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/core-api/dma-api-howto.rst 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-map-ops.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 <linux/uaccess.h>
  36 #include <asm/tlbflush.h>       /* for purge_tlb_*() macros */
  37
  38 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
  39 static unsigned long pcxl_used_bytes __read_mostly = 0;
  40 static unsigned long pcxl_used_pages __read_mostly = 0;
  41
  42 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
  43 static DEFINE_SPINLOCK(pcxl_res_lock);
  44 static char    *pcxl_res_map;
  45 static int     pcxl_res_hint;
  46 static int     pcxl_res_size;
  47
  48 #ifdef DEBUG_PCXL_RESOURCE
  49 #define DBG_RES(x...)   printk(x)
  50 #else
  51 #define DBG_RES(x...)
  52 #endif
  53
  54
  55 /*
  56 ** Dump a hex representation of the resource map.
  57 */
  58
  59 #ifdef DUMP_RESMAP
  60 static
  61 void dump_resmap(void)
  62 {
  63         u_long *res_ptr = (unsigned long *)pcxl_res_map;
  64         u_long i = 0;
  65
  66         printk("res_map: ");
  67         for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
  68                 printk("%08lx ", *res_ptr);
  69
  70         printk("\n");
  71 }
  72 #else
  73 static inline void dump_resmap(void) {;}
  74 #endif
  75
  76 static inline int map_pte_uncached(pte_t * pte,
  77                 unsigned long vaddr,
  78                 unsigned long size, unsigned long *paddr_ptr)
  79 {
  80         unsigned long end;
  81         unsigned long orig_vaddr = vaddr;
  82
  83         vaddr &= ~PMD_MASK;
  84         end = vaddr + size;
  85         if (end > PMD_SIZE)
  86                 end = PMD_SIZE;
  87         do {
  88                 unsigned long flags;
  89
  90                 if (!pte_none(*pte))
  91                         printk(KERN_ERR "map_pte_uncached: page already exists\n");
  92                 purge_tlb_start(flags);
  93                 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
  94                 pdtlb_kernel(orig_vaddr);
  95                 purge_tlb_end(flags);
  96                 vaddr += PAGE_SIZE;
  97                 orig_vaddr += PAGE_SIZE;
  98                 (*paddr_ptr) += PAGE_SIZE;
  99                 pte++;
 100         } while (vaddr < end);
 101         return 0;
 102 }
 103
 104 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
 105                 unsigned long size, unsigned long *paddr_ptr)
 106 {
 107         unsigned long end;
 108         unsigned long orig_vaddr = vaddr;
 109
 110         vaddr &= ~PGDIR_MASK;
 111         end = vaddr + size;
 112         if (end > PGDIR_SIZE)
 113                 end = PGDIR_SIZE;
 114         do {
 115                 pte_t * pte = pte_alloc_kernel(pmd, vaddr);
 116                 if (!pte)
 117                         return -ENOMEM;
 118                 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
 119                         return -ENOMEM;
 120                 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
 121                 orig_vaddr += PMD_SIZE;
 122                 pmd++;
 123         } while (vaddr < end);
 124         return 0;
 125 }
 126
 127 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
 128                 unsigned long paddr)
 129 {
 130         pgd_t * dir;
 131         unsigned long end = vaddr + size;
 132
 133         dir = pgd_offset_k(vaddr);
 134         do {
 135                 p4d_t *p4d;
 136                 pud_t *pud;
 137                 pmd_t *pmd;
 138
 139                 p4d = p4d_offset(dir, vaddr);
 140                 pud = pud_offset(p4d, vaddr);
 141                 pmd = pmd_alloc(NULL, pud, vaddr);
 142
 143                 if (!pmd)
 144                         return -ENOMEM;
 145                 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
 146                         return -ENOMEM;
 147                 vaddr = vaddr + PGDIR_SIZE;
 148                 dir++;
 149         } while (vaddr && (vaddr < end));
 150         return 0;
 151 }
 152
 153 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
 154                 unsigned long size)
 155 {
 156         pte_t * pte;
 157         unsigned long end;
 158         unsigned long orig_vaddr = vaddr;
 159
 160         if (pmd_none(*pmd))
 161                 return;
 162         if (pmd_bad(*pmd)) {
 163                 pmd_ERROR(*pmd);
 164                 pmd_clear(pmd);
 165                 return;
 166         }
 167         pte = pte_offset_map(pmd, vaddr);
 168         vaddr &= ~PMD_MASK;
 169         end = vaddr + size;
 170         if (end > PMD_SIZE)
 171                 end = PMD_SIZE;
 172         do {
 173                 unsigned long flags;
 174                 pte_t page = *pte;
 175
 176                 pte_clear(&init_mm, vaddr, pte);
 177                 purge_tlb_start(flags);
 178                 pdtlb_kernel(orig_vaddr);
 179                 purge_tlb_end(flags);
 180                 vaddr += PAGE_SIZE;
 181                 orig_vaddr += PAGE_SIZE;
