Merge tag 'drm-misc-fixes-2022-04-22' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

Two fixes for the raspberrypi panel initialisation, one fix for a logic
inversion in radeon, a build and pm refcounting fix for vc4, two reverts
for drm_of_get_bridge that caused a number of regression and a locking
regression for amdgpu.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220422084403.2xrhf3jusdej5yo4@houat

12 files changed, 94 insertions, 358 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 970b065e9a6b..d0d0ea565e3d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -128,6 +128,8 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs
 		goto free_chunk;
 	}
 
+	mutex_lock(&p->ctx->lock);
+
 	/* skip guilty context job */
 	if (atomic_read(&p->ctx->guilty) == 1) {
 		ret = -ECANCELED;
@@ -709,6 +711,7 @@ static void amdgpu_cs_parser_fini(struct amdgpu_cs_parser *parser, int error,
 	dma_fence_put(parser->fence);
 
 	if (parser->ctx) {
+		mutex_unlock(&parser->ctx->lock);
 		amdgpu_ctx_put(parser->ctx);
 	}
 	if (parser->bo_list)
@@ -1157,6 +1160,9 @@ static int amdgpu_cs_dependencies(struct amdgpu_device *adev,
 {
 	int i, r;
 
+	/* TODO: Investigate why we still need the context lock */
+	mutex_unlock(&p->ctx->lock);
+
 	for (i = 0; i < p->nchunks; ++i) {
 		struct amdgpu_cs_chunk *chunk;
 
@@ -1167,32 +1173,34 @@ static int amdgpu_cs_dependencies(struct amdgpu_device *adev,
 		case AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES:
 			r = amdgpu_cs_process_fence_dep(p, chunk);
 			if (r)
-				return r;
+				goto out;
 			break;
 		case AMDGPU_CHUNK_ID_SYNCOBJ_IN:
 			r = amdgpu_cs_process_syncobj_in_dep(p, chunk);
 			if (r)
-				return r;
+				goto out;
 			break;
 		case AMDGPU_CHUNK_ID_SYNCOBJ_OUT:
 			r = amdgpu_cs_process_syncobj_out_dep(p, chunk);
 			if (r)
-				return r;
+				goto out;
 			break;
 		case AMDGPU_CHUNK_ID_SYNCOBJ_TIMELINE_WAIT:
 			r = amdgpu_cs_process_syncobj_timeline_in_dep(p, chunk);
 			if (r)
-				return r;
+				goto out;
 			break;
 		case AMDGPU_CHUNK_ID_SYNCOBJ_TIMELINE_SIGNAL:
 			r = amdgpu_cs_process_syncobj_timeline_out_dep(p, chunk);
 			if (r)
-				return r;
+				goto out;
 			break;
 		}
 	}
 
-	return 0;
+out:
+	mutex_lock(&p->ctx->lock);
+	return r;
 }
 
 static void amdgpu_cs_post_dependencies(struct amdgpu_cs_parser *p)
@@ -1368,6 +1376,7 @@ int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 		goto out;
 
 	r = amdgpu_cs_submit(&parser, cs);
+
 out:
 	amdgpu_cs_parser_fini(&parser, r, reserved_buffers);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index 5981c7d9bd48..8f0e6d93bb9c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -237,6 +237,7 @@ static int amdgpu_ctx_init(struct amdgpu_device *adev,
 
 	kref_init(&ctx->refcount);
 	spin_lock_init(&ctx->ring_lock);
+	mutex_init(&ctx->lock);
 
 	ctx->reset_counter = atomic_read(&adev->gpu_reset_counter);
 	ctx->reset_counter_query = ctx->reset_counter;
@@ -357,6 +358,7 @@ static void amdgpu_ctx_fini(struct kref *ref)
 		drm_dev_exit(idx);
 	}
 
