linux/arch/sparc/mm/iommu.c
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   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 */
  41extern int viking_mxcc_present;
  42BTFIXUPDEF_CALL(void, flush_page_for_dma, unsigned long)
  43#define flush_page_for_dma(page) BTFIXUP_CALL(flush_page_for_dma)(page)
  44extern int flush_page_for_dma_global;
  45static int viking_flush;
  46/* viking.S */
  47extern void viking_flush_page(unsigned long page);
  48extern void viking_mxcc_flush_page(unsigned long page);
  49
  50/*
  51 * Values precomputed according to CPU type.
  52 */
  53static unsigned int ioperm_noc;         /* Consistent mapping iopte flags */
  54static 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
  59static 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
 130static 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
 144subsys_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. */
 149static 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
 175static 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
 205static 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
 219static __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
 224static __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
 230static __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
 241static 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
 254static 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
 268static 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
 299static 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
 315static 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
 325static 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
 340static 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
 407static 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
 429static char *iommu_lockarea(char *vaddr, unsigned long len)
 430{
 431        return vaddr;
 432}
 433
 434static void iommu_unlockarea(char *vaddr, unsigned long len)
 435{
 436}
 437
 438void __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}
 472
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