drm/msm: Deprecate MSM_BO_UNCACHED harder

Handle the demotion to MSM_BO_WC at the userspace ABI level, and fix
the remaining internal MSM_BO_UNCACHED user.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/489339/
Link: https://lore.kernel.org/r/20220613194623.2588353-1-robdclark@gmail.com

drivers/gpu/drm/msm/msm_drv.c

@@ -678,12 +678,25 @@ static int msm_ioctl_gem_new(struct drm_device *dev, void *data,
 		struct drm_file *file)
 {
 	struct drm_msm_gem_new *args = data;
+	uint32_t flags = args->flags;
 
 	if (args->flags & ~MSM_BO_FLAGS) {
 		DRM_ERROR("invalid flags: %08x\n", args->flags);
 		return -EINVAL;
 	}
 
+	/*
+	 * Uncached CPU mappings are deprecated, as of:
+	 *
+	 * 9ef364432db4 ("drm/msm: deprecate MSM_BO_UNCACHED (map as writecombine instead)")
+	 *
+	 * So promote them to WC.
+	 */
+	if (flags & MSM_BO_UNCACHED) {
+		flags &= ~MSM_BO_CACHED;
+		flags |= MSM_BO_WC;
+	}
+
 	return msm_gem_new_handle(dev, file, args->size,
 			args->flags, &args->handle, NULL);
 }

drivers/gpu/drm/msm/msm_gem.c

@@ -129,7 +129,7 @@ static struct page **get_pages(struct drm_gem_object *obj)
 		/* For non-cached buffers, ensure the new pages are clean
 		 * because display controller, GPU, etc. are not coherent:
 		 */
-		if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
+		if (msm_obj->flags & MSM_BO_WC)
 			sync_for_device(msm_obj);
 
 		update_inactive(msm_obj);
@@ -160,7 +160,7 @@ static void put_pages(struct drm_gem_object *obj)
 			 * pages are clean because display controller,
 			 * GPU, etc. are not coherent:
 			 */
-			if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
+			if (msm_obj->flags & MSM_BO_WC)
 				sync_for_cpu(msm_obj);
 
 			sg_free_table(msm_obj->sgt);
@@ -213,7 +213,7 @@ void msm_gem_put_pages(struct drm_gem_object *obj)
 
 static pgprot_t msm_gem_pgprot(struct msm_gem_object *msm_obj, pgprot_t prot)
 {
-	if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
+	if (msm_obj->flags & MSM_BO_WC)
 		return pgprot_writecombine(prot);
 	return prot;
 }
@@ -1106,7 +1106,6 @@ static int msm_gem_new_impl(struct drm_device *dev,
 	struct msm_gem_object *msm_obj;
 
 	switch (flags & MSM_BO_CACHE_MASK) {
-	case MSM_BO_UNCACHED:
 	case MSM_BO_CACHED:
 	case MSM_BO_WC:
 		break;

drivers/gpu/drm/msm/msm_gpu.c

@@ -918,7 +918,7 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 
 	memptrs = msm_gem_kernel_new(drm,
 		sizeof(struct msm_rbmemptrs) * nr_rings,
-		check_apriv(gpu, MSM_BO_UNCACHED), gpu->aspace, &gpu->memptrs_bo,
+		check_apriv(gpu, MSM_BO_WC), gpu->aspace, &gpu->memptrs_bo,
 		&memptrs_iova);
 
 	if (IS_ERR(memptrs)) {