+	mutex_destroy(&ctx->lock);
 	kfree(ctx);
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
index d0cbfcea90f7..142f2f87d44c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.h
@@ -49,6 +49,7 @@ struct amdgpu_ctx {
 	bool				preamble_presented;
 	int32_t				init_priority;
 	int32_t				override_priority;
+	struct mutex			lock;
 	atomic_t			guilty;
 	unsigned long			ras_counter_ce;
 	unsigned long			ras_counter_ue;
diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index f4df344509a8..9a2cfab3a177 100644
--- a/drivers/gpu/drm/drm_of.c
+++ b/drivers/gpu/drm/drm_of.c
@@ -214,29 +214,6 @@ int drm_of_encoder_active_endpoint(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
 
-static int find_panel_or_bridge(struct device_node *node,
-				struct drm_panel **panel,
-				struct drm_bridge **bridge)
-{
-	if (panel) {
-		*panel = of_drm_find_panel(node);
-		if (!IS_ERR(*panel))
-			return 0;
-
-		/* Clear the panel pointer in case of error. */
-		*panel = NULL;
-	}
-
-	/* No panel found yet, check for a bridge next. */
-	if (bridge) {
-		*bridge = of_drm_find_bridge(node);
-		if (*bridge)
-			return 0;
-	}
-
-	return -EPROBE_DEFER;
-}
-
 /**
  * drm_of_find_panel_or_bridge - return connected panel or bridge device
  * @np: device tree node containing encoder output ports
@@ -259,44 +236,49 @@ int drm_of_find_panel_or_bridge(const struct device_node *np,
 				struct drm_panel **panel,
 				struct drm_bridge **bridge)
 {
-	struct device_node *node;
-	int ret;
+	int ret = -EPROBE_DEFER;
+	struct device_node *remote;
 
 	if (!panel && !bridge)
 		return -EINVAL;
-
 	if (panel)
 		*panel = NULL;
-	if (bridge)
-		*bridge = NULL;
-
-	/* Check for a graph on the device node first. */
-	if (of_graph_is_present(np)) {
-		node = of_graph_get_remote_node(np, port, endpoint);
-		if (node) {
-			ret = find_panel_or_bridge(node, panel, bridge);
-			of_node_put(node);
-
-			if (!ret)
-				return 0;
-		}
-	}
 
-	/* Otherwise check for any child node other than port/ports. */
-	for_each_available_child_of_node(np, node) {
-		if (of_node_name_eq(node, "port") ||
-		    of_node_name_eq(node, "ports"))
-			continue;
+	/*
+	 * of_graph_get_remote_node() produces a noisy error message if port
+	 * node isn't found and the absence of the port is a legit case here,
+	 * so at first we silently check whether graph presents in the
+	 * device-tree node.
+	 */
+	if (!of_graph_is_present(np))
+		return -ENODEV;
 
-		ret = find_panel_or_bridge(node, panel, bridge);
-		of_node_put(node);
+	remote = of_graph_get_remote_node(np, port, endpoint);
+	if (!remote)
+		return -ENODEV;
+
+	if (panel) {
+		*panel = of_drm_find_panel(remote);
+		if (!IS_ERR(*panel))
+			ret = 0;
+		else
+			*panel = NULL;
+	}
+
+	/* No panel found yet, check for a bridge next. */
+	if (bridge) {
+		if (ret) {
+			*bridge = of_drm_find_bridge(remote);
+			if (*bridge)
+				ret = 0;
+		} else {
+			*bridge = NULL;
+		}
 
-		/* Stop at the first found occurrence. */
-		if (!ret)
-			return 0;
 	}
 
-	return -EPROBE_DEFER;
+	of_node_put(remote);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
 
diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
index 46029c5610c8..145047e19394 100644
--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -229,7 +229,7 @@ static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
 
 	ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
 	if (ret)
-		dev_err(&ts->dsi->dev, "I2C write failed: %d\n", ret);
+		dev_err(&ts->i2c->dev, "I2C write failed: %d\n", ret);
 }
 
 static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
@@ -265,7 +265,7 @@ static int rpi_touchscreen_noop(struct drm_panel *panel)
 	return 0;
 }
 
