Merge tag 'drm-misc-next-2022-10-20' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 6.2:

UAPI Changes:
  - Documentation for page-flip flags

Cross-subsystem Changes:
  - dma-buf: Add unlocked variant of vmapping and attachment-mapping
    functions

Core Changes:
  - atomic-helpers: CRTC primary plane test fixes
  - connector: TV API consistency improvements, cmdline parsing
    improvements
  - crtc-helpers: Introduce drm_crtc_helper_atomic_check() helper
  - edid: Fixes for HFVSDB parsing,
  - fourcc: Addition of the Vivante tiled modifier
  - makefile: Sort and reorganize the objects files
  - mode_config: Remove fb_base from drm_mode_config_funcs
  - sched: Add a module parameter to change the scheduling policy,
    refcounting fix for fences
  - tests: Sort the Kunit tests in the Makefile, improvements to the
    DP-MST tests
  - ttm: Remove unnecessary drm_mm_clean() call

Driver Changes:
  - New driver: ofdrm
  - Move all drivers to a common dma-buf locking convention
  - bridge:
    - adv7533: Remove dynamic lane switching
    - it6505: Runtime PM support
    - ps8640: Handle AUX defer messages
    - tc358775: Drop soft-reset over I2C
  - ast: Atomic Gamma LUT Support, Convert to SHMEM, various
    improvements
  - lcdif: Support for YUV planes
  - mgag200: Fix PLL Setup on some revisions
  - udl: Modesetting improvements, hot-unplug support
  - vc4: Fix support for PAL-M

Signed-off-by: Dave Airlie <[email protected]>

From: Maxime Ripard <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20221020072405.g3o4hxuk75gmeumw@houat

Author: airlied

Documentation/driver-api/dma-buf.rst

@@ -119,6 +119,12 @@ DMA Buffer ioctls
 
 .. kernel-doc:: include/uapi/linux/dma-buf.h
 
+DMA-BUF locking convention
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/dma-buf/dma-buf.c
+   :doc: locking convention
+
 Kernel Functions and Structures Reference
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

MAINTAINERS

@@ -6692,6 +6692,7 @@ L:	[email protected]
 S:	Maintained
 T:	git git://anongit.freedesktop.org/drm/drm-misc
 F:	drivers/gpu/drm/drm_aperture.c
+F:	drivers/gpu/drm/tiny/ofdrm.c
 F:	drivers/gpu/drm/tiny/simpledrm.c
 F:	drivers/video/aperture.c
 F:	include/drm/drm_aperture.h

drivers/dma-buf/dma-buf.c

@@ -657,7 +657,6 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 
 	dmabuf->file = file;
 
-	mutex_init(&dmabuf->lock);
 	INIT_LIST_HEAD(&dmabuf->attachments);
 
 	mutex_lock(&db_list.lock);
@@ -795,6 +794,70 @@ static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach,
 	return sg_table;
 }
 
+/**
+ * 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.
@@ -859,8 +922,8 @@ 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;
@@ -873,8 +936,7 @@ 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;
 	}
@@ -890,8 +952,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 		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);
@@ -937,21 +998,19 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
 	if (WARN_ON(!dmabuf || !attach))
 		return;
 
+	dma_resv_lock(attach->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);
 
@@ -1042,8 +1101,7 @@ 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) {
 		/*
@@ -1058,7 +1116,6 @@ 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)
@@ -1100,6 +1157,34 @@ 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
@@ -1119,15 +1204,11 @@ 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) &&
@@ -1136,6 +1217,31 @@ 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
  *
@@ -1347,6 +1453,8 @@ 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;
 
@@ -1367,7 +1475,11 @@ 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);
 
@@ -1390,41 +1502,67 @@ 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
@@ -1435,20 +1573,36 @@ 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)
 {