[PATCH v4 10/14] drm/vkms: Re-introduce line-per-line composition algorithm

From: Louis Chauvet
Date: Mon Mar 04 2024 - 10:32:40 EST

Re-introduce a line-by-line composition algorithm for each pixel format.
This allows more performance by not requiring an indirection per pixel
read. This patch is focused on readability of the code.

Line-by-line composition was introduced by [1] but rewritten back to
pixel-by-pixel algorithm in [2]. At this time, nobody noticed the impact
on performance, and it was merged.

This patch is almost a revert of [2], but in addition efforts have been
made to increase readability and maintainability of the rotation handling.
The blend function is now divided in two parts:
- Transformation of coordinates from the output referential to the source
referential
- Line conversion and blending

Most of the complexity of the rotation management is avoided by using
drm_rect_* helpers. The remaining complexity is around the clipping, to
avoid reading/writing outside source/destination buffers.

The pixel conversion is now done line-by-line, so the read_pixel_t was
replaced with read_pixel_line_t callback. This way the indirection is only
required once per line and per plane, instead of once per pixel and per
plane.

The read_line_t callbacks are very similar for most pixel format, but it
is required to avoid performance impact. Some helpers were created to
avoid code repetition:
- get_step_1x1: get the step in byte to reach next pixel block in a
certain direction
- *_to_argb_u16: helpers to perform colors conversion. They should be
inlined by the compiler, and they are used to avoid repetition between
multiple variants of the same format (argb/xrgb and maybe in the
future for formats like bgr formats).

This new algorithm was tested with:
- kms_plane (for color conversions)
- kms_rotation_crc (for rotations of planes)
- kms_cursor_crc (for translations of planes)
The performance gain was mesured with:
- kms_fb_stress

[1]: commit 8ba1648567e2 ("drm: vkms: Refactor the plane composer to accept
new formats")
https://lore.kernel.org/all/20220905190811.25024-7-igormtorrente@xxxxxxxxx/
[2]: commit 322d716a3e8a ("drm/vkms: isolate pixel conversion
functionality")
https://lore.kernel.org/all/20230418130525.128733-2-mcanal@xxxxxxxxxx/

Signed-off-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>
---
drivers/gpu/drm/vkms/vkms_composer.c | 169 ++++++++++++++++++++-------
drivers/gpu/drm/vkms/vkms_drv.h | 27 +++--
drivers/gpu/drm/vkms/vkms_formats.c | 218 +++++++++++++++++++++--------------
drivers/gpu/drm/vkms/vkms_formats.h | 2 +-
drivers/gpu/drm/vkms/vkms_plane.c | 5 +-
5 files changed, 280 insertions(+), 141 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index 068b6d838d7a..62122ade7d67 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -54,33 +54,6 @@ static void pre_mul_alpha_blend(
}
}

-static int get_y_pos(struct vkms_frame_info *frame_info, int y)
-{
- if (frame_info->rotation & DRM_MODE_REFLECT_Y)
- return drm_rect_height(&frame_info->rotated) - y - 1;
-
- switch (frame_info->rotation & DRM_MODE_ROTATE_MASK) {
- case DRM_MODE_ROTATE_90:
- return frame_info->rotated.x2 - y - 1;
- case DRM_MODE_ROTATE_270:
- return y + frame_info->rotated.x1;
- default:
- return y;
- }
-}
-
-static bool check_limit(struct vkms_frame_info *frame_info, int pos)
-{
- if (drm_rotation_90_or_270(frame_info->rotation)) {
- if (pos >= 0 && pos < drm_rect_width(&frame_info->rotated))
- return true;
- } else {
- if (pos >= frame_info->rotated.y1 && pos < frame_info->rotated.y2)
- return true;
- }
-
- return false;
-}

static void fill_background(const struct pixel_argb_u16 *background_color,
struct line_buffer *output_buffer)
@@ -218,34 +191,150 @@ static void blend(struct vkms_writeback_job *wb,
{
struct vkms_plane_state **plane = crtc_state->active_planes;
u32 n_active_planes = crtc_state->num_active_planes;
- int y_pos, x_dst, x_limit;

const struct pixel_argb_u16 background_color = { .a = 0xffff };

- size_t crtc_y_limit = crtc_state->base.crtc->mode.vdisplay;
+ int crtc_y_limit = crtc_state->base.crtc->mode.vdisplay;
+ int crtc_x_limit = crtc_state->base.crtc->mode.hdisplay;

