arch/sparc/mm/iommu.c

   1 /*
   2  * iommu.c:  IOMMU specific routines for memory management.
   3  *
   4  * Copyright (C) 1995 David S. Miller  (davem@caip.rutgers.edu)
   5  * Copyright (C) 1995,2002 Pete Zaitcev     (zaitcev@yahoo.com)
   6  * Copyright (C) 1996 Eddie C. Dost    (ecd@skynet.be)
   7  * Copyright (C) 1997,1998 Jakub Jelinek    (jj@sunsite.mff.cuni.cz)
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/mm.h>
  13 #include <linux/slab.h>
  14 #include <linux/highmem.h>      /* pte_offset_map => kmap_atomic */
  15 #include <linux/scatterlist.h>
  16 #include <linux/of.h>
  17 #include <linux/of_device.h>
  18
  19 #include <asm/pgalloc.h>
  20 #include <asm/pgtable.h>
  21 #include <asm/io.h>
  22 #include <asm/mxcc.h>
  23 #include <asm/mbus.h>
  24 #include <asm/cacheflush.h>
  25 #include <asm/tlbflush.h>
  26 #include <asm/bitext.h>
  27 #include <asm/iommu.h>
  28 #include <asm/dma.h>
  29
  30 /*
  31  * This can be sized dynamically, but we will do this
  32  * only when we have a guidance about actual I/O pressures.
  33  */
  34 #define IOMMU_RNGE      IOMMU_RNGE_256MB
  35 #define IOMMU_START     0xF0000000
  36 #define IOMMU_WINSIZE   (256*1024*1024U)
  37 #define IOMMU_NPTES     (IOMMU_WINSIZE/PAGE_SIZE)       /* 64K PTEs, 265KB */
  38 #define IOMMU_ORDER     6                               /* 4096 * (1<<6) */
  39
  40 /* srmmu.c */
  41 extern int viking_mxcc_present;
  42 BTFIXUPDEF_CALL(void, flush_page_for_dma, unsigned long)
  43 #define flush_page_for_dma(page) BTFIXUP_CALL(flush_page_for_dma)(page)
  44 extern int flush_page_for_dma_global;
  45 static int viking_flush;
  46 /* viking.S */
  47 extern void viking_flush_page(unsigned long page);
  48 extern void viking_mxcc_flush_page(unsigned long page);
  49
  50 /*
  51  * Values precomputed according to CPU type.
  52  */
  53 static unsigned int ioperm_noc;         /* Consistent mapping iopte flags */
  54 static pgprot_t dvma_prot;              /* Consistent mapping pte flags */
  55
  56 #define IOPERM        (IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID)
  57 #define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) | (perm)) & ~IOPTE_WAZ)
  58
  59 static void __init sbus_iommu_init(struct of_device *op)
  60 {
  61         struct iommu_struct *iommu;
  62         unsigned int impl, vers;
  63         unsigned long *bitmap;
  64         unsigned long tmp;
  65
  66         iommu = kmalloc(sizeof(struct iommu_struct), GFP_ATOMIC);
  67         if (!iommu) {
  68                 prom_printf("Unable to allocate iommu structure\n");
  69                 prom_halt();
  70         }
  71
  72         iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
  73                                  "iommu_regs");
  74         if (!iommu->regs) {
  75                 prom_printf("Cannot map IOMMU registers\n");
  76                 prom_halt();
  77         }
  78         impl = (iommu->regs->control & IOMMU_CTRL_IMPL) >> 28;
  79         vers = (iommu->regs->control & IOMMU_CTRL_VERS) >> 24;
  80         tmp = iommu->regs->control;
  81         tmp &= ~(IOMMU_CTRL_RNGE);
  82         tmp |= (IOMMU_RNGE_256MB | IOMMU_CTRL_ENAB);
  83         iommu->regs->control = tmp;
  84         iommu_invalidate(iommu->regs);
  85         iommu->start = IOMMU_START;
  86         iommu->end = 0xffffffff;
  87
  88         /* Allocate IOMMU page table */
  89         /* Stupid alignment constraints give me a headache.
