Merge drm/drm-fixes into drm-misc-fixes

Let's start the fixes cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

8 files changed, 213 insertions, 40 deletions

diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c
index 4b680e10c15a..fbf725fae7c1 100644
--- a/drivers/dma-buf/dma-buf-sysfs-stats.c
+++ b/drivers/dma-buf/dma-buf-sysfs-stats.c
@@ -132,7 +132,7 @@ void dma_buf_stats_teardown(struct dma_buf *dmabuf)
 
 
 /* Statistics files do not need to send uevents. */
-static int dmabuf_sysfs_uevent_filter(struct kobject *kobj)
+static int dmabuf_sysfs_uevent_filter(const struct kobject *kobj)
 {
 	return 0;
 }
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index eb6b59363c4f..e6528767efc7 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -131,6 +131,7 @@ static struct file_system_type dma_buf_fs_type = {
 static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
 {
 	struct dma_buf *dmabuf;
+	int ret;
 
 	if (!is_dma_buf_file(file))
 		return -EINVAL;
@@ -146,7 +147,11 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
 	    dmabuf->size >> PAGE_SHIFT)
 		return -EINVAL;
 
-	return dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_lock(dmabuf->resv, NULL);
+	ret = dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_unlock(dmabuf->resv);
+
+	return ret;
 }
 
 static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
@@ -655,7 +660,6 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 	init_waitqueue_head(&dmabuf->poll);
 	dmabuf->cb_in.poll = dmabuf->cb_out.poll = &dmabuf->poll;
 	dmabuf->cb_in.active = dmabuf->cb_out.active = 0;
-	mutex_init(&dmabuf->lock);
 	INIT_LIST_HEAD(&dmabuf->attachments);
 
 	if (!resv) {
@@ -801,6 +805,70 @@ static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach,
 }
 
 /**
+ * DOC: locking convention
+ *
+ * In order to avoid deadlock situations between dma-buf exports and importers,
+ * all dma-buf API users must follow the common dma-buf locking convention.
+ *
+ * Convention for importers
+ *
+ * 1. Importers must hold the dma-buf reservation lock when calling these
+ *    functions:
+ *
+ *     - dma_buf_pin()
+ *     - dma_buf_unpin()
+ *     - dma_buf_map_attachment()
+ *     - dma_buf_unmap_attachment()
+ *     - dma_buf_vmap()
+ *     - dma_buf_vunmap()
+ *
+ * 2. Importers must not hold the dma-buf reservation lock when calling these
+ *    functions:
+ *
+ *     - dma_buf_attach()
+ *     - dma_buf_dynamic_attach()
+ *     - dma_buf_detach()
+ *     - dma_buf_export(
+ *     - dma_buf_fd()
+ *     - dma_buf_get()
+ *     - dma_buf_put()
+ *     - dma_buf_mmap()
+ *     - dma_buf_begin_cpu_access()
+ *     - dma_buf_end_cpu_access()
+ *     - dma_buf_map_attachment_unlocked()
+ *     - dma_buf_unmap_attachment_unlocked()
+ *     - dma_buf_vmap_unlocked()
+ *     - dma_buf_vunmap_unlocked()
+ *
+ * Convention for exporters
+ *
+ * 1. These &dma_buf_ops callbacks are invoked with unlocked dma-buf
+ *    reservation and exporter can take the lock:
+ *
+ *     - &dma_buf_ops.attach()
+ *     - &dma_buf_ops.detach()
+ *     - &dma_buf_ops.release()
+ *     - &dma_buf_ops.begin_cpu_access()
+ *     - &dma_buf_ops.end_cpu_access()
+ *
+ * 2. These &dma_buf_ops callbacks are invoked with locked dma-buf
+ *    reservation and exporter can't take the lock:
+ *
+ *     - &dma_buf_ops.pin()
+ *     - &dma_buf_ops.unpin()
+ *     - &dma_buf_ops.map_dma_buf()
+ *     - &dma_buf_ops.unmap_dma_buf()
+ *     - &dma_buf_ops.mmap()
+ *     - &dma_buf_ops.vmap()
+ *     - &dma_buf_ops.vunmap()
+ *
+ * 3. Exporters must hold the dma-buf reservation lock when calling these
+ *    functions:
+ *
+ *     - dma_buf_move_notify()
+ */
+
+/**
  * dma_buf_dynamic_attach - Add the device to dma_buf's attachments list
  * @dmabuf:		[in]	buffer to attach device to.
  * @dev:		[in]	device to be attached.
@@ -864,8 +932,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 	    dma_buf_is_dynamic(dmabuf)) {
 		struct sg_table *sgt;
 
