drivers/gpu/drm/vmwgfx/vmwgfx_blit.c

   1 // SPDX-License-Identifier: GPL-2.0 OR MIT
   2 /**************************************************************************
   3  *
   4  * Copyright 2017 VMware, Inc., Palo Alto, CA., USA
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28
  29 #include "vmwgfx_drv.h"
  30 #include <linux/highmem.h>
  31
  32 /*
  33  * Template that implements find_first_diff() for a generic
  34  * unsigned integer type. @size and return value are in bytes.
  35  */
  36 #define VMW_FIND_FIRST_DIFF(_type)                       \
  37 static size_t vmw_find_first_diff_ ## _type              \
  38         (const _type * dst, const _type * src, size_t size)\
  39 {                                                        \
  40         size_t i;                                        \
  41                                                          \
  42         for (i = 0; i < size; i += sizeof(_type)) {      \
  43                 if (*dst++ != *src++)                    \
  44                         break;                           \
  45         }                                                \
  46                                                          \
  47         return i;                                        \
  48 }
  49
  50
  51 /*
  52  * Template that implements find_last_diff() for a generic
  53  * unsigned integer type. Pointers point to the item following the
  54  * *end* of the area to be examined. @size and return value are in
  55  * bytes.
  56  */
  57 #define VMW_FIND_LAST_DIFF(_type)                                       \
  58 static ssize_t vmw_find_last_diff_ ## _type(                            \
  59         const _type * dst, const _type * src, size_t size)              \
  60 {                                                                       \
  61         while (size) {                                                  \
  62                 if (*--dst != *--src)                                   \
  63                         break;                                          \
  64                                                                         \
  65                 size -= sizeof(_type);                                  \
  66         }                                                               \
  67         return size;                                                    \
  68 }
  69
  70
  71 /*
  72  * Instantiate find diff functions for relevant unsigned integer sizes,
  73  * assuming that wider integers are faster (including aligning) up to the
  74  * architecture native width, which is assumed to be 32 bit unless
  75  * CONFIG_64BIT is defined.
  76  */
  77 VMW_FIND_FIRST_DIFF(u8);
  78 VMW_FIND_LAST_DIFF(u8);
  79
  80 VMW_FIND_FIRST_DIFF(u16);
  81 VMW_FIND_LAST_DIFF(u16);
  82
  83 VMW_FIND_FIRST_DIFF(u32);
  84 VMW_FIND_LAST_DIFF(u32);
  85
  86 #ifdef CONFIG_64BIT
  87 VMW_FIND_FIRST_DIFF(u64);
  88 VMW_FIND_LAST_DIFF(u64);
  89 #endif
  90
  91
  92 /* We use size aligned copies. This computes (addr - align(addr)) */
  93 #define SPILL(_var, _type) ((unsigned long) _var & (sizeof(_type) - 1))
  94
  95
  96 /*
  97  * Template to compute find_first_diff() for a certain integer type
  98  * including a head copy for alignment, and adjustment of parameters
  99  * for tail find or increased resolution find using an unsigned integer find
 100  * of smaller width. If finding is complete, and resolution is sufficient,
 101  * the macro executes a return statement. Otherwise it falls through.
 102  */
 103 #define VMW_TRY_FIND_FIRST_DIFF(_type)                                  \
 104 do {                                                                    \
 105         unsigned int spill = SPILL(dst, _type);                         \
 106         size_t diff_offs;                                               \
 107                                                                         \
 108         if (spill && spill == SPILL(src, _type) &&                      \
 109             sizeof(_type) - spill <= size) {                            \
 110                 spill = sizeof(_type) - spill;                          \
 111                 diff_offs = vmw_find_first_diff_u8(dst, src, spill);    \
 112                 if (diff_offs < spill)                                  \
 113                         return round_down(offset + diff_offs, granularity); \
 114                                                                         \
 115                 dst += spill;                                           \
 116                 src += spill;                                           \
 117                 size -= spill;                                          \
 118                 offset += spill;                                        \
 119                 spill = 0;                                              \
 120         }                                                               \
 121         if (!spill && !SPILL(src, _type)) {                             \
 122                 size_t to_copy = size &  ~(sizeof(_type) - 1);          \
 123                                                                         \
 124                 diff_offs = vmw_find_first_diff_ ## _type               \
 125                         ((_type *) dst, (_type *) src, to_copy);        \
 126                 if (diff_offs >= size || granularity == sizeof(_type))  \
 127                         return (offset + diff_offs);                    \
 128                                                                         \
 129                 dst += diff_offs;                                       \
 130                 src += diff_offs;                                       \
 131                 size -= diff_offs;                                      \
 132                 offset += diff_offs;                                    \
 133         }                                                               \
 134 } while (0)                                                             \
 135
 136
 137 /**
 138  * vmw_find_first_diff - find the first difference between dst and src
 139  *
 140  * @dst: The destination address
 141  * @src: The source address
 142  * @size: Number of bytes to compare
 143  * @granularity: The granularity needed for the return value in bytes.
