1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c
new file mode 100644
index 000000000000..e4c220cf9115
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_sync.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#include "xe_sync.h"
+
+#include <linux/dma-fence-array.h>
+#include <linux/kthread.h>
+#include <linux/sched/mm.h>
+#include <linux/uaccess.h>
+
+#include <drm/drm_print.h>
+#include <drm/drm_syncobj.h>
+#include <drm/xe_drm.h>
+
+#include "xe_device_types.h"
+#include "xe_exec_queue.h"
+#include "xe_macros.h"
+#include "xe_sched_job_types.h"
+
+struct user_fence {
+	struct xe_device *xe;
+	struct kref refcount;
+	struct dma_fence_cb cb;
+	struct work_struct worker;
+	struct mm_struct *mm;
+	u64 __user *addr;
+	u64 value;
+};
+
+static void user_fence_destroy(struct kref *kref)
+{
+	struct user_fence *ufence = container_of(kref, struct user_fence,
+						 refcount);
+
+	mmdrop(ufence->mm);
+	kfree(ufence);
+}
+
+static void user_fence_get(struct user_fence *ufence)
+{
+	kref_get(&ufence->refcount);
+}
+
+static void user_fence_put(struct user_fence *ufence)
+{
+	kref_put(&ufence->refcount, user_fence_destroy);
+}
+
+static struct user_fence *user_fence_create(struct xe_device *xe, u64 addr,
+					    u64 value)
+{
+	struct user_fence *ufence;
+
+	ufence = kmalloc(sizeof(*ufence), GFP_KERNEL);
+	if (!ufence)
+		return NULL;
+
+	ufence->xe = xe;
+	kref_init(&ufence->refcount);
+	ufence->addr = u64_to_user_ptr(addr);
+	ufence->value = value;
+	ufence->mm = current->mm;
+	mmgrab(ufence->mm);
+
+	return ufence;
+}
+
+static void user_fence_worker(struct work_struct *w)
+{
+	struct user_fence *ufence = container_of(w, struct user_fence, worker);
+
+	if (mmget_not_zero(ufence->mm)) {
+		kthread_use_mm(ufence->mm);
+		if (copy_to_user(ufence->addr, &ufence->value, sizeof(ufence->value)))
+			XE_WARN_ON("Copy to user failed");
+		kthread_unuse_mm(ufence->mm);
+		mmput(ufence->mm);
+	}
+
+	wake_up_all(&ufence->xe->ufence_wq);
+	user_fence_put(ufence);
+}
+
+static void kick_ufence(struct user_fence *ufence, struct dma_fence *fence)
+{
+	INIT_WORK(&ufence->worker, user_fence_worker);
+	queue_work(ufence->xe->ordered_wq, &ufence->worker);
+	dma_fence_put(fence);
+}
+
+static void user_fence_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+	struct user_fence *ufence = container_of(cb, struct user_fence, cb);
+
+	kick_ufence(ufence, fence);
+}
+
+int xe_sync_entry_parse(struct xe_device *xe, struct xe_file *xef,
+			struct xe_sync_entry *sync,
+			struct drm_xe_sync __user *sync_user,
+			unsigned int flags)
+{
+	struct drm_xe_sync sync_in;
+	int err;
+	bool exec = flags & SYNC_PARSE_FLAG_EXEC;
+	bool in_lr_mode = flags & SYNC_PARSE_FLAG_LR_MODE;
+	bool disallow_user_fence = flags & SYNC_PARSE_FLAG_DISALLOW_USER_FENCE;
+	bool signal;
+
+	if (copy_from_user(&sync_in, sync_user, sizeof(*sync_user)))
+		return -EFAULT;
+
