Merge branch 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall...
[linux-2.6-microblaze.git] / drivers / dma-buf / dma-resv.c
index 6ddbeb5..f26c717 100644 (file)
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: MIT
 /*
  * Copyright (C) 2012-2014 Canonical Ltd (Maarten Lankhorst)
  *
@@ -92,49 +93,6 @@ static void dma_resv_list_free(struct dma_resv_list *list)
        kfree_rcu(list, rcu);
 }
 
-#if IS_ENABLED(CONFIG_LOCKDEP)
-static int __init dma_resv_lockdep(void)
-{
-       struct mm_struct *mm = mm_alloc();
-       struct ww_acquire_ctx ctx;
-       struct dma_resv obj;
-       struct address_space mapping;
-       int ret;
-
-       if (!mm)
-               return -ENOMEM;
-
-       dma_resv_init(&obj);
-       address_space_init_once(&mapping);
-
-       mmap_read_lock(mm);
-       ww_acquire_init(&ctx, &reservation_ww_class);
-       ret = dma_resv_lock(&obj, &ctx);
-       if (ret == -EDEADLK)
-               dma_resv_lock_slow(&obj, &ctx);
-       fs_reclaim_acquire(GFP_KERNEL);
-       /* for unmap_mapping_range on trylocked buffer objects in shrinkers */
-       i_mmap_lock_write(&mapping);
-       i_mmap_unlock_write(&mapping);
-#ifdef CONFIG_MMU_NOTIFIER
-       lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
-       __dma_fence_might_wait();
-       lock_map_release(&__mmu_notifier_invalidate_range_start_map);
-#else
-       __dma_fence_might_wait();
-#endif
-       fs_reclaim_release(GFP_KERNEL);
-       ww_mutex_unlock(&obj.lock);
-       ww_acquire_fini(&ctx);
-       mmap_read_unlock(mm);
-       
-       mmput(mm);
-
-       return 0;
-}
-subsys_initcall(dma_resv_lockdep);
-#endif
-
 /**
  * dma_resv_init - initialize a reservation object
  * @obj: the reservation object
@@ -191,14 +149,11 @@ int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences)
 
        dma_resv_assert_held(obj);
 
-       old = dma_resv_get_list(obj);
-
+       old = dma_resv_shared_list(obj);
        if (old && old->shared_max) {
                if ((old->shared_count + num_fences) <= old->shared_max)
                        return 0;
-               else
-                       max = max(old->shared_count + num_fences,
-                                 old->shared_max * 2);
+               max = max(old->shared_count + num_fences, old->shared_max * 2);
        } else {
                max = max(4ul, roundup_pow_of_two(num_fences));
        }
@@ -252,6 +207,28 @@ int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences)
 }
 EXPORT_SYMBOL(dma_resv_reserve_shared);
 
+#ifdef CONFIG_DEBUG_MUTEXES
+/**
+ * dma_resv_reset_shared_max - reset shared fences for debugging
+ * @obj: the dma_resv object to reset
+ *
+ * Reset the number of pre-reserved shared slots to test that drivers do
+ * correct slot allocation using dma_resv_reserve_shared(). See also
+ * &dma_resv_list.shared_max.
+ */
+void dma_resv_reset_shared_max(struct dma_resv *obj)
+{
+       struct dma_resv_list *fences = dma_resv_shared_list(obj);
+
+       dma_resv_assert_held(obj);
+
+       /* Test shared fence slot reservation */
+       if (fences)
+               fences->shared_max = fences->shared_count;
+}
+EXPORT_SYMBOL(dma_resv_reset_shared_max);
+#endif
+
 /**
  * dma_resv_add_shared_fence - Add a fence to a shared slot
  * @obj: the reservation object
@@ -270,7 +247,7 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence)
 
        dma_resv_assert_held(obj);
 
-       fobj = dma_resv_get_list(obj);
+       fobj = dma_resv_shared_list(obj);
        count = fobj->shared_count;
 
        write_seqcount_begin(&obj->seq);
@@ -307,13 +284,13 @@ EXPORT_SYMBOL(dma_resv_add_shared_fence);
  */
 void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence)
 {
-       struct dma_fence *old_fence = dma_resv_get_excl(obj);
+       struct dma_fence *old_fence = dma_resv_excl_fence(obj);
        struct dma_resv_list *old;
        u32 i = 0;
 
        dma_resv_assert_held(obj);
 
-       old = dma_resv_get_list(obj);
+       old = dma_resv_shared_list(obj);
        if (old)
                i = old->shared_count;
 
@@ -337,26 +314,26 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence)
 EXPORT_SYMBOL(dma_resv_add_excl_fence);
 
