Merge branch 'WIP.locking/seqlocks' into locking/urgent

Pick up the full seqlock series PeterZ is working on.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 3 insertions, 18 deletions

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index b45f8514dc82..a7631352a486 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -51,12 +51,6 @@
 DEFINE_WD_CLASS(reservation_ww_class);
 EXPORT_SYMBOL(reservation_ww_class);
 
-struct lock_class_key reservation_seqcount_class;
-EXPORT_SYMBOL(reservation_seqcount_class);
-
-const char reservation_seqcount_string[] = "reservation_seqcount";
-EXPORT_SYMBOL(reservation_seqcount_string);
-
 /**
  * dma_resv_list_alloc - allocate fence list
  * @shared_max: number of fences we need space for
@@ -135,9 +129,8 @@ subsys_initcall(dma_resv_lockdep);
 void dma_resv_init(struct dma_resv *obj)
 {
 	ww_mutex_init(&obj->lock, &reservation_ww_class);
+	seqcount_ww_mutex_init(&obj->seq, &obj->lock);
 
-	__seqcount_init(&obj->seq, reservation_seqcount_string,
-			&reservation_seqcount_class);
 	RCU_INIT_POINTER(obj->fence, NULL);
 	RCU_INIT_POINTER(obj->fence_excl, NULL);
 }
@@ -267,7 +260,6 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence)
 	fobj = dma_resv_get_list(obj);
 	count = fobj->shared_count;
 
-	preempt_disable();
 	write_seqcount_begin(&obj->seq);
 
 	for (i = 0; i < count; ++i) {
@@ -289,7 +281,6 @@ replace:
 	smp_store_mb(fobj->shared_count, count);
 
 	write_seqcount_end(&obj->seq);
-	preempt_enable();
 	dma_fence_put(old);
 }
 EXPORT_SYMBOL(dma_resv_add_shared_fence);
@@ -316,14 +307,12 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence)
 	if (fence)
 		dma_fence_get(fence);
 
-	preempt_disable();
 	write_seqcount_begin(&obj->seq);
 	/* write_seqcount_begin provides the necessary memory barrier */
 	RCU_INIT_POINTER(obj->fence_excl, fence);
 	if (old)
 		old->shared_count = 0;
 	write_seqcount_end(&obj->seq);
-	preempt_enable();
 
 	/* inplace update, no shared fences */
 	while (i--)
@@ -401,13 +390,11 @@ retry:
 	src_list = dma_resv_get_list(dst);
 	old = dma_resv_get_excl(dst);
 
-	preempt_disable();
 	write_seqcount_begin(&dst->seq);
 	/* write_seqcount_begin provides the necessary memory barrier */
 	RCU_INIT_POINTER(dst->fence_excl, new);
 	RCU_INIT_POINTER(dst->fence, dst_list);
 	write_seqcount_end(&dst->seq);
-	preempt_enable();
 
 	dma_resv_list_free(src_list);
 	dma_fence_put(old);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index b91b5171270f..ff4b583cb96a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -258,11 +258,9 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
 	new->shared_count = k;
 
 	/* Install the new fence list, seqcount provides the barriers */
-	preempt_disable();
 	write_seqcount_begin(&resv->seq);
 	RCU_INIT_POINTER(resv->fence, new);
 	write_seqcount_end(&resv->seq);
-	preempt_enable();
 
 	/* Drop the references to the removed fences or move them to ef_list */
 	for (i = j, k = 0; i < old->shared_count; ++i) {
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ab8067f9ce8c..892aefe88fa7 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6935,7 +6935,7 @@ static struct r5conf *setup_conf(struct mddev *mddev)
 	} else
 		goto abort;
 	spin_lock_init(&conf->device_lock);
-	seqcount_init(&conf->gen_lock);
+	seqcount_spinlock_init(&conf->gen_lock, &conf->device_lock);
 	mutex_init(&conf->cache_size_mutex);
 	init_waitqueue_head(&conf->wait_for_quiescent);
 	init_waitqueue_head(&conf->wait_for_stripe);
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index f90e0704bed9..a2c9e9e9f5ac 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -589,7 +589,7 @@ struct r5conf {
 	int			prev_chunk_sectors;
 	int			prev_algo;
 	short			generation; /* increments with every reshape */
-	seqcount_t		gen_lock;	/* lock against generation changes */
+	seqcount_spinlock_t	gen_lock;	/* lock against generation changes */
 	unsigned long		reshape_checkpoint; /* Time we last updated
 						     * metadata */
 	long long		min_offset_diff; /* minimum difference between