linux/arch/parisc/kernel/pci-dma.c
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   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
  38static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
  39static unsigned long pcxl_used_bytes __read_mostly = 0;
  40static unsigned long pcxl_used_pages __read_mostly = 0;
  41
  42extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
  43static DEFINE_SPINLOCK(pcxl_res_lock);
  44static char    *pcxl_res_map;
  45static int     pcxl_res_hint;
  46static 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
  60static
  61void 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
  73static inline void dump_resmap(void) {;}
  74#endif
  75
  76static 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
 104static 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
 127static 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
 153static 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
 189static 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
 216static 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
 248unsigned long
 249pcxl_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        
 278resource_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*/
 304static void
 305pcxl_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
 338static 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
 373static int __init
 374pcxl_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
 401void *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
 431void 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
 446void 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
 452void 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}
 457