 /**
-* dma_resv_copy_fences - Copy all fences from src to dst.
-* @dst: the destination reservation object
-* @src: the source reservation object
-*
-* Copy all fences from src to dst. dst-lock must be held.
-*/
+ * dma_resv_copy_fences - Copy all fences from src to dst.
+ * @dst: the destination reservation object
+ * @src: the source reservation object
+ *
+ * Copy all fences from src to dst. dst-lock must be held.
+ */
 int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
 {
        struct dma_resv_list *src_list, *dst_list;
        struct dma_fence *old, *new;
-       unsigned i;
+       unsigned int i;
 
        dma_resv_assert_held(dst);
 
        rcu_read_lock();
-       src_list = rcu_dereference(src->fence);
+       src_list = dma_resv_shared_list(src);
 
 retry:
        if (src_list) {
-               unsigned shared_count = src_list->shared_count;
+               unsigned int shared_count = src_list->shared_count;
 
                rcu_read_unlock();
 
@@ -365,7 +342,7 @@ retry:
                        return -ENOMEM;
 
                rcu_read_lock();
-               src_list = rcu_dereference(src->fence);
+               src_list = dma_resv_shared_list(src);
                if (!src_list || src_list->shared_count > shared_count) {
                        kfree(dst_list);
                        goto retry;
@@ -373,6 +350,7 @@ retry:
 
                dst_list->shared_count = 0;
                for (i = 0; i < src_list->shared_count; ++i) {
+                       struct dma_fence __rcu **dst;
                        struct dma_fence *fence;
 
                        fence = rcu_dereference(src_list->shared[i]);
@@ -382,7 +360,7 @@ retry:
 
                        if (!dma_fence_get_rcu(fence)) {
                                dma_resv_list_free(dst_list);
-                               src_list = rcu_dereference(src->fence);
+                               src_list = dma_resv_shared_list(src);
                                goto retry;
                        }
 
@@ -391,7 +369,8 @@ retry:
                                continue;
                        }
 
-                       rcu_assign_pointer(dst_list->shared[dst_list->shared_count++], fence);
+                       dst = &dst_list->shared[dst_list->shared_count++];
+                       rcu_assign_pointer(*dst, fence);
                }
        } else {
                dst_list = NULL;
@@ -400,8 +379,8 @@ retry:
        new = dma_fence_get_rcu_safe(&src->fence_excl);
        rcu_read_unlock();
 
-       src_list = dma_resv_get_list(dst);
-       old = dma_resv_get_excl(dst);
+       src_list = dma_resv_shared_list(dst);
+       old = dma_resv_excl_fence(dst);
 
        write_seqcount_begin(&dst->seq);
        /* write_seqcount_begin provides the necessary memory barrier */
@@ -417,7 +396,7 @@ retry:
 EXPORT_SYMBOL(dma_resv_copy_fences);
 
 /**
- * dma_resv_get_fences_rcu - Get an object's shared and exclusive
+ * dma_resv_get_fences - Get an object's shared and exclusive
  * fences without update side lock held
  * @obj: the reservation object
  * @pfence_excl: the returned exclusive fence (or NULL)
@@ -429,10 +408,9 @@ EXPORT_SYMBOL(dma_resv_copy_fences);
  * exclusive fence is not specified the fence is put into the array of the
  * shared fences as well. Returns either zero or -ENOMEM.
  */
-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_get_fences(struct dma_resv *obj, struct dma_fence **pfence_excl,
+                       unsigned int *pshared_count,
+                       struct dma_fence ***pshared)
 {
        struct dma_fence **shared = NULL;
        struct dma_fence *fence_excl;
@@ -449,11 +427,11 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj,
                rcu_read_lock();
                seq = read_seqcount_begin(&obj->seq);
 
-               fence_excl = rcu_dereference(obj->fence_excl);
+               fence_excl = dma_resv_excl_fence(obj);
                if (fence_excl && !dma_fence_get_rcu(fence_excl))
                        goto unlock;
 
-               fobj = rcu_dereference(obj->fence);
+               fobj = dma_resv_shared_list(obj);
                if (fobj)
                        sz += sizeof(*shared) * fobj->shared_max;
 
@@ -515,27 +493,28 @@ unlock:
        *pshared = shared;
        return ret;
 }
-EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu);
+EXPORT_SYMBOL_GPL(dma_resv_get_fences);
 
 /**
- * dma_resv_wait_timeout_rcu - Wait on reservation's objects
+ * dma_resv_wait_timeout - Wait on reservation's objects
  * shared and/or exclusive fences.
  * @obj: the reservation object
  * @wait_all: if true, wait on all fences, else wait on just exclusive fence
  * @intr: if true, do interruptible wait
  * @timeout: timeout value in jiffies or zero to return immediately
  *
+ * Callers are not required to hold specific locks, but maybe hold
+ * dma_resv_lock() already
  * RETURNS
  * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
  * greater than zer on success.
  */
-long dma_resv_wait_timeout_rcu(struct dma_resv *obj,
-                              bool wait_all, bool intr,
-                              unsigned long timeout)
+long dma_resv_wait_timeout(struct dma_resv *obj, bool wait_all, bool intr,
+                          unsigned long timeout)
 {
-       struct dma_fence *fence;
-       unsigned seq, shared_count;
        long ret = timeout ? timeout : 1;
+       unsigned int seq, shared_count;
+       struct dma_fence *fence;
        int i;
 
 retry:
@@ -544,7 +523,7 @@ retry:
        rcu_read_lock();
        i = -1;
 
