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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
udl-kms: avoid division
Division is slow, so it shouldn't be done by the pixel generating code. The driver supports only 2 or 4 bytes per pixel, so we can replace division with a shift. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
parent
09a00abe3a
commit
91ba11fb7d
3 changed files with 30 additions and 26 deletions
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@ -112,7 +112,7 @@ udl_fb_user_fb_create(struct drm_device *dev,
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struct drm_file *file,
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const struct drm_mode_fb_cmd2 *mode_cmd);
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int udl_render_hline(struct drm_device *dev, int bpp, struct urb **urb_ptr,
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int udl_render_hline(struct drm_device *dev, int log_bpp, struct urb **urb_ptr,
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const char *front, char **urb_buf_ptr,
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u32 byte_offset, u32 device_byte_offset, u32 byte_width,
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int *ident_ptr, int *sent_ptr);
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@ -90,7 +90,10 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
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int bytes_identical = 0;
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struct urb *urb;
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int aligned_x;
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int bpp = fb->base.format->cpp[0];
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int log_bpp;
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BUG_ON(!is_power_of_2(fb->base.format->cpp[0]));
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log_bpp = __ffs(fb->base.format->cpp[0]);
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if (!fb->active_16)
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return 0;
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@ -125,12 +128,12 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
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for (i = y; i < y + height ; i++) {
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const int line_offset = fb->base.pitches[0] * i;
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const int byte_offset = line_offset + (x * bpp);
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const int dev_byte_offset = (fb->base.width * bpp * i) + (x * bpp);
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if (udl_render_hline(dev, bpp, &urb,
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const int byte_offset = line_offset + (x << log_bpp);
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const int dev_byte_offset = (fb->base.width * i + x) << log_bpp;
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if (udl_render_hline(dev, log_bpp, &urb,
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(char *) fb->obj->vmapping,
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&cmd, byte_offset, dev_byte_offset,
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width * bpp,
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width << log_bpp,
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&bytes_identical, &bytes_sent))
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goto error;
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}
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@ -149,7 +152,7 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
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error:
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atomic_add(bytes_sent, &udl->bytes_sent);
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atomic_add(bytes_identical, &udl->bytes_identical);
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atomic_add(width*height*bpp, &udl->bytes_rendered);
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atomic_add((width * height) << log_bpp, &udl->bytes_rendered);
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end_cycles = get_cycles();
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atomic_add(((unsigned int) ((end_cycles - start_cycles)
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>> 10)), /* Kcycles */
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@ -83,12 +83,12 @@ static inline u16 pixel32_to_be16(const uint32_t pixel)
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((pixel >> 8) & 0xf800));
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}
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static inline u16 get_pixel_val16(const uint8_t *pixel, int bpp)
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static inline u16 get_pixel_val16(const uint8_t *pixel, int log_bpp)
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{
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u16 pixel_val16 = 0;
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if (bpp == 2)
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u16 pixel_val16;
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if (log_bpp == 1)
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pixel_val16 = *(const uint16_t *)pixel;
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else if (bpp == 4)
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else
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pixel_val16 = pixel32_to_be16(*(const uint32_t *)pixel);
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return pixel_val16;
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}
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@ -125,8 +125,9 @@ static void udl_compress_hline16(
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const u8 *const pixel_end,
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uint32_t *device_address_ptr,
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uint8_t **command_buffer_ptr,
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const uint8_t *const cmd_buffer_end, int bpp)
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const uint8_t *const cmd_buffer_end, int log_bpp)
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{
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const int bpp = 1 << log_bpp;
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const u8 *pixel = *pixel_start_ptr;
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uint32_t dev_addr = *device_address_ptr;
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uint8_t *cmd = *command_buffer_ptr;
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@ -153,12 +154,12 @@ static void udl_compress_hline16(
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raw_pixels_count_byte = cmd++; /* we'll know this later */
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raw_pixel_start = pixel;