/*
* The planes are composed line-by-line to avoid heavy memory usage. It is a necessary
* complexity to avoid poor blending performance.
*
- * The function vkms_compose_row is used to read a line, pixel-by-pixel, into the staging
- * buffer.
+ * The function pixel_read_line callback is used to read a line, using an efficient
+ * algorithm for a specific format, into the staging buffer.
*/
for (size_t y = 0; y < crtc_y_limit; y++) {
fill_background(&background_color, output_buffer);

/* The active planes are composed associatively in z-order. */
for (size_t i = 0; i < n_active_planes; i++) {
- x_dst = plane[i]->frame_info->dst.x1;
- x_limit = min_t(size_t, drm_rect_width(&plane[i]->frame_info->dst),
- stage_buffer->n_pixels);
- y_pos = get_y_pos(plane[i]->frame_info, y);
+ struct vkms_plane_state *current_plane = plane[i];

- if (!check_limit(plane[i]->frame_info, y_pos))
+ /* Avoid rendering useless lines */
+ if (y < current_plane->frame_info->dst.y1 ||
+ y >= current_plane->frame_info->dst.y2)
continue;

- vkms_compose_row(stage_buffer, plane[i], y_pos);
- pre_mul_alpha_blend(stage_buffer, output_buffer, x_dst, x_limit);
+ /*
+ * dst_line is the line to copy. The initial coordinates are inside the
+ * destination framebuffer, and then drm_rect_* helpers are used to
+ * compute the correct position into the source framebuffer.
+ */
+ struct drm_rect dst_line = DRM_RECT_INIT(
+ current_plane->frame_info->dst.x1, y,
+ drm_rect_width(&current_plane->frame_info->dst), 1);
+ struct drm_rect tmp_src;
+
+ drm_rect_fp_to_int(&tmp_src, &current_plane->frame_info->src);
+
+ /*
+ * [1]: Clamping src_line to the crtc_x_limit to avoid writing outside of
+ * the destination buffer
+ */
+ dst_line.x1 = max_t(int, dst_line.x1, 0);
+ dst_line.x2 = min_t(int, dst_line.x2, crtc_x_limit);
+ /* The destination is completely outside of the crtc. */
+ if (dst_line.x2 <= dst_line.x1)
+ continue;
+
+ struct drm_rect src_line = dst_line;
+
+ /*
+ * Transform the coordinate x/y from the crtc to coordinates into
+ * coordinates for the src buffer.
+ *
+ * - Cancel the offset of the dst buffer.
+ * - Invert the rotation. This assumes that
+ * dst = drm_rect_rotate(src, rotation) (dst and src have the
+ * same size, but can be rotated).
+ * - Apply the offset of the source rectangle to the coordinate.
+ */
+ drm_rect_translate(&src_line, -current_plane->frame_info->dst.x1,
+ -current_plane->frame_info->dst.y1);
+ drm_rect_rotate_inv(&src_line,
+ drm_rect_width(&tmp_src),
+ drm_rect_height(&tmp_src),
+ current_plane->frame_info->rotation);
+ drm_rect_translate(&src_line, tmp_src.x1, tmp_src.y1);
+
+ /* Get the correct reading direction in the source buffer. */
+
+ enum pixel_read_direction direction =
+ direction_for_rotation(current_plane->frame_info->rotation);
+
+ int x_start = src_line.x1;
+ int y_start = src_line.y1;
+ int pixel_count;
+ /* [2]: Compute and clamp the number of pixel to read */
+ if (direction == READ_LEFT_TO_RIGHT || direction == READ_RIGHT_TO_LEFT) {
+ /*
+ * In horizontal reading, the src_line width is the number of pixel
+ * to read
+ */
+ pixel_count = drm_rect_width(&src_line);
+ if (x_start < 0) {
+ pixel_count += x_start;
+ x_start = 0;
+ }
+ if (x_start + pixel_count > current_plane->frame_info->fb->width) {
+ pixel_count =
+ (int)current_plane->frame_info->fb->width - x_start;
+ }
+ } else {
+ /*
+ * In vertical reading, the src_line height is the number of pixel
+ * to read
+ */
+ pixel_count = drm_rect_height(&src_line);
+ if (y_start < 0) {
+ pixel_count += y_start;
+ y_start = 0;
+ }
+ if (y_start + pixel_count > current_plane->frame_info->fb->height) {
+ pixel_count =
+ (int)current_plane->frame_info->fb->width - y_start;
+ }
+ }
+
+ if (pixel_count <= 0) {
+ /* Nothing to read, so avoid multiple function calls for nothing */
+ continue;
+ }
+
+ /*
+ * Modify the starting point to take in account the rotation
+ *
+ * src_line is the top-left corner, so when reading READ_RIGHT_TO_LEFT or
+ * READ_BOTTOM_TO_TOP, it must be changed to the top-right/bottom-left
+ * corner.
+ */
+ if (direction == READ_RIGHT_TO_LEFT) {
+ // x_start is now the right point
+ x_start += pixel_count - 1;
+ } else if (direction == READ_BOTTOM_TO_TOP) {
+ // y_start is now the bottom point
+ y_start += pixel_count - 1;
+ }
+
+ /*
+ * Perform the conversion and the blending
+ *
+ * Here we know that the read line (x_start, y_start, pixel_count) is
+ * inside the source buffer [2] and we don't write outside the stage
+ * buffer [1]
+ */
+ current_plane->pixel_read_line(
+ current_plane,
+ x_start,
+ y_start,
+ direction,
+ pixel_count,
+ &stage_buffer->pixels[current_plane->frame_info->dst.x1]);
+
+ pre_mul_alpha_blend(stage_buffer, output_buffer,
+ current_plane->frame_info->dst.x1,
+ pixel_count);
}