  90            We need 256K or 512K or 1M or 2M area aligned to
  91            its size and current gfp will fortunately give
  92            it to us. */
  93         tmp = __get_free_pages(GFP_KERNEL, IOMMU_ORDER);
  94         if (!tmp) {
  95                 prom_printf("Unable to allocate iommu table [0x%08x]\n",
  96                             IOMMU_NPTES*sizeof(iopte_t));
  97                 prom_halt();
  98         }
  99         iommu->page_table = (iopte_t *)tmp;
 100
 101         /* Initialize new table. */
 102         memset(iommu->page_table, 0, IOMMU_NPTES*sizeof(iopte_t));
 103         flush_cache_all();
 104         flush_tlb_all();
 105         iommu->regs->base = __pa((unsigned long) iommu->page_table) >> 4;
 106         iommu_invalidate(iommu->regs);
 107
 108         bitmap = kmalloc(IOMMU_NPTES>>3, GFP_KERNEL);
 109         if (!bitmap) {
 110                 prom_printf("Unable to allocate iommu bitmap [%d]\n",
 111                             (int)(IOMMU_NPTES>>3));
 112                 prom_halt();
 113         }
 114         bit_map_init(&iommu->usemap, bitmap, IOMMU_NPTES);
 115         /* To be coherent on HyperSparc, the page color of DVMA
 116          * and physical addresses must match.
 117          */
 118         if (srmmu_modtype == HyperSparc)
 119                 iommu->usemap.num_colors = vac_cache_size >> PAGE_SHIFT;
 120         else
 121                 iommu->usemap.num_colors = 1;
 122
 123         printk(KERN_INFO "IOMMU: impl %d vers %d table 0x%p[%d B] map [%d b]\n",
 124                impl, vers, iommu->page_table,
 125                (int)(IOMMU_NPTES*sizeof(iopte_t)), (int)IOMMU_NPTES);
 126
 127         op->dev.archdata.iommu = iommu;
 128 }
 129
 130 static int __init iommu_init(void)
 131 {
 132         struct device_node *dp;
 133
 134         for_each_node_by_name(dp, "iommu") {
 135                 struct of_device *op = of_find_device_by_node(dp);
 136
 137                 sbus_iommu_init(op);
 138                 of_propagate_archdata(op);
 139         }
 140
 141         return 0;
 142 }
 143
 144 subsys_initcall(iommu_init);
 145
 146 /* This begs to be btfixup-ed by srmmu. */
 147 /* Flush the iotlb entries to ram. */
 148 /* This could be better if we didn't have to flush whole pages. */
 149 static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
 150 {
 151         unsigned long start;
 152         unsigned long end;
 153
 154         start = (unsigned long)iopte;
 155         end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
 156         start &= PAGE_MASK;
 157         if (viking_mxcc_present) {
 158                 while(start < end) {
 159                         viking_mxcc_flush_page(start);
 160                         start += PAGE_SIZE;
 161                 }
 162         } else if (viking_flush) {
 163                 while(start < end) {
 164                         viking_flush_page(start);
 165                         start += PAGE_SIZE;
 166                 }
 167         } else {
 168                 while(start < end) {
 169                         __flush_page_to_ram(start);
 170                         start += PAGE_SIZE;
 171                 }
 172         }
 173 }
 174
 175 static u32 iommu_get_one(struct device *dev, struct page *page, int npages)
 176 {
 177         struct iommu_struct *iommu = dev->archdata.iommu;
 178         int ioptex;
 179         iopte_t *iopte, *iopte0;
 180         unsigned int busa, busa0;
 181         int i;
 182
 183         /* page color = pfn of page */
 184         ioptex = bit_map_string_get(&iommu->usemap, npages, page_to_pfn(page));
 185         if (ioptex < 0)
 186                 panic("iommu out");
 187         busa0 = iommu->start + (ioptex << PAGE_SHIFT);
 188         iopte0 = &iommu->page_table[ioptex];
 189
 190         busa = busa0;
 191         iopte = iopte0;
 192         for (i = 0; i < npages; i++) {
 193                 iopte_val(*iopte) = MKIOPTE(page_to_pfn(page), IOPERM);
 194                 iommu_invalidate_page(iommu->regs, busa);
 195                 busa += PAGE_SIZE;
 196                 iopte++;
 197                 page++;
 198         }
 199
 200         iommu_flush_iotlb(iopte0, npages);
 201
 202         return busa0;
 203 }
 204
 205 static u32 iommu_get_scsi_one(struct device *dev, char *vaddr, unsigned int len)
 206 {
 207         unsigned long off;
 208         int npages;
 209         struct page *page;
 210         u32 busa;
 211
 212         off = (unsigned long)vaddr & ~PAGE_MASK;
 213         npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
 214         page = virt_to_page((unsigned long)vaddr & PAGE_MASK);
 215         busa = iommu_get_one(dev, page, npages);
 216         return busa + off;
 217 }
 218
 219 static __u32 iommu_get_scsi_one_noflush(struct device *dev, char *vaddr, unsigned long len)
 220 {
 221         return iommu_get_scsi_one(dev, vaddr, len);
 222 }
 223
 224 static __u32 iommu_get_scsi_one_gflush(struct device *dev, char *vaddr, unsigned long len)
 225 {
 226         flush_page_for_dma(0);
 227         return iommu_get_scsi_one(dev, vaddr, len);
 228 }
 229
 230 static __u32 iommu_get_scsi_one_pflush(struct device *dev, char *vaddr, unsigned long len)
 231 {
 232         unsigned long page = ((unsigned long) vaddr) & PAGE_MASK;
 233
 234         while(page < ((unsigned long)(vaddr + len))) {
 235                 flush_page_for_dma(page);
 236                 page += PAGE_SIZE;
 237         }
 238         return iommu_get_scsi_one(dev, vaddr, len);
 239 }
