dma-buf: rename reservation_object to dma_resv

Be more consistent with the naming of the other DMA-buf objects.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/323401/

1 files changed, 312 insertions, 0 deletions

diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
new file mode 100644
index 000000000000..38f2802afabb
--- /dev/null
+++ b/include/linux/dma-resv.h
@@ -0,0 +1,312 @@
+/*
+ * Header file for reservations for dma-buf and ttm
+ *
+ * Copyright(C) 2011 Linaro Limited. All rights reserved.
+ * Copyright (C) 2012-2013 Canonical Ltd
+ * Copyright (C) 2012 Texas Instruments
+ *
+ * Authors:
+ * Rob Clark <robdclark@gmail.com>
+ * Maarten Lankhorst <maarten.lankhorst@canonical.com>
+ * Thomas Hellstrom <thellstrom-at-vmware-dot-com>
+ *
+ * Based on bo.c which bears the following copyright notice,
+ * but is dual licensed:
+ *
+ * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef _LINUX_RESERVATION_H
+#define _LINUX_RESERVATION_H
+
+#include <linux/ww_mutex.h>
+#include <linux/dma-fence.h>
+#include <linux/slab.h>
+#include <linux/seqlock.h>
+#include <linux/rcupdate.h>
+
+extern struct ww_class reservation_ww_class;
+
+/**
+ * struct dma_resv_list - a list of shared fences
+ * @rcu: for internal use
+ * @shared_count: table of shared fences
+ * @shared_max: for growing shared fence table
+ * @shared: shared fence table
+ */
+struct dma_resv_list {
+	struct rcu_head rcu;
+	u32 shared_count, shared_max;
+	struct dma_fence __rcu *shared[];
+};
+
+/**
+ * struct dma_resv - a reservation object manages fences for a buffer
+ * @lock: update side lock
+ * @seq: sequence count for managing RCU read-side synchronization
+ * @fence_excl: the exclusive fence, if there is one currently
+ * @fence: list of current shared fences
+ */
+struct dma_resv {
+	struct ww_mutex lock;
+
+	struct dma_fence __rcu *fence_excl;
+	struct dma_resv_list __rcu *fence;
+};
+
+#define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
+#define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
+
+/**
+ * dma_resv_get_excl - get the reservation object's
+ * exclusive fence, with update-side lock held
+ * @obj: the reservation object
+ *
+ * Returns the exclusive fence (if any).  Does NOT take a
+ * reference. Writers must hold obj->lock, readers may only
+ * hold a RCU read side lock.
+ *
+ * RETURNS
+ * The exclusive fence or NULL
+ */
+static inline struct dma_fence *dma_resv_get_excl(struct dma_resv *obj)
+{
+	return rcu_dereference_protected(obj->fence_excl,
+					 dma_resv_held(obj));
+}
+
+/**
+ * dma_resv_get_list - get the reservation object's
+ * shared fence list, with update-side lock held
+ * @obj: the reservation object
+ *
+ * Returns the shared fence list.  Does NOT take references to
+ * the fence.  The obj->lock must be held.
+ */
+static inline struct dma_resv_list *dma_resv_get_list(struct dma_resv *obj)
+{
+	return rcu_dereference_protected(obj->fence,
+					 dma_resv_held(obj));
+}
+
+/**
+ * dma_resv_fences - read consistent fence pointers
+ * @obj: reservation object where we get the fences from
+ * @excl: pointer for the exclusive fence
+ * @list: pointer for the shared fence list
+ *
+ * Make sure we have a consisten exclusive fence and shared fence list.
+ * Must be called with rcu read side lock held.
+ */
+static inline void dma_resv_fences(struct dma_resv *obj,
+				   struct dma_fence **excl,
+				   struct dma_resv_list **list,
+				   u32 *shared_count)
+{
+	do {
+		*excl = rcu_dereference(obj->fence_excl);
+		*list = rcu_dereference(obj->fence);
+		*shared_count = *list ? (*list)->shared_count : 0;
+		smp_rmb(); /* See dma_resv_add_excl_fence */
+	} while (rcu_access_pointer(obj->fence_excl) != *excl);
+}
+
+/**
+ * dma_resv_get_excl_rcu - get the reservation object's
+ * exclusive fence, without lock held.
+ * @obj: the reservation object
+ *
+ * If there is an exclusive fence, this atomically increments it's
+ * reference count and returns it.
+ *
+ * RETURNS
+ * The exclusive fence or NULL if none
+ */
+static inline struct dma_fence *dma_resv_get_excl_rcu(struct dma_resv *obj)
+{
+	struct dma_fence *fence;
+
+	if (!rcu_access_pointer(obj->fence_excl))
+		return NULL;
+
+	rcu_read_lock();
+	fence = dma_fence_get_rcu_safe(&obj->fence_excl);
+	rcu_read_unlock();
+
+	return fence;
+}
+
+/**
+ * dma_resv_lock - lock the reservation object
+ * @obj: the reservation object
+ * @ctx: the locking context
+ *
+ * Locks the reservation object for exclusive access and modification. Note,
+ * that the lock is only against other writers, readers will run concurrently
+ * with a writer under RCU. The seqlock is used to notify readers if they
+ * overlap with a writer.
+ *
