arch/parisc/kernel/pci-dma.c

   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(dir, 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 }