apply_lut(crtc_state, output_buffer);
@@ -253,7 +342,7 @@ static void blend(struct vkms_writeback_job *wb,
*crc32 = crc32_le(*crc32, (void *)output_buffer->pixels, row_size);

if (wb)
- vkms_writeback_row(wb, output_buffer, y_pos);
+ vkms_writeback_row(wb, output_buffer, y);
}
}

@@ -264,7 +353,7 @@ static int check_format_funcs(struct vkms_crtc_state *crtc_state,
u32 n_active_planes = crtc_state->num_active_planes;

for (size_t i = 0; i < n_active_planes; i++)
- if (!planes[i]->pixel_read)
+ if (!planes[i]->pixel_read_line)
return -1;

if (active_wb && !active_wb->pixel_write)
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 985e7a92b7bc..23e1d247468d 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -39,7 +39,6 @@
struct vkms_frame_info {
struct drm_framebuffer *fb;
struct drm_rect src, dst;
- struct drm_rect rotated;
struct iosys_map map[DRM_FORMAT_MAX_PLANES];
unsigned int rotation;
};
@@ -80,26 +79,37 @@ enum pixel_read_direction {
READ_LEFT_TO_RIGHT
};

+struct vkms_plane_state;
+
/**
- * typedef pixel_read_t - These functions are used to read a pixel in the source frame,
+ * typedef pixel_read_line_t - These functions are used to read a pixel line in the source frame,
* convert it to `struct pixel_argb_u16` and write it to @out_pixel.
*
- * @in_pixel: Pointer to the pixel to read
- * @out_pixel: Pointer to write the converted pixel
+ * @plane: Plane used as source for the pixel value
+ * @x_start: X (width) coordinate of the first pixel to copy. The caller must ensure that x_start
+ * is positive and smaller than @plane->frame_info->fb->width.
+ * @y_start: Y (width) coordinate of the first pixel to copy. The caller must ensure that y_start
+ * is positive and smaller than @plane->frame_info->fb->height.
+ * @direction: Direction to use for the copy, starting at @x_start/@y_start
+ * @count: Number of pixels to copy
+ * @out_pixel: Pointer where to write the pixel values. They will be written from @out_pixel[0]
+ * to @out_pixel[@count]. The caller must ensure that out_pixel have a length of at least @count.
*/
-typedef void (*pixel_read_t)(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel);
+typedef void (*pixel_read_line_t)(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[]);

/**
* vkms_plane_state - Driver specific plane state
* @base: base plane state
* @frame_info: data required for composing computation
- * @pixel_read: function to read a pixel in this plane. The creator of a vkms_plane_state must
- * ensure that this pointer is valid
+ * @pixel_read_line: function to read a pixel line in this plane. The creator of a vkms_plane_state
+ * must ensure that this pointer is valid
*/
struct vkms_plane_state {
struct drm_shadow_plane_state base;
struct vkms_frame_info *frame_info;
- pixel_read_t pixel_read;
+ pixel_read_line_t pixel_read_line;
};

struct vkms_plane {
@@ -204,7 +214,6 @@ int vkms_verify_crc_source(struct drm_crtc *crtc, const char *source_name,
/* Composer Support */
void vkms_composer_worker(struct work_struct *work);
void vkms_set_composer(struct vkms_output *out, bool enabled);
-void vkms_compose_row(struct line_buffer *stage_buffer, struct vkms_plane_state *plane, int y);
void vkms_writeback_row(struct vkms_writeback_job *wb, const struct line_buffer *src_buffer, int y);

