root/drivers/gpu/drm/vkms/vkms_composer.c

DEFINITIONS

1. compute_crc
2. blend
3. compose_cursor
4. _vkms_get_crc
5. vkms_composer_worker
6. vkms_get_crc_sources
7. vkms_crc_parse_source
8. vkms_verify_crc_source
9. vkms_set_crc_source

   1 // SPDX-License-Identifier: GPL-2.0+
   2 
   3 #include <linux/crc32.h>
   4 
   5 #include <drm/drm_atomic.h>
   6 #include <drm/drm_atomic_helper.h>
   7 #include <drm/drm_gem_framebuffer_helper.h>
   8 #include <drm/drm_vblank.h>
   9 
  10 #include "vkms_drv.h"
  11 
  12 /**
  13  * compute_crc - Compute CRC value on output frame
  14  *
  15  * @vaddr_out: address to final framebuffer
  16  * @composer: framebuffer's metadata
  17  *
  18  * returns CRC value computed using crc32 on the visible portion of
  19  * the final framebuffer at vaddr_out
  20  */
  21 static uint32_t compute_crc(void *vaddr_out, struct vkms_composer *composer)
  22 {
  23         int i, j, src_offset;
  24         int x_src = composer->src.x1 >> 16;
  25         int y_src = composer->src.y1 >> 16;
  26         int h_src = drm_rect_height(&composer->src) >> 16;
  27         int w_src = drm_rect_width(&composer->src) >> 16;
  28         u32 crc = 0;
  29 
  30         for (i = y_src; i < y_src + h_src; ++i) {
  31                 for (j = x_src; j < x_src + w_src; ++j) {
  32                         src_offset = composer->offset
  33                                      + (i * composer->pitch)
  34                                      + (j * composer->cpp);
  35                         /* XRGB format ignores Alpha channel */
  36                         memset(vaddr_out + src_offset + 24, 0,  8);
  37                         crc = crc32_le(crc, vaddr_out + src_offset,
  38                                        sizeof(u32));
  39                 }
  40         }
  41 
  42         return crc;
  43 }
  44 
  45 /**
  46  * blend - belnd value at vaddr_src with value at vaddr_dst
  47  * @vaddr_dst: destination address
  48  * @vaddr_src: source address
  49  * @dest_composer: destination framebuffer's metadata
  50  * @src_composer: source framebuffer's metadata
  51  *
  52  * Blend value at vaddr_src with value at vaddr_dst.
  53  * Currently, this function write value at vaddr_src on value
  54  * at vaddr_dst using buffer's metadata to locate the new values
  55  * from vaddr_src and their distenation at vaddr_dst.
  56  *
  57  * Todo: Use the alpha value to blend vaddr_src with vaddr_dst
  58  *       instead of overwriting it.
  59  */
  60 static void blend(void *vaddr_dst, void *vaddr_src,
  61                   struct vkms_composer *dest_composer,
  62                   struct vkms_composer *src_composer)
  63 {
  64         int i, j, j_dst, i_dst;
  65         int offset_src, offset_dst;
  66 
  67         int x_src = src_composer->src.x1 >> 16;
  68         int y_src = src_composer->src.y1 >> 16;
  69 
  70         int x_dst = src_composer->dst.x1;
  71         int y_dst = src_composer->dst.y1;
  72         int h_dst = drm_rect_height(&src_composer->dst);
  73         int w_dst = drm_rect_width(&src_composer->dst);
  74 
  75         int y_limit = y_src + h_dst;
  76         int x_limit = x_src + w_dst;
  77 
  78         for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
  79                 for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
  80                         offset_dst = dest_composer->offset
  81                                      + (i_dst * dest_composer->pitch)
  82                                      + (j_dst++ * dest_composer->cpp);
  83                         offset_src = src_composer->offset
  84                                      + (i * src_composer->pitch)
  85                                      + (j * src_composer->cpp);
  86 
  87                         memcpy(vaddr_dst + offset_dst,
  88                                vaddr_src + offset_src, sizeof(u32));
  89                 }
  90                 i_dst++;
  91         }
  92 }
  93 
  94 static void compose_cursor(struct vkms_composer *cursor_composer,
  95                            struct vkms_composer *primary_composer,
  96                            void *vaddr_out)
  97 {
  98         struct drm_gem_object *cursor_obj;
  99         struct vkms_gem_object *cursor_vkms_obj;
 100 
 101         cursor_obj = drm_gem_fb_get_obj(&cursor_composer->fb, 0);
 102         cursor_vkms_obj = drm_gem_to_vkms_gem(cursor_obj);
 103 
 104         if (WARN_ON(!cursor_vkms_obj->vaddr))
 105                 return;
 106 
 107         blend(vaddr_out, cursor_vkms_obj->vaddr,
 108               primary_composer, cursor_composer);
 109 }
 110 
 111 static uint32_t _vkms_get_crc(struct vkms_composer *primary_composer,
 112                               struct vkms_composer *cursor_composer)
 113 {
