ASR_BASE

Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/dma-buf/dma-fence.c b/marvell/linux/drivers/dma-buf/dma-fence.c
new file mode 100644
index 0000000..052a41e
--- /dev/null
+++ b/marvell/linux/drivers/dma-buf/dma-fence.c
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Fence mechanism for dma-buf and to allow for asynchronous dma access
+ *
+ * Copyright (C) 2012 Canonical Ltd
+ * Copyright (C) 2012 Texas Instruments
+ *
+ * Authors:
+ * Rob Clark <robdclark@gmail.com>
+ * Maarten Lankhorst <maarten.lankhorst@canonical.com>
+ */
+
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/atomic.h>
+#include <linux/dma-fence.h>
+#include <linux/sched/signal.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/dma_fence.h>
+
+EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit);
+EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
+EXPORT_TRACEPOINT_SYMBOL(dma_fence_signaled);
+
+static DEFINE_SPINLOCK(dma_fence_stub_lock);
+static struct dma_fence dma_fence_stub;
+
+/*
+ * fence context counter: each execution context should have its own
+ * fence context, this allows checking if fences belong to the same
+ * context or not. One device can have multiple separate contexts,
+ * and they're used if some engine can run independently of another.
+ */
+static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
+
+/**
+ * DOC: DMA fences overview
+ *
+ * DMA fences, represented by &struct dma_fence, are the kernel internal
+ * synchronization primitive for DMA operations like GPU rendering, video
+ * encoding/decoding, or displaying buffers on a screen.
+ *
+ * A fence is initialized using dma_fence_init() and completed using
+ * dma_fence_signal(). Fences are associated with a context, allocated through
+ * dma_fence_context_alloc(), and all fences on the same context are
+ * fully ordered.
+ *
+ * Since the purposes of fences is to facilitate cross-device and
+ * cross-application synchronization, there's multiple ways to use one:
+ *
+ * - Individual fences can be exposed as a &sync_file, accessed as a file
+ *   descriptor from userspace, created by calling sync_file_create(). This is
+ *   called explicit fencing, since userspace passes around explicit
+ *   synchronization points.
+ *
+ * - Some subsystems also have their own explicit fencing primitives, like
+ *   &drm_syncobj. Compared to &sync_file, a &drm_syncobj allows the underlying
+ *   fence to be updated.
+ *
+ * - Then there's also implicit fencing, where the synchronization points are
+ *   implicitly passed around as part of shared &dma_buf instances. Such
+ *   implicit fences are stored in &struct dma_resv through the
+ *   &dma_buf.resv pointer.
+ */
+
+static const char *dma_fence_stub_get_name(struct dma_fence *fence)
+{
+        return "stub";
+}
+
+static const struct dma_fence_ops dma_fence_stub_ops = {
+	.get_driver_name = dma_fence_stub_get_name,
+	.get_timeline_name = dma_fence_stub_get_name,
+};
+
+/**
+ * dma_fence_get_stub - return a signaled fence
+ *
+ * Return a stub fence which is already signaled.
+ */
+struct dma_fence *dma_fence_get_stub(void)
+{
+	spin_lock(&dma_fence_stub_lock);
+	if (!dma_fence_stub.ops) {
+		dma_fence_init(&dma_fence_stub,
+			       &dma_fence_stub_ops,
+			       &dma_fence_stub_lock,
+			       0, 0);
+		dma_fence_signal_locked(&dma_fence_stub);
+	}
+	spin_unlock(&dma_fence_stub_lock);
+
+	return dma_fence_get(&dma_fence_stub);
+}
+EXPORT_SYMBOL(dma_fence_get_stub);
+
+/**
+ * dma_fence_context_alloc - allocate an array of fence contexts
+ * @num: amount of contexts to allocate
+ *
+ * This function will return the first index of the number of fence contexts
+ * allocated.  The fence context is used for setting &dma_fence.context to a
+ * unique number by passing the context to dma_fence_init().
