LXR linux/arch/powerpc/mm/pgtable

   1/*
   2 *  This file contains ioremap and related functions for 64-bit machines.
   3 *
   4 *  Derived from arch/ppc64/mm/init.c
   5 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6 *
   7 *  Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
   8 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
   9 *    Copyright (C) 1996 Paul Mackerras
  10 *
  11 *  Derived from "arch/i386/mm/init.c"
  12 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  13 *
  14 *  Dave Engebretsen <engebret@us.ibm.com>
  15 *      Rework for PPC64 port.
  16 *
  17 *  This program is free software; you can redistribute it and/or
  18 *  modify it under the terms of the GNU General Public License
  19 *  as published by the Free Software Foundation; either version
  20 *  2 of the License, or (at your option) any later version.
  21 *
  22 */
  23
  24#include <linux/signal.h>
  25#include <linux/sched.h>
  26#include <linux/kernel.h>
  27#include <linux/errno.h>
  28#include <linux/string.h>
  29#include <linux/export.h>
  30#include <linux/types.h>
  31#include <linux/mman.h>
  32#include <linux/mm.h>
  33#include <linux/swap.h>
  34#include <linux/stddef.h>
  35#include <linux/vmalloc.h>
  36#include <linux/memblock.h>
  37#include <linux/slab.h>
  38#include <linux/hugetlb.h>
  39
  40#include <asm/pgalloc.h>
  41#include <asm/page.h>
  42#include <asm/prom.h>
  43#include <asm/io.h>
  44#include <asm/mmu_context.h>
  45#include <asm/pgtable.h>
  46#include <asm/mmu.h>
  47#include <asm/smp.h>
  48#include <asm/machdep.h>
  49#include <asm/tlb.h>
  50#include <asm/processor.h>
  51#include <asm/cputable.h>
  52#include <asm/sections.h>
  53#include <asm/firmware.h>
  54#include <asm/dma.h>
  55#include <asm/powernv.h>
  56
  57#include "mmu_decl.h"
  58
  59#ifdef CONFIG_PPC_STD_MMU_64
  60#if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
  61#error TASK_SIZE_USER64 exceeds user VSID range
  62#endif
  63#endif
  64
  65#ifdef CONFIG_PPC_BOOK3S_64
  66/*
  67 * partition table and process table for ISA 3.0
  68 */
  69struct prtb_entry *process_tb;
  70struct patb_entry *partition_tb;
  71/*
  72 * page table size
  73 */
  74unsigned long __pte_index_size;
  75EXPORT_SYMBOL(__pte_index_size);
  76unsigned long __pmd_index_size;
  77EXPORT_SYMBOL(__pmd_index_size);
  78unsigned long __pud_index_size;
  79EXPORT_SYMBOL(__pud_index_size);
  80unsigned long __pgd_index_size;
  81EXPORT_SYMBOL(__pgd_index_size);
  82unsigned long __pmd_cache_index;
  83EXPORT_SYMBOL(__pmd_cache_index);
  84unsigned long __pte_table_size;
  85EXPORT_SYMBOL(__pte_table_size);
  86unsigned long __pmd_table_size;
  87EXPORT_SYMBOL(__pmd_table_size);
  88unsigned long __pud_table_size;
  89EXPORT_SYMBOL(__pud_table_size);
  90unsigned long __pgd_table_size;
  91EXPORT_SYMBOL(__pgd_table_size);
  92unsigned long __pmd_val_bits;
  93EXPORT_SYMBOL(__pmd_val_bits);
  94unsigned long __pud_val_bits;
  95EXPORT_SYMBOL(__pud_val_bits);
  96unsigned long __pgd_val_bits;
  97EXPORT_SYMBOL(__pgd_val_bits);
  98unsigned long __kernel_virt_start;
  99EXPORT_SYMBOL(__kernel_virt_start);
 100unsigned long __kernel_virt_size;
 101EXPORT_SYMBOL(__kernel_virt_size);
 102unsigned long __vmalloc_start;
 103EXPORT_SYMBOL(__vmalloc_start);
 104unsigned long __vmalloc_end;
 105EXPORT_SYMBOL(__vmalloc_end);
 106struct page *vmemmap;
 107EXPORT_SYMBOL(vmemmap);
 108unsigned long __pte_frag_nr;
 109EXPORT_SYMBOL(__pte_frag_nr);
 110unsigned long __pte_frag_size_shift;
 111EXPORT_SYMBOL(__pte_frag_size_shift);
 112unsigned long ioremap_bot;
 113#else /* !CONFIG_PPC_BOOK3S_64 */
 114unsigned long ioremap_bot = IOREMAP_BASE;
 115#endif
 116
 117/**
 118 * __ioremap_at - Low level function to establish the page tables
 119 *                for an IO mapping
 120 */
 121void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
 122                            unsigned long flags)
 123{
 124        unsigned long i;
 125
 126        /* Make sure we have the base flags */
 127        if ((flags & _PAGE_PRESENT) == 0)
 128                flags |= pgprot_val(PAGE_KERNEL);