 182                 pte++;
 183                 if (pte_none(page) || pte_present(page))
 184                         continue;
 185                 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
 186         } while (vaddr < end);
 187 }
 188
 189 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
 190                 unsigned long size)
 191 {
 192         pmd_t * pmd;
 193         unsigned long end;
 194         unsigned long orig_vaddr = vaddr;
 195
 196         if (pgd_none(*dir))
 197                 return;
 198         if (pgd_bad(*dir)) {
 199                 pgd_ERROR(*dir);
 200                 pgd_clear(dir);
 201                 return;
 202         }
 203         pmd = pmd_offset(pud_offset(p4d_offset(dir, vaddr), vaddr), vaddr);
 204         vaddr &= ~PGDIR_MASK;
 205         end = vaddr + size;
 206         if (end > PGDIR_SIZE)
 207                 end = PGDIR_SIZE;
 208         do {
 209                 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
 210                 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
 211                 orig_vaddr += PMD_SIZE;
 212                 pmd++;
 213         } while (vaddr < end);
 214 }
 215
 216 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
 217 {
 218         pgd_t * dir;
 219         unsigned long end = vaddr + size;
 220
 221         dir = pgd_offset_k(vaddr);
 222         do {
 223                 unmap_uncached_pmd(dir, vaddr, end - vaddr);
 224                 vaddr = vaddr + PGDIR_SIZE;
 225                 dir++;
 226         } while (vaddr && (vaddr < end));
 227 }
 228
 229 #define PCXL_SEARCH_LOOP(idx, mask, size)  \
 230        for(; res_ptr < res_end; ++res_ptr) \
 231        { \
 232                if(0 == ((*res_ptr) & mask)) { \
 233                        *res_ptr |= mask; \
 234                        idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
 235                        pcxl_res_hint = idx + (size >> 3); \
 236                        goto resource_found; \
 237                } \
 238        }
 239
 240 #define PCXL_FIND_FREE_MAPPING(idx, mask, size)  { \
 241        u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
 242        u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
 243        PCXL_SEARCH_LOOP(idx, mask, size); \
 244        res_ptr = (u##size *)&pcxl_res_map[0]; \
 245        PCXL_SEARCH_LOOP(idx, mask, size); \
 246 }
 247
 248 unsigned long
 249 pcxl_alloc_range(size_t size)
 250 {
 251         int res_idx;
 252         u_long mask, flags;
 253         unsigned int pages_needed = size >> PAGE_SHIFT;
 254
 255         mask = (u_long) -1L;
 256         mask >>= BITS_PER_LONG - pages_needed;
 257
 258         DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
 259                 size, pages_needed, mask);
 260
 261         spin_lock_irqsave(&pcxl_res_lock, flags);
 262
 263         if(pages_needed <= 8) {
 264                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
 265         } else if(pages_needed <= 16) {
 266                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
 267         } else if(pages_needed <= 32) {
 268                 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
 269         } else {
 270                 panic("%s: pcxl_alloc_range() Too many pages to map.\n",
 271                       __FILE__);
 272         }
 273
 274         dump_resmap();
 275         panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
 276               __FILE__);
 277
 278 resource_found:
 279
 280         DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
 281                 res_idx, mask, pcxl_res_hint);
 282
 283         pcxl_used_pages += pages_needed;
 284         pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
 285
 286         spin_unlock_irqrestore(&pcxl_res_lock, flags);
 287
 288         dump_resmap();
 289
 290         /*
 291         ** return the corresponding vaddr in the pcxl dma map
 292         */
 293         return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
 294 }
 295
 296 #define PCXL_FREE_MAPPINGS(idx, m, size) \
 297                 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
 298                 /* BUG_ON((*res_ptr & m) != m); */ \
 299                 *res_ptr &= ~m;
 300
 301 /*
 302 ** clear bits in the pcxl resource map
 303 */
 304 static void
 305 pcxl_free_range(unsigned long vaddr, size_t size)
 306 {
 307         u_long mask, flags;
 308         unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
 309         unsigned int pages_mapped = size >> PAGE_SHIFT;
 310
 311         mask = (u_long) -1L;
 312         mask >>= BITS_PER_LONG - pages_mapped;
 313
 314         DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
 315                 res_idx, size, pages_mapped, mask);
 316
 317         spin_lock_irqsave(&pcxl_res_lock, flags);
 318
 319         if(pages_mapped <= 8) {
 320                 PCXL_FREE_MAPPINGS(res_idx, mask, 8);
 321         } else if(pages_mapped <= 16) {
 322                 PCXL_FREE_MAPPINGS(res_idx, mask, 16);