+ */
+u64 dma_fence_context_alloc(unsigned num)
+{
+	WARN_ON(!num);
+	return atomic64_add_return(num, &dma_fence_context_counter) - num;
+}
+EXPORT_SYMBOL(dma_fence_context_alloc);
+
+/**
+ * dma_fence_signal_locked - signal completion of a fence
+ * @fence: the fence to signal
+ *
+ * Signal completion for software callbacks on a fence, this will unblock
+ * dma_fence_wait() calls and run all the callbacks added with
+ * dma_fence_add_callback(). Can be called multiple times, but since a fence
+ * can only go from the unsignaled to the signaled state and not back, it will
+ * only be effective the first time.
+ *
+ * Unlike dma_fence_signal(), this function must be called with &dma_fence.lock
+ * held.
+ *
+ * Returns 0 on success and a negative error value when @fence has been
+ * signalled already.
+ */
+int dma_fence_signal_locked(struct dma_fence *fence)
+{
+	struct dma_fence_cb *cur, *tmp;
+	struct list_head cb_list;
+
+	lockdep_assert_held(fence->lock);
+
+	if (unlikely(test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+				      &fence->flags)))
+		return -EINVAL;
+
+	/* Stash the cb_list before replacing it with the timestamp */
+	list_replace(&fence->cb_list, &cb_list);
+
+	fence->timestamp = ktime_get();
+	set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
+	trace_dma_fence_signaled(fence);
+
+	list_for_each_entry_safe(cur, tmp, &cb_list, node) {
+		INIT_LIST_HEAD(&cur->node);
+		cur->func(fence, cur);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(dma_fence_signal_locked);
+
+/**
+ * dma_fence_signal - signal completion of a fence
+ * @fence: the fence to signal
+ *
+ * Signal completion for software callbacks on a fence, this will unblock
+ * dma_fence_wait() calls and run all the callbacks added with
+ * dma_fence_add_callback(). Can be called multiple times, but since a fence
+ * can only go from the unsignaled to the signaled state and not back, it will
+ * only be effective the first time.
+ *
+ * Returns 0 on success and a negative error value when @fence has been
+ * signalled already.
+ */
+int dma_fence_signal(struct dma_fence *fence)
+{
+	unsigned long flags;
+	int ret;
+
+	if (!fence)
+		return -EINVAL;
+
+	spin_lock_irqsave(fence->lock, flags);
+	ret = dma_fence_signal_locked(fence);
+	spin_unlock_irqrestore(fence->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_fence_signal);
+
+/**
+ * dma_fence_wait_timeout - sleep until the fence gets signaled
+ * or until timeout elapses
+ * @fence: the fence to wait on
+ * @intr: if true, do an interruptible wait
+ * @timeout: timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
+ *
+ * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or the
+ * remaining timeout in jiffies on success. Other error values may be
+ * returned on custom implementations.
+ *
+ * Performs a synchronous wait on this fence. It is assumed the caller
+ * directly or indirectly (buf-mgr between reservation and committing)
+ * holds a reference to the fence, otherwise the fence might be
+ * freed before return, resulting in undefined behavior.
+ *
+ * See also dma_fence_wait() and dma_fence_wait_any_timeout().
+ */
+signed long
+dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout)
+{
+	signed long ret;
+
+	if (WARN_ON(timeout < 0))
+		return -EINVAL;
+
+	trace_dma_fence_wait_start(fence);
+	if (fence->ops->wait)
+		ret = fence->ops->wait(fence, intr, timeout);
+	else
+		ret = dma_fence_default_wait(fence, intr, timeout);
+	trace_dma_fence_wait_end(fence);
+	return ret;
+}
+EXPORT_SYMBOL(dma_fence_wait_timeout);
+
+/**
+ * dma_fence_release - default relese function for fences
+ * @kref: &dma_fence.recfount
+ *
+ * This is the default release functions for &dma_fence. Drivers shouldn't call
+ * this directly, but instead call dma_fence_put().
+ */
+void dma_fence_release(struct kref *kref)
+{
+	struct dma_fence *fence =
+		container_of(kref, struct dma_fence, refcount);
+
+	trace_dma_fence_destroy(fence);
+
+	if (WARN(!list_empty(&fence->cb_list) &&
+		 !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags),
+		 "Fence %s:%s:%llx:%llx released with pending signals!\n",
+		 fence->ops->get_driver_name(fence),
+		 fence->ops->get_timeline_name(fence),
+		 fence->context, fence->seqno)) {
+		unsigned long flags;
+
+		/*
+		 * Failed to signal before release, likely a refcounting issue.