/* Writeback */
diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
index 7a1bc1d8651f..87af3962ee12 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.c
+++ b/drivers/gpu/drm/vkms/vkms_formats.c
@@ -90,74 +90,45 @@ static int get_step_1x1(struct drm_framebuffer *fb, enum pixel_read_direction di
return 0;
}

-static void *get_packed_src_addr(const struct vkms_frame_info *frame_info, int y,
- size_t plane_index)
-{
- int x_src = frame_info->src.x1 >> 16;
- int y_src = y - frame_info->rotated.y1 + (frame_info->src.y1 >> 16);
-
- return packed_pixels_addr(frame_info, x_src, y_src, plane_index);
-}
-
-static int get_x_position(const struct vkms_frame_info *frame_info, int limit, int x)
-{
- if (frame_info->rotation & (DRM_MODE_REFLECT_X | DRM_MODE_ROTATE_270))
- return limit - x - 1;
- return x;
-}
-
/*
- * The following functions take pixel data from the buffer and convert them to the format
+ * The following functions take pixel data (a, r, g, b, pixel, ...), convert them to the format
* ARGB16161616 in out_pixel.
*
- * They are used in the `vkms_compose_row` function to handle multiple formats.
+ * They are used in the `read_line`s functions to avoid duplicate work for some pixel formats.
*/

-static void ARGB8888_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static struct pixel_argb_u16 argb_u16_from_u8888(int a, int r, int g, int b)
{
+ struct pixel_argb_u16 out_pixel;
/*
* The 257 is the "conversion ratio". This number is obtained by the
* (2^16 - 1) / (2^8 - 1) division. Which, in this case, tries to get
* the best color value in a pixel format with more possibilities.
* A similar idea applies to others RGB color conversions.
*/
- out_pixel->a = (u16)in_pixel[3] * 257;
- out_pixel->r = (u16)in_pixel[2] * 257;
- out_pixel->g = (u16)in_pixel[1] * 257;
- out_pixel->b = (u16)in_pixel[0] * 257;
-}
+ out_pixel.a = (u16)a * 257;
+ out_pixel.r = (u16)r * 257;
+ out_pixel.g = (u16)g * 257;
+ out_pixel.b = (u16)b * 257;

-static void XRGB8888_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
-{
- out_pixel->a = (u16)0xffff;
- out_pixel->r = (u16)in_pixel[2] * 257;
- out_pixel->g = (u16)in_pixel[1] * 257;
- out_pixel->b = (u16)in_pixel[0] * 257;
+ return out_pixel;
}

-static void ARGB16161616_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static struct pixel_argb_u16 argb_u16_from_u16161616(int a, int r, int g, int b)
{
- u16 *pixel = (u16 *)in_pixel;
+ struct pixel_argb_u16 out_pixel;

- out_pixel->a = le16_to_cpu(pixel[3]);
- out_pixel->r = le16_to_cpu(pixel[2]);
- out_pixel->g = le16_to_cpu(pixel[1]);
- out_pixel->b = le16_to_cpu(pixel[0]);
-}
-
-static void XRGB16161616_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
-{
- u16 *pixel = (u16 *)in_pixel;
+ out_pixel.a = le16_to_cpu(a);
+ out_pixel.r = le16_to_cpu(r);
+ out_pixel.g = le16_to_cpu(g);
+ out_pixel.b = le16_to_cpu(b);

- out_pixel->a = (u16)0xffff;
- out_pixel->r = le16_to_cpu(pixel[2]);
- out_pixel->g = le16_to_cpu(pixel[1]);
- out_pixel->b = le16_to_cpu(pixel[0]);
+ return out_pixel;
}

-static void RGB565_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static struct pixel_argb_u16 argb_u16_from_RGB565(const u16 *pixel)
{
- u16 *pixel = (u16 *)in_pixel;
+ struct pixel_argb_u16 out_pixel;

s64 fp_rb_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(31));
s64 fp_g_ratio = drm_fixp_div(drm_int2fixp(65535), drm_int2fixp(63));
@@ -167,12 +138,26 @@ static void RGB565_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pi
s64 fp_g = drm_int2fixp((rgb_565 >> 5) & 0x3f);
s64 fp_b = drm_int2fixp(rgb_565 & 0x1f);

