1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 ** PARISC 1.1 Dynamic DMA mapping support. 4 ** This implementation is for PA-RISC platforms that do not support 5 ** I/O TLBs (aka DMA address translation hardware). 6 ** See Documentation/DMA-API-HOWTO.txt for interface definitions. 7 ** 8 ** (c) Copyright 1999,2000 Hewlett-Packard Company 9 ** (c) Copyright 2000 Grant Grundler 10 ** (c) Copyright 2000 Philipp Rumpf <prumpf@tux.org> 11 ** (c) Copyright 2000 John Marvin 12 ** 13 ** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c. 14 ** (I assume it's from David Mosberger-Tang but there was no Copyright) 15 ** 16 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code. 17 ** 18 ** - ggg 19 */ 20 21 #include <linux/init.h> 22 #include <linux/gfp.h> 23 #include <linux/mm.h> 24 #include <linux/proc_fs.h> 25 #include <linux/seq_file.h> 26 #include <linux/string.h> 27 #include <linux/types.h> 28 #include <linux/dma-direct.h> 29 #include <linux/dma-noncoherent.h> 30 31 #include <asm/cacheflush.h> 32 #include <asm/dma.h> /* for DMA_CHUNK_SIZE */ 33 #include <asm/io.h> 34 #include <asm/page.h> /* get_order */ 35 #include <asm/pgalloc.h> 36 #include <linux/uaccess.h> 37 #include <asm/tlbflush.h> /* for purge_tlb_*() macros */ 38 39 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL; 40 static unsigned long pcxl_used_bytes __read_mostly = 0; 41 static unsigned long pcxl_used_pages __read_mostly = 0; 42 43 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */ 44 static DEFINE_SPINLOCK(pcxl_res_lock); 45 static char *pcxl_res_map; 46 static int pcxl_res_hint; 47 static int pcxl_res_size; 48 49 #ifdef DEBUG_PCXL_RESOURCE 50 #define DBG_RES(x...) printk(x) 51 #else 52 #define DBG_RES(x...) 53 #endif 54 55 56 /* 57 ** Dump a hex representation of the resource map. 58 */ 59 60 #ifdef DUMP_RESMAP 61 static 62 void dump_resmap(void) 63 { 64 u_long *res_ptr = (unsigned long *)pcxl_res_map; 65 u_long i = 0; 66 67 printk("res_map: "); 68 for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr) 69 printk("%08lx ", *res_ptr); 70 71 printk("\n"); 72 } 73 #else 74 static inline void dump_resmap(void) {;} 75 #endif 76 77 static inline int map_pte_uncached(pte_t * pte, 78 unsigned long vaddr, 79 unsigned long size, unsigned long *paddr_ptr) 80 { 81 unsigned long end; 82 unsigned long orig_vaddr = vaddr; 83 84 vaddr &= ~PMD_MASK; 85 end = vaddr + size; 86 if (end > PMD_SIZE) 87 end = PMD_SIZE; 88 do { 89 unsigned long flags; 90 91 if (!pte_none(*pte)) 92 printk(KERN_ERR "map_pte_uncached: page already exists\n"); 93 purge_tlb_start(flags); 94 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC)); 95 pdtlb_kernel(orig_vaddr); 96 purge_tlb_end(flags); 97 vaddr += PAGE_SIZE; 98 orig_vaddr += PAGE_SIZE; 99 (*paddr_ptr) += PAGE_SIZE; 100 pte++; 101 } while (vaddr < end); 102 return 0; 103 } 104 105 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr, 106 unsigned long size, unsigned long *paddr_ptr) 107 { 108 unsigned long end; 109 unsigned long orig_vaddr = vaddr; 110 111 vaddr &= ~PGDIR_MASK; 112 end = vaddr + size; 113 if (end > PGDIR_SIZE) 114 end = PGDIR_SIZE; 115 do { 116 pte_t * pte = pte_alloc_kernel(pmd, vaddr); 117 if (!pte) 118 return -ENOMEM; 119 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr)) 120 return -ENOMEM; 121 vaddr = (vaddr + PMD_SIZE) & PMD_MASK; 122 orig_vaddr += PMD_SIZE; 123 pmd++; 124 } while (vaddr < end); 125 return 0; 126 } 127 128 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size, 129 unsigned long paddr) 130 { 131 pgd_t * dir; 132 unsigned long end = vaddr + size; 133 134 dir = pgd_offset_k(vaddr); 135 do { 136 pmd_t *pmd; 137 138 pmd = pmd_alloc(NULL, dir, vaddr); 139 if (!pmd) 140 return -ENOMEM; 141 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr)) 142 return -ENOMEM; 143 vaddr = vaddr + PGDIR_SIZE; 144 dir++; 145 } while (vaddr && (vaddr < end)); 146 return 0; 147 } 148 149 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr, 150 unsigned long size) 151 { 152 pte_t * pte; 153 unsigned long end; 154 unsigned long orig_vaddr = vaddr; 155 156 if (pmd_none(*pmd)) 157 return; 158 if (pmd_bad(*pmd)) { 159 pmd_ERROR(*pmd); 160 pmd_clear(pmd); 161 return; 162 } 163 pte = pte_offset_map(pmd, vaddr); 164 vaddr &= ~PMD_MASK; 165 end = vaddr + size; 166 if (end > PMD_SIZE) 167 end = PMD_SIZE; 168 do { 169 unsigned long flags; 170 pte_t page = *pte; 171 172 pte_clear(&init_mm, vaddr, pte); 