 144  * return: The offset from find start where the first difference was
 145  * encountered in bytes. If no difference was found, the function returns
 146  * a value >= @size.
 147  */
 148 static size_t vmw_find_first_diff(const u8 *dst, const u8 *src, size_t size,
 149                                   size_t granularity)
 150 {
 151         size_t offset = 0;
 152
 153         /*
 154          * Try finding with large integers if alignment allows, or we can
 155          * fix it. Fall through if we need better resolution or alignment
 156          * was bad.
 157          */
 158 #ifdef CONFIG_64BIT
 159         VMW_TRY_FIND_FIRST_DIFF(u64);
 160 #endif
 161         VMW_TRY_FIND_FIRST_DIFF(u32);
 162         VMW_TRY_FIND_FIRST_DIFF(u16);
 163
 164         return round_down(offset + vmw_find_first_diff_u8(dst, src, size),
 165                           granularity);
 166 }
 167
 168
 169 /*
 170  * Template to compute find_last_diff() for a certain integer type
 171  * including a tail copy for alignment, and adjustment of parameters
 172  * for head find or increased resolution find using an unsigned integer find
 173  * of smaller width. If finding is complete, and resolution is sufficient,
 174  * the macro executes a return statement. Otherwise it falls through.
 175  */
 176 #define VMW_TRY_FIND_LAST_DIFF(_type)                                   \
 177 do {                                                                    \
 178         unsigned int spill = SPILL(dst, _type);                         \
 179         ssize_t location;                                               \
 180         ssize_t diff_offs;                                              \
 181                                                                         \
 182         if (spill && spill <= size && spill == SPILL(src, _type)) {     \
 183                 diff_offs = vmw_find_last_diff_u8(dst, src, spill);     \
 184                 if (diff_offs) {                                        \
 185                         location = size - spill + diff_offs - 1;        \
 186                         return round_down(location, granularity);       \
 187                 }                                                       \
 188                                                                         \
 189                 dst -= spill;                                           \
 190                 src -= spill;                                           \
 191                 size -= spill;                                          \
 192                 spill = 0;                                              \
 193         }                                                               \
 194         if (!spill && !SPILL(src, _type)) {                             \
 195                 size_t to_copy = round_down(size, sizeof(_type));       \
 196                                                                         \
 197                 diff_offs = vmw_find_last_diff_ ## _type                \
 198                         ((_type *) dst, (_type *) src, to_copy);        \
 199                 location = size - to_copy + diff_offs - sizeof(_type);  \
 200                 if (location < 0 || granularity == sizeof(_type))       \
 201                         return location;                                \
 202                                                                         \
 203                 dst -= to_copy - diff_offs;                             \
 204                 src -= to_copy - diff_offs;                             \
 205                 size -= to_copy - diff_offs;                            \
 206         }                                                               \
 207 } while (0)
 208
 209
 210 /**
 211  * vmw_find_last_diff - find the last difference between dst and src
 212  *
 213  * @dst: The destination address
 214  * @src: The source address
 215  * @size: Number of bytes to compare
 216  * @granularity: The granularity needed for the return value in bytes.
 217  * return: The offset from find start where the last difference was
 218  * encountered in bytes, or a negative value if no difference was found.