 129
 130        /* We don't support the 4K PFN hack with ioremap */
 131        if (flags & H_PAGE_4K_PFN)
 132                return NULL;
 133
 134        WARN_ON(pa & ~PAGE_MASK);
 135        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 136        WARN_ON(size & ~PAGE_MASK);
 137
 138        for (i = 0; i < size; i += PAGE_SIZE)
 139                if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
 140                        return NULL;
 141
 142        return (void __iomem *)ea;
 143}
 144
 145/**
 146 * __iounmap_from - Low level function to tear down the page tables
 147 *                  for an IO mapping. This is used for mappings that
 148 *                  are manipulated manually, like partial unmapping of
 149 *                  PCI IOs or ISA space.
 150 */
 151void __iounmap_at(void *ea, unsigned long size)
 152{
 153        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 154        WARN_ON(size & ~PAGE_MASK);
 155
 156        unmap_kernel_range((unsigned long)ea, size);
 157}
 158
 159void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
 160                                unsigned long flags, void *caller)
 161{
 162        phys_addr_t paligned;
 163        void __iomem *ret;
 164
 165        /*
 166         * Choose an address to map it to.
 167         * Once the imalloc system is running, we use it.
 168         * Before that, we map using addresses going
 169         * up from ioremap_bot.  imalloc will use
 170         * the addresses from ioremap_bot through
 171         * IMALLOC_END
 172         * 
 173         */
 174        paligned = addr & PAGE_MASK;
 175        size = PAGE_ALIGN(addr + size) - paligned;
 176
 177        if ((size == 0) || (paligned == 0))
 178                return NULL;
 179
 180        if (slab_is_available()) {
 181                struct vm_struct *area;
 182
 183                area = __get_vm_area_caller(size, VM_IOREMAP,
 184                                            ioremap_bot, IOREMAP_END,
 185                                            caller);
 186                if (area == NULL)
 187                        return NULL;
 188
 189                area->phys_addr = paligned;
 190                ret = __ioremap_at(paligned, area->addr, size, flags);
 191                if (!ret)
 192                        vunmap(area->addr);
 193        } else {
 194                ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
 195                if (ret)
 196                        ioremap_bot += size;
 197        }
 198
 199        if (ret)
 200                ret += addr & ~PAGE_MASK;
 201        return ret;
 202}
 203
 204void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
 205                         unsigned long flags)
 206{
 207        return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 208}
 209
 210void __iomem * ioremap(phys_addr_t addr, unsigned long size)
 211{
 212        unsigned long flags = pgprot_val(pgprot_noncached(__pgprot(0)));
 213        void *caller = __builtin_return_address(0);
 214
 215        if (ppc_md.ioremap)
 216                return ppc_md.ioremap(addr, size, flags, caller);
 217        return __ioremap_caller(addr, size, flags, caller);
 218}
 219
 220void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
 221{
 222        unsigned long flags = pgprot_val(pgprot_noncached_wc(__pgprot(0)));
 223        void *caller = __builtin_return_address(0);
 224
 225        if (ppc_md.ioremap)
 226                return ppc_md.ioremap(addr, size, flags, caller);
 227        return __ioremap_caller(addr, size, flags, caller);
 228}
 229
 230void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
 231                             unsigned long flags)
 232{
 233        void *caller = __builtin_return_address(0);
 234
 235        /* writeable implies dirty for kernel addresses */
 236        if (flags & _PAGE_WRITE)
 237                flags |= _PAGE_DIRTY;
 238
 239        /* we don't want to let _PAGE_EXEC leak out */
 240        flags &= ~_PAGE_EXEC;
 241        /*
 242         * Force kernel mapping.