 114         struct drm_framebuffer *fb = &primary_composer->fb;
 115         struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
 116         struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(gem_obj);
 117         void *vaddr_out = kzalloc(vkms_obj->gem.size, GFP_KERNEL);
 118         u32 crc = 0;
 119 
 120         if (!vaddr_out) {
 121                 DRM_ERROR("Failed to allocate memory for output frame.");
 122                 return 0;
 123         }
 124 
 125         if (WARN_ON(!vkms_obj->vaddr)) {
 126                 kfree(vaddr_out);
 127                 return crc;
 128         }
 129 
 130         memcpy(vaddr_out, vkms_obj->vaddr, vkms_obj->gem.size);
 131 
 132         if (cursor_composer)
 133                 compose_cursor(cursor_composer, primary_composer, vaddr_out);
 134 
 135         crc = compute_crc(vaddr_out, primary_composer);
 136 
 137         kfree(vaddr_out);
 138 
 139         return crc;
 140 }
 141 
 142 /**
 143  * vkms_composer_worker - ordered work_struct to compute CRC
 144  *
 145  * @work: work_struct
 146  *
 147  * Work handler for composing and computing CRCs. work_struct scheduled in
 148  * an ordered workqueue that's periodically scheduled to run by
 149  * _vblank_handle() and flushed at vkms_atomic_crtc_destroy_state().
 150  */
 151 void vkms_composer_worker(struct work_struct *work)
 152 {
 153         struct vkms_crtc_state *crtc_state = container_of(work,
 154                                                 struct vkms_crtc_state,
 155                                                 composer_work);
 156         struct drm_crtc *crtc = crtc_state->base.crtc;
 157         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
 158         struct vkms_composer *primary_composer = NULL;
 159         struct vkms_composer *cursor_composer = NULL;
 160         u32 crc32 = 0;
 161         u64 frame_start, frame_end;
 162         bool crc_pending;
 163 
 164         spin_lock_irq(&out->composer_lock);
 165         frame_start = crtc_state->frame_start;
 166         frame_end = crtc_state->frame_end;
 167         crc_pending = crtc_state->crc_pending;
 168         crtc_state->frame_start = 0;
 169         crtc_state->frame_end = 0;
 170         crtc_state->crc_pending = false;
 171         spin_unlock_irq(&out->composer_lock);
 172 
 173         /*
 174          * We raced with the vblank hrtimer and previous work already computed
 175          * the crc, nothing to do.
 176          */
 177         if (!crc_pending)
 178                 return;
 179 
 180         if (crtc_state->num_active_planes >= 1)
 181                 primary_composer = crtc_state->active_planes[0]->composer;
 182 
 183         if (crtc_state->num_active_planes == 2)
 184                 cursor_composer = crtc_state->active_planes[1]->composer;
 185 
 186         if (primary_composer)
 187                 crc32 = _vkms_get_crc(primary_composer, cursor_composer);
 188 
 189         /*
 190          * The worker can fall behind the vblank hrtimer, make sure we catch up.
 191          */
 192         while (frame_start <= frame_end)
 193                 drm_crtc_add_crc_entry(crtc, true, frame_start++, &crc32);
 194 }
 195 
 196 static const char * const pipe_crc_sources[] = {"auto"};
 197 
 198 const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
 199                                         size_t *count)
 200 {
 201         *count = ARRAY_SIZE(pipe_crc_sources);
 202         return pipe_crc_sources;
 203 }
 204 
 205 static int vkms_crc_parse_source(const char *src_name, bool *enabled)
 206 {
 207         int ret = 0;
 208 
 209         if (!src_name) {
 210                 *enabled = false;
 211         } else if (strcmp(src_name, "auto") == 0) {
 212                 *enabled = true;
 213         } else {
 214                 *enabled = false;
 215                 ret = -EINVAL;
 216         }
 217 
 218         return ret;
 219 }
 220 
 221 int vkms_verify_crc_source(struct drm_crtc *crtc, const char *src_name,
 222                            size_t *values_cnt)
 223 {
 224         bool enabled;
 225 
 226         if (vkms_crc_parse_source(src_name, &enabled) < 0) {
 227                 DRM_DEBUG_DRIVER("unknown source %s\n", src_name);
 228                 return -EINVAL;
 229         }
 230 
 231         *values_cnt = 1;
 232 
 233         return 0;
 234 }
 235 
 236 int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name)
 237 {
 238         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
 239         bool enabled = false;
 240         int ret = 0;
 241 
 242         ret = vkms_crc_parse_source(src_name, &enabled);
 243 
 244         spin_lock_irq(&out->lock);
 245         out->composer_enabled = enabled;
 246         spin_unlock_irq(&out->lock);
 247 
 248         return ret;
 249 }