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 p4d_t *p4d; 137 pud_t *pud; 138 pmd_t *pmd; 139 140 p4d = p4d_offset(dir, vaddr); 141 pud = pud_offset(p4d, vaddr); 142 pmd = pmd_alloc(NULL, pud, vaddr); 143 144 if (!pmd) 145 return -ENOMEM; 146 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr)) 147 return -ENOMEM; 148 vaddr = vaddr + PGDIR_SIZE; 149 dir++; 150 } while (vaddr && (vaddr < end)); 151 return 0; 152 } 153 154 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr, 155 unsigned long size) 156 { 157 pte_t * pte; 158 unsigned long end; 159 unsigned long orig_vaddr = vaddr; 160 161 if (pmd_none(*pmd)) 162 return; 163 if (pmd_bad(*pmd)) { 164 pmd_ERROR(*pmd); 165 pmd_clear(pmd); 166 return; 167 } 168 pte = pte_offset_map(pmd, vaddr); 169 vaddr &= ~PMD_MASK; 170 end = vaddr + size; 171 if (end > PMD_SIZE) 172 end = PMD_SIZE; 173 do { 174 unsigned long flags; 175 pte_t page = *pte; 176 177 pte_clear(&init_mm, vaddr, pte); 178 purge_tlb_start(flags); 179 pdtlb_kernel(orig_vaddr); 180 purge_tlb_end(flags); 181 vaddr += PAGE_SIZE; 182 orig_vaddr += PAGE_SIZE; 183 pte++; 184 if (pte_none(page) || pte_present(page)) 185 continue; 186 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n"); 187 } while (vaddr < end); 188 } 189 190 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr, 191 unsigned long size) 192 { 193 pmd_t * pmd; 194 unsigned long end; 195 unsigned long orig_vaddr = vaddr; 196 197 if (pgd_none(*dir)) 198 return; 199 if (pgd_bad(*dir)) { 200 pgd_ERROR(*dir); 201 pgd_clear(dir); 202 return; 203 } 204 pmd = pmd_offset(pud_offset(p4d_offset(dir, vaddr), vaddr), vaddr); 205 vaddr &= ~PGDIR_MASK; 206 end = vaddr + size; 207 if (end > PGDIR_SIZE) 208 end = PGDIR_SIZE; 209 do { 210 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr); 211 vaddr = (vaddr + PMD_SIZE) & PMD_MASK; 212 orig_vaddr += PMD_SIZE; 213 pmd++; 214 } while (vaddr < end); 215 } 216 217 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size) 218 { 219 pgd_t * dir; 220 unsigned long end = vaddr + size; 221 222 dir = pgd_offset_k(vaddr); 223 do { 224 unmap_uncached_pmd(dir, vaddr, end - vaddr); 225 vaddr = vaddr + PGDIR_SIZE; 226 dir++; 227 } while (vaddr && (vaddr < end)); 228 } 229 230 #define PCXL_SEARCH_LOOP(idx, mask, size) \ 231 for(; res_ptr < res_end; ++res_ptr) \ 232 { \ 233 if(0 == ((*res_ptr) & mask)) { \ 234 *res_ptr |= mask; \ 235 idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \ 236 pcxl_res_hint = idx + (size >> 3); \ 237 goto resource_found; \ 238 } \ 239 } 240 241 #define PCXL_FIND_FREE_MAPPING(idx, mask, size) { \ 242 u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \ 243 u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \ 244 PCXL_SEARCH_LOOP(idx, mask, size); \ 245 res_ptr = (u##size *)&pcxl_res_map[0]; \ 246 PCXL_SEARCH_LOOP(idx, mask, size); \ 247 } 248 249 unsigned long 250 pcxl_alloc_range(size_t size) 251 { 252 int res_idx; 253 u_long mask, flags; 254 unsigned int pages_needed = size >> PAGE_SHIFT; 255 256 mask = (u_long) -1L; 257 mask >>= BITS_PER_LONG - pages_needed; 258 259 DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n", 260 size, pages_needed, mask); 261 262 spin_lock_irqsave(&pcxl_res_lock, flags); 263 264 if(pages_needed <= 8) { 265 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8); 266 } else if(pages_needed <= 16) { 267 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16); 268 } else if(pages_needed <= 32) { 269 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32); 270 } else { 271 panic("%s: pcxl_alloc_range() Too many pages to map.\n", 272 __FILE__); 273 } 274 275 dump_resmap(); 276 panic("%s: pcxl_alloc_range() out of dma mapping resources\n", 277 __FILE__); 278 279 resource_found: 280 281 DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n", 282 res_idx, mask, pcxl_res_hint); 283 284 pcxl_used_pages += pages_needed; 285 pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1); 286 287 spin_unlock_irqrestore(&pcxl_res_lock, flags); 288 289 dump_resmap(); 290 291 /* 292 ** return the corresponding vaddr in the pcxl dma map 293 */ 294 return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3))); 295 } 296 297 #define PCXL_FREE_MAPPINGS(idx, m, size) \ 298 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \ 299 /* BUG_ON((*res_ptr & m) != m); */ \ 300 *res_ptr &= ~m; 301 302 /* 303 ** clear bits in the pcxl resource map 304 */ 305 static void 306 pcxl_free_range(unsigned long vaddr, size_t size) 307 { 308 u_long mask, flags; 309 unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3); 310 unsigned int pages_mapped = size >> PAGE_SHIFT; 311 312 mask = (u_long) -1L; 313 mask >>= BITS_PER_LONG - pages_mapped; 314 315 DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n", 316 res_idx, size, pages_mapped, mask); 317 318 spin_lock_irqsave(&pcxl_res_lock, flags); 319 320 if(pages_mapped <= 8) { 321 PCXL_FREE_MAPPINGS(res_idx, mask, 8); 322 } else if(pages_mapped <= 16) { 323 PCXL_FREE_MAPPINGS(res_idx, mask, 16); 324 } else if(pages_mapped <= 32) { 325 PCXL_FREE_MAPPINGS(res_idx, mask, 32); 326 } else { 327 panic("%s: pcxl_free_range() Too many pages to unmap.