- out_pixel->a = (u16)0xffff;
- out_pixel->r = drm_fixp2int_round(drm_fixp_mul(fp_r, fp_rb_ratio));
- out_pixel->g = drm_fixp2int_round(drm_fixp_mul(fp_g, fp_g_ratio));
- out_pixel->b = drm_fixp2int_round(drm_fixp_mul(fp_b, fp_rb_ratio));
+ out_pixel.a = (u16)0xffff;
+ out_pixel.r = drm_fixp2int_round(drm_fixp_mul(fp_r, fp_rb_ratio));
+ out_pixel.g = drm_fixp2int_round(drm_fixp_mul(fp_g, fp_g_ratio));
+ out_pixel.b = drm_fixp2int_round(drm_fixp_mul(fp_b, fp_rb_ratio));
+
+ return out_pixel;
}

+/*
+ * 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.
+ *
+ * Those function are very similar, but it is required for performance reason. In the past, some
+ * experiment were done, and with a generic loop the performance are very reduced [1].
+ *
+ * [1]: https://lore.kernel.org/dri-devel/d258c8dc-78e9-4509-9037-a98f7f33b3a3@xxxxxxxxxx/
+ */
+
/**
* black_to_argb_u16() - pixel_read callback which always read black
*
@@ -180,42 +165,101 @@ static void RGB565_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pi
* It is used to avoid null pointer to be used as a function. In theory, this function should
* never be called, except if you found a bug in the driver/DRM core.
*/
-static void black_to_argb_u16(const u8 *in_pixel, struct pixel_argb_u16 *out_pixel)
+static void black_to_argb_u16(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[])
{
- out_pixel->a = (u16) 0xFFFF;
- out_pixel->r = 0;
- out_pixel->g = 0;
- out_pixel->b = 0;
+ struct pixel_argb_u16 *end = out_pixel + count;
+
+ while (out_pixel < end) {
+ *out_pixel = argb_u16_from_u8888(255, 0, 0, 0);
+ out_pixel += 1;
+ }
}

-/**
- * vkms_compose_row - compose a single row of a plane
- * @stage_buffer: output line with the composed pixels
- * @plane: state of the plane that is being composed
- * @y: y coordinate of the row
- *
- * This function composes a single row of a plane. It gets the source pixels
- * through the y coordinate (see get_packed_src_addr()) and goes linearly
- * through the source pixel, reading the pixels and converting it to
- * ARGB16161616 (see the pixel_read() callback). For rotate-90 and rotate-270,
- * the source pixels are not traversed linearly. The source pixels are queried
- * on each iteration in order to traverse the pixels vertically.
- */
-void vkms_compose_row(struct line_buffer *stage_buffer, struct vkms_plane_state *plane, int y)
+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[])
+{
+ struct pixel_argb_u16 *end = out_pixel + count;
+ u8 *src_pixels = packed_pixels_addr(plane->frame_info, x_start, y_start, 0);
+
+ int step = get_step_1x1(plane->frame_info->fb, direction, 0);
+
+ while (out_pixel < end) {
+ u8 *px = (u8 *)src_pixels;
+ *out_pixel = argb_u16_from_u8888(px[3], px[2], px[1], px[0]);
+ out_pixel += 1;
+ src_pixels += step;
+ }
+}
+
+static void XRGB8888_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 = packed_pixels_addr(plane->frame_info, x_start, y_start, 0);
+
+ int step = get_step_1x1(plane->frame_info->fb, direction, 0);
+
+ while (out_pixel < end) {
+ u8 *px = (u8 *)src_pixels;
+ *out_pixel = argb_u16_from_u8888(255, px[2], px[1], px[0]);
+ out_pixel += 1;
+ src_pixels += step;
+ }
+}
+
+static void ARGB16161616_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 = packed_pixels_addr(plane->frame_info, x_start, y_start, 0);
+
+ int step = get_step_1x1(plane->frame_info->fb, direction, 0);
+
+ while (out_pixel < end) {
+ u16 *px = (u16 *)src_pixels;
+ *out_pixel = argb_u16_from_u16161616(px[3], px[2], px[1], px[0]);
+ out_pixel += 1;
+ src_pixels += step;
+ }
+}
+
+static void XRGB16161616_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 = packed_pixels_addr(plane->frame_info, x_start, y_start, 0);
+
+ int step = get_step_1x1(plane->frame_info->fb, direction, 0);
+
+ while (out_pixel < end) {
+ u16 *px = (u16 *)src_pixels;
+ *out_pixel = argb_u16_from_u16161616(0xFFFF, px[2], px[1], px[0]);
+ out_pixel += 1;
+ src_pixels += step;
+ }
+}
+
+static void RGB565_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 *out_pixels = stage_buffer->pixels;
- struct vkms_frame_info *frame_info = plane->frame_info;
- u8 *src_pixels = get_packed_src_addr(frame_info, y, 0);
- int limit = min_t(size_t, drm_rect_width(&frame_info->dst), stage_buffer->n_pixels);
+ struct pixel_argb_u16 *end = out_pixel + count;
+ u8 *src_pixels = packed_pixels_addr(plane->frame_info, x_start, y_start, 0);