 323         } else if(pages_mapped <= 32) {
 324                 PCXL_FREE_MAPPINGS(res_idx, mask, 32);
 325         } else {
 326                 panic("%s: pcxl_free_range() Too many pages to unmap.\n",
 327                       __FILE__);
 328         }
 329
 330         pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
 331         pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
 332
 333         spin_unlock_irqrestore(&pcxl_res_lock, flags);
 334
 335         dump_resmap();
 336 }
 337
 338 static int __maybe_unused proc_pcxl_dma_show(struct seq_file *m, void *v)
 339 {
 340 #if 0
 341         u_long i = 0;
 342         unsigned long *res_ptr = (u_long *)pcxl_res_map;
 343 #endif
 344         unsigned long total_pages = pcxl_res_size << 3;   /* 8 bits per byte */
 345
 346         seq_printf(m, "\nDMA Mapping Area size    : %d bytes (%ld pages)\n",
 347                 PCXL_DMA_MAP_SIZE, total_pages);
 348
 349         seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
 350
 351         seq_puts(m,  "            total:    free:    used:   % used:\n");
 352         seq_printf(m, "blocks  %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
 353                 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
 354                 (pcxl_used_bytes * 100) / pcxl_res_size);
 355
 356         seq_printf(m, "pages   %8ld %8ld %8ld %8ld%%\n", total_pages,
 357                 total_pages - pcxl_used_pages, pcxl_used_pages,
 358                 (pcxl_used_pages * 100 / total_pages));
 359
 360 #if 0
 361         seq_puts(m, "\nResource bitmap:");
 362
 363         for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
 364                 if ((i & 7) == 0)
 365                     seq_puts(m,"\n   ");
 366                 seq_printf(m, "%s %08lx", buf, *res_ptr);
 367         }
 368 #endif
 369         seq_putc(m, '\n');
 370         return 0;
 371 }
 372
 373 static int __init
 374 pcxl_dma_init(void)
 375 {
 376         if (pcxl_dma_start == 0)
 377                 return 0;
 378
 379         pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
 380         pcxl_res_hint = 0;
 381         pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
 382                                             get_order(pcxl_res_size));
 383         memset(pcxl_res_map, 0, pcxl_res_size);
 384         proc_gsc_root = proc_mkdir("gsc", NULL);
 385         if (!proc_gsc_root)
 386                 printk(KERN_WARNING
 387                         "pcxl_dma_init: Unable to create gsc /proc dir entry\n");
 388         else {
 389                 struct proc_dir_entry* ent;
 390                 ent = proc_create_single("pcxl_dma", 0, proc_gsc_root,
 391                                 proc_pcxl_dma_show);
 392                 if (!ent)
 393                         printk(KERN_WARNING
 394                                 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
 395         }
 396         return 0;
 397 }
 398
 399 __initcall(pcxl_dma_init);
 400
 401 void *arch_dma_alloc(struct device *dev, size_t size,
 402                 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 403 {
 404         unsigned long vaddr;
 405         unsigned long paddr;
 406         int order;
 407
 408         if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl)
 409                 return NULL;
 410
 411         order = get_order(size);
 412         size = 1 << (order + PAGE_SHIFT);
 413         vaddr = pcxl_alloc_range(size);
 414         paddr = __get_free_pages(gfp | __GFP_ZERO, order);
 415         flush_kernel_dcache_range(paddr, size);
 416         paddr = __pa(paddr);
 417         map_uncached_pages(vaddr, size, paddr);
 418         *dma_handle = (dma_addr_t) paddr;
 419
 420 #if 0
 421 /* This probably isn't needed to support EISA cards.
 422 ** ISA cards will certainly only support 24-bit DMA addressing.
 423 ** Not clear if we can, want, or need to support ISA.
 424 */
 425         if (!dev || *dev->coherent_dma_mask < 0xffffffff)
 426                 gfp |= GFP_DMA;
 427 #endif
 428         return (void *)vaddr;
 429 }
 430
 431 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
 432                 dma_addr_t dma_handle, unsigned long attrs)
 433 {
 434         int order = get_order(size);
 435
 436         WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 &&
 437                      boot_cpu_data.cpu_type != pcxl);
 438
 439         size = 1 << (order + PAGE_SHIFT);
 440         unmap_uncached_pages((unsigned long)vaddr, size);
 441         pcxl_free_range((unsigned long)vaddr, size);
 442
 443         free_pages((unsigned long)__va(dma_handle), order);
 444 }
 445
 446 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
 447                 enum dma_data_direction dir)
 448 {
 449         flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
 450 }
 451
 452 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
 453                 enum dma_data_direction dir)
 454 {
 455         flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
 456 }