drm/msm: Add syncobj support.

This

1) Enables core DRM syncobj support.
2) Adds options to the submission ioctl to wait/signal syncobjs.

Just like the wait fence fd, this does inline waits. Using the
scheduler would be nice but I believe it is out of scope for
this work.

Support for timeline syncobjs is implemented and the interface
is ready for it, but I'm not enabling it yet until there is
some code for turnip to use it.

The reset is mostly in there because in the presence of waiting
and signalling the same semaphores, resetting them after
signalling can become very annoying.

v2:
  - Fixed style issues
  - Removed a cleanup issue in a failure case
  - Moved to a copy_from_user per syncobj

v3:
 - Fixed a missing declaration introduced in v2
 - Reworked to use ERR_PTR/PTR_ERR
 - Simplified failure gotos.

Used by: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2769

Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 231 insertions, 1 deletions

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 385d4965a8d0..6630aa817505 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -8,7 +8,9 @@
 #include <linux/sync_file.h>
 #include <linux/uaccess.h>
 
+#include <drm/drm_drv.h>
 #include <drm/drm_file.h>
+#include <drm/drm_syncobj.h>
 
 #include "msm_drv.h"
 #include "msm_gpu.h"
@@ -391,6 +393,186 @@ static void submit_cleanup(struct msm_gem_submit *submit)
 	}
 }
 
+
+struct msm_submit_post_dep {
+	struct drm_syncobj *syncobj;
+	uint64_t point;
+	struct dma_fence_chain *chain;
+};
+
+static struct drm_syncobj **msm_wait_deps(struct drm_device *dev,
+                                          struct drm_file *file,
+                                          uint64_t in_syncobjs_addr,
+                                          uint32_t nr_in_syncobjs,
+                                          size_t syncobj_stride,
+                                          struct msm_ringbuffer *ring)
+{
+	struct drm_syncobj **syncobjs = NULL;
+	struct drm_msm_gem_submit_syncobj syncobj_desc = {0};
+	int ret = 0;
+	uint32_t i, j;
+
+	syncobjs = kcalloc(nr_in_syncobjs, sizeof(*syncobjs),
+	                   GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
+	if (!syncobjs)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < nr_in_syncobjs; ++i) {
+		uint64_t address = in_syncobjs_addr + i * syncobj_stride;
+		struct dma_fence *fence;
+
+		if (copy_from_user(&syncobj_desc,
+			           u64_to_user_ptr(address),
+			           min(syncobj_stride, sizeof(syncobj_desc)))) {
+			ret = -EFAULT;
+			break;
+		}
+
+		if (syncobj_desc.point &&
+		    !drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE)) {
+			ret = -EOPNOTSUPP;
+			break;
+		}
+
+		if (syncobj_desc.flags & ~MSM_SUBMIT_SYNCOBJ_FLAGS) {
+			ret = -EINVAL;
+			break;
+		}
+
+		ret = drm_syncobj_find_fence(file, syncobj_desc.handle,
+		                             syncobj_desc.point, 0, &fence);
+		if (ret)
+			break;
+
+		if (!dma_fence_match_context(fence, ring->fctx->context))
+			ret = dma_fence_wait(fence, true);
+
+		dma_fence_put(fence);
+		if (ret)
+			break;
+
+		if (syncobj_desc.flags & MSM_SUBMIT_SYNCOBJ_RESET) {
+			syncobjs[i] =
+				drm_syncobj_find(file, syncobj_desc.handle);
+			if (!syncobjs[i]) {
+				ret = -EINVAL;
+				break;
+			}
+		}
+	}
+
+	if (ret) {
+		for (j = 0; j <= i; ++j) {
+			if (syncobjs[j])
+				drm_syncobj_put(syncobjs[j]);
+		}
+		kfree(syncobjs);
+		return ERR_PTR(ret);
+	}
+	return syncobjs;
+}
+
+static void msm_reset_syncobjs(struct drm_syncobj **syncobjs,
+                               uint32_t nr_syncobjs)
+{
+	uint32_t i;
+
+	for (i = 0; syncobjs && i < nr_syncobjs; ++i) {
+		if (syncobjs[i])
+			drm_syncobj_replace_fence(syncobjs[i], NULL);
+	}
+}
+
+static struct msm_submit_post_dep *msm_parse_post_deps(struct drm_device *dev,
+                                                       struct drm_file *file,
+                                                       uint64_t syncobjs_addr,
+                                                       uint32_t nr_syncobjs,
+                                                       size_t syncobj_stride)
+{
+	struct msm_submit_post_dep *post_deps;
+	struct drm_msm_gem_submit_syncobj syncobj_desc = {0};
+	int ret = 0;
+	uint32_t i, j;
+
+	post_deps = kmalloc_array(nr_syncobjs, sizeof(*post_deps),
+	                          GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
+	if (!post_deps)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < nr_syncobjs; ++i) {
+		uint64_t address = syncobjs_addr + i * syncobj_stride;
+
+		if (copy_from_user(&syncobj_desc,
+			           u64_to_user_ptr(address),
+			           min(syncobj_stride, sizeof(syncobj_desc)))) {
+			ret = -EFAULT;
+			break;
+		}
+
+		post_deps[i].point = syncobj_desc.point;
+		post_deps[i].chain = NULL;
+
+		if (syncobj_desc.flags) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (syncobj_desc.point) {
+			if (!drm_core_check_feature(dev,
+			                            DRIVER_SYNCOBJ_TIMELINE)) {
+				ret = -EOPNOTSUPP;
+				break;
+			}
+
+			post_deps[i].chain =
+				kmalloc(sizeof(*post_deps[i].chain),
+				        GFP_KERNEL);
+			if (!post_deps[i].chain) {
+				ret = -ENOMEM;
+				break;
+			}
+		}
+
+		post_deps[i].syncobj =
+			drm_syncobj_find(file, syncobj_desc.handle);
+		if (!post_deps[i].syncobj) {
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	if (ret) {
+		for (j = 0; j <= i; ++j) {
+			kfree(post_deps[j].chain);
+			if (post_deps[j].syncobj)
+				drm_syncobj_put(post_deps[j].syncobj);
+		}
+
+		kfree(post_deps);
+		return ERR_PTR(ret);
+	}
+
+	return post_deps;
+}
+
+static void msm_process_post_deps(struct msm_submit_post_dep *post_deps,
+                                  uint32_t count, struct dma_fence *fence)
+{
+	uint32_t i;
+
+	for (i = 0; post_deps && i < count; ++i) {
+		if (post_deps[i].chain) {
+			drm_syncobj_add_point(post_deps[i].syncobj,
+			                      post_deps[i].chain,
+			                      fence, post_deps[i].point);
+			post_deps[i].chain = NULL;
+		} else {
+			drm_syncobj_replace_fence(post_deps[i].syncobj,
+			                          fence);
+		}
+	}
+}
+
 int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 		struct drm_file *file)
 {
@@ -403,6 +585,8 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	struct sync_file *sync_file = NULL;
 	struct msm_gpu_submitqueue *queue;
 	struct msm_ringbuffer *ring;
+	struct msm_submit_post_dep *post_deps = NULL;
+	struct drm_syncobj **syncobjs_to_reset = NULL;
 	int out_fence_fd = -1;
 	struct pid *pid = get_pid(task_pid(current));
 	bool has_ww_ticket = false;
@@ -411,6 +595,9 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	if (!gpu)
 		return -ENXIO;
 
