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                 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 void *arch_dma_alloc(struct device *dev, size_t size,
 398                 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 399 {
 400         unsigned long vaddr;
 401         unsigned long paddr;
 402         int order;
 403
 404         if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl)
 405                 return NULL;
 406
 407         order = get_order(size);
 408         size = 1 << (order + PAGE_SHIFT);
 409         vaddr = pcxl_alloc_range(size);
 410         paddr = __get_free_pages(gfp | __GFP_ZERO, order);
 411         flush_kernel_dcache_range(paddr, size);
 412         paddr = __pa(paddr);
 413         map_uncached_pages(vaddr, size, paddr);
 414         *dma_handle = (dma_addr_t) paddr;
 415
 416 #if 0
 417 /* This probably isn't needed to support EISA cards.
 418 ** ISA cards will certainly only support 24-bit DMA addressing.
 419 ** Not clear if we can, want, or need to support ISA.
 420 */
 421         if (!dev || *dev->coherent_dma_mask < 0xffffffff)
 422                 gfp |= GFP_DMA;
 423 #endif
 424         return (void *)vaddr;
 425 }
 426
 427 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
 428                 dma_addr_t dma_handle, unsigned long attrs)
 429 {
 430         int order = get_order(size);
 431
 432         WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 &&
 433                      boot_cpu_data.cpu_type != pcxl);
 434
 435         size = 1 << (order + PAGE_SHIFT);
 436         unmap_uncached_pages((unsigned long)vaddr, size);
 437         pcxl_free_range((unsigned long)vaddr, size);
 438
 439         free_pages((unsigned long)__va(dma_handle), order);
 440 }
 441
 442 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
 443                 size_t size, enum dma_data_direction dir)
 444 {
 445         flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
 446 }
 447
 448 void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
 449                 size_t size, enum dma_data_direction dir)
 450 {
 451         flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
 452 }
 453
 454 void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 455                enum dma_data_direction direction)
 456 {
 457         flush_kernel_dcache_range((unsigned long)vaddr, size);
 458 }