[PATCH RESEND v2 16/32] drm/vkms: Introduce config for plane format

Louis Chauvet
2025-10-29T14:37:21Z

VKMS driver supports all the pixel formats for planes, but for testing it
can be useful to only advertise few of them. This new configuration
interface will allow configuring the pixel format per planes.

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
drivers/gpu/drm/vkms/vkms_config.c | 114 +++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/vkms/vkms_config.h | 51 +++++++++++++++++
drivers/gpu/drm/vkms/vkms_plane.c | 39 +------------
3 files changed, 167 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_config.c b/drivers/gpu/drm/vkms/vkms_config.c
index 823039fb4145..a3fb80451b30 100644
--- a/drivers/gpu/drm/vkms/vkms_config.c
+++ b/drivers/gpu/drm/vkms/vkms_config.c
@@ -12,6 +12,42 @@

#include "vkms_config.h"

+static const u32 vkms_supported_plane_formats[] = {
+ DRM_FORMAT_ARGB8888,
+ DRM_FORMAT_ABGR8888,
+ DRM_FORMAT_BGRA8888,
+ DRM_FORMAT_RGBA8888,
+ DRM_FORMAT_XRGB8888,
+ DRM_FORMAT_XBGR8888,
+ DRM_FORMAT_RGB888,
+ DRM_FORMAT_BGR888,
+ DRM_FORMAT_XRGB16161616,
+ DRM_FORMAT_XBGR16161616,
+ DRM_FORMAT_ARGB16161616,
+ DRM_FORMAT_ABGR16161616,
+ DRM_FORMAT_RGB565,
+ DRM_FORMAT_BGR565,
+ DRM_FORMAT_NV12,
+ DRM_FORMAT_NV16,
+ DRM_FORMAT_NV24,
+ DRM_FORMAT_NV21,
+ DRM_FORMAT_NV61,
+ DRM_FORMAT_NV42,
+ DRM_FORMAT_YUV420,
+ DRM_FORMAT_YUV422,
+ DRM_FORMAT_YUV444,
+ DRM_FORMAT_YVU420,
+ DRM_FORMAT_YVU422,
+ DRM_FORMAT_YVU444,
+ DRM_FORMAT_P010,
+ DRM_FORMAT_P012,
+ DRM_FORMAT_P016,
+ DRM_FORMAT_R1,
+ DRM_FORMAT_R2,
+ DRM_FORMAT_R4,
+ DRM_FORMAT_R8,
+};
+
struct vkms_config *vkms_config_create(const char *dev_name)
{
struct vkms_config *config;
@@ -437,6 +473,15 @@ static void show_bitfield(struct seq_file *m, uint32_t value, const char *callba
}
}

+static void show_formats(struct seq_file *m, u32 *formats, size_t formats_count)
+{
+ for (int i = 0; i < formats_count; i++) {
+ seq_printf(m, "%p4cc", &formats[i]);
+ if (i != formats_count - 1)
+ seq_puts(m, ", ");
+ }
+}
+
static int vkms_config_show(struct seq_file *m, void *data)
{
struct drm_debugfs_entry *entry = m->private;
@@ -477,6 +522,10 @@ static int vkms_config_show(struct seq_file *m, void *data)
seq_puts(m, "\n");
seq_printf(m, "\tdefault color range=%s\n",
drm_get_color_range_name(vkms_config_plane_get_default_color_range(plane_cfg)));
+ seq_puts(m, "\tsupported formats=");
+ show_formats(m, vkms_config_plane_get_supported_formats(plane_cfg),
+ vkms_config_plane_get_supported_formats_count(plane_cfg));
+ seq_puts(m, "\n");
}

vkms_config_for_each_crtc(vkmsdev->config, crtc_cfg) {
@@ -515,6 +564,11 @@ struct vkms_config_plane *vkms_config_create_plane(struct vkms_config *config)
if (!plane_cfg)
return ERR_PTR(-ENOMEM);

