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, 256KB */
  38 #define IOMMU_ORDER     6                               /* 4096 * (1<<6) */
  39
  40 /* srmmu.c */
  41 extern int viking_mxcc_present;
  42 extern int flush_page_for_dma_global;
  43 static int viking_flush;
  44 /* viking.S */
  45 extern void viking_flush_page(unsigned long page);
  46 extern void viking_mxcc_flush_page(unsigned long page);
  47
  48 /*
  49  * Values precomputed according to CPU type.
  50  */
  51 static unsigned int ioperm_noc;         /* Consistent mapping iopte flags */
  52 static pgprot_t dvma_prot;              /* Consistent mapping pte flags */
  53
  54 #define IOPERM        (IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID)
  55 #define MKIOPTE(pfn, perm) (((((pfn)<<8) & IOPTE_PAGE) | (perm)) & ~IOPTE_WAZ)
  56
  57 static void __init sbus_iommu_init(struct platform_device *op)
  58 {
  59         struct iommu_struct *iommu;
  60         unsigned int impl, vers;
  61         unsigned long *bitmap;
  62         unsigned long tmp;
  63
  64         iommu = kmalloc(sizeof(struct iommu_struct), GFP_KERNEL);
  65         if (!iommu) {
  66                 prom_printf("Unable to allocate iommu structure\n");
  67                 prom_halt();
  68         }
  69
  70         iommu->regs = of_ioremap(&op->resource[0], 0, PAGE_SIZE * 3,
  71                                  "iommu_regs");
  72         if (!iommu->regs) {
  73                 prom_printf("Cannot map IOMMU registers\n");
  74                 prom_halt();
  75         }
  76         impl = (iommu->regs->control & IOMMU_CTRL_IMPL) >> 28;
  77         vers = (iommu->regs->control & IOMMU_CTRL_VERS) >> 24;
  78         tmp = iommu->regs->control;
  79         tmp &= ~(IOMMU_CTRL_RNGE);
  80         tmp |= (IOMMU_RNGE_256MB | IOMMU_CTRL_ENAB);
  81         iommu->regs->control = tmp;
  82         iommu_invalidate(iommu->regs);
  83         iommu->start = IOMMU_START;
  84         iommu->end = 0xffffffff;
  85
  86         /* Allocate IOMMU page table */
  87         /* Stupid alignment constraints give me a headache.
  88            We need 256K or 512K or 1M or 2M area aligned to
  89            its size and current gfp will fortunately give
  90            it to us. */
  91         tmp = __get_free_pages(GFP_KERNEL, IOMMU_ORDER);
  92         if (!tmp) {
  93                 prom_printf("Unable to allocate iommu table [0x%lx]\n",
  94                             IOMMU_NPTES * sizeof(iopte_t));
  95                 prom_halt();
  96         }
  97         iommu->page_table = (iopte_t *)tmp;
  98
  99         /* Initialize new table. */
 100         memset(iommu->page_table, 0, IOMMU_NPTES*sizeof(iopte_t));
 101         flush_cache_all();
 102         flush_tlb_all();
 103         iommu->regs->base = __pa((unsigned long) iommu->page_table) >> 4;
 104         iommu_invalidate(iommu->regs);
 105
 106         bitmap = kmalloc(IOMMU_NPTES>>3, GFP_KERNEL);
 107         if (!bitmap) {
 108                 prom_printf("Unable to allocate iommu bitmap [%d]\n",
 109                             (int)(IOMMU_NPTES>>3));
 110                 prom_halt();
 111         }
 112         bit_map_init(&iommu->usemap, bitmap, IOMMU_NPTES);
 113         /* To be coherent on HyperSparc, the page color of DVMA
 114          * and physical addresses must match.