+		 *
+		 * This should never happen, but if it does make sure that we
+		 * don't leave chains dangling. We set the error flag first
+		 * so that the callbacks know this signal is due to an error.
+		 */
+		spin_lock_irqsave(fence->lock, flags);
+		fence->error = -EDEADLK;
+		dma_fence_signal_locked(fence);
+		spin_unlock_irqrestore(fence->lock, flags);
+	}
+
+	if (fence->ops->release)
+		fence->ops->release(fence);
+	else
+		dma_fence_free(fence);
+}
+EXPORT_SYMBOL(dma_fence_release);
+
+/**
+ * dma_fence_free - default release function for &dma_fence.
+ * @fence: fence to release
+ *
+ * This is the default implementation for &dma_fence_ops.release. It calls
+ * kfree_rcu() on @fence.
+ */
+void dma_fence_free(struct dma_fence *fence)
+{
+	kfree_rcu(fence, rcu);
+}
+EXPORT_SYMBOL(dma_fence_free);
+
+static bool __dma_fence_enable_signaling(struct dma_fence *fence)
+{
+	bool was_set;
+
+	lockdep_assert_held(fence->lock);
+
+	was_set = test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
+				   &fence->flags);
+
+	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+		return false;
+
+	if (!was_set && fence->ops->enable_signaling) {
+		trace_dma_fence_enable_signal(fence);
+
+		if (!fence->ops->enable_signaling(fence)) {
+			dma_fence_signal_locked(fence);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/**
+ * dma_fence_enable_sw_signaling - enable signaling on fence
+ * @fence: the fence to enable
+ *
+ * This will request for sw signaling to be enabled, to make the fence
+ * complete as soon as possible. This calls &dma_fence_ops.enable_signaling
+ * internally.
+ */
+void dma_fence_enable_sw_signaling(struct dma_fence *fence)
+{
+	unsigned long flags;
+
+	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+		return;
+
+	spin_lock_irqsave(fence->lock, flags);
+	__dma_fence_enable_signaling(fence);
+	spin_unlock_irqrestore(fence->lock, flags);
+}
+EXPORT_SYMBOL(dma_fence_enable_sw_signaling);
+
+/**
+ * dma_fence_add_callback - add a callback to be called when the fence
+ * is signaled
+ * @fence: the fence to wait on
+ * @cb: the callback to register
+ * @func: the function to call
+ *
+ * @cb will be initialized by dma_fence_add_callback(), no initialization
+ * by the caller is required. Any number of callbacks can be registered
+ * to a fence, but a callback can only be registered to one fence at a time.
+ *
+ * Note that the callback can be called from an atomic context.  If
+ * fence is already signaled, this function will return -ENOENT (and
+ * *not* call the callback).
+ *
+ * Add a software callback to the fence. Same restrictions apply to
+ * refcount as it does to dma_fence_wait(), however the caller doesn't need to
+ * keep a refcount to fence afterward dma_fence_add_callback() has returned:
+ * when software access is enabled, the creator of the fence is required to keep
+ * the fence alive until after it signals with dma_fence_signal(). The callback
+ * itself can be called from irq context.
+ *
+ * Returns 0 in case of success, -ENOENT if the fence is already signaled
+ * and -EINVAL in case of error.
+ */
+int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb,
+			   dma_fence_func_t func)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (WARN_ON(!fence || !func))
+		return -EINVAL;
+
+	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
+		INIT_LIST_HEAD(&cb->node);
+		return -ENOENT;
+	}
+
+	spin_lock_irqsave(fence->lock, flags);
+
+	if (__dma_fence_enable_signaling(fence)) {
+		cb->func = func;
+		list_add_tail(&cb->node, &fence->cb_list);
+	} else {
+		INIT_LIST_HEAD(&cb->node);
+		ret = -ENOENT;
+	}
+
+	spin_unlock_irqrestore(fence->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_fence_add_callback);
+
+/**
+ * dma_fence_get_status - returns the status upon completion
+ * @fence: the dma_fence to query
+ *
+ * This wraps dma_fence_get_status_locked() to return the error status
+ * condition on a signaled fence. See dma_fence_get_status_locked() for more
+ * details.