+	if (XE_IOCTL_DBG(xe, sync_in.flags & ~DRM_XE_SYNC_FLAG_SIGNAL) ||
+	    XE_IOCTL_DBG(xe, sync_in.reserved[0] || sync_in.reserved[1]))
+		return -EINVAL;
+
+	signal = sync_in.flags & DRM_XE_SYNC_FLAG_SIGNAL;
+	switch (sync_in.type) {
+	case DRM_XE_SYNC_TYPE_SYNCOBJ:
+		if (XE_IOCTL_DBG(xe, in_lr_mode && signal))
+			return -EOPNOTSUPP;
+
+		if (XE_IOCTL_DBG(xe, upper_32_bits(sync_in.addr)))
+			return -EINVAL;
+
+		sync->syncobj = drm_syncobj_find(xef->drm, sync_in.handle);
+		if (XE_IOCTL_DBG(xe, !sync->syncobj))
+			return -ENOENT;
+
+		if (!signal) {
+			sync->fence = drm_syncobj_fence_get(sync->syncobj);
+			if (XE_IOCTL_DBG(xe, !sync->fence))
+				return -EINVAL;
+		}
+		break;
+
+	case DRM_XE_SYNC_TYPE_TIMELINE_SYNCOBJ:
+		if (XE_IOCTL_DBG(xe, in_lr_mode && signal))
+			return -EOPNOTSUPP;
+
+		if (XE_IOCTL_DBG(xe, upper_32_bits(sync_in.addr)))
+			return -EINVAL;
+
+		if (XE_IOCTL_DBG(xe, sync_in.timeline_value == 0))
+			return -EINVAL;
+
+		sync->syncobj = drm_syncobj_find(xef->drm, sync_in.handle);
+		if (XE_IOCTL_DBG(xe, !sync->syncobj))
+			return -ENOENT;
+
+		if (signal) {
+			sync->chain_fence = dma_fence_chain_alloc();
+			if (!sync->chain_fence)
+				return -ENOMEM;
+		} else {
+			sync->fence = drm_syncobj_fence_get(sync->syncobj);
+			if (XE_IOCTL_DBG(xe, !sync->fence))
+				return -EINVAL;
+
+			err = dma_fence_chain_find_seqno(&sync->fence,
+							 sync_in.timeline_value);
+			if (err)
+				return err;
+		}
+		break;
+
+	case DRM_XE_SYNC_TYPE_USER_FENCE:
+		if (XE_IOCTL_DBG(xe, disallow_user_fence))
+			return -EOPNOTSUPP;
+
+		if (XE_IOCTL_DBG(xe, !signal))
+			return -EOPNOTSUPP;
+
+		if (XE_IOCTL_DBG(xe, sync_in.addr & 0x7))
+			return -EINVAL;
+
+		if (exec) {
+			sync->addr = sync_in.addr;
+		} else {
+			sync->ufence = user_fence_create(xe, sync_in.addr,
+							 sync_in.timeline_value);
+			if (XE_IOCTL_DBG(xe, !sync->ufence))
+				return -ENOMEM;
+		}
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	sync->type = sync_in.type;
+	sync->flags = sync_in.flags;
+	sync->timeline_value = sync_in.timeline_value;
+
+	return 0;
+}
+
+int xe_sync_entry_wait(struct xe_sync_entry *sync)
+{
+	if (sync->fence)
+		dma_fence_wait(sync->fence, true);
+
+	return 0;
+}
+
+int xe_sync_entry_add_deps(struct xe_sync_entry *sync, struct xe_sched_job *job)
+{
+	int err;
+
+	if (sync->fence) {
+		err = drm_sched_job_add_dependency(&job->drm,
+						   dma_fence_get(sync->fence));
+		if (err) {
+			dma_fence_put(sync->fence);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+void xe_sync_entry_signal(struct xe_sync_entry *sync, struct xe_sched_job *job,
+			  struct dma_fence *fence)
+{
+	if (!(sync->flags & DRM_XE_SYNC_FLAG_SIGNAL))
+		return;
+
+	if (sync->chain_fence) {
+		drm_syncobj_add_point(sync->syncobj, sync->chain_fence,
+				      fence, sync->timeline_value);
+		/*
+		 * The chain's ownership is transferred to the
+		 * timeline.