-static int rpi_touchscreen_enable(struct drm_panel *panel)
+static int rpi_touchscreen_prepare(struct drm_panel *panel)
 {
 	struct rpi_touchscreen *ts = panel_to_ts(panel);
 	int i;
@@ -295,6 +295,13 @@ static int rpi_touchscreen_enable(struct drm_panel *panel)
 	rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
 	msleep(100);
 
+	return 0;
+}
+
+static int rpi_touchscreen_enable(struct drm_panel *panel)
+{
+	struct rpi_touchscreen *ts = panel_to_ts(panel);
+
 	/* Turn on the backlight. */
 	rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
 
@@ -349,7 +356,7 @@ static int rpi_touchscreen_get_modes(struct drm_panel *panel,
 static const struct drm_panel_funcs rpi_touchscreen_funcs = {
 	.disable = rpi_touchscreen_disable,
 	.unprepare = rpi_touchscreen_noop,
-	.prepare = rpi_touchscreen_noop,
+	.prepare = rpi_touchscreen_prepare,
 	.enable = rpi_touchscreen_enable,
 	.get_modes = rpi_touchscreen_get_modes,
 };
diff --git a/drivers/gpu/drm/radeon/radeon_sync.c b/drivers/gpu/drm/radeon/radeon_sync.c
index b991ba1bcd51..f63efd8d5e52 100644
--- a/drivers/gpu/drm/radeon/radeon_sync.c
+++ b/drivers/gpu/drm/radeon/radeon_sync.c
@@ -96,7 +96,7 @@ int radeon_sync_resv(struct radeon_device *rdev,
 	struct dma_fence *f;
 	int r = 0;
 
-	dma_resv_for_each_fence(&cursor, resv, shared, f) {
+	dma_resv_for_each_fence(&cursor, resv, !shared, f) {
 		fence = to_radeon_fence(f);
 		if (fence && fence->rdev == rdev)
 			radeon_sync_fence(sync, fence);
diff --git a/drivers/gpu/drm/vc4/Kconfig b/drivers/gpu/drm/vc4/Kconfig
index de3424fed2fc..6cf2621786e6 100644
--- a/drivers/gpu/drm/vc4/Kconfig
+++ b/drivers/gpu/drm/vc4/Kconfig
@@ -2,6 +2,9 @@
 config DRM_VC4
 	tristate "Broadcom VC4 Graphics"
 	depends on ARCH_BCM || ARCH_BCM2835 || COMPILE_TEST
+	# Make sure not 'y' when RASPBERRYPI_FIRMWARE is 'm'. This can only
+	# happen when COMPILE_TEST=y, hence the added !RASPBERRYPI_FIRMWARE.
+	depends on RASPBERRYPI_FIRMWARE || (COMPILE_TEST && !RASPBERRYPI_FIRMWARE)
 	depends on DRM
 	depends on SND && SND_SOC
 	depends on COMMON_CLK
diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index 752f921735c6..98308a17e4ed 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -846,7 +846,7 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
 	unsigned long phy_clock;
 	int ret;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret) {
 		DRM_ERROR("Failed to runtime PM enable on DSI%d\n", dsi->variant->port);
 		return;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index 31aecc46624b..04c8a378aeed 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -46,6 +46,21 @@ vmw_buffer_object(struct ttm_buffer_object *bo)
 	return container_of(bo, struct vmw_buffer_object, base);
 }
 
+/**
+ * bo_is_vmw - check if the buffer object is a &vmw_buffer_object
+ * @bo: ttm buffer object to be checked
+ *
+ * Uses destroy function associated with the object to determine if this is
+ * a &vmw_buffer_object.
+ *
+ * Returns:
+ * true if the object is of &vmw_buffer_object type, false if not.
+ */
+static bool bo_is_vmw(struct ttm_buffer_object *bo)
+{
+	return bo->destroy == &vmw_bo_bo_free ||
+	       bo->destroy == &vmw_gem_destroy;
+}
 