+ *
+ * Returns 0 if the fence has not yet been signaled, 1 if the fence has
+ * been signaled without an error condition, or a negative error code
+ * if the fence has been completed in err.
+ */
+int dma_fence_get_status(struct dma_fence *fence)
+{
+	unsigned long flags;
+	int status;
+
+	spin_lock_irqsave(fence->lock, flags);
+	status = dma_fence_get_status_locked(fence);
+	spin_unlock_irqrestore(fence->lock, flags);
+
+	return status;
+}
+EXPORT_SYMBOL(dma_fence_get_status);
+
+/**
+ * dma_fence_remove_callback - remove a callback from the signaling list
+ * @fence: the fence to wait on
+ * @cb: the callback to remove
+ *
+ * Remove a previously queued callback from the fence. This function returns
+ * true if the callback is successfully removed, or false if the fence has
+ * already been signaled.
+ *
+ * *WARNING*:
+ * Cancelling a callback should only be done if you really know what you're
+ * doing, since deadlocks and race conditions could occur all too easily. For
+ * this reason, it should only ever be done on hardware lockup recovery,
+ * with a reference held to the fence.
+ *
+ * Behaviour is undefined if @cb has not been added to @fence using
+ * dma_fence_add_callback() beforehand.
+ */
+bool
+dma_fence_remove_callback(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+	unsigned long flags;
+	bool ret;
+
+	spin_lock_irqsave(fence->lock, flags);
+
+	ret = !list_empty(&cb->node);
+	if (ret)
+		list_del_init(&cb->node);
+
+	spin_unlock_irqrestore(fence->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_fence_remove_callback);
+
+struct default_wait_cb {
+	struct dma_fence_cb base;
+	struct task_struct *task;
+};
+
+static void
+dma_fence_default_wait_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+	struct default_wait_cb *wait =
+		container_of(cb, struct default_wait_cb, base);
+
+	wake_up_state(wait->task, TASK_NORMAL);
+}
+
+/**
+ * dma_fence_default_wait - default sleep until the fence gets signaled
+ * or until timeout elapses
+ * @fence: the fence to wait on
+ * @intr: if true, do an interruptible wait
+ * @timeout: timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
+ *
+ * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or the
+ * remaining timeout in jiffies on success. If timeout is zero the value one is
+ * returned if the fence is already signaled for consistency with other
+ * functions taking a jiffies timeout.
+ */
+signed long
+dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout)
+{
+	struct default_wait_cb cb;
+	unsigned long flags;
+	signed long ret = timeout ? timeout : 1;
+
+	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
+		return ret;
+
+	spin_lock_irqsave(fence->lock, flags);
+
+	if (intr && signal_pending(current)) {
+		ret = -ERESTARTSYS;
+		goto out;
+	}
+
+	if (!__dma_fence_enable_signaling(fence))
+		goto out;
+
+	if (!timeout) {
+		ret = 0;
+		goto out;
+	}
+
+	cb.base.func = dma_fence_default_wait_cb;
+	cb.task = current;
+	list_add(&cb.base.node, &fence->cb_list);
+
+	while (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) && ret > 0) {
+		if (intr)
+			__set_current_state(TASK_INTERRUPTIBLE);
+		else
+			__set_current_state(TASK_UNINTERRUPTIBLE);
+		spin_unlock_irqrestore(fence->lock, flags);
+
+		ret = schedule_timeout(ret);
+
+		spin_lock_irqsave(fence->lock, flags);
+		if (ret > 0 && intr && signal_pending(current))
+			ret = -ERESTARTSYS;
+	}
+
+	if (!list_empty(&cb.base.node))
+		list_del(&cb.base.node);
+	__set_current_state(TASK_RUNNING);
+
+out:
+	spin_unlock_irqrestore(fence->lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL(dma_fence_default_wait);
+
+static bool
+dma_fence_test_signaled_any(struct dma_fence **fences, uint32_t count,
+			    uint32_t *idx)
+{
+	int i;
+
+	for (i = 0; i < count; ++i) {
+		struct dma_fence *fence = fences[i];
+		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
+			if (idx)
+				*idx = i;
+			return true;
+		}
+	}
+	return false;
+}
+
+/**
+ * dma_fence_wait_any_timeout - sleep until any fence gets signaled
+ * or until timeout elapses
+ * @fences: array of fences to wait on
+ * @count: number of fences to wait on
+ * @intr: if true, do an interruptible wait
+ * @timeout: timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
+ * @idx: used to store the first signaled fence index, meaningful only on
+ *	positive return
+ *
+ * Returns -EINVAL on custom fence wait implementation, -ERESTARTSYS if
+ * interrupted, 0 if the wait timed out, or the remaining timeout in jiffies
+ * on success.