 219  */
 220 static ssize_t vmw_find_last_diff(const u8 *dst, const u8 *src, size_t size,
 221                                   size_t granularity)
 222 {
 223         dst += size;
 224         src += size;
 225
 226 #ifdef CONFIG_64BIT
 227         VMW_TRY_FIND_LAST_DIFF(u64);
 228 #endif
 229         VMW_TRY_FIND_LAST_DIFF(u32);
 230         VMW_TRY_FIND_LAST_DIFF(u16);
 231
 232         return round_down(vmw_find_last_diff_u8(dst, src, size) - 1,
 233                           granularity);
 234 }
 235
 236
 237 /**
 238  * vmw_memcpy - A wrapper around kernel memcpy with allowing to plug it into a
 239  * struct vmw_diff_cpy.
 240  *
 241  * @diff: The struct vmw_diff_cpy closure argument (unused).
 242  * @dest: The copy destination.
 243  * @src: The copy source.
 244  * @n: Number of bytes to copy.
 245  */
 246 void vmw_memcpy(struct vmw_diff_cpy *diff, u8 *dest, const u8 *src, size_t n)
 247 {
 248         memcpy(dest, src, n);
 249 }
 250
 251
 252 /**
 253  * vmw_adjust_rect - Adjust rectangle coordinates for newly found difference
 254  *
 255  * @diff: The struct vmw_diff_cpy used to track the modified bounding box.
 256  * @diff_offs: The offset from @diff->line_offset where the difference was
 257  * found.
 258  */
 259 static void vmw_adjust_rect(struct vmw_diff_cpy *diff, size_t diff_offs)
 260 {
 261         size_t offs = (diff_offs + diff->line_offset) / diff->cpp;
 262         struct drm_rect *rect = &diff->rect;
 263
 264         rect->x1 = min_t(int, rect->x1, offs);
 265         rect->x2 = max_t(int, rect->x2, offs + 1);
 266         rect->y1 = min_t(int, rect->y1, diff->line);
 267         rect->y2 = max_t(int, rect->y2, diff->line + 1);
 268 }
 269
 270 /**
 271  * vmw_diff_memcpy - memcpy that creates a bounding box of modified content.
 272  *
 273  * @diff: The struct vmw_diff_cpy used to track the modified bounding box.
 274  * @dest: The copy destination.
 275  * @src: The copy source.
 276  * @n: Number of bytes to copy.
 277  *
 278  * In order to correctly track the modified content, the field @diff->line must
 279  * be pre-loaded with the current line number, the field @diff->line_offset must
 280  * be pre-loaded with the line offset in bytes where the copy starts, and
 281  * finally the field @diff->cpp need to be preloaded with the number of bytes
 282  * per unit in the horizontal direction of the area we're examining.
 283  * Typically bytes per pixel.
 284  * This is needed to know the needed granularity of the difference computing
 285  * operations. A higher cpp generally leads to faster execution at the cost of
 286  * bounding box width precision.
 287  */
 288 void vmw_diff_memcpy(struct vmw_diff_cpy *diff, u8 *dest, const u8 *src,
 289                      size_t n)
 290 {
 291         ssize_t csize, byte_len;
 292
 293         if (WARN_ON_ONCE(round_down(n, diff->cpp) != n))
 294                 return;
 295
 296         /* TODO: Possibly use a single vmw_find_first_diff per line? */
 297         csize = vmw_find_first_diff(dest, src, n, diff->cpp);
 298         if (csize < n) {
 299                 vmw_adjust_rect(diff, csize);
 300                 byte_len = diff->cpp;
 301
 302                 /*
 303                  * Starting from where first difference was found, find
 304                  * location of last difference, and then copy.
 305                  */
 306                 diff->line_offset += csize;
 307                 dest += csize;
 308                 src += csize;
 309                 n -= csize;
 310                 csize = vmw_find_last_diff(dest, src, n, diff->cpp);
 311                 if (csize >= 0) {
 312                         byte_len += csize;
 313                         vmw_adjust_rect(diff, csize);
 314                 }
 315                 memcpy(dest, src, byte_len);
 316         }
 317         diff->line_offset += n;
 318 }
 319
 320 /**
 321  * struct vmw_bo_blit_line_data - Convenience argument to vmw_bo_cpu_blit_line
 322  *
 323  * @mapped_dst: Already mapped destination page index in @dst_pages.