 /**
  * vmw_bo_pin_in_placement - Validate a buffer to placement.
@@ -615,8 +630,9 @@ int vmw_user_bo_synccpu_ioctl(struct drm_device *dev, void *data,
 
 		ret = vmw_user_bo_synccpu_grab(vbo, arg->flags);
 		vmw_bo_unreference(&vbo);
-		if (unlikely(ret != 0 && ret != -ERESTARTSYS &&
-			     ret != -EBUSY)) {
+		if (unlikely(ret != 0)) {
+			if (ret == -ERESTARTSYS || ret == -EBUSY)
+				return -EBUSY;
 			DRM_ERROR("Failed synccpu grab on handle 0x%08x.\n",
 				  (unsigned int) arg->handle);
 			return ret;
@@ -798,7 +814,7 @@ int vmw_dumb_create(struct drm_file *file_priv,
 void vmw_bo_swap_notify(struct ttm_buffer_object *bo)
 {
 	/* Is @bo embedded in a struct vmw_buffer_object? */
-	if (vmw_bo_is_vmw_bo(bo))
+	if (!bo_is_vmw(bo))
 		return;
 
 	/* Kill any cached kernel maps before swapout */
@@ -822,7 +838,7 @@ void vmw_bo_move_notify(struct ttm_buffer_object *bo,
 	struct vmw_buffer_object *vbo;
 
 	/* Make sure @bo is embedded in a struct vmw_buffer_object? */
-	if (vmw_bo_is_vmw_bo(bo))
+	if (!bo_is_vmw(bo))
 		return;
 
 	vbo = container_of(bo, struct vmw_buffer_object, base);
@@ -843,22 +859,3 @@ void vmw_bo_move_notify(struct ttm_buffer_object *bo,
 	if (mem->mem_type != VMW_PL_MOB && bo->resource->mem_type == VMW_PL_MOB)
 		vmw_resource_unbind_list(vbo);
 }
-
-/**
- * vmw_bo_is_vmw_bo - check if the buffer object is a &vmw_buffer_object
- * @bo: buffer object to be checked
- *
- * Uses destroy function associated with the object to determine if this is
- * a &vmw_buffer_object.
- *
- * Returns:
- * true if the object is of &vmw_buffer_object type, false if not.
- */
-bool vmw_bo_is_vmw_bo(struct ttm_buffer_object *bo)
-{
-	if (bo->destroy == &vmw_bo_bo_free ||
-	    bo->destroy == &vmw_gem_destroy)
-		return true;
-
-	return false;
-}
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 26eb5478394a..163c00793eb1 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -998,13 +998,10 @@ static int vmw_driver_load(struct vmw_private *dev_priv, u32 pci_id)
 		goto out_no_fman;
 	}
 
-	drm_vma_offset_manager_init(&dev_priv->vma_manager,
-				    DRM_FILE_PAGE_OFFSET_START,
-				    DRM_FILE_PAGE_OFFSET_SIZE);
 	ret = ttm_device_init(&dev_priv->bdev, &vmw_bo_driver,
 			      dev_priv->drm.dev,
 			      dev_priv->drm.anon_inode->i_mapping,
-			      &dev_priv->vma_manager,
+			      dev_priv->drm.vma_offset_manager,
 			      dev_priv->map_mode == vmw_dma_alloc_coherent,
 			      false);
 	if (unlikely(ret != 0)) {
@@ -1174,7 +1171,6 @@ static void vmw_driver_unload(struct drm_device *dev)
 	vmw_devcaps_destroy(dev_priv);
 	vmw_vram_manager_fini(dev_priv);
 	ttm_device_fini(&dev_priv->bdev);
-	drm_vma_offset_manager_destroy(&dev_priv->vma_manager);
 	vmw_release_device_late(dev_priv);
 	vmw_fence_manager_takedown(dev_priv->fman);
 	if (dev_priv->capabilities & SVGA_CAP_IRQMASK)
@@ -1398,7 +1394,7 @@ vmw_get_unmapped_area(struct file *file, unsigned long uaddr,
 	struct vmw_private *dev_priv = vmw_priv(file_priv->minor->dev);
 