+ *
+ * Synchronous waits for the first fence in the array to be signaled. The
+ * caller needs to hold a reference to all fences in the array, otherwise a
+ * fence might be freed before return, resulting in undefined behavior.
+ *
+ * See also dma_fence_wait() and dma_fence_wait_timeout().
+ */
+signed long
+dma_fence_wait_any_timeout(struct dma_fence **fences, uint32_t count,
+			   bool intr, signed long timeout, uint32_t *idx)
+{
+	struct default_wait_cb *cb;
+	signed long ret = timeout;
+	unsigned i;
+
+	if (WARN_ON(!fences || !count || timeout < 0))
+		return -EINVAL;
+
+	if (timeout == 0) {
+		for (i = 0; i < count; ++i)
+			if (dma_fence_is_signaled(fences[i])) {
+				if (idx)
+					*idx = i;
+				return 1;
+			}
+
+		return 0;
+	}
+
+	cb = kcalloc(count, sizeof(struct default_wait_cb), GFP_KERNEL);
+	if (cb == NULL) {
+		ret = -ENOMEM;
+		goto err_free_cb;
+	}
+
+	for (i = 0; i < count; ++i) {
+		struct dma_fence *fence = fences[i];
+
+		cb[i].task = current;
+		if (dma_fence_add_callback(fence, &cb[i].base,
+					   dma_fence_default_wait_cb)) {
+			/* This fence is already signaled */
+			if (idx)
+				*idx = i;
+			goto fence_rm_cb;
+		}
+	}
+
+	while (ret > 0) {
+		if (intr)
+			set_current_state(TASK_INTERRUPTIBLE);
+		else
+			set_current_state(TASK_UNINTERRUPTIBLE);
+
+		if (dma_fence_test_signaled_any(fences, count, idx))
+			break;
+
+		ret = schedule_timeout(ret);
+
+		if (ret > 0 && intr && signal_pending(current))
+			ret = -ERESTARTSYS;
+	}
+
+	__set_current_state(TASK_RUNNING);
+
+fence_rm_cb:
+	while (i-- > 0)
+		dma_fence_remove_callback(fences[i], &cb[i].base);
+
+err_free_cb:
+	kfree(cb);
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_fence_wait_any_timeout);
+
+/**
+ * dma_fence_init - Initialize a custom fence.
+ * @fence: the fence to initialize
+ * @ops: the dma_fence_ops for operations on this fence
+ * @lock: the irqsafe spinlock to use for locking this fence
+ * @context: the execution context this fence is run on
+ * @seqno: a linear increasing sequence number for this context
+ *
+ * Initializes an allocated fence, the caller doesn't have to keep its
+ * refcount after committing with this fence, but it will need to hold a
+ * refcount again if &dma_fence_ops.enable_signaling gets called.
+ *
+ * context and seqno are used for easy comparison between fences, allowing
+ * to check which fence is later by simply using dma_fence_later().
+ */
+void
+dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops,
+	       spinlock_t *lock, u64 context, u64 seqno)
+{
+	BUG_ON(!lock);
+	BUG_ON(!ops || !ops->get_driver_name || !ops->get_timeline_name);
+
+	kref_init(&fence->refcount);
+	fence->ops = ops;
+	INIT_LIST_HEAD(&fence->cb_list);
+	fence->lock = lock;
+	fence->context = context;
+	fence->seqno = seqno;
+	fence->flags = 0UL;
+	fence->error = 0;
+
+	trace_dma_fence_init(fence);
+}
+EXPORT_SYMBOL(dma_fence_init);