+		 */
+		sync->chain_fence = NULL;
+	} else if (sync->syncobj) {
+		drm_syncobj_replace_fence(sync->syncobj, fence);
+	} else if (sync->ufence) {
+		int err;
+
+		dma_fence_get(fence);
+		user_fence_get(sync->ufence);
+		err = dma_fence_add_callback(fence, &sync->ufence->cb,
+					     user_fence_cb);
+		if (err == -ENOENT) {
+			kick_ufence(sync->ufence, fence);
+		} else if (err) {
+			XE_WARN_ON("failed to add user fence");
+			user_fence_put(sync->ufence);
+			dma_fence_put(fence);
+		}
+	} else if (sync->type == DRM_XE_SYNC_TYPE_USER_FENCE) {
+		job->user_fence.used = true;
+		job->user_fence.addr = sync->addr;
+		job->user_fence.value = sync->timeline_value;
+	}
+}
+
+void xe_sync_entry_cleanup(struct xe_sync_entry *sync)
+{
+	if (sync->syncobj)
+		drm_syncobj_put(sync->syncobj);
+	if (sync->fence)
+		dma_fence_put(sync->fence);
+	if (sync->chain_fence)
+		dma_fence_put(&sync->chain_fence->base);
+	if (sync->ufence)
+		user_fence_put(sync->ufence);
+}
+
+/**
+ * xe_sync_in_fence_get() - Get a fence from syncs, exec queue, and VM
+ * @sync: input syncs
+ * @num_sync: number of syncs
+ * @q: exec queue
+ * @vm: VM
+ *
+ * Get a fence from syncs, exec queue, and VM. If syncs contain in-fences create
+ * and return a composite fence of all in-fences + last fence. If no in-fences
+ * return last fence on  input exec queue. Caller must drop reference to
+ * returned fence.
+ *
+ * Return: fence on success, ERR_PTR(-ENOMEM) on failure
+ */
+struct dma_fence *
+xe_sync_in_fence_get(struct xe_sync_entry *sync, int num_sync,
+		     struct xe_exec_queue *q, struct xe_vm *vm)
+{
+	struct dma_fence **fences = NULL;
+	struct dma_fence_array *cf = NULL;
+	struct dma_fence *fence;
+	int i, num_in_fence = 0, current_fence = 0;
+
+	lockdep_assert_held(&vm->lock);
+
+	/* Count in-fences */
+	for (i = 0; i < num_sync; ++i) {
+		if (sync[i].fence) {
+			++num_in_fence;
+			fence = sync[i].fence;
+		}
+	}
+
+	/* Easy case... */
+	if (!num_in_fence) {
+		fence = xe_exec_queue_last_fence_get(q, vm);
+		dma_fence_get(fence);
+		return fence;
+	}
+
+	/* Create composite fence */
+	fences = kmalloc_array(num_in_fence + 1, sizeof(*fences), GFP_KERNEL);
+	if (!fences)
+		return ERR_PTR(-ENOMEM);
+	for (i = 0; i < num_sync; ++i) {
+		if (sync[i].fence) {
+			dma_fence_get(sync[i].fence);
+			fences[current_fence++] = sync[i].fence;
+		}
+	}
+	fences[current_fence++] = xe_exec_queue_last_fence_get(q, vm);
+	dma_fence_get(fences[current_fence - 1]);
+	cf = dma_fence_array_create(num_in_fence, fences,
+				    vm->composite_fence_ctx,
+				    vm->composite_fence_seqno++,
+				    false);
+	if (!cf) {
+		--vm->composite_fence_seqno;
+		goto err_out;
+	}
+
+	return &cf->base;
+
+err_out:
+	while (current_fence)
+		dma_fence_put(fences[--current_fence]);
+	kfree(fences);
+	kfree(cf);
+
+	return ERR_PTR(-ENOMEM);
+}