[PATCH v16 7/7] drm/vkms: Add support for DRM_FORMAT_R*

Louis Chauvet
2025-01-21T10:48:22Z

This add the support for:
- R1/R2/R4/R8

R1 format was tested with [1] and [2].

[1]: https://lore.kernel.org/r/20240313-new_rotation-v2-0-6230fd5cae59@bootlin.com
[2]: https://lore.kernel.org/igt-dev/20240306-b4-kms_tests-v1-0-8fe451efd2ac@bootlin.com/

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
drivers/gpu/drm/vkms/vkms_formats.c | 110 +++++++++++++++++++++++++++++++++++-
drivers/gpu/drm/vkms/vkms_plane.c | 4 ++
2 files changed, 113 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index 0b867444999105262c855a24bf03bc66d9ebea1b..2edf1ceccd37ad3a2f9f6d2dcf2044c98d9e10f0 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -249,6 +249,16 @@ static struct pixel_argb_u16 argb_u16_from_RGB565(const __le16 *pixel)
return out_pixel;
}

+static struct pixel_argb_u16 argb_u16_from_gray8(u8 gray)
+{
+ return argb_u16_from_u8888(255, gray, gray, gray);
+}
+
+static struct pixel_argb_u16 argb_u16_from_grayu16(u16 gray)
+{
+ return argb_u16_from_u16161616(0xFFFF, gray, gray, gray);
+}
+
VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
const struct conversion_matrix *matrix)
{
@@ -286,7 +296,7 @@ EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
* The following functions are read_line function for each pixel format supported by VKMS.
*
* They read a line starting at the point @x_start,@y_start following the @direction. The result
- * is stored in @out_pixel and in the format ARGB16161616.
+ * is stored in @out_pixel and in a 64 bits format, see struct pixel_argb_u16.
*
* These functions are very repetitive, but the innermost pixel loops must be kept inside these
* functions for performance reasons. Some benchmarking was done in [1] where having the innermost
@@ -295,6 +305,96 @@ EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
* [1]: https://lore.kernel.org/dri-devel/d258c8dc-78e9-4509-9037-a98f7f33b3a3@riseup.net/
*/

+static void Rx_read_line(const struct vkms_plane_state *plane, int x_start,
+ int y_start, enum pixel_read_direction direction, int count,
+ struct pixel_argb_u16 out_pixel[])
+{
+ struct pixel_argb_u16 *end = out_pixel + count;
+ int bits_per_pixel = drm_format_info_bpp(plane->frame_info->fb->format, 0);
+ u8 *src_pixels;
+ int rem_x, rem_y;
+
+ WARN_ONCE(drm_format_info_block_height(plane->frame_info->fb->format, 0) != 1,
+ "%s() only support formats with block_h == 1", __func__);
+
+ packed_pixels_addr(plane->frame_info, x_start, y_start, 0, &src_pixels, &rem_x, &rem_y);
+ int bit_offset = (8 - bits_per_pixel) - rem_x * bits_per_pixel;
+ int step = get_block_step_bytes(plane->frame_info->fb, direction, 0);
+ int mask = (0x1 << bits_per_pixel) - 1;
+ int lum_per_level = 0xFFFF / mask;
+
+ if (direction == READ_LEFT_TO_RIGHT || direction == READ_RIGHT_TO_LEFT) {
+ int restart_bit_offset;
+ int step_bit_offset;
+
+ if (direction == READ_LEFT_TO_RIGHT) {
+ restart_bit_offset = 8 - bits_per_pixel;
+ step_bit_offset = -bits_per_pixel;
+ } else {
+ restart_bit_offset = 0;
+ step_bit_offset = bits_per_pixel;
+ }
+
+ while (out_pixel < end) {
+ u8 val = ((*src_pixels) >> bit_offset) & mask;
+
+ *out_pixel = argb_u16_from_grayu16((int)val * lum_per_level);
+
+ bit_offset += step_bit_offset;
+ if (bit_offset < 0 || 8 <= bit_offset) {
+ bit_offset = restart_bit_offset;
+ src_pixels += step;
+ }
+ out_pixel += 1;
+ }
+ } else if (direction == READ_TOP_TO_BOTTOM || direction == READ_BOTTOM_TO_TOP) {
+ while (out_pixel < end) {
+ u8 val = (*src_pixels >> bit_offset) & mask;
+ *out_pixel = argb_u16_from_grayu16((int)val * lum_per_level);
+ src_pixels += step;
+ out_pixel += 1;
+ }
+ }
+}
+
+static void R1_read_line(const struct vkms_plane_state *plane, int x_start,
+ int y_start, enum pixel_read_direction direction, int count,
+ struct pixel_argb_u16 out_pixel[])
+{
+ Rx_read_line(plane, x_start, y_start, direction, count, out_pixel);
+}
+
+static void R2_read_line(const struct vkms_plane_state *plane, int x_start,
+ int y_start, enum pixel_read_direction direction, int count,
+ struct pixel_argb_u16 out_pixel[])
+{
+ Rx_read_line(plane, x_start, y_start, direction, count, out_pixel);
+}
+
+static void R4_read_line(const struct vkms_plane_state *plane, int x_start,
+ int y_start, enum pixel_read_direction direction, int count,
+ struct pixel_argb_u16 out_pixel[])
+{
+ Rx_read_line(plane, x_start, y_start, direction, count, out_pixel);
+}
+
+static void R8_read_line(const struct vkms_plane_state *plane, int x_start,
+ int y_start, enum pixel_read_direction direction, int count,
+ struct pixel_argb_u16 out_pixel[])
+{
+ struct pixel_argb_u16 *end = out_pixel + count;
+ u8 *src_pixels;
+ int step = get_block_step_bytes(plane->frame_info->fb, direction, 0);
+
+ packed_pixels_addr_1x1(plane->frame_info, x_start, y_start, 0, &src_pixels);
+
+ while (out_pixel < end) {
+ *out_pixel = argb_u16_from_gray8(*src_pixels);
+ src_pixels += step;
+ out_pixel += 1;
+ }
+}
+
static void ARGB8888_read_line(const struct vkms_plane_state *plane, int x_start, int y_start,
enum pixel_read_direction direction, int count,
struct pixel_argb_u16 out_pixel[])
@@ -606,6 +706,14 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
case DRM_FORMAT_YVU422:
case DRM_FORMAT_YVU444:
return &planar_yuv_read_line;
+ case DRM_FORMAT_R1:
+ return &R1_read_line;
+ case DRM_FORMAT_R2:
+ return &R2_read_line;
+ case DRM_FORMAT_R4:
+ return &R4_read_line;
+ case DRM_FORMAT_R8:
+ return &R8_read_line;
default:
/*
* This is a bug in vkms_plane_atomic_check(). All the supported
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index e6ca8f2db32d92068ddba7eed92cfae0d28cd45f..81941914af87fcefb180dc393f2ec311f1a1d3fa 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -30,6 +30,10 @@ static const u32 vkms_formats[] = {
DRM_FORMAT_YVU420,
DRM_FORMAT_YVU422,
DRM_FORMAT_YVU444,
+ DRM_FORMAT_R1,
+ DRM_FORMAT_R2,
+ DRM_FORMAT_R4,
+ DRM_FORMAT_R8,
};

static struct drm_plane_state *

--
2.47.1