 	return drm_get_unmapped_area(file, uaddr, len, pgoff, flags,
-				     &dev_priv->vma_manager);
+				     dev_priv->drm.vma_offset_manager);
 }
 
 static int vmwgfx_pm_notifier(struct notifier_block *nb, unsigned long val,
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index 00e8e27e4884..ace7ca150b03 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -683,6 +683,9 @@ static void vmw_user_surface_base_release(struct ttm_base_object **p_base)
 	    container_of(base, struct vmw_user_surface, prime.base);
 	struct vmw_resource *res = &user_srf->srf.res;
 
+	if (base->shareable && res && res->backup)
+		drm_gem_object_put(&res->backup->base.base);
+
 	*p_base = NULL;
 	vmw_resource_unreference(&res);
 }
@@ -857,6 +860,7 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data,
 			goto out_unlock;
 		}
 		vmw_bo_reference(res->backup);
+		drm_gem_object_get(&res->backup->base.base);
 	}
 
 	tmp = vmw_resource_reference(&srf->res);
@@ -1513,7 +1517,6 @@ vmw_gb_surface_define_internal(struct drm_device *dev,
 							&res->backup);
 		if (ret == 0)
 			vmw_bo_reference(res->backup);
-
 	}
 
 	if (unlikely(ret != 0)) {
@@ -1561,6 +1564,8 @@ vmw_gb_surface_define_internal(struct drm_device *dev,
 			drm_vma_node_offset_addr(&res->backup->base.base.vma_node);
 		rep->buffer_size = res->backup->base.base.size;
 		rep->buffer_handle = backup_handle;
+		if (user_srf->prime.base.shareable)
+			drm_gem_object_get(&res->backup->base.base);
 	} else {
 		rep->buffer_map_handle = 0;
 		rep->buffer_size = 0;
diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
deleted file mode 100644
index 19fa0b5ae5ec..000000000000
--- a/include/linux/dma-buf-map.h
+++ /dev/null
@@ -1,266 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Pointer to dma-buf-mapped memory, plus helpers.
- */
-
-#ifndef __DMA_BUF_MAP_H__
-#define __DMA_BUF_MAP_H__
-
-#include <linux/io.h>
-#include <linux/string.h>
-
-/**
- * DOC: overview
- *
- * Calling dma-buf's vmap operation returns a pointer to the buffer's memory.
- * Depending on the location of the buffer, users may have to access it with
- * I/O operations or memory load/store operations. For example, copying to
- * system memory could be done with memcpy(), copying to I/O memory would be
- * done with memcpy_toio().
- *
- * .. code-block:: c
- *
- *	void *vaddr = ...; // pointer to system memory
- *	memcpy(vaddr, src, len);
- *
- *	void *vaddr_iomem = ...; // pointer to I/O memory
- *	memcpy_toio(vaddr, _iomem, src, len);
- *
- * When using dma-buf's vmap operation, the returned pointer is encoded as
- * :c:type:`struct dma_buf_map <dma_buf_map>`.
- * :c:type:`struct dma_buf_map <dma_buf_map>` stores the buffer's address in
- * system or I/O memory and a flag that signals the required method of
- * accessing the buffer. Use the returned instance and the helper functions
- * to access the buffer's memory in the correct way.
- *
- * The type :c:type:`struct dma_buf_map <dma_buf_map>` and its helpers are
- * actually independent from the dma-buf infrastructure. When sharing buffers
- * among devices, drivers have to know the location of the memory to access
- * the buffers in a safe way. :c:type:`struct dma_buf_map <dma_buf_map>`
- * solves this problem for dma-buf and its users. If other drivers or
- * sub-systems require similar functionality, the type could be generalized
- * and moved to a more prominent header file.
- *