 324  * @dst_addr: Kernel virtual address of mapped destination page.
 325  * @dst_pages: Array of destination bo pages.
 326  * @dst_num_pages: Number of destination bo pages.
 327  * @dst_prot: Destination bo page protection.
 328  * @mapped_src: Already mapped source page index in @dst_pages.
 329  * @src_addr: Kernel virtual address of mapped source page.
 330  * @src_pages: Array of source bo pages.
 331  * @src_num_pages: Number of source bo pages.
 332  * @src_prot: Source bo page protection.
 333  * @diff: Struct vmw_diff_cpy, in the end forwarded to the memcpy routine.
 334  */
 335 struct vmw_bo_blit_line_data {
 336         u32 mapped_dst;
 337         u8 *dst_addr;
 338         struct page **dst_pages;
 339         u32 dst_num_pages;
 340         pgprot_t dst_prot;
 341         u32 mapped_src;
 342         u8 *src_addr;
 343         struct page **src_pages;
 344         u32 src_num_pages;
 345         pgprot_t src_prot;
 346         struct vmw_diff_cpy *diff;
 347 };
 348
 349 /**
 350  * vmw_bo_cpu_blit_line - Blit part of a line from one bo to another.
 351  *
 352  * @d: Blit data as described above.
 353  * @dst_offset: Destination copy start offset from start of bo.
 354  * @src_offset: Source copy start offset from start of bo.
 355  * @bytes_to_copy: Number of bytes to copy in this line.
 356  */
 357 static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
 358                                 u32 dst_offset,
 359                                 u32 src_offset,
 360                                 u32 bytes_to_copy)
 361 {
 362         struct vmw_diff_cpy *diff = d->diff;
 363
 364         while (bytes_to_copy) {
 365                 u32 copy_size = bytes_to_copy;
 366                 u32 dst_page = dst_offset >> PAGE_SHIFT;
 367                 u32 src_page = src_offset >> PAGE_SHIFT;
 368                 u32 dst_page_offset = dst_offset & ~PAGE_MASK;
 369                 u32 src_page_offset = src_offset & ~PAGE_MASK;
 370                 bool unmap_dst = d->dst_addr && dst_page != d->mapped_dst;
 371                 bool unmap_src = d->src_addr && (src_page != d->mapped_src ||
 372                                                  unmap_dst);
 373
 374                 copy_size = min_t(u32, copy_size, PAGE_SIZE - dst_page_offset);
 375                 copy_size = min_t(u32, copy_size, PAGE_SIZE - src_page_offset);
 376
 377                 if (unmap_src) {
 378                         kunmap_atomic(d->src_addr);
 379                         d->src_addr = NULL;
 380                 }
 381
 382                 if (unmap_dst) {
 383                         kunmap_atomic(d->dst_addr);
 384                         d->dst_addr = NULL;
 385                 }
 386
 387                 if (!d->dst_addr) {
 388                         if (WARN_ON_ONCE(dst_page >= d->dst_num_pages))
 389                                 return -EINVAL;
 390
 391                         d->dst_addr =
 392                                 kmap_atomic_prot(d->dst_pages[dst_page],
 393                                                  d->dst_prot);
 394                         if (!d->dst_addr)
 395                                 return -ENOMEM;
 396
 397                         d->mapped_dst = dst_page;
 398                 }
 399
 400                 if (!d->src_addr) {
 401                         if (WARN_ON_ONCE(src_page >= d->src_num_pages))
 402                                 return -EINVAL;
 403
 404                         d->src_addr =
 405                                 kmap_atomic_prot(d->src_pages[src_page],
 406                                                  d->src_prot);
 407                         if (!d->src_addr)
 408                                 return -ENOMEM;
 409
 410                         d->mapped_src = src_page;
 411                 }
 412                 diff->do_cpy(diff, d->dst_addr + dst_page_offset,
 413                              d->src_addr + src_page_offset, copy_size);
 414
 415                 bytes_to_copy -= copy_size;
 416                 dst_offset += copy_size;
 417                 src_offset += copy_size;
 418         }
 419
 420         return 0;
 421 }
 422
 423 /**
 424  * vmw_bo_cpu_blit - in-kernel cpu blit.
