drivers/gpu/drm/vkms/vkms_composer.c

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