173 purge_tlb_start(flags); 174 pdtlb_kernel(orig_vaddr); 175 purge_tlb_end(flags); 176 vaddr += PAGE_SIZE; 177 orig_vaddr += PAGE_SIZE; 178 pte++; 179 if (pte_none(page) || pte_present(page)) 180 continue; 181 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n"); 182 } while (vaddr < end); 183 } 184 185 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr, 186 unsigned long size) 187 { 188 pmd_t * pmd; 189 unsigned long end; 190 unsigned long orig_vaddr = vaddr; 191 192 if (pgd_none(*dir)) 193 return; 194 if (pgd_bad(*dir)) { 195 pgd_ERROR(*dir); 196 pgd_clear(dir); 197 return; 198 } 199 pmd = pmd_offset(dir, vaddr); 200 vaddr &= ~PGDIR_MASK; 201 end = vaddr + size; 202 if (end > PGDIR_SIZE) 203 end = PGDIR_SIZE; 204 do { 205 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr); 206 vaddr = (vaddr + PMD_SIZE) & PMD_MASK; 207 orig_vaddr += PMD_SIZE; 208 pmd++; 209 } while (vaddr < end); 210 } 211 212 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size) 213 { 214 pgd_t * dir; 215 unsigned long end = vaddr + size; 216 217 dir = pgd_offset_k(vaddr); 218 do { 219 unmap_uncached_pmd(dir, vaddr, end - vaddr); 220 vaddr = vaddr + PGDIR_SIZE; 221 dir++; 222 } while (vaddr && (vaddr < end)); 223 } 224 225 #define PCXL_SEARCH_LOOP(idx, mask, size) \ 226 for(; res_ptr < res_end; ++res_ptr) \ 227 { \ 228 if(0 == ((*res_ptr) & mask)) { \ 229 *res_ptr |= mask; \ 230 idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \ 231 pcxl_res_hint = idx + (size >> 3); \ 232 goto resource_found; \ 233 } \ 234 } 235 236 #define PCXL_FIND_FREE_MAPPING(idx, mask, size) { \ 237 u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \ 238 u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \ 239 PCXL_SEARCH_LOOP(idx, mask, size); \ 240 res_ptr = (u##size *)&pcxl_res_map[0]; \ 241 PCXL_SEARCH_LOOP(idx, mask, size); \ 242 } 243 244 unsigned long 245 pcxl_alloc_range(size_t size) 246 { 247 int res_idx; 248 u_long mask, flags; 249 unsigned int pages_needed = size >> PAGE_SHIFT; 250 251 mask = (u_long) -1L; 252 mask >>= BITS_PER_LONG - pages_needed; 253 254 DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n", 255 size, pages_needed, mask); 256 257 spin_lock_irqsave(&pcxl_res_lock, flags); 258 259 if(pages_needed <= 8) { 260 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8); 261 } else if(pages_needed <= 16) { 262 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16); 263 } else if(pages_needed <= 32) { 264 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32); 265 } else { 266 panic("%s: pcxl_alloc_range() Too many pages to map.\n", 267 __FILE__); 268 } 269 270 dump_resmap(); 271 panic("%s: pcxl_alloc_range() out of dma mapping resources\n", 272 __FILE__); 273 274 resource_found: 275 276 DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n", 277 res_idx, mask, pcxl_res_hint); 278 279 pcxl_used_pages += pages_needed; 280 pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1); 281 282 spin_unlock_irqrestore(&pcxl_res_lock, flags); 283 284 dump_resmap(); 285 286 /* 287 ** return the corresponding vaddr in the pcxl dma map 288 */ 289 return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3))); 290 } 291 292 #define PCXL_FREE_MAPPINGS(idx, m, size) \ 293 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \ 294 /* BUG_ON((*res_ptr & m) != m); */ \ 295 *res_ptr &= ~m; 296 297 /* 298 ** clear bits in the pcxl resource map 299 */ 300 static void 301 pcxl_free_range(unsigned long vaddr, size_t size) 302 { 303 u_long mask, flags; 304 unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3); 305 unsigned int pages_mapped = size >> PAGE_SHIFT; 306 307 mask = (u_long) -1L; 308 mask >>= BITS_PER_LONG - pages_mapped; 309 310 DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n", 311 res_idx, size, pages_mapped, mask); 312 313 spin_lock_irqsave(&pcxl_res_lock, flags); 314 315 if(pages_mapped <= 8) { 316 PCXL_FREE_MAPPINGS(res_idx, mask, 8); 317 } else if(pages_mapped <= 16) { 318 PCXL_FREE_MAPPINGS(res_idx, mask, 16); 319 } else if(pages_mapped <= 32) { 320 PCXL_FREE_MAPPINGS(res_idx, mask, 32); 321 } else { 322 panic("%s: pcxl_free_range() Too many pages to unmap.