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