 115          */
 116         if (srmmu_modtype == HyperSparc)
 117                 iommu->usemap.num_colors = vac_cache_size >> PAGE_SHIFT;
 118         else
 119                 iommu->usemap.num_colors = 1;
 120
 121         printk(KERN_INFO "IOMMU: impl %d vers %d table 0x%p[%d B] map [%d b]\n",
 122                impl, vers, iommu->page_table,
 123                (int)(IOMMU_NPTES*sizeof(iopte_t)), (int)IOMMU_NPTES);
 124
 125         op->dev.archdata.iommu = iommu;
 126 }
 127
 128 static int __init iommu_init(void)
 129 {
 130         struct device_node *dp;
 131
 132         for_each_node_by_name(dp, "iommu") {
 133                 struct platform_device *op = of_find_device_by_node(dp);
 134
 135                 sbus_iommu_init(op);
 136                 of_propagate_archdata(op);
 137         }
 138
 139         return 0;
 140 }
 141
 142 subsys_initcall(iommu_init);
 143
 144 /* Flush the iotlb entries to ram. */
 145 /* This could be better if we didn't have to flush whole pages. */
 146 static void iommu_flush_iotlb(iopte_t *iopte, unsigned int niopte)
 147 {
 148         unsigned long start;
 149         unsigned long end;
 150
 151         start = (unsigned long)iopte;
 152         end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
 153         start &= PAGE_MASK;
 154         if (viking_mxcc_present) {
 155                 while(start < end) {
 156                         viking_mxcc_flush_page(start);
 157                         start += PAGE_SIZE;
 158                 }
 159         } else if (viking_flush) {
 160                 while(start < end) {
 161                         viking_flush_page(start);
 162                         start += PAGE_SIZE;
 163                 }
 164         } else {
 165                 while(start < end) {
 166                         __flush_page_to_ram(start);
 167                         start += PAGE_SIZE;
 168                 }
 169         }
 170 }
 171
 172 static u32 iommu_get_one(struct device *dev, struct page *page, int npages)
 173 {
 174         struct iommu_struct *iommu = dev->archdata.iommu;
 175         int ioptex;
 176         iopte_t *iopte, *iopte0;
 177         unsigned int busa, busa0;
 178         int i;
 179
 180         /* page color = pfn of page */
 181         ioptex = bit_map_string_get(&iommu->usemap, npages, page_to_pfn(page));
 182         if (ioptex < 0)
 183                 panic("iommu out");
 184         busa0 = iommu->start + (ioptex << PAGE_SHIFT);
 185         iopte0 = &iommu->page_table[ioptex];
 186
 187         busa = busa0;
 188         iopte = iopte0;
 189         for (i = 0; i < npages; i++) {
 190                 iopte_val(*iopte) = MKIOPTE(page_to_pfn(page), IOPERM);
 191                 iommu_invalidate_page(iommu->regs, busa);
 192                 busa += PAGE_SIZE;
 193                 iopte++;
 194                 page++;
 195         }
 196
 197         iommu_flush_iotlb(iopte0, npages);
 198
 199         return busa0;
 200 }
 201
 202 static u32 iommu_get_scsi_one(struct device *dev, char *vaddr, unsigned int len)
 203 {
 204         unsigned long off;
 205         int npages;
 206         struct page *page;
 207         u32 busa;
 208
 209         off = (unsigned long)vaddr & ~PAGE_MASK;
 210         npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
 211         page = virt_to_page((unsigned long)vaddr & PAGE_MASK);
 212         busa = iommu_get_one(dev, page, npages);
 213         return busa + off;
 214 }
 215
 216 static __u32 iommu_get_scsi_one_gflush(struct device *dev, char *vaddr, unsigned long len)
 217 {
 218         flush_page_for_dma(0);
 219         return iommu_get_scsi_one(dev, vaddr, len);
 220 }
 221
 222 static __u32 iommu_get_scsi_one_pflush(struct device *dev, char *vaddr, unsigned long len)
 223 {
 224         unsigned long page = ((unsigned long) vaddr) & PAGE_MASK;
 225
 226         while(page < ((unsigned long)(vaddr + len))) {
 227                 flush_page_for_dma(page);
 228                 page += PAGE_SIZE;
 229         }
 230         return iommu_get_scsi_one(dev, vaddr, len);
 231 }
 232
 233 static void iommu_get_scsi_sgl_gflush(struct device *dev, struct scatterlist *sg, int sz)
 234 {
 235         int n;
 236
 237         flush_page_for_dma(0);
 238         while (sz != 0) {
 239                 --sz;
 240                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
 241                 sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
 242                 sg->dma_length = sg->length;
 243                 sg = sg_next(sg);
 244         }
 245 }
 246
 247 static void iommu_get_scsi_sgl_pflush(struct device *dev, struct scatterlist *sg, int sz)
 248 {
 249         unsigned long page, oldpage = 0;
 250         int n, i;
 251
 252         while(sz != 0) {
 253                 --sz;
 254
 255                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
 256
 257                 /*
 258                  * We expect unmapped highmem pages to be not in the cache.