+		dma_resv_lock(attach->dmabuf->resv, NULL);
 		if (dma_buf_is_dynamic(attach->dmabuf)) {
-			dma_resv_lock(attach->dmabuf->resv, NULL);
 			ret = dmabuf->ops->pin(attach);
 			if (ret)
 				goto err_unlock;
@@ -878,8 +946,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 			ret = PTR_ERR(sgt);
 			goto err_unpin;
 		}
-		if (dma_buf_is_dynamic(attach->dmabuf))
-			dma_resv_unlock(attach->dmabuf->resv);
+		dma_resv_unlock(attach->dmabuf->resv);
 		attach->sgt = sgt;
 		attach->dir = DMA_BIDIRECTIONAL;
 	}
@@ -895,8 +962,7 @@ err_unpin:
 		dmabuf->ops->unpin(attach);
 
 err_unlock:
-	if (dma_buf_is_dynamic(attach->dmabuf))
-		dma_resv_unlock(attach->dmabuf->resv);
+	dma_resv_unlock(attach->dmabuf->resv);
 
 	dma_buf_detach(dmabuf, attach);
 	return ERR_PTR(ret);
@@ -939,24 +1005,22 @@ static void __unmap_dma_buf(struct dma_buf_attachment *attach,
  */
 void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
 {
-	if (WARN_ON(!dmabuf || !attach))
+	if (WARN_ON(!dmabuf || !attach || dmabuf != attach->dmabuf))
 		return;
 
+	dma_resv_lock(dmabuf->resv, NULL);
+
 	if (attach->sgt) {
-		if (dma_buf_is_dynamic(attach->dmabuf))
-			dma_resv_lock(attach->dmabuf->resv, NULL);
 
 		__unmap_dma_buf(attach, attach->sgt, attach->dir);
 
-		if (dma_buf_is_dynamic(attach->dmabuf)) {
+		if (dma_buf_is_dynamic(attach->dmabuf))
 			dmabuf->ops->unpin(attach);
-			dma_resv_unlock(attach->dmabuf->resv);
-		}
 	}
-
-	dma_resv_lock(dmabuf->resv, NULL);
 	list_del(&attach->node);
+
 	dma_resv_unlock(dmabuf->resv);
+
 	if (dmabuf->ops->detach)
 		dmabuf->ops->detach(dmabuf, attach);
 
@@ -1047,8 +1111,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf))
 		return ERR_PTR(-EINVAL);
 
-	if (dma_buf_attachment_is_dynamic(attach))
-		dma_resv_assert_held(attach->dmabuf->resv);
+	dma_resv_assert_held(attach->dmabuf->resv);
 
 	if (attach->sgt) {
 		/*
@@ -1063,7 +1126,6 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 	}
 
 	if (dma_buf_is_dynamic(attach->dmabuf)) {
-		dma_resv_assert_held(attach->dmabuf->resv);
 		if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
 			r = attach->dmabuf->ops->pin(attach);
 			if (r)
@@ -1106,6 +1168,34 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment, DMA_BUF);
 
 /**
+ * dma_buf_map_attachment_unlocked - Returns the scatterlist table of the attachment;
+ * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
+ * dma_buf_ops.
+ * @attach:	[in]	attachment whose scatterlist is to be returned
+ * @direction:	[in]	direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_map_attachment().
+ */
+struct sg_table *
+dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,
+				enum dma_data_direction direction)
+{
+	struct sg_table *sg_table;
+
+	might_sleep();
+
+	if (WARN_ON(!attach || !attach->dmabuf))
+		return ERR_PTR(-EINVAL);
+
+	dma_resv_lock(attach->dmabuf->resv, NULL);
+	sg_table = dma_buf_map_attachment(attach, direction);
+	dma_resv_unlock(attach->dmabuf->resv);
+
+	return sg_table;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment_unlocked, DMA_BUF);
+
+/**
  * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
  * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
  * dma_buf_ops.
@@ -1124,15 +1214,11 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
 		return;
 
-	if (dma_buf_attachment_is_dynamic(attach))
-		dma_resv_assert_held(attach->dmabuf->resv);
+	dma_resv_assert_held(attach->dmabuf->resv);
 
 	if (attach->sgt == sg_table)
 		return;
 
-	if (dma_buf_is_dynamic(attach->dmabuf))
-		dma_resv_assert_held(attach->dmabuf->resv);
-
 	__unmap_dma_buf(attach, sg_table, direction);
 
 	if (dma_buf_is_dynamic(attach->dmabuf) &&
@@ -1142,6 +1228,31 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment, DMA_BUF);
 
