linux/arch/sparc/mm/iommu.c
<<
>>
Prefs
   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 */
  41extern int viking_mxcc_present;
  42extern int flush_page_for_dma_global;
  43static int viking_flush;
  44/* viking.S */
  45extern void viking_flush_page(unsigned long page);
  46extern void viking_mxcc_flush_page(unsigned long page);
  47
  48/*
  49 * Values precomputed according to CPU type.
  50 */
  51static unsigned int ioperm_noc;         /* Consistent mapping iopte flags */
  52static 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
  57static 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
 128static 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
 142subsys_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. */
 146static 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
 172static 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
 202static 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
 216static __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
 222static __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
 233static 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
 247static 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
 278static 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
 294static 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
 304static 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
 319static 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
 386static 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
 408static 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
 419static 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
 430void __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}
 447