wb_connector->timeline_name,
+ sizeof(wb_connector->timeline_name),
+ "CONNECTOR:%d-%s", connector->base.id, connector->name);
+
+ drm_object_attach_property(&connector->base,
+ config->writeback_out_fence_ptr_property, 0);
+
drm_object_attach_property(&connector->base,
config->writeback_fb_id_property, 0);
@@ -210,6 +285,7 @@ static void cleanup_work(struct work_struct *work)
/**
* drm_writeback_signal_completion - Signal the completion of a writeback job
* @wb_connector: The writeback connector whose job is complete
+ * @status: Status code to set in the writeback out_fence (0 for success)
*
* Drivers should call this to signal the completion of a previously queued
* writeback job. It should be called as soon as possible after the hardware
@@ -223,7 +299,8 @@ static void cleanup_work(struct work_struct *work)
* See also: drm_writeback_queue_job()
*/
void
-drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector)
+drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
+ int status)
{
unsigned long flags;
struct drm_writeback_job *job;
@@ -232,8 +309,15 @@ drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector)
job = list_first_entry_or_null(&wb_connector->job_queue,
struct drm_writeback_job,
list_entry);
- if (job)
+ if (job) {
list_del(&job->list_entry);
+ if (job->out_fence) {
+ if (status)
+ dma_fence_set_error(job->out_fence, status);
+ dma_fence_signal(job->out_fence);
+ dma_fence_put(job->out_fence);
+ }
+ }
spin_unlock_irqrestore(&wb_connector->job_lock, flags);
if (WARN_ON(!job))
@@ -243,3 +327,24 @@ drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector)
queue_work(system_long_wq, &job->cleanup_work);
}
EXPORT_SYMBOL(drm_writeback_signal_completion);
+
+struct dma_fence *
+drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector)
+{
+ struct dma_fence *fence;
+
+ if (WARN_ON(wb_connector->base.connector_type !=
+ DRM_MODE_CONNECTOR_WRITEBACK))
+ return NULL;
+
+ fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+ if (!fence)
+ return NULL;
+
+ dma_fence_init(fence, &drm_writeback_fence_ops,
+ &wb_connector->fence_lock, wb_connector->fence_context,
+ ++wb_connector->fence_seqno);
+
+ return fence;
+}
+EXPORT_SYMBOL(drm_writeback_get_out_fence);