 259                  * XXX Is this a good assumption?
 260                  * XXX What if someone else unmaps it here and races us?
 261                  */
 262                 if ((page = (unsigned long) page_address(sg_page(sg))) != 0) {
 263                         for (i = 0; i < n; i++) {
 264                                 if (page != oldpage) {  /* Already flushed? */
 265                                         flush_page_for_dma(page);
 266                                         oldpage = page;
 267                                 }
 268                                 page += PAGE_SIZE;
 269                         }
 270                 }
 271
 272                 sg->dma_address = iommu_get_one(dev, sg_page(sg), n) + sg->offset;
 273                 sg->dma_length = sg->length;
 274                 sg = sg_next(sg);
 275         }
 276 }
 277
 278 static void iommu_release_one(struct device *dev, u32 busa, int npages)
 279 {
 280         struct iommu_struct *iommu = dev->archdata.iommu;
 281         int ioptex;
 282         int i;
 283
 284         BUG_ON(busa < iommu->start);
 285         ioptex = (busa - iommu->start) >> PAGE_SHIFT;
 286         for (i = 0; i < npages; i++) {
 287                 iopte_val(iommu->page_table[ioptex + i]) = 0;
 288                 iommu_invalidate_page(iommu->regs, busa);
 289                 busa += PAGE_SIZE;
 290         }
 291         bit_map_clear(&iommu->usemap, ioptex, npages);
 292 }
 293
 294 static void iommu_release_scsi_one(struct device *dev, __u32 vaddr, unsigned long len)
 295 {
 296         unsigned long off;
 297         int npages;
 298
 299         off = vaddr & ~PAGE_MASK;
 300         npages = (off + len + PAGE_SIZE-1) >> PAGE_SHIFT;
 301         iommu_release_one(dev, vaddr & PAGE_MASK, npages);
 302 }
 303
 304 static void iommu_release_scsi_sgl(struct device *dev, struct scatterlist *sg, int sz)
 305 {
 306         int n;
 307
 308         while(sz != 0) {
 309                 --sz;
 310
 311                 n = (sg->length + sg->offset + PAGE_SIZE-1) >> PAGE_SHIFT;
 312                 iommu_release_one(dev, sg->dma_address & PAGE_MASK, n);
 313                 sg->dma_address = 0x21212121;
 314                 sg = sg_next(sg);
 315         }
 316 }
 317
 318 #ifdef CONFIG_SBUS
 319 static int iommu_map_dma_area(struct device *dev, dma_addr_t *pba, unsigned long va,
 320                               unsigned long addr, int len)
 321 {
 322         struct iommu_struct *iommu = dev->archdata.iommu;
 323         unsigned long page, end;
 324         iopte_t *iopte = iommu->page_table;
 325         iopte_t *first;
 326         int ioptex;
 327
 328         BUG_ON((va & ~PAGE_MASK) != 0);
 329         BUG_ON((addr & ~PAGE_MASK) != 0);
 330         BUG_ON((len & ~PAGE_MASK) != 0);
 331
 332         /* page color = physical address */
 333         ioptex = bit_map_string_get(&iommu->usemap, len >> PAGE_SHIFT,
 334                 addr >> PAGE_SHIFT);
 335         if (ioptex < 0)
 336                 panic("iommu out");
 337
 338         iopte += ioptex;
 339         first = iopte;
 340         end = addr + len;
 341         while(addr < end) {
 342                 page = va;
 343                 {
 344                         pgd_t *pgdp;
 345                         pmd_t *pmdp;
 346                         pte_t *ptep;
 347
 348                         if (viking_mxcc_present)
 349                                 viking_mxcc_flush_page(page);
 350                         else if (viking_flush)
 351                                 viking_flush_page(page);
 352                         else
 353                                 __flush_page_to_ram(page);
 354
 355                         pgdp = pgd_offset(&init_mm, addr);
 356                         pmdp = pmd_offset(pgdp, addr);
 357                         ptep = pte_offset_map(pmdp, addr);
 358
 359                         set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
 360                 }
 361                 iopte_val(*iopte++) =
 362                     MKIOPTE(page_to_pfn(virt_to_page(page)), ioperm_noc);
 363                 addr += PAGE_SIZE;
 364                 va += PAGE_SIZE;
 365         }
 366         /* P3: why do we need this?