 425  *
 426  * @dst: Destination buffer object.
 427  * @dst_offset: Destination offset of blit start in bytes.
 428  * @dst_stride: Destination stride in bytes.
 429  * @src: Source buffer object.
 430  * @src_offset: Source offset of blit start in bytes.
 431  * @src_stride: Source stride in bytes.
 432  * @w: Width of blit.
 433  * @h: Height of blit.
 434  * @diff: The struct vmw_diff_cpy used to track the modified bounding box.
 435  * return: Zero on success. Negative error value on failure. Will print out
 436  * kernel warnings on caller bugs.
 437  *
 438  * Performs a CPU blit from one buffer object to another avoiding a full
 439  * bo vmap which may exhaust- or fragment vmalloc space.
 440  * On supported architectures (x86), we're using kmap_atomic which avoids
 441  * cross-processor TLB- and cache flushes and may, on non-HIGHMEM systems
 442  * reference already set-up mappings.
 443  *
 444  * Neither of the buffer objects may be placed in PCI memory
 445  * (Fixed memory in TTM terminology) when using this function.
 446  */
 447 int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
 448                     u32 dst_offset, u32 dst_stride,
 449                     struct ttm_buffer_object *src,
 450                     u32 src_offset, u32 src_stride,
 451                     u32 w, u32 h,
 452                     struct vmw_diff_cpy *diff)
 453 {
 454         struct ttm_operation_ctx ctx = {
 455                 .interruptible = false,
 456                 .no_wait_gpu = false
 457         };
 458         u32 j, initial_line = dst_offset / dst_stride;
 459         struct vmw_bo_blit_line_data d;
 460         int ret = 0;
 461
 462         /* Buffer objects need to be either pinned or reserved: */
 463         if (!(dst->pin_count))
 464                 dma_resv_assert_held(dst->base.resv);
 465         if (!(src->pin_count))
 466                 dma_resv_assert_held(src->base.resv);
 467
 468         if (!ttm_tt_is_populated(dst->ttm)) {
 469                 ret = dst->bdev->funcs->ttm_tt_populate(dst->bdev, dst->ttm, &ctx);
 470                 if (ret)
 471                         return ret;
 472         }
 473
 474         if (!ttm_tt_is_populated(src->ttm)) {
 475                 ret = src->bdev->funcs->ttm_tt_populate(src->bdev, src->ttm, &ctx);
 476                 if (ret)
 477                         return ret;
 478         }
 479
 480         d.mapped_dst = 0;
 481         d.mapped_src = 0;
 482         d.dst_addr = NULL;
 483         d.src_addr = NULL;
 484         d.dst_pages = dst->ttm->pages;
 485         d.src_pages = src->ttm->pages;
 486         d.dst_num_pages = PFN_UP(dst->resource->size);
 487         d.src_num_pages = PFN_UP(src->resource->size);
 488         d.dst_prot = ttm_io_prot(dst, dst->resource, PAGE_KERNEL);
 489         d.src_prot = ttm_io_prot(src, src->resource, PAGE_KERNEL);
 490         d.diff = diff;
 491
 492         for (j = 0; j < h; ++j) {
 493                 diff->line = j + initial_line;
 494                 diff->line_offset = dst_offset % dst_stride;
 495                 ret = vmw_bo_cpu_blit_line(&d, dst_offset, src_offset, w);
 496                 if (ret)
 497                         goto out;
 498
 499                 dst_offset += dst_stride;
 500                 src_offset += src_stride;
 501         }
 502 out:
 503         if (d.src_addr)
 504                 kunmap_atomic(d.src_addr);
 505         if (d.dst_addr)
 506                 kunmap_atomic(d.dst_addr);
 507
 508         return ret;
 509 }