- * Open-coding access to :c:type:`struct dma_buf_map <dma_buf_map>` is
- * considered bad style. Rather then accessing its fields directly, use one
- * of the provided helper functions, or implement your own. For example,
- * instances of :c:type:`struct dma_buf_map <dma_buf_map>` can be initialized
- * statically with DMA_BUF_MAP_INIT_VADDR(), or at runtime with
- * dma_buf_map_set_vaddr(). These helpers will set an address in system memory.
- *
- * .. code-block:: c
- *
- *	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(0xdeadbeaf);
- *
- *	dma_buf_map_set_vaddr(&map, 0xdeadbeaf);
- *
- * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem().
- *
- * .. code-block:: c
- *
- *	dma_buf_map_set_vaddr_iomem(&map, 0xdeadbeaf);
- *
- * Instances of struct dma_buf_map do not have to be cleaned up, but
- * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings
- * always refer to system memory.
- *
- * .. code-block:: c
- *
- *	dma_buf_map_clear(&map);
- *
- * Test if a mapping is valid with either dma_buf_map_is_set() or
- * dma_buf_map_is_null().
- *
- * .. code-block:: c
- *
- *	if (dma_buf_map_is_set(&map) != dma_buf_map_is_null(&map))
- *		// always true
- *
- * Instances of :c:type:`struct dma_buf_map <dma_buf_map>` can be compared
- * for equality with dma_buf_map_is_equal(). Mappings the point to different
- * memory spaces, system or I/O, are never equal. That's even true if both
- * spaces are located in the same address space, both mappings contain the
- * same address value, or both mappings refer to NULL.
- *
- * .. code-block:: c
- *
- *	struct dma_buf_map sys_map; // refers to system memory
- *	struct dma_buf_map io_map; // refers to I/O memory
- *
- *	if (dma_buf_map_is_equal(&sys_map, &io_map))
- *		// always false
- *
- * A set up instance of struct dma_buf_map can be used to access or manipulate
- * the buffer memory. Depending on the location of the memory, the provided
- * helpers will pick the correct operations. Data can be copied into the memory
- * with dma_buf_map_memcpy_to(). The address can be manipulated with
- * dma_buf_map_incr().
- *
- * .. code-block:: c
- *
- *	const void *src = ...; // source buffer
- *	size_t len = ...; // length of src
- *
- *	dma_buf_map_memcpy_to(&map, src, len);
- *	dma_buf_map_incr(&map, len); // go to first byte after the memcpy
- */
-
-/**
- * struct dma_buf_map - Pointer to vmap'ed dma-buf memory.
- * @vaddr_iomem:	The buffer's address if in I/O memory
- * @vaddr:		The buffer's address if in system memory
- * @is_iomem:		True if the dma-buf memory is located in I/O
- *			memory, or false otherwise.
- */
-struct dma_buf_map {
-	union {
-		void __iomem *vaddr_iomem;
-		void *vaddr;
-	};
-	bool is_iomem;
-};
-
-/**
- * DMA_BUF_MAP_INIT_VADDR - Initializes struct dma_buf_map to an address in system memory
- * @vaddr_:	A system-memory address
- */
-#define DMA_BUF_MAP_INIT_VADDR(vaddr_) \
-	{ \
-		.vaddr = (vaddr_), \
-		.is_iomem = false, \
-	}
-
-/**
- * dma_buf_map_set_vaddr - Sets a dma-buf mapping structure to an address in system memory
- * @map:	The dma-buf mapping structure
- * @vaddr:	A system-memory address
- *
- * Sets the address and clears the I/O-memory flag.
- */
-static inline void dma_buf_map_set_vaddr(struct dma_buf_map *map, void *vaddr)
-{
-	map->vaddr = vaddr;
-	map->is_iomem = false;
-}
-
-/**
- * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an address in I/O memory