\n", 323 __FILE__); 324 } 325 326 pcxl_used_pages -= (pages_mapped ? pages_mapped : 1); 327 pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1); 328 329 spin_unlock_irqrestore(&pcxl_res_lock, flags); 330 331 dump_resmap(); 332 } 333 334 static int proc_pcxl_dma_show(struct seq_file *m, void *v) 335 { 336 #if 0 337 u_long i = 0; 338 unsigned long *res_ptr = (u_long *)pcxl_res_map; 339 #endif 340 unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */ 341 342 seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n", 343 PCXL_DMA_MAP_SIZE, total_pages); 344 345 seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size); 346 347 seq_puts(m, " total: free: used: % used:\n"); 348 seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size, 349 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes, 350 (pcxl_used_bytes * 100) / pcxl_res_size); 351 352 seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages, 353 total_pages - pcxl_used_pages, pcxl_used_pages, 354 (pcxl_used_pages * 100 / total_pages)); 355 356 #if 0 357 seq_puts(m, "\nResource bitmap:"); 358 359 for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) { 360 if ((i & 7) == 0) 361 seq_puts(m,"\n "); 362 seq_printf(m, "%s %08lx", buf, *res_ptr); 363 } 364 #endif 365 seq_putc(m, '\n'); 366 return 0; 367 } 368 369 static int __init 370 pcxl_dma_init(void) 371 { 372 if (pcxl_dma_start == 0) 373 return 0; 374 375 pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3); 376 pcxl_res_hint = 0; 377 pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL, 378 get_order(pcxl_res_size)); 379 memset(pcxl_res_map, 0, pcxl_res_size); 380 proc_gsc_root = proc_mkdir("gsc", NULL); 381 if (!proc_gsc_root) 382 printk(KERN_WARNING 383 "pcxl_dma_init: Unable to create gsc /proc dir entry\n"); 384 else { 385 struct proc_dir_entry* ent; 386 ent = proc_create_single("pcxl_dma", 0, proc_gsc_root, 387 proc_pcxl_dma_show); 388 if (!ent) 389 printk(KERN_WARNING 390 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n"); 391 } 392 return 0; 393 } 394 395 __initcall(pcxl_dma_init); 396 397 static void *pcxl_dma_alloc(struct device *dev, size_t size, 398 dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs) 399 { 400 unsigned long vaddr; 401 unsigned long paddr; 402 int order; 403 404 order = get_order(size); 405 size = 1 << (order + PAGE_SHIFT); 406 vaddr = pcxl_alloc_range(size); 407 paddr = __get_free_pages(flag | __GFP_ZERO, order); 408 flush_kernel_dcache_range(paddr, size); 409 paddr = __pa(paddr); 410 map_uncached_pages(vaddr, size, paddr); 411 *dma_handle = (dma_addr_t) paddr; 412 413 #if 0 414 /* This probably isn't needed to support EISA cards. 415 ** ISA cards will certainly only support 24-bit DMA addressing. 416 ** Not clear if we can, want, or need to support ISA. 417 */ 418 if (!dev || *dev->coherent_dma_mask < 0xffffffff) 419 gfp |= GFP_DMA; 420 #endif 421 return (void *)vaddr; 422 } 423 424 static void *pcx_dma_alloc(struct device *dev, size_t size, 425 dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs) 426 { 427 void *addr; 428 429 if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) 430 return NULL; 431 432 addr = (void *)__get_free_pages(flag | __GFP_ZERO, get_order(size)); 433 if (addr) 434 *dma_handle = (dma_addr_t)virt_to_phys(addr); 435 436 return addr; 437 } 438 439 void *arch_dma_alloc(struct device *dev, size_t size, 440 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) 441 { 442 443 if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) 444 return pcxl_dma_alloc(dev, size, dma_handle, gfp, attrs); 445 else 446 return pcx_dma_alloc(dev, size, dma_handle, gfp, attrs); 447 } 448 449 void arch_dma_free(struct device *dev, size_t size, void *vaddr, 450 dma_addr_t dma_handle, unsigned long attrs) 451 { 452 int order = get_order(size); 453 454 if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) { 455 size = 1 << (order + PAGE_SHIFT); 456 unmap_uncached_pages((unsigned long)vaddr, size); 457 pcxl_free_range((unsigned long)vaddr, size); 458 459 vaddr = __va(dma_handle); 460 } 461 free_pages((unsigned long)vaddr, get_order(size)); 462 } 463 464 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, 465 size_t size, enum dma_data_direction dir) 466 { 467 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size); 468 } 469 470 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr, 471 size_t size, enum dma_data_direction dir) 472 { 473 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size); 474 } 475 476 void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size, 477 enum dma_data_direction direction) 478 { 479 flush_kernel_dcache_range((unsigned long)vaddr, size); 480 } 481