 /**
+ * dma_buf_unmap_attachment_unlocked - unmaps and decreases usecount of the buffer;might
+ * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
+ * dma_buf_ops.
+ * @attach:	[in]	attachment to unmap buffer from
+ * @sg_table:	[in]	scatterlist info of the buffer to unmap
+ * @direction:	[in]	direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_unmap_attachment().
+ */
+void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,
+				       struct sg_table *sg_table,
+				       enum dma_data_direction direction)
+{
+	might_sleep();
+
+	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
+		return;
+
+	dma_resv_lock(attach->dmabuf->resv, NULL);
+	dma_buf_unmap_attachment(attach, sg_table, direction);
+	dma_resv_unlock(attach->dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment_unlocked, DMA_BUF);
+
+/**
  * dma_buf_move_notify - notify attachments that DMA-buf is moving
  *
  * @dmabuf:	[in]	buffer which is moving
@@ -1352,6 +1463,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF);
 int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 		 unsigned long pgoff)
 {
+	int ret;
+
 	if (WARN_ON(!dmabuf || !vma))
 		return -EINVAL;
 
@@ -1372,7 +1485,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 	vma_set_file(vma, dmabuf->file);
 	vma->vm_pgoff = pgoff;
 
-	return dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_lock(dmabuf->resv, NULL);
+	ret = dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_unlock(dmabuf->resv);
+
+	return ret;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
 
@@ -1395,42 +1512,68 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
 int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 {
 	struct iosys_map ptr;
-	int ret = 0;
+	int ret;
 
 	iosys_map_clear(map);
 
 	if (WARN_ON(!dmabuf))
 		return -EINVAL;
 
+	dma_resv_assert_held(dmabuf->resv);
+
 	if (!dmabuf->ops->vmap)
 		return -EINVAL;
 
-	mutex_lock(&dmabuf->lock);
 	if (dmabuf->vmapping_counter) {
 		dmabuf->vmapping_counter++;
 		BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
 		*map = dmabuf->vmap_ptr;
-		goto out_unlock;
+		return 0;
 	}
 
 	BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));
 
 	ret = dmabuf->ops->vmap(dmabuf, &ptr);
 	if (WARN_ON_ONCE(ret))
-		goto out_unlock;
+		return ret;
 
 	dmabuf->vmap_ptr = ptr;
 	dmabuf->vmapping_counter = 1;
 
 	*map = dmabuf->vmap_ptr;
 
-out_unlock:
-	mutex_unlock(&dmabuf->lock);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
 
 /**
+ * dma_buf_vmap_unlocked - Create virtual mapping for the buffer object into kernel
+ * address space. Same restrictions as for vmap and friends apply.
+ * @dmabuf:	[in]	buffer to vmap
+ * @map:	[out]	returns the vmap pointer
+ *
+ * Unlocked version of dma_buf_vmap()
+ *
+ * Returns 0 on success, or a negative errno code otherwise.
+ */
+int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+	int ret;
+
+	iosys_map_clear(map);
+
+	if (WARN_ON(!dmabuf))
+		return -EINVAL;
+
+	dma_resv_lock(dmabuf->resv, NULL);
+	ret = dma_buf_vmap(dmabuf, map);
+	dma_resv_unlock(dmabuf->resv);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vmap_unlocked, DMA_BUF);
+
+/**
  * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
  * @dmabuf:	[in]	buffer to vunmap
  * @map:	[in]	vmap pointer to vunmap
@@ -1440,20 +1583,36 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	if (WARN_ON(!dmabuf))
 		return;
 
+	dma_resv_assert_held(dmabuf->resv);
+
 	BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
 	BUG_ON(dmabuf->vmapping_counter == 0);
 	BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));
 
-	mutex_lock(&dmabuf->lock);
 	if (--dmabuf->vmapping_counter == 0) {
 		if (dmabuf->ops->vunmap)
 			dmabuf->ops->vunmap(dmabuf, map);
 		iosys_map_clear(&dmabuf->vmap_ptr);
 	}
-	mutex_unlock(&dmabuf->lock);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
 