 367          *
 368          * DAVEM: Because there are several aspects, none of which
 369          *        are handled by a single interface.  Some cpus are
 370          *        completely not I/O DMA coherent, and some have
 371          *        virtually indexed caches.  The driver DMA flushing
 372          *        methods handle the former case, but here during
 373          *        IOMMU page table modifications, and usage of non-cacheable
 374          *        cpu mappings of pages potentially in the cpu caches, we have
 375          *        to handle the latter case as well.
 376          */
 377         flush_cache_all();
 378         iommu_flush_iotlb(first, len >> PAGE_SHIFT);
 379         flush_tlb_all();
 380         iommu_invalidate(iommu->regs);
 381
 382         *pba = iommu->start + (ioptex << PAGE_SHIFT);
 383         return 0;
 384 }
 385
 386 static void iommu_unmap_dma_area(struct device *dev, unsigned long busa, int len)
 387 {
 388         struct iommu_struct *iommu = dev->archdata.iommu;
 389         iopte_t *iopte = iommu->page_table;
 390         unsigned long end;
 391         int ioptex = (busa - iommu->start) >> PAGE_SHIFT;
 392
 393         BUG_ON((busa & ~PAGE_MASK) != 0);
 394         BUG_ON((len & ~PAGE_MASK) != 0);
 395
 396         iopte += ioptex;
 397         end = busa + len;
 398         while (busa < end) {
 399                 iopte_val(*iopte++) = 0;
 400                 busa += PAGE_SIZE;
 401         }
 402         flush_tlb_all();
 403         iommu_invalidate(iommu->regs);
 404         bit_map_clear(&iommu->usemap, ioptex, len >> PAGE_SHIFT);
 405 }
 406 #endif
 407
 408 static const struct sparc32_dma_ops iommu_dma_gflush_ops = {
 409         .get_scsi_one           = iommu_get_scsi_one_gflush,
 410         .get_scsi_sgl           = iommu_get_scsi_sgl_gflush,
 411         .release_scsi_one       = iommu_release_scsi_one,
 412         .release_scsi_sgl       = iommu_release_scsi_sgl,
 413 #ifdef CONFIG_SBUS
 414         .map_dma_area           = iommu_map_dma_area,
 415         .unmap_dma_area         = iommu_unmap_dma_area,
 416 #endif
 417 };
 418
 419 static const struct sparc32_dma_ops iommu_dma_pflush_ops = {
 420         .get_scsi_one           = iommu_get_scsi_one_pflush,
 421         .get_scsi_sgl           = iommu_get_scsi_sgl_pflush,
 422         .release_scsi_one       = iommu_release_scsi_one,
 423         .release_scsi_sgl       = iommu_release_scsi_sgl,
 424 #ifdef CONFIG_SBUS
 425         .map_dma_area           = iommu_map_dma_area,
 426         .unmap_dma_area         = iommu_unmap_dma_area,
 427 #endif
 428 };
 429
 430 void __init ld_mmu_iommu(void)
 431 {
 432         if (flush_page_for_dma_global) {
 433                 /* flush_page_for_dma flushes everything, no matter of what page is it */
 434                 sparc32_dma_ops = &iommu_dma_gflush_ops;
 435         } else {
 436                 sparc32_dma_ops = &iommu_dma_pflush_ops;
 437         }
 438
 439         if (viking_mxcc_present || srmmu_modtype == HyperSparc) {
 440                 dvma_prot = __pgprot(SRMMU_CACHE | SRMMU_ET_PTE | SRMMU_PRIV);
 441                 ioperm_noc = IOPTE_CACHE | IOPTE_WRITE | IOPTE_VALID;
 442         } else {
 443                 dvma_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV);
 444                 ioperm_noc = IOPTE_WRITE | IOPTE_VALID;
 445         }
 446 }