drm/xe/uapi: Separate bo_create placement from flags

Although the flags are about the creation, the memory placement
of the BO deserves a proper dedicated field in the uapi.

Besides getting more clear, it also allows to remove the
'magic' shifts from the flags that was a concern during the
uapi reviews.
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>

drivers/gpu/drm/xe/xe_bo.c

@@ -1890,15 +1890,15 @@ int xe_gem_create_ioctl(struct drm_device *dev, void *data,
 	    XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))
 		return -EINVAL;
 
+	/* at least one valid memory placement must be specified */
+	if (XE_IOCTL_DBG(xe, (args->placement & ~xe->info.mem_region_mask) ||
+			 !args->placement))
+		return -EINVAL;
+
 	if (XE_IOCTL_DBG(xe, args->flags &
 			 ~(DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING |
 			   DRM_XE_GEM_CREATE_FLAG_SCANOUT |
-			   DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM |
-			   xe->info.mem_region_mask)))
-		return -EINVAL;
-
-	/* at least one memory type must be specified */
-	if (XE_IOCTL_DBG(xe, !(args->flags & xe->info.mem_region_mask)))
+			   DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM)))
 		return -EINVAL;
 
 	if (XE_IOCTL_DBG(xe, args->handle))
@@ -1920,7 +1920,7 @@ int xe_gem_create_ioctl(struct drm_device *dev, void *data,
 	if (args->flags & DRM_XE_GEM_CREATE_FLAG_SCANOUT)
 		bo_flags |= XE_BO_SCANOUT_BIT;
 
-	bo_flags |= args->flags << (ffs(XE_BO_CREATE_SYSTEM_BIT) - 1);
+	bo_flags |= args->placement << (ffs(XE_BO_CREATE_SYSTEM_BIT) - 1);
 
 	if (args->flags & DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM) {
 		if (XE_IOCTL_DBG(xe, !(bo_flags & XE_BO_CREATE_VRAM_MASK)))

include/uapi/drm/xe_drm.h

@@ -500,8 +500,11 @@ struct drm_xe_gem_create {
 	 */
 	__u64 size;
 
-#define DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING		(0x1 << 24)
-#define DRM_XE_GEM_CREATE_FLAG_SCANOUT			(0x1 << 25)
+	/** @placement: A mask of memory instances of where BO can be placed. */
+	__u32 placement;
+
+#define DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING		(1 << 0)
+#define DRM_XE_GEM_CREATE_FLAG_SCANOUT			(1 << 1)
 /*
  * When using VRAM as a possible placement, ensure that the corresponding VRAM
  * allocation will always use the CPU accessible part of VRAM. This is important
@@ -517,7 +520,7 @@ struct drm_xe_gem_create {
  * display surfaces, therefore the kernel requires setting this flag for such
  * objects, otherwise an error is thrown on small-bar systems.
  */
-#define DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM	(0x1 << 26)
+#define DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM	(1 << 2)
 	/**
 	 * @flags: Flags, currently a mask of memory instances of where BO can
 	 * be placed