-       fence = rcu_dereference(obj->fence_excl);
+       fence = dma_resv_excl_fence(obj);
        if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
                if (!dma_fence_get_rcu(fence))
                        goto unlock_retry;
@@ -559,14 +538,15 @@ retry:
        }
 
        if (wait_all) {
-               struct dma_resv_list *fobj = rcu_dereference(obj->fence);
+               struct dma_resv_list *fobj = dma_resv_shared_list(obj);
 
                if (fobj)
                        shared_count = fobj->shared_count;
 
                for (i = 0; !fence && i < shared_count; ++i) {
-                       struct dma_fence *lfence = rcu_dereference(fobj->shared[i]);
+                       struct dma_fence *lfence;
 
+                       lfence = rcu_dereference(fobj->shared[i]);
                        if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
                                     &lfence->flags))
                                continue;
@@ -602,7 +582,7 @@ unlock_retry:
        rcu_read_unlock();
        goto retry;
 }
-EXPORT_SYMBOL_GPL(dma_resv_wait_timeout_rcu);
+EXPORT_SYMBOL_GPL(dma_resv_wait_timeout);
 
 
 static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
@@ -622,18 +602,20 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
 }
 
 /**
- * dma_resv_test_signaled_rcu - Test if a reservation object's
- * fences have been signaled.
+ * dma_resv_test_signaled - Test if a reservation object's fences have been
+ * signaled.
  * @obj: the reservation object
  * @test_all: if true, test all fences, otherwise only test the exclusive
  * fence
  *
+ * Callers are not required to hold specific locks, but maybe hold
+ * dma_resv_lock() already
  * RETURNS
  * true if all fences signaled, else false
  */
-bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
+bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all)
 {
-       unsigned seq, shared_count;
+       unsigned int seq, shared_count;
        int ret;
 
        rcu_read_lock();
@@ -643,16 +625,16 @@ retry:
        seq = read_seqcount_begin(&obj->seq);
 
        if (test_all) {
-               unsigned i;
-
-               struct dma_resv_list *fobj = rcu_dereference(obj->fence);
+               struct dma_resv_list *fobj = dma_resv_shared_list(obj);
+               unsigned int i;
 
                if (fobj)
                        shared_count = fobj->shared_count;
 
                for (i = 0; i < shared_count; ++i) {
-                       struct dma_fence *fence = rcu_dereference(fobj->shared[i]);
+                       struct dma_fence *fence;
 
+                       fence = rcu_dereference(fobj->shared[i]);
                        ret = dma_resv_test_signaled_single(fence);
                        if (ret < 0)
                                goto retry;
@@ -665,7 +647,7 @@ retry:
        }
 
        if (!shared_count) {
-               struct dma_fence *fence_excl = rcu_dereference(obj->fence_excl);
+               struct dma_fence *fence_excl = dma_resv_excl_fence(obj);
 
                if (fence_excl) {
                        ret = dma_resv_test_signaled_single(fence_excl);
@@ -680,4 +662,47 @@ retry:
        rcu_read_unlock();
        return ret;
 }
-EXPORT_SYMBOL_GPL(dma_resv_test_signaled_rcu);
+EXPORT_SYMBOL_GPL(dma_resv_test_signaled);
+
+#if IS_ENABLED(CONFIG_LOCKDEP)
+static int __init dma_resv_lockdep(void)
+{
+       struct mm_struct *mm = mm_alloc();
+       struct ww_acquire_ctx ctx;
+       struct dma_resv obj;
+       struct address_space mapping;
+       int ret;
+
+       if (!mm)
+               return -ENOMEM;
+
+       dma_resv_init(&obj);
+       address_space_init_once(&mapping);
+
+       mmap_read_lock(mm);
+       ww_acquire_init(&ctx, &reservation_ww_class);
+       ret = dma_resv_lock(&obj, &ctx);
+       if (ret == -EDEADLK)
+               dma_resv_lock_slow(&obj, &ctx);
+       fs_reclaim_acquire(GFP_KERNEL);
+       /* for unmap_mapping_range on trylocked buffer objects in shrinkers */
+       i_mmap_lock_write(&mapping);
+       i_mmap_unlock_write(&mapping);
+#ifdef CONFIG_MMU_NOTIFIER
+       lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
+       __dma_fence_might_wait();
+       lock_map_release(&__mmu_notifier_invalidate_range_start_map);
+#else
+       __dma_fence_might_wait();
+#endif
+       fs_reclaim_release(GFP_KERNEL);
+       ww_mutex_unlock(&obj.lock);
+       ww_acquire_fini(&ctx);
+       mmap_read_unlock(mm);
+
+       mmput(mm);
+
+       return 0;
+}
+subsys_initcall(dma_resv_lockdep);
+#endif