 240
 241 static void iommu_get_scsi_sgl_noflush(struct device *dev, struct scatterlist *sg, int sz)
 242 {
 243         int n;
 244
 245         while (sz != 0) {
 246                 --sz;
 247                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
 248                 sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
 249                 sg->dma_length = sg->length;
 250                 sg = sg_next(sg);
 251         }
 252 }
 253
 254 static void iommu_get_scsi_sgl_gflush(struct device *dev, struct scatterlist *sg, int sz)
 255 {
 256         int n;
 257
 258         flush_page_for_dma(0);
 259         while (sz != 0) {
 260                 --sz;
 261                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
 262                 sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
 263                 sg->dma_length = sg->length;
 264                 sg = sg_next(sg);
 265         }
 266 }
 267
 268 static void iommu_get_scsi_sgl_pflush(struct device *dev, struct scatterlist *sg, int sz)
 269 {
 270         unsigned long page, oldpage = 0;
 271         int n, i;
 272
 273         while(sz != 0) {
 274                 --sz;
 275
 276                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
 277
 278                 /*
 279                  * We expect unmapped highmem pages to be not in the cache.
 280                  * XXX Is this a good assumption?
 281                  * XXX What if someone else unmaps it here and races us?
 282                  */
 283                 if ((page = (unsigned long) page_address(sg_page(sg))) != 0) {
 284                         for (i = 0; i < n; i++) {
 285                                 if (page != oldpage) {  /* Already flushed? */
 286                                         flush_page_for_dma(page);
 287                                         oldpage = page;
 288                                 }
 289                                 page += PAGE_SIZE;
 290                         }
 291                 }
 292
 293                 sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
 294                 sg->dma_length = sg->length;
 295                 sg = sg_next(sg);
 296         }
 297 }
 298
 299 static void iommu_release_one(struct device *dev, u32 busa, int npages)
 300 {
 301         struct iommu_struct *iommu = dev->archdata.iommu;
 302         int ioptex;
 303         int i;
 304
 305         BUG_ON(busa < iommu->start);
 306         ioptex = (busa - iommu->start) >> PAGE_SHIFT;
 307         for (i = 0; i < npages; i++) {
 308                 iopte_val(iommu->page_table[ioptex + i]) = 0;
 309                 iommu_invalidate_page(iommu->regs, busa);
 310                 busa += PAGE_SIZE;
 311         }
 312         bit_map_clear(&iommu->usemap, ioptex, npages);
 313 }
 314
 315 static void iommu_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
 316 {
 317         unsigned long off;
 318         int npages;
 319
 320         off = vaddr & ~PAGE_MASK;
 321         npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
 322         iommu_release_one(dev, vaddr & PAGE_MASK, npages);
 323 }
 324
 325 static void iommu_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
 326 {
 327         int n;
 328
 329         while(sz != 0) {
 330                 --sz;
 331
 332                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
 333                 iommu_release_one(dev, sg->dma_address & PAGE_MASK, n);
 334                 sg->dma_address = 0x21212121;
 335                 sg = sg_next(sg);
 336         }
 337 }
 338
 339 #ifdef CONFIG_SBUS
 340 static int iommu_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va,
 341                               unsigned long addr, int len)
 342 {
 343         struct iommu_struct *iommu = dev->archdata.iommu;
 344         unsigned long page, end;
 345         iopte_t *iopte = iommu->page_table;
 346         iopte_t *first;
 347         int ioptex;
 348
 349         BUG_ON((va & ~PAGE_MASK) != 0);
 350         BUG_ON((addr & ~PAGE_MASK) != 0);
 351         BUG_ON((len & ~PAGE_MASK) != 0);
 352
 353         /* page color = physical address */
 354         ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
 355                 addr >> PAGE_SHIFT);
 356         if (ioptex < 0)
 357                 panic("iommu out");
 358
 359         iopte += ioptex;
 360         first = iopte;
 361         end = addr + len;
 362         while(addr < end) {
 363                 page = va;
 364                 {
 365                         pgd_t *pgdp;
 366                         pmd_t *pmdp;
 367                         pte_t *ptep;
 368
 369                         if (viking_mxcc_present)
 370                                 viking_mxcc_flush_page(page);
 371                         else if (viking_flush)
 372                                 viking_flush_page(page);
 373                         else
 374                                 __flush_page_to_ram(page);
 375
 376                         pgdp = pgd_offset(&init_mm, addr);
 377                         pmdp = pmd_offset(pgdp, addr);
 378                         ptep = pte_offset_map(pmdp, addr);
 379
 380                         set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
 381                 }
 382                 iopte_val(*iopte++) =
 383                     MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
 384                 addr += PAGE_SIZE;
 385                 va += PAGE_SIZE;
 386         }
 387         /* P3: why do we need this?