+ if (vkms_config_plane_add_all_formats(plane_cfg)) {
+ kfree(plane_cfg);
+ return ERR_PTR(-ENOMEM);
+ }
+
plane_cfg->config = config;
vkms_config_plane_set_type(plane_cfg, DRM_PLANE_TYPE_OVERLAY);
vkms_config_plane_set_name(plane_cfg, NULL);
@@ -644,6 +698,66 @@ static struct vkms_config_plane *vkms_config_crtc_get_plane(const struct vkms_co
return NULL;
}

+int __must_check vkms_config_plane_add_all_formats(struct vkms_config_plane *plane_cfg)
+{
+ u32 *ret = krealloc_array(plane_cfg->supported_formats,
+ ARRAY_SIZE(vkms_supported_plane_formats),
+ sizeof(uint32_t), GFP_KERNEL);
+ if (!ret)
+ return -ENOMEM;
+ plane_cfg->supported_formats = ret;
+
+ memcpy(plane_cfg->supported_formats, vkms_supported_plane_formats,
+ sizeof(vkms_supported_plane_formats));
+ plane_cfg->supported_formats_count = ARRAY_SIZE(vkms_supported_plane_formats);
+ return 0;
+}
+
+int __must_check vkms_config_plane_add_format(struct vkms_config_plane *plane_cfg, u32 drm_format)
+{
+ bool found = false;
+
+ for (int i = 0; i < ARRAY_SIZE(vkms_supported_plane_formats); i++) {
+ if (vkms_supported_plane_formats[i] == drm_format) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ return -EINVAL;
+ for (unsigned int i = 0; i < plane_cfg->supported_formats_count; i++) {
+ if (plane_cfg->supported_formats[i] == drm_format)
+ return 0;
+ }
+ u32 *new_ptr = krealloc_array(plane_cfg->supported_formats,
+ plane_cfg->supported_formats_count + 1,
+ sizeof(*plane_cfg->supported_formats), GFP_KERNEL);
+ if (!new_ptr)
+ return -ENOMEM;
+
+ plane_cfg->supported_formats = new_ptr;
+ plane_cfg->supported_formats[plane_cfg->supported_formats_count] = drm_format;
+ plane_cfg->supported_formats_count++;
+
+ return 0;
+}
+
+void vkms_config_plane_remove_all_formats(struct vkms_config_plane *plane_cfg)
+{
+ plane_cfg->supported_formats_count = 0;
+}
+
+void vkms_config_plane_remove_format(struct vkms_config_plane *plane_cfg, u32 drm_format)
+{
+ for (unsigned int i = 0; i < plane_cfg->supported_formats_count; i++) {
+ if (plane_cfg->supported_formats[i] == drm_format) {
+ plane_cfg->supported_formats[i] = plane_cfg->supported_formats[plane_cfg->supported_formats_count - 1];
+ plane_cfg->supported_formats_count--;
+ }
+ }
+}
+
struct vkms_config_plane *vkms_config_crtc_primary_plane(const struct vkms_config *config,
struct vkms_config_crtc *crtc_cfg)
{
diff --git a/drivers/gpu/drm/vkms/vkms_config.h b/drivers/gpu/drm/vkms/vkms_config.h
index d8648bf844d4..2d9e35b7caad 100644
--- a/drivers/gpu/drm/vkms/vkms_config.h
+++ b/drivers/gpu/drm/vkms/vkms_config.h
@@ -49,6 +49,8 @@ struct vkms_config {
* @supported_color_encodings: Color encoding that this plane will support
* @default_color_range: Default color range that should be used by this plane
* @supported_color_ranges: Color range that this plane will support
+ * @supported_formats: List of supported formats
+ * @supported_formats_count: Length of @supported_formats
*/
struct vkms_config_plane {
struct list_head link;
@@ -62,6 +64,8 @@ struct vkms_config_plane {
unsigned int supported_color_encodings;
enum drm_color_range default_color_range;
unsigned int supported_color_ranges;
+ u32 *supported_formats;
+ unsigned int supported_formats_count;
struct xarray possible_crtcs;

/* Internal usage */
@@ -448,6 +452,53 @@ bool vkms_config_valid_plane_color_range(const struct vkms_config *config,
const struct vkms_config_plane *plane_cfg);
#endif