\n", 328 __FILE__); 329 } 330 331 pcxl_used_pages -= (pages_mapped ? pages_mapped : 1); 332 pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1); 333 334 spin_unlock_irqrestore(&pcxl_res_lock, flags); 335 336 dump_resmap(); 337 } 338 339 static int proc_pcxl_dma_show(struct seq_file *m, void *v) 340 { 341 #if 0 342 u_long i = 0; 343 unsigned long *res_ptr = (u_long *)pcxl_res_map; 344 #endif 345 unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */ 346 347 seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n", 348 PCXL_DMA_MAP_SIZE, total_pages); 349 350 seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size); 351 352 seq_puts(m, " total: free: used: % used:\n"); 353 seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size, 354 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes, 355 (pcxl_used_bytes * 100) / pcxl_res_size); 356 357 seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages, 358 total_pages - pcxl_used_pages, pcxl_used_pages, 359 (pcxl_used_pages * 100 / total_pages)); 360 361 #if 0 362 seq_puts(m, "\nResource bitmap:"); 363 364 for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) { 365 if ((i & 7) == 0) 366 seq_puts(m,"\n "); 367 seq_printf(m, "%s %08lx", buf, *res_ptr); 368 } 369 #endif 370 seq_putc(m, '\n'); 371 return 0; 372 } 373 374 static int __init 375 pcxl_dma_init(void) 376 { 377 if (pcxl_dma_start == 0) 378 return 0; 379 380 pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3); 381 pcxl_res_hint = 0; 382 pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL, 383 get_order(pcxl_res_size)); 384 memset(pcxl_res_map, 0, pcxl_res_size); 385 proc_gsc_root = proc_mkdir("gsc", NULL); 386 if (!proc_gsc_root) 387 printk(KERN_WARNING 388 "pcxl_dma_init: Unable to create gsc /proc dir entry\n"); 389 else { 390 struct proc_dir_entry* ent; 391 ent = proc_create_single("pcxl_dma", 0, proc_gsc_root, 392 proc_pcxl_dma_show); 393 if (!ent) 394 printk(KERN_WARNING 395 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n"); 396 } 397 return 0; 398 } 399 400 __initcall(pcxl_dma_init); 401 402 void *arch_dma_alloc(struct device *dev, size_t size, 403 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) 404 { 405 unsigned long vaddr; 406 unsigned long paddr; 407 int order; 408 409 if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl) 410 return NULL; 411 412 order = get_order(size); 413 size = 1 << (order + PAGE_SHIFT); 414 vaddr = pcxl_alloc_range(size); 415 paddr = __get_free_pages(gfp | __GFP_ZERO, order); 416 flush_kernel_dcache_range(paddr, size); 417 paddr = __pa(paddr); 418 map_uncached_pages(vaddr, size, paddr); 419 *dma_handle = (dma_addr_t) paddr; 420 421 #if 0 422 /* This probably isn't needed to support EISA cards. 423 ** ISA cards will certainly only support 24-bit DMA addressing. 424 ** Not clear if we can, want, or need to support ISA. 425 */ 426 if (!dev || *dev->coherent_dma_mask < 0xffffffff) 427 gfp |= GFP_DMA; 428 #endif 429 return (void *)vaddr; 430 } 431 432 void arch_dma_free(struct device *dev, size_t size, void *vaddr, 433 dma_addr_t dma_handle, unsigned long attrs) 434 { 435 int order = get_order(size); 436 437 WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 && 438 boot_cpu_data.cpu_type != pcxl); 439 440 size = 1 << (order + PAGE_SHIFT); 441 unmap_uncached_pages((unsigned long)vaddr, size); 442 pcxl_free_range((unsigned long)vaddr, size); 443 444 free_pages((unsigned long)__va(dma_handle), order); 445 } 446 447 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, 448 enum dma_data_direction dir) 449 { 450 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size); 451 } 452 453 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, 454 enum dma_data_direction dir) 455 { 456 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size); 457 } 458 459 void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size, 460 enum dma_data_direction direction) 461 { 462 flush_kernel_dcache_range((unsigned long)vaddr, size); 463 } 464