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cmd_pixel_end = pixel + min3(MAX_CMD_PIXELS + 1UL,
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(unsigned long)(pixel_end - pixel) / bpp,
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(unsigned long)(cmd_buffer_end - 1 - cmd) / 2) * bpp;
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cmd_pixel_end = pixel + (min3(MAX_CMD_PIXELS + 1UL,
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(unsigned long)(pixel_end - pixel) >> log_bpp,
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(unsigned long)(cmd_buffer_end - 1 - cmd) / 2) << log_bpp);
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prefetch_range((void *) pixel, cmd_pixel_end - pixel);
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pixel_val16 = get_pixel_val16(pixel, bpp);
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pixel_val16 = get_pixel_val16(pixel, log_bpp);
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while (pixel < cmd_pixel_end) {
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const u8 *const start = pixel;
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@ -170,7 +171,7 @@ static void udl_compress_hline16(
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pixel += bpp;
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while (pixel < cmd_pixel_end) {
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pixel_val16 = get_pixel_val16(pixel, bpp);
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pixel_val16 = get_pixel_val16(pixel, log_bpp);
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if (pixel_val16 != repeating_pixel_val16)
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break;
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pixel += bpp;
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@ -179,10 +180,10 @@ static void udl_compress_hline16(
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if (unlikely(pixel > start + bpp)) {
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/* go back and fill in raw pixel count */
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*raw_pixels_count_byte = (((start -
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raw_pixel_start) / bpp) + 1) & 0xFF;
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raw_pixel_start) >> log_bpp) + 1) & 0xFF;
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/* immediately after raw data is repeat byte */
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*cmd++ = (((pixel - start) / bpp) - 1) & 0xFF;
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*cmd++ = (((pixel - start) >> log_bpp) - 1) & 0xFF;
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/* Then start another raw pixel span */
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raw_pixel_start = pixel;
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@ -192,14 +193,14 @@ static void udl_compress_hline16(
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if (pixel > raw_pixel_start) {
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/* finalize last RAW span */
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*raw_pixels_count_byte = ((pixel-raw_pixel_start) / bpp) & 0xFF;
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*raw_pixels_count_byte = ((pixel - raw_pixel_start) >> log_bpp) & 0xFF;
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} else {
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/* undo unused byte */
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cmd--;
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}
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*cmd_pixels_count_byte = ((pixel - cmd_pixel_start) / bpp) & 0xFF;
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dev_addr += ((pixel - cmd_pixel_start) / bpp) * 2;
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*cmd_pixels_count_byte = ((pixel - cmd_pixel_start) >> log_bpp) & 0xFF;
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dev_addr += ((pixel - cmd_pixel_start) >> log_bpp) * 2;
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}
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if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
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@ -222,19 +223,19 @@ static void udl_compress_hline16(
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* (that we can only write to, slowly, and can never read), and (optionally)
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* our shadow copy that tracks what's been sent to that hardware buffer.
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*/
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int udl_render_hline(struct drm_device *dev, int bpp, struct urb **urb_ptr,
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int udl_render_hline(struct drm_device *dev, int log_bpp, struct urb **urb_ptr,
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const char *front, char **urb_buf_ptr,
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u32 byte_offset, u32 device_byte_offset,
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u32 byte_width,
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int *ident_ptr, int *sent_ptr)
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{
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const u8 *line_start, *line_end, *next_pixel;
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u32 base16 = 0 + (device_byte_offset / bpp) * 2;
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u32 base16 = 0 + (device_byte_offset >> log_bpp) * 2;
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struct urb *urb = *urb_ptr;
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u8 *cmd = *urb_buf_ptr;
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u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
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BUG_ON(!(bpp == 2 || bpp == 4));
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BUG_ON(!(log_bpp == 1 || log_bpp == 2));
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line_start = (u8 *) (front + byte_offset);
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next_pixel = line_start;
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@ -244,7 +245,7 @@ int udl_render_hline(struct drm_device *dev, int bpp, struct urb **urb_ptr,
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udl_compress_hline16(&next_pixel,
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line_end, &base16,
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(u8 **) &cmd, (u8 *) cmd_end, bpp);
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(u8 **) &cmd, (u8 *) cmd_end, log_bpp);
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if (cmd >= cmd_end) {
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int len = cmd - (u8 *) urb->transfer_buffer;
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