+static inline u32 *
+vkms_config_plane_get_supported_formats(const struct vkms_config_plane *plane_cfg)
+{
+ return plane_cfg->supported_formats;
+}
+
+static inline unsigned int
+vkms_config_plane_get_supported_formats_count(struct vkms_config_plane *plane_cfg)
+{
+ return plane_cfg->supported_formats_count;
+}
+
+/** vkms_config_plane_add_format - Add a format to the list of supported format of a plane
+ *
+ * The passed drm_format can already be present in the list. This may fail if the allocation of a
+ * bigger array fails.
+ *
+ * @plane_cfg: Plane to add the format to
+ * @drm_format: Format to add to this plane
+ *
+ * Returns: 0 on success, -ENOMEM if array allocation fails, -EINVAL if the format is not supported
+ * by VKMS
+ */
+int __must_check vkms_config_plane_add_format(struct vkms_config_plane *plane_cfg, u32 drm_format);
+
+/**
+ * vkms_config_plane_add_all_formats - Helper to quickly add all the supported formats
+ * @plane_cfg: Plane to add the formats to
+ *
+ * Returns: 0 on success, -ENOMEM if array allocation fails, -EINVAL if the format is not supported
+ * by VKMS
+ */
+int __must_check vkms_config_plane_add_all_formats(struct vkms_config_plane *plane_cfg);
+
+/**
+ * vkms_config_plane_remove_format - Remove a specific format from a plane
+ * @plane_cfg: Plane to remove the format to
+ * @drm_format: Format to remove
+ */
+void vkms_config_plane_remove_format(struct vkms_config_plane *plane_cfg, u32 drm_format);
+
+/**
+ * vkms_config_plane_remove_all_formats - Remove all formast from a plane
+ * @plane_cfg: Plane to remove the formats from
+ */
+void vkms_config_plane_remove_all_formats(struct vkms_config_plane *plane_cfg);
+
/**
* vkms_config_plane_set_name() - Set the plane name
* @plane_cfg: Plane to set the name to
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 5dbc7c67de1d..945abbbeac99 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -14,42 +14,6 @@
#include "vkms_drv.h"
#include "vkms_formats.h"

-static const u32 vkms_formats[] = {
- DRM_FORMAT_ARGB8888,
- DRM_FORMAT_ABGR8888,
- DRM_FORMAT_BGRA8888,
- DRM_FORMAT_RGBA8888,
- DRM_FORMAT_XRGB8888,
- DRM_FORMAT_XBGR8888,
- DRM_FORMAT_RGB888,
- DRM_FORMAT_BGR888,
- DRM_FORMAT_XRGB16161616,
- DRM_FORMAT_XBGR16161616,
- DRM_FORMAT_ARGB16161616,
- DRM_FORMAT_ABGR16161616,
- DRM_FORMAT_RGB565,
- DRM_FORMAT_BGR565,
- DRM_FORMAT_NV12,
- DRM_FORMAT_NV16,
- DRM_FORMAT_NV24,
- DRM_FORMAT_NV21,
- DRM_FORMAT_NV61,
- DRM_FORMAT_NV42,
- DRM_FORMAT_YUV420,
- DRM_FORMAT_YUV422,
- DRM_FORMAT_YUV444,
- DRM_FORMAT_YVU420,
- DRM_FORMAT_YVU422,
- DRM_FORMAT_YVU444,
- DRM_FORMAT_P010,
- DRM_FORMAT_P012,
- DRM_FORMAT_P016,
- DRM_FORMAT_R1,
- DRM_FORMAT_R2,
- DRM_FORMAT_R4,
- DRM_FORMAT_R8,
-};
-
static struct drm_plane_state *
vkms_plane_duplicate_state(struct drm_plane *plane)
{
@@ -226,7 +190,8 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,

plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 0,
&vkms_plane_funcs,
- vkms_formats, ARRAY_SIZE(vkms_formats),
+ vkms_config_plane_get_supported_formats(config),
+ vkms_config_plane_get_supported_formats_count(config),
NULL, vkms_config_plane_get_type(config),
vkms_config_plane_get_name(config));
if (IS_ERR(plane))

--
2.51.0