+	if (args->pad)
+		return -EINVAL;
+
 	/* for now, we just have 3d pipe.. eventually this would need to
 	 * be more clever to dispatch to appropriate gpu module:
 	 */
@@ -458,9 +645,29 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 			return ret;
 	}
 
+	if (args->flags & MSM_SUBMIT_SYNCOBJ_IN) {
+		syncobjs_to_reset = msm_wait_deps(dev, file,
+		                                  args->in_syncobjs,
+		                                  args->nr_in_syncobjs,
+		                                  args->syncobj_stride, ring);
+		if (IS_ERR(syncobjs_to_reset))
+			return PTR_ERR(syncobjs_to_reset);
+	}
+
+	if (args->flags & MSM_SUBMIT_SYNCOBJ_OUT) {
+		post_deps = msm_parse_post_deps(dev, file,
+		                                args->out_syncobjs,
+		                                args->nr_out_syncobjs,
+		                                args->syncobj_stride);
+		if (IS_ERR(post_deps)) {
+			ret = PTR_ERR(post_deps);
+			goto out_post_unlock;
+		}
+	}
+
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
 	if (ret)
-		return ret;
+		goto out_post_unlock;
 
 	if (args->flags & MSM_SUBMIT_FENCE_FD_OUT) {
 		out_fence_fd = get_unused_fd_flags(O_CLOEXEC);
@@ -587,6 +794,11 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 		args->fence_fd = out_fence_fd;
 	}
 
+	msm_reset_syncobjs(syncobjs_to_reset, args->nr_in_syncobjs);
+	msm_process_post_deps(post_deps, args->nr_out_syncobjs,
+	                      submit->fence);
+
+
 out:
 	submit_cleanup(submit);
 	if (has_ww_ticket)
@@ -597,5 +809,23 @@ out_unlock:
 	if (ret && (out_fence_fd >= 0))
 		put_unused_fd(out_fence_fd);
 	mutex_unlock(&dev->struct_mutex);
+
+out_post_unlock:
+	if (!IS_ERR_OR_NULL(post_deps)) {
+		for (i = 0; i < args->nr_out_syncobjs; ++i) {
+			kfree(post_deps[i].chain);
+			drm_syncobj_put(post_deps[i].syncobj);
+		}
+		kfree(post_deps);
+	}
+
+	if (!IS_ERR_OR_NULL(syncobjs_to_reset)) {
+		for (i = 0; i < args->nr_in_syncobjs; ++i) {
+			if (syncobjs_to_reset[i])
+				drm_syncobj_put(syncobjs_to_reset[i]);
+		}
+		kfree(syncobjs_to_reset);
+	}
+
 	return ret;
 }