+ * As the reservation object may be locked by multiple parties in an
+ * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle
+ * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation
+ * object may be locked by itself by passing NULL as @ctx.
+ */
+static inline int dma_resv_lock(struct dma_resv *obj,
+				struct ww_acquire_ctx *ctx)
+{
+	return ww_mutex_lock(&obj->lock, ctx);
+}
+
+/**
+ * dma_resv_lock_interruptible - lock the reservation object
+ * @obj: the reservation object
+ * @ctx: the locking context
+ *
+ * Locks the reservation object interruptible for exclusive access and
+ * modification. Note, that the lock is only against other writers, readers
+ * will run concurrently with a writer under RCU. The seqlock is used to
+ * notify readers if they overlap with a writer.
+ *
+ * As the reservation object may be locked by multiple parties in an
+ * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle
+ * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation
+ * object may be locked by itself by passing NULL as @ctx.
+ */
+static inline int dma_resv_lock_interruptible(struct dma_resv *obj,
+					      struct ww_acquire_ctx *ctx)
+{
+	return ww_mutex_lock_interruptible(&obj->lock, ctx);
+}
+
+/**
+ * dma_resv_lock_slow - slowpath lock the reservation object
+ * @obj: the reservation object
+ * @ctx: the locking context
+ *
+ * Acquires the reservation object after a die case. This function
+ * will sleep until the lock becomes available. See dma_resv_lock() as
+ * well.
+ */
+static inline void dma_resv_lock_slow(struct dma_resv *obj,
+				      struct ww_acquire_ctx *ctx)
+{
+	ww_mutex_lock_slow(&obj->lock, ctx);
+}
+
+/**
+ * dma_resv_lock_slow_interruptible - slowpath lock the reservation
+ * object, interruptible
+ * @obj: the reservation object
+ * @ctx: the locking context
+ *
+ * Acquires the reservation object interruptible after a die case. This function
+ * will sleep until the lock becomes available. See
+ * dma_resv_lock_interruptible() as well.
+ */
+static inline int dma_resv_lock_slow_interruptible(struct dma_resv *obj,
+						   struct ww_acquire_ctx *ctx)
+{
+	return ww_mutex_lock_slow_interruptible(&obj->lock, ctx);
+}
+
+/**
+ * dma_resv_trylock - trylock the reservation object
+ * @obj: the reservation object
+ *
+ * Tries to lock the reservation object for exclusive access and modification.
+ * Note, that the lock is only against other writers, readers will run
+ * concurrently with a writer under RCU. The seqlock is used to notify readers
+ * if they overlap with a writer.
+ *
+ * Also note that since no context is provided, no deadlock protection is
+ * possible.
+ *
+ * Returns true if the lock was acquired, false otherwise.
+ */
+static inline bool __must_check dma_resv_trylock(struct dma_resv *obj)
+{
+	return ww_mutex_trylock(&obj->lock);
+}
+
+/**
+ * dma_resv_is_locked - is the reservation object locked
+ * @obj: the reservation object
+ *
+ * Returns true if the mutex is locked, false if unlocked.
+ */
+static inline bool dma_resv_is_locked(struct dma_resv *obj)
+{
+	return ww_mutex_is_locked(&obj->lock);
+}
+
+/**
+ * dma_resv_locking_ctx - returns the context used to lock the object
+ * @obj: the reservation object
+ *
+ * Returns the context used to lock a reservation object or NULL if no context
+ * was used or the object is not locked at all.
+ */
+static inline struct ww_acquire_ctx *dma_resv_locking_ctx(struct dma_resv *obj)
+{
+	return READ_ONCE(obj->lock.ctx);
+}
+
+/**
+ * dma_resv_unlock - unlock the reservation object
+ * @obj: the reservation object
+ *
+ * Unlocks the reservation object following exclusive access.
+ */
+static inline void dma_resv_unlock(struct dma_resv *obj)
+{
+#ifdef CONFIG_DEBUG_MUTEXES
+	/* Test shared fence slot reservation */
+	if (rcu_access_pointer(obj->fence)) {
+		struct dma_resv_list *fence = dma_resv_get_list(obj);
+
+		fence->shared_max = fence->shared_count;
+	}
+#endif
+	ww_mutex_unlock(&obj->lock);
+}
+
+void dma_resv_init(struct dma_resv *obj);
+void dma_resv_fini(struct dma_resv *obj);
+int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences);
+void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence);
+
+void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence);
+
+int dma_resv_get_fences_rcu(struct dma_resv *obj,
+			    struct dma_fence **pfence_excl,
+			    unsigned *pshared_count,
+			    struct dma_fence ***pshared);
+
+int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src);
+
+long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr,
+			       unsigned long timeout);
+
+bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all);
+
+#endif /* _LINUX_RESERVATION_H */