[PATCH v4 3/6] drm/bochs: fix DRM_FORMAT_* handling for big endian machines.

From: Gerd Hoffmann
Date: Fri Sep 21 2018 - 09:47:13 EST


Use DRM_FORMAT_HOST_XRGB8888, so we are using the correct format code
on bigendian machines. Also set the quirk_addfb_prefer_host_byte_order
mode_config bit so drm_mode_addfb() asks for the correct format code.

Create our own plane and use drm_crtc_init_with_planes() instead of
depending on the default created by drm_crtc_init(). That way the plane
format list is correct on bigendian machines.

Also re-add the framebuffer format check dropped by "df2052cc92 bochs:
convert to drm_fb_helper_fbdev_setup/teardown".

With this patch applied both ADDFB and ADDFB2 ioctls work correctly in
the bochs-drm.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>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
---
drivers/gpu/drm/bochs/bochs_fbdev.c | 17 +++++++++++++----
drivers/gpu/drm/bochs/bochs_kms.c | 34 +++++++++++++++++++++++++++++++++-
2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bochs/bochs_fbdev.c b/drivers/gpu/drm/bochs/bochs_fbdev.c
index 8f4d6c052f..c46fdae44e 100644
--- a/drivers/gpu/drm/bochs/bochs_fbdev.c
+++ b/drivers/gpu/drm/bochs/bochs_fbdev.c
@@ -63,9 +63,8 @@ static int bochsfb_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 * ((sizes->surface_bpp + 7) / 8);
- mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
- sizes->surface_depth);
+ mode_cmd.pitches[0] = sizes->surface_width * 4;
+ mode_cmd.pixel_format = DRM_FORMAT_HOST_XRGB8888;
size = mode_cmd.pitches[0] * mode_cmd.height;

/* alloc, pin & map bo */
@@ -137,8 +136,18 @@ static const struct drm_fb_helper_funcs bochs_fb_helper_funcs = {
.fb_probe = bochsfb_create,
};

+static struct drm_framebuffer *
+bochs_gem_fb_create(struct drm_device *dev, struct drm_file *file,
+ const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+ if (mode_cmd->pixel_format != DRM_FORMAT_HOST_XRGB8888)
+ return ERR_PTR(-EINVAL);
+
+ return drm_gem_fb_create(dev, file, mode_cmd);
+}
+
const struct drm_mode_config_funcs bochs_mode_funcs = {
- .fb_create = drm_gem_fb_create,
+ .fb_create = bochs_gem_fb_create,
};

int bochs_fbdev_init(struct bochs_device *bochs)
diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c
index ea9a43d31b..f3fdaf9456 100644
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@@ -126,12 +126,43 @@ static const struct drm_crtc_helper_funcs bochs_helper_funcs = {
.commit = bochs_crtc_commit,
};

+static const uint32_t bochs_formats[] = {
+ DRM_FORMAT_HOST_XRGB8888,
+};
+
+static struct drm_plane *bochs_primary_plane(struct drm_device *dev)
+{
+ struct drm_plane *primary;
+ int ret;
+
+ primary = kzalloc(sizeof(*primary), GFP_KERNEL);
+ if (primary == NULL) {
+ DRM_DEBUG_KMS("Failed to allocate primary plane\n");
+ return NULL;
+ }
+
+ ret = drm_universal_plane_init(dev, primary, 0,
+ &drm_primary_helper_funcs,
+ bochs_formats,
+ ARRAY_SIZE(bochs_formats),
+ NULL,
+ DRM_PLANE_TYPE_PRIMARY, NULL);
+ if (ret) {
+ kfree(primary);
+ primary = NULL;
+ }
+
+ return primary;
+}
+
static void bochs_crtc_init(struct drm_device *dev)
{
struct bochs_device *bochs = dev->dev_private;
struct drm_crtc *crtc = &bochs->crtc;
+ struct drm_plane *primary = bochs_primary_plane(dev);

- drm_crtc_init(dev, crtc, &bochs_crtc_funcs);
+ drm_crtc_init_with_planes(dev, crtc, primary, NULL,
+ &bochs_crtc_funcs, NULL);
drm_crtc_helper_add(crtc, &bochs_helper_funcs);
}

@@ -250,6 +281,7 @@ int bochs_kms_init(struct bochs_device *bochs)
bochs->dev->mode_config.fb_base = bochs->fb_base;
bochs->dev->mode_config.preferred_depth = 24;
bochs->dev->mode_config.prefer_shadow = 0;
+ bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true;

bochs->dev->mode_config.funcs = &bochs_mode_funcs;

--
2.9.3