- * @map:		The dma-buf mapping structure
- * @vaddr_iomem:	An I/O-memory address
- *
- * Sets the address and the I/O-memory flag.
- */
-static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map,
-					       void __iomem *vaddr_iomem)
-{
-	map->vaddr_iomem = vaddr_iomem;
-	map->is_iomem = true;
-}
-
-/**
- * dma_buf_map_is_equal - Compares two dma-buf mapping structures for equality
- * @lhs:	The dma-buf mapping structure
- * @rhs:	A dma-buf mapping structure to compare with
- *
- * Two dma-buf mapping structures are equal if they both refer to the same type of memory
- * and to the same address within that memory.
- *
- * Returns:
- * True is both structures are equal, or false otherwise.
- */
-static inline bool dma_buf_map_is_equal(const struct dma_buf_map *lhs,
-					const struct dma_buf_map *rhs)
-{
-	if (lhs->is_iomem != rhs->is_iomem)
-		return false;
-	else if (lhs->is_iomem)
-		return lhs->vaddr_iomem == rhs->vaddr_iomem;
-	else
-		return lhs->vaddr == rhs->vaddr;
-}
-
-/**
- * dma_buf_map_is_null - Tests for a dma-buf mapping to be NULL
- * @map:	The dma-buf mapping structure
- *
- * Depending on the state of struct dma_buf_map.is_iomem, tests if the
- * mapping is NULL.
- *
- * Returns:
- * True if the mapping is NULL, or false otherwise.
- */
-static inline bool dma_buf_map_is_null(const struct dma_buf_map *map)
-{
-	if (map->is_iomem)
-		return !map->vaddr_iomem;
-	return !map->vaddr;
-}
-
-/**
- * dma_buf_map_is_set - Tests is the dma-buf mapping has been set
- * @map:	The dma-buf mapping structure
- *
- * Depending on the state of struct dma_buf_map.is_iomem, tests if the
- * mapping has been set.
- *
- * Returns:
- * True if the mapping is been set, or false otherwise.
- */
-static inline bool dma_buf_map_is_set(const struct dma_buf_map *map)
-{
-	return !dma_buf_map_is_null(map);
-}
-
-/**
- * dma_buf_map_clear - Clears a dma-buf mapping structure
- * @map:	The dma-buf mapping structure
- *
- * Clears all fields to zero; including struct dma_buf_map.is_iomem. So
- * mapping structures that were set to point to I/O memory are reset for
- * system memory. Pointers are cleared to NULL. This is the default.
- */
-static inline void dma_buf_map_clear(struct dma_buf_map *map)
-{
-	if (map->is_iomem) {
-		map->vaddr_iomem = NULL;
-		map->is_iomem = false;
-	} else {
-		map->vaddr = NULL;
-	}
-}
-
-/**
- * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping
- * @dst:	The dma-buf mapping structure
- * @src:	The source buffer
- * @len:	The number of byte in src
- *
- * Copies data into a dma-buf mapping. The source buffer is in system
- * memory. Depending on the buffer's location, the helper picks the correct
- * method of accessing the memory.
- */
-static inline void dma_buf_map_memcpy_to(struct dma_buf_map *dst, const void *src, size_t len)
-{
-	if (dst->is_iomem)
-		memcpy_toio(dst->vaddr_iomem, src, len);
-	else
-		memcpy(dst->vaddr, src, len);
-}
-
-/**
- * dma_buf_map_incr - Increments the address stored in a dma-buf mapping
- * @map:	The dma-buf mapping structure
- * @incr:	The number of bytes to increment
- *
- * Increments the address stored in a dma-buf mapping. Depending on the
- * buffer's location, the correct value will be updated.
- */
-static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr)
-{
-	if (map->is_iomem)
-		map->vaddr_iomem += incr;
-	else
-		map->vaddr += incr;
-}
-
-#endif /* __DMA_BUF_MAP_H__ */