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 * ttm_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 * return: Zero on success. Negative error value on failure. Will print out 435 * kernel warnings on caller bugs. 436 * 437 * Performs a CPU blit from one buffer object to another avoiding a full 438 * bo vmap which may exhaust- or fragment vmalloc space. 439 * On supported architectures (x86), we're using kmap_atomic which avoids 440 * cross-processor TLB- and cache flushes and may, on non-HIGHMEM systems 441 * reference already set-up mappings. 442 * 443 * Neither of the buffer objects may be placed in PCI memory 444 * (Fixed memory in TTM terminology) when using this function. 445 */ 446 int vmw_bo_cpu_blit(struct ttm_buffer_object *dst, 447 u32 dst_offset, u32 dst_stride, 448 struct ttm_buffer_object *src, 449 u32 src_offset, u32 src_stride, 450 u32 w, u32 h, 451 struct vmw_diff_cpy *diff) 452 { 453 struct ttm_operation_ctx ctx = { 454 .interruptible = false, 455 .no_wait_gpu = false 456 }; 457 u32 j, initial_line = dst_offset / dst_stride; 458 struct vmw_bo_blit_line_data d; 459 int ret = 0; 460 461 /* Buffer objects need to be either pinned or reserved: */ 462 if (!(dst->mem.placement & TTM_PL_FLAG_NO_EVICT)) 463 dma_resv_assert_held(dst->base.resv); 464 if (!(src->mem.placement & TTM_PL_FLAG_NO_EVICT)) 465 dma_resv_assert_held(src->base.resv); 466 467 if (dst->ttm->state == tt_unpopulated) { 468 ret = dst->ttm->bdev->driver->ttm_tt_populate(dst->ttm, &ctx); 469 if (ret) 470 return ret; 471 } 472 473 if (src->ttm->state == tt_unpopulated) { 474 ret = src->ttm->bdev->driver->ttm_tt_populate(src->ttm, &ctx); 475 if (ret) 476 return ret; 477 } 478 479 d.mapped_dst = 0; 480 d.mapped_src = 0; 481 d.dst_addr = NULL; 482 d.src_addr = NULL; 483 d.dst_pages = dst->ttm->pages; 484 d.src_pages = src->ttm->pages; 485 d.dst_num_pages = dst->num_pages; 486 d.src_num_pages = src->num_pages; 487 d.dst_prot = ttm_io_prot(dst->mem.placement, PAGE_KERNEL); 488 d.src_prot = ttm_io_prot(src->mem.placement, PAGE_KERNEL); 489 d.diff = diff; 490 491 for (j = 0; j < h; ++j) { 492 diff->line = j + initial_line; 493 diff->line_offset = dst_offset % dst_stride; 494 ret = vmw_bo_cpu_blit_line(&d, dst_offset, src_offset, w); 495 if (ret) 496 goto out; 497 498 dst_offset += dst_stride; 499 src_offset += src_stride; 500 } 501 out: 502 if (d.src_addr) 503 kunmap_atomic(d.src_addr); 504 if (d.dst_addr) 505 kunmap_atomic(d.dst_addr); 506 507 return ret; 508 } 509