- for (size_t x = 0; x < limit; x++, src_pixels += frame_info->fb->format->cpp[0]) {
- int x_pos = get_x_position(frame_info, limit, x);
+ int step = get_step_1x1(plane->frame_info->fb, direction, 0);

- if (drm_rotation_90_or_270(frame_info->rotation))
- src_pixels = get_packed_src_addr(frame_info, x + frame_info->rotated.y1, 0)
- + frame_info->fb->format->cpp[0] * y;
+ while (out_pixel < end) {
+ u16 *px = (u16 *)src_pixels;

- plane->pixel_read(src_pixels, &out_pixels[x_pos]);
+ *out_pixel = argb_u16_from_RGB565(px);
+ out_pixel += 1;
+ src_pixels += step;
}
}

@@ -321,25 +365,25 @@ void vkms_writeback_row(struct vkms_writeback_job *wb,
}

/**
- * Retrieve the correct read_pixel function for a specific format.
+ * Retrieve the correct read_line function for a specific format.
* If the format is not supported by VKMS a warn is emitted and a dummy "always read black"
* function is returned.
*
* @format: DRM_FORMAT_* value for which to obtain a conversion function (see [drm_fourcc.h])
*/
-pixel_read_t get_pixel_read_function(u32 format)
+pixel_read_line_t get_pixel_read_line_function(u32 format)
{
switch (format) {
case DRM_FORMAT_ARGB8888:
- return &ARGB8888_to_argb_u16;
+ return &ARGB8888_read_line;
case DRM_FORMAT_XRGB8888:
- return &XRGB8888_to_argb_u16;
+ return &XRGB8888_read_line;
case DRM_FORMAT_ARGB16161616:
- return &ARGB16161616_to_argb_u16;
+ return &ARGB16161616_read_line;
case DRM_FORMAT_XRGB16161616:
- return &XRGB16161616_to_argb_u16;
+ return &XRGB16161616_read_line;
case DRM_FORMAT_RGB565:
- return &RGB565_to_argb_u16;
+ return &RGB565_read_line;
default:
/*
* This is a bug in vkms_plane_atomic_check. All the supported
diff --git a/drivers/gpu/drm/vkms/vkms_formats.h b/drivers/gpu/drm/vkms/vkms_formats.h
index 3ecea4563254..8d2bef95ff79 100644
--- a/drivers/gpu/drm/vkms/vkms_formats.h
+++ b/drivers/gpu/drm/vkms/vkms_formats.h
@@ -5,7 +5,7 @@

#include "vkms_drv.h"

-pixel_read_t get_pixel_read_function(u32 format);
+pixel_read_line_t get_pixel_read_line_function(u32 format);

pixel_write_t get_pixel_write_function(u32 format);

diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 10e9b23dab28..8875bed76410 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -112,7 +112,6 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
frame_info = vkms_plane_state->frame_info;
memcpy(&frame_info->src, &new_state->src, sizeof(struct drm_rect));
memcpy(&frame_info->dst, &new_state->dst, sizeof(struct drm_rect));
- memcpy(&frame_info->rotated, &new_state->dst, sizeof(struct drm_rect));
frame_info->fb = fb;
memcpy(&frame_info->map, &shadow_plane_state->data, sizeof(frame_info->map));
drm_framebuffer_get(frame_info->fb);
@@ -122,10 +121,8 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
DRM_MODE_REFLECT_X |
DRM_MODE_REFLECT_Y);

- drm_rect_rotate(&frame_info->rotated, drm_rect_width(&frame_info->rotated),
- drm_rect_height(&frame_info->rotated), frame_info->rotation);

- vkms_plane_state->pixel_read = get_pixel_read_function(fmt);
+ vkms_plane_state->pixel_read_line = get_pixel_read_line_function(fmt);
}

static int vkms_plane_atomic_check(struct drm_plane *plane,

--
2.43.0