drm: dumb scanout create/mmap for intel/radeon (v3)

This is just an idea that might or might not be a good idea,
it basically adds two ioctls to create a dumb and map a dumb buffer
suitable for scanout. The handle can be passed to the KMS ioctls to create
a framebuffer.

It looks to me like it would be useful in the following cases:
a) in development drivers - we can always provide a shadowfb fallback.
b) libkms users - we can clean up libkms a lot and avoid linking
to libdrm_*.
c) plymouth via libkms is a lot easier.

Userspace bits would be just calls + mmaps. We could probably
mark these handles somehow as not being suitable for acceleartion
so as top stop people who are dumber than dumb.

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

5 files changed, 72 insertions, 6 deletions

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 56c48b67ef3d..a4605362c528 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -288,6 +288,15 @@ int radeon_gem_object_pin(struct drm_gem_object *obj, uint32_t pin_domain,
 			  uint64_t *gpu_addr);
 void radeon_gem_object_unpin(struct drm_gem_object *obj);
 
+int radeon_mode_dumb_create(struct drm_file *file_priv,
+			    struct drm_device *dev,
+			    struct drm_mode_create_dumb *args);
+int radeon_mode_dumb_mmap(struct drm_file *filp,
+			  struct drm_device *dev,
+			  uint32_t handle, uint64_t *offset_p);
+int radeon_mode_dumb_destroy(struct drm_file *file_priv,
+			     struct drm_device *dev,
+			     uint32_t handle);
 
 /*
  * GART structures, functions & helpers
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index 275b26a708d6..ca1b7d4c1d83 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -84,6 +84,16 @@ extern int radeon_get_crtc_scanoutpos(struct drm_device *dev, int crtc,
 extern struct drm_ioctl_desc radeon_ioctls_kms[];
 extern int radeon_max_kms_ioctl;
 int radeon_mmap(struct file *filp, struct vm_area_struct *vma);
+int radeon_mode_dumb_mmap(struct drm_file *filp,
+			  struct drm_device *dev,
+			  uint32_t handle, uint64_t *offset_p);
+int radeon_mode_dumb_create(struct drm_file *file_priv,
+			    struct drm_device *dev,
+			    struct drm_mode_create_dumb *args);
+int radeon_mode_dumb_destroy(struct drm_file *file_priv,
+			     struct drm_device *dev,
+			     uint32_t handle);
+
 #if defined(CONFIG_DEBUG_FS)
 int radeon_debugfs_init(struct drm_minor *minor);
 void radeon_debugfs_cleanup(struct drm_minor *minor);
@@ -322,6 +332,9 @@ static struct drm_driver kms_driver = {
 	.gem_init_object = radeon_gem_object_init,
 	.gem_free_object = radeon_gem_object_free,
 	.dma_ioctl = radeon_dma_ioctl_kms,
+	.dumb_create = radeon_mode_dumb_create,
+	.dumb_map_offset = radeon_mode_dumb_mmap,
+	.dumb_destroy = radeon_mode_dumb_destroy,
 	.fops = {
 		 .owner = THIS_MODULE,
 		 .open = drm_open,
diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c
index 66324b5bb5ba..cb968f997ce7 100644
--- a/drivers/gpu/drm/radeon/radeon_fb.c
+++ b/drivers/gpu/drm/radeon/radeon_fb.c
@@ -64,7 +64,7 @@ static struct fb_ops radeonfb_ops = {
 };
 
 
-static int radeon_align_pitch(struct radeon_device *rdev, int width, int bpp, bool tiled)
+int radeon_align_pitch(struct radeon_device *rdev, int width, int bpp, bool tiled)
 {
 	int aligned = width;
 	int align_large = (ASIC_IS_AVIVO(rdev)) || tiled;
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index df95eb83dac6..ede5dccdf79f 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -236,23 +236,31 @@ int radeon_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 	return r;
 }
 
-int radeon_gem_mmap_ioctl(struct drm_device *dev, void *data,
-			  struct drm_file *filp)
+int radeon_mode_dumb_mmap(struct drm_file *filp,
+			  struct drm_device *dev,
+			  uint32_t handle, uint64_t *offset_p)
 {
-	struct drm_radeon_gem_mmap *args = data;
 	struct drm_gem_object *gobj;
 	struct radeon_bo *robj;
 
-	gobj = drm_gem_object_lookup(dev, filp, args->handle);
+	gobj = drm_gem_object_lookup(dev, filp, handle);
 	if (gobj == NULL) {
 		return -ENOENT;
 	}
 	robj = gobj->driver_private;
-	args->addr_ptr = radeon_bo_mmap_offset(robj);
+	*offset_p = radeon_bo_mmap_offset(robj);
 	drm_gem_object_unreference_unlocked(gobj);
 	return 0;
 }
 
+int radeon_gem_mmap_ioctl(struct drm_device *dev, void *data,
+			  struct drm_file *filp)
+{
+	struct drm_radeon_gem_mmap *args = data;
+
+	return radeon_mode_dumb_mmap(filp, dev, args->handle, &args->addr_ptr);
+}
+
 int radeon_gem_busy_ioctl(struct drm_device *dev, void *data,
 			  struct drm_file *filp)
 {
@@ -345,3 +353,38 @@ out:
 	drm_gem_object_unreference_unlocked(gobj);
 	return r;
 }
+
+int radeon_mode_dumb_create(struct drm_file *file_priv,
+			    struct drm_device *dev,
+			    struct drm_mode_create_dumb *args)
+{
+	struct radeon_device *rdev = dev->dev_private;
+	struct drm_gem_object *gobj;
+	int r;
+
+	args->pitch = radeon_align_pitch(rdev, args->width, args->bpp, 0) * ((args->bpp + 1) / 8);
+	args->size = args->pitch * args->height;
+	args->size = ALIGN(args->size, PAGE_SIZE);
+
+	r = radeon_gem_object_create(rdev, args->size, 0,
+				     RADEON_GEM_DOMAIN_VRAM,
+				     false, ttm_bo_type_device,
+				     &gobj);
+	if (r)
+		return -ENOMEM;
+
+	r = drm_gem_handle_create(file_priv, gobj, &args->handle);
+	if (r) {
+		drm_gem_object_unreference_unlocked(gobj);
+		return r;
+	}
+	drm_gem_object_handle_unreference_unlocked(gobj);
+	return 0;
+}
+
+int radeon_mode_dumb_destroy(struct drm_file *file_priv,
+			     struct drm_device *dev,
+			     uint32_t handle)
+{
+	return drm_gem_handle_delete(file_priv, handle);
+}
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 6794cdf91f28..c3f23f6ff60e 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -675,4 +675,5 @@ void radeon_fb_output_poll_changed(struct radeon_device *rdev);
 
 void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id);
 
+int radeon_align_pitch(struct radeon_device *rdev, int width, int bpp, bool tiled);
 #endif