[PATCH 5/5] drm/virtio: fix DRM_FORMAT_* handling

From: Gerd Hoffmann
Date: Mon Sep 03 2018 - 06:58:05 EST


Use DRM_FORMAT_HOST_XRGB8888, so we are using the correct format code
on bigendian machines. Also add DRIVER_PREFER_HOST_BYTE_ORDER driver
feature flag so drm_mode_addfb() asks for the correct format code.

Both DRM_FORMAT_* and VIRTIO_GPU_FORMAT_* are defined to be little
endian, so using a different mapping on bigendian machines is wrong.
It's there because of broken drm_mode_addfb() behavior. So with
drm_mode_addfb() being fixed we can fix this too.

While wading through the code I've noticed we have a little issue in
virtio: We attach a format to the bo when it is created
(DRM_IOCTL_MODE_CREATE_DUMB), not when we map it as framebuffer
(DRM_IOCTL_MODE_ADDFB). Easy way out: Support a single format only.
Pick DRM_FORMAT_HOST_XRGB8888, it is the only one actually used in
practice. Drop unused mappings in virtio_gpu_translate_format().

With this patch applied both ADDFB and ADDFB2 ioctls work correctly in
the virtio-gpu.ko driver on big endian machines. Without the patch only
ADDFB (which still seems to be used by the majority of userspace) works
correctly.

Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_display.c | 4 +++
drivers/gpu/drm/virtio/virtgpu_drv.c | 4 ++-
drivers/gpu/drm/virtio/virtgpu_fb.c | 2 +-
drivers/gpu/drm/virtio/virtgpu_gem.c | 7 +++--
drivers/gpu/drm/virtio/virtgpu_plane.c | 54 ++------------------------------
5 files changed, 15 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c
index 25503b9335..f6c4af1db4 100644
--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@@ -306,6 +306,10 @@ virtio_gpu_user_framebuffer_create(struct drm_device *dev,
struct virtio_gpu_framebuffer *virtio_gpu_fb;
int ret;

+ if (mode_cmd->pixel_format != DRM_FORMAT_HOST_XRGB8888 &&
+ mode_cmd->pixel_format != DRM_FORMAT_HOST_ARGB8888)
+ return ERR_PTR(-ENOENT);
+
/* lookup object associated with res handle */
obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[0]);
if (!obj)
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index d9287c144f..4b28f41ac1 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -114,7 +114,9 @@ static const struct file_operations virtio_gpu_driver_fops = {
};

static struct drm_driver driver = {
- .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME | DRIVER_RENDER | DRIVER_ATOMIC,
+ .driver_features = (DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
+ DRIVER_RENDER | DRIVER_ATOMIC |
+ DRIVER_PREFER_HOST_BYTE_ORDER),
.load = virtio_gpu_driver_load,
.unload = virtio_gpu_driver_unload,
.open = virtio_gpu_driver_open,
diff --git a/drivers/gpu/drm/virtio/virtgpu_fb.c b/drivers/gpu/drm/virtio/virtgpu_fb.c
index a121b1c795..9d87ebd645 100644
--- a/drivers/gpu/drm/virtio/virtgpu_fb.c
+++ b/drivers/gpu/drm/virtio/virtgpu_fb.c
@@ -233,7 +233,7 @@ static int virtio_gpufb_create(struct drm_fb_helper *helper,
mode_cmd.width = sizes->surface_width;
mode_cmd.height = sizes->surface_height;
mode_cmd.pitches[0] = mode_cmd.width * 4;
- mode_cmd.pixel_format = drm_mode_legacy_fb_format(32, 24);
+ mode_cmd.pixel_format = DRM_FORMAT_HOST_XRGB8888;

format = virtio_gpu_translate_format(mode_cmd.pixel_format);
if (format == 0)
diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 0f2768eaca..82c817f37c 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -90,7 +90,10 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
uint32_t resid;
uint32_t format;

- pitch = args->width * ((args->bpp + 1) / 8);
+ if (args->bpp != 32)
+ return -EINVAL;
+
+ pitch = args->width * 4;
args->size = pitch * args->height;
args->size = ALIGN(args->size, PAGE_SIZE);

@@ -99,7 +102,7 @@ int virtio_gpu_mode_dumb_create(struct drm_file *file_priv,
if (ret)
goto fail;

- format = virtio_gpu_translate_format(DRM_FORMAT_XRGB8888);
+ format = virtio_gpu_translate_format(DRM_FORMAT_HOST_XRGB8888);
virtio_gpu_resource_id_get(vgdev, &resid);
virtio_gpu_cmd_create_resource(vgdev, resid, format,
args->width, args->height);
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index dc5b5b2b7a..3221d50b9a 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -28,22 +28,11 @@
#include <drm/drm_atomic_helper.h>

static const uint32_t virtio_gpu_formats[] = {
- DRM_FORMAT_XRGB8888,
- DRM_FORMAT_ARGB8888,
- DRM_FORMAT_BGRX8888,
- DRM_FORMAT_BGRA8888,
- DRM_FORMAT_RGBX8888,
- DRM_FORMAT_RGBA8888,
- DRM_FORMAT_XBGR8888,
- DRM_FORMAT_ABGR8888,
+ DRM_FORMAT_HOST_XRGB8888,
};

static const uint32_t virtio_gpu_cursor_formats[] = {
-#ifdef __BIG_ENDIAN
- DRM_FORMAT_BGRA8888,
-#else
- DRM_FORMAT_ARGB8888,
-#endif
+ DRM_FORMAT_HOST_ARGB8888,
};

uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
@@ -51,32 +40,6 @@ uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
uint32_t format;

switch (drm_fourcc) {
-#ifdef __BIG_ENDIAN
- case DRM_FORMAT_XRGB8888:
- format = VIRTIO_GPU_FORMAT_X8R8G8B8_UNORM;
- break;
- case DRM_FORMAT_ARGB8888:
- format = VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM;
- break;
- case DRM_FORMAT_BGRX8888:
- format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
- break;
- case DRM_FORMAT_BGRA8888:
- format = VIRTIO_GPU_FORMAT_B8G8R8A8_UNORM;
- break;
- case DRM_FORMAT_RGBX8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8X8_UNORM;
- break;
- case DRM_FORMAT_RGBA8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8A8_UNORM;
- break;
- case DRM_FORMAT_XBGR8888:
- format = VIRTIO_GPU_FORMAT_X8B8G8R8_UNORM;
- break;
- case DRM_FORMAT_ABGR8888:
- format = VIRTIO_GPU_FORMAT_A8B8G8R8_UNORM;
- break;
-#else
case DRM_FORMAT_XRGB8888:
format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
break;
@@ -89,19 +52,6 @@ uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
case DRM_FORMAT_BGRA8888:
format = VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM;
break;
- case DRM_FORMAT_RGBX8888:
- format = VIRTIO_GPU_FORMAT_X8B8G8R8_UNORM;
- break;
- case DRM_FORMAT_RGBA8888:
- format = VIRTIO_GPU_FORMAT_A8B8G8R8_UNORM;
- break;
- case DRM_FORMAT_XBGR8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8X8_UNORM;
- break;
- case DRM_FORMAT_ABGR8888:
- format = VIRTIO_GPU_FORMAT_R8G8B8A8_UNORM;
- break;
-#endif
default:
/*
* This should not happen, we handle everything listed
--
2.9.3