+/**
+ * dma_buf_vunmap_unlocked - Unmap a vmap obtained by dma_buf_vmap.
+ * @dmabuf:	[in]	buffer to vunmap
+ * @map:	[in]	vmap pointer to vunmap
+ */
+void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+	if (WARN_ON(!dmabuf))
+		return;
+
+	dma_resv_lock(dmabuf->resv, NULL);
+	dma_buf_vunmap(dmabuf, map);
+	dma_resv_unlock(dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap_unlocked, DMA_BUF);
+
 #ifdef CONFIG_DEBUG_FS
 static int dma_buf_debug_show(struct seq_file *s, void *unused)
 {
diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index 59d158873f4c..c9e41e8a9e27 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -301,7 +301,7 @@ err0:
 	return err_ret;
 }
 
-static char *dma_heap_devnode(struct device *dev, umode_t *mode)
+static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
 }
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index e3885c90a3ac..1c76aed8e262 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -98,12 +98,17 @@ static void dma_resv_list_set(struct dma_resv_list *list,
 static struct dma_resv_list *dma_resv_list_alloc(unsigned int max_fences)
 {
 	struct dma_resv_list *list;
+	size_t size;
 
-	list = kmalloc(struct_size(list, table, max_fences), GFP_KERNEL);
+	/* Round up to the next kmalloc bucket size. */
+	size = kmalloc_size_roundup(struct_size(list, table, max_fences));
+
+	list = kmalloc(size, GFP_KERNEL);
 	if (!list)
 		return NULL;
 
-	list->max_fences = (ksize(list) - offsetof(typeof(*list), table)) /
+	/* Given the resulting bucket size, recalculated max_fences. */
+	list->max_fences = (size - offsetof(typeof(*list), table)) /
 		sizeof(*list->table);
 
 	return list;
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 28fb04eccdd0..1131fb943992 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -13,6 +13,7 @@
 #include <linux/dma-buf.h>
 #include <linux/dma-heap.h>
 #include <linux/dma-map-ops.h>
+#include <linux/dma-resv.h>
 #include <linux/err.h>
 #include <linux/highmem.h>
 #include <linux/io.h>
@@ -182,6 +183,8 @@ static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
 {
 	struct cma_heap_buffer *buffer = dmabuf->priv;
 
+	dma_resv_assert_held(dmabuf->resv);
+
 	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
 		return -EINVAL;
 
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index fcf836ba9c1f..e8bd10e60998 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -13,6 +13,7 @@
 #include <linux/dma-buf.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-heap.h>
+#include <linux/dma-resv.h>
 #include <linux/err.h>
 #include <linux/highmem.h>
 #include <linux/mm.h>
@@ -201,6 +202,8 @@ static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
 	struct sg_page_iter piter;
 	int ret;
 
+	dma_resv_assert_held(dmabuf->resv);
+
 	for_each_sgtable_page(table, &piter, vma->vm_pgoff) {
 		struct page *page = sg_page_iter_page(&piter);
 
diff --git a/drivers/dma-buf/st-dma-fence-chain.c b/drivers/dma-buf/st-dma-fence-chain.c
index 0a9b099d0518..c0979c8049b5 100644
--- a/drivers/dma-buf/st-dma-fence-chain.c
+++ b/drivers/dma-buf/st-dma-fence-chain.c
@@ -400,7 +400,7 @@ static int __find_race(void *arg)
 		struct dma_fence *fence = dma_fence_get(data->fc.tail);
 		int seqno;
 
-		seqno = prandom_u32_max(data->fc.chain_length) + 1;
+		seqno = get_random_u32_inclusive(1, data->fc.chain_length);
 
 		err = dma_fence_chain_find_seqno(&fence, seqno);
 		if (err) {
@@ -429,7 +429,7 @@ static int __find_race(void *arg)
 		dma_fence_put(fence);
 
 signal:
-		seqno = prandom_u32_max(data->fc.chain_length - 1);
+		seqno = get_random_u32_below(data->fc.chain_length - 1);
 		dma_fence_signal(data->fc.fences[seqno]);
 		cond_resched();
 	}
@@ -637,7 +637,7 @@ static void randomise_fences(struct fence_chains *fc)
 	while (--count) {
 		unsigned int swp;
 
-		swp = prandom_u32_max(count + 1);
+		swp = get_random_u32_below(count + 1);
 		if (swp == count)
 			continue;
 
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 2bcdb935a3ac..283816fbd72f 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -2,6 +2,7 @@
 #include <linux/cred.h>
 #include <linux/device.h>
 #include <linux/dma-buf.h>
+#include <linux/dma-resv.h>
 #include <linux/highmem.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -49,6 +50,8 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma)
 {
 	struct udmabuf *ubuf = buf->priv;
 
+	dma_resv_assert_held(buf->resv);
+
 	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
 		return -EINVAL;