 388          *
 389          * DAVEM: Because there are several aspects, none of which
 390          *        are handled by a single interface.  Some cpus are
 391          *        completely not I/O DMA coherent, and some have
 392          *        virtually indexed caches.  The driver DMA flushing
 393          *        methods handle the former case, but here during
 394          *        IOMMU page table modifications, and usage of non-cacheable
 395          *        cpu mappings of pages potentially in the cpu caches, we have
 396          *        to handle the latter case as well.
 397          */
 398         flush_cache_all();
 399         iommu_flush_iotlb(first, len >> PAGE_SHIFT);
 400         flush_tlb_all();
 401         iommu_invalidate(iommu->regs);
 402
 403         *pba = iommu->start + (ioptex << PAGE_SHIFT);
 404         return 0;
 405 }
 406
 407 static void iommu_unmap_dma_area(struct device *dev, unsigned long busa, int len)
 408 {
 409         struct iommu_struct *iommu = dev->archdata.iommu;
 410         iopte_t *iopte = iommu->page_table;
 411         unsigned long end;
 412         int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
 413
 414         BUG_ON((busa & ~PAGE_MASK) != 0);
 415         BUG_ON((len & ~PAGE_MASK) != 0);
 416
 417         iopte += ioptex;
 418         end = busa + len;
 419         while (busa < end) {
 420                 iopte_val(*iopte++) = 0;
 421                 busa += PAGE_SIZE;
 422         }
 423         flush_tlb_all();
 424         iommu_invalidate(iommu->regs);
 425         bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
 426 }
 427 #endif
 428
 429 static char *iommu_lockarea(char *vaddr, unsigned long len)
 430 {
 431         return vaddr;
 432 }
 433
 434 static void iommu_unlockarea(char *vaddr, unsigned long len)
 435 {
 436 }
 437
 438 void __init ld_mmu_iommu(void)
 439 {
 440         viking_flush = (BTFIXUPVAL_CALL(flush_page_for_dma) == (unsigned long)viking_flush_page);
 441         BTFIXUPSET_CALL(mmu_lockarea, iommu_lockarea, BTFIXUPCALL_RETO0);
 442         BTFIXUPSET_CALL(mmu_unlockarea, iommu_unlockarea, BTFIXUPCALL_NOP);
 443
 444         if (!BTFIXUPVAL_CALL(flush_page_for_dma)) {
 445                 /* IO coherent chip */
 446                 BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_noflush, BTFIXUPCALL_RETO0);
 447                 BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_noflush, BTFIXUPCALL_NORM);
 448         } else if (flush_page_for_dma_global) {
 449                 /* flush_page_for_dma flushes everything, no matter of what page is it */
 450                 BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_gflush, BTFIXUPCALL_NORM);
 451                 BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_gflush, BTFIXUPCALL_NORM);
 452         } else {
 453                 BTFIXUPSET_CALL(mmu_get_scsi_one, iommu_get_scsi_one_pflush, BTFIXUPCALL_NORM);
 454                 BTFIXUPSET_CALL(mmu_get_scsi_sgl, iommu_get_scsi_sgl_pflush, BTFIXUPCALL_NORM);
 455         }
 456         BTFIXUPSET_CALL(mmu_release_scsi_one, iommu_release_scsi_one, BTFIXUPCALL_NORM);
 457         BTFIXUPSET_CALL(mmu_release_scsi_sgl, iommu_release_scsi_sgl, BTFIXUPCALL_NORM);
 458
 459 #ifdef CONFIG_SBUS
 460         BTFIXUPSET_CALL(mmu_map_dma_area, iommu_map_dma_area, BTFIXUPCALL_NORM);
 461         BTFIXUPSET_CALL(mmu_unmap_dma_area, iommu_unmap_dma_area, BTFIXUPCALL_NORM);
 462 #endif
 463
 464         if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
 465                 dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
 466                 ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
 467         } else {
 468                 dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
 469                 ioperm_noc = IOPTE_WRITE | IOPTE_VALID;
 470         }
 471 }