 243         */
 244#if defined(CONFIG_PPC_BOOK3S_64)
 245        flags |= _PAGE_PRIVILEGED;
 246#else
 247        flags &= ~_PAGE_USER;
 248#endif
 249
 250
 251#ifdef _PAGE_BAP_SR
 252        /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
 253         * which means that we just cleared supervisor access... oops ;-) This
 254         * restores it
 255         */
 256        flags |= _PAGE_BAP_SR;
 257#endif
 258
 259        if (ppc_md.ioremap)
 260                return ppc_md.ioremap(addr, size, flags, caller);
 261        return __ioremap_caller(addr, size, flags, caller);
 262}
 263
 264
 265/*  
 266 * Unmap an IO region and remove it from imalloc'd list.
 267 * Access to IO memory should be serialized by driver.
 268 */
 269void __iounmap(volatile void __iomem *token)
 270{
 271        void *addr;
 272
 273        if (!slab_is_available())
 274                return;
 275        
 276        addr = (void *) ((unsigned long __force)
 277                         PCI_FIX_ADDR(token) & PAGE_MASK);
 278        if ((unsigned long)addr < ioremap_bot) {
 279                printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
 280                       " at 0x%p\n", addr);
 281                return;
 282        }
 283        vunmap(addr);
 284}
 285
 286void iounmap(volatile void __iomem *token)
 287{
 288        if (ppc_md.iounmap)
 289                ppc_md.iounmap(token);
 290        else
 291                __iounmap(token);
 292}
 293
 294EXPORT_SYMBOL(ioremap);
 295EXPORT_SYMBOL(ioremap_wc);
 296EXPORT_SYMBOL(ioremap_prot);
 297EXPORT_SYMBOL(__ioremap);
 298EXPORT_SYMBOL(__ioremap_at);
 299EXPORT_SYMBOL(iounmap);
 300EXPORT_SYMBOL(__iounmap);
 301EXPORT_SYMBOL(__iounmap_at);
 302
 303#ifndef __PAGETABLE_PUD_FOLDED
 304/* 4 level page table */
 305struct page *pgd_page(pgd_t pgd)
 306{
 307        if (pgd_huge(pgd))
 308                return pte_page(pgd_pte(pgd));
 309        return virt_to_page(pgd_page_vaddr(pgd));
 310}
 311#endif
 312
 313struct page *pud_page(pud_t pud)
 314{
 315        if (pud_huge(pud))
 316                return pte_page(pud_pte(pud));
 317        return virt_to_page(pud_page_vaddr(pud));
 318}
 319
 320/*
 321 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
 322 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
 323 */
 324struct page *pmd_page(pmd_t pmd)
 325{
 326        if (pmd_trans_huge(pmd) || pmd_huge(pmd))
 327                return pte_page(pmd_pte(pmd));
 328        return virt_to_page(pmd_page_vaddr(pmd));
 329}
 330
 331#ifdef CONFIG_PPC_64K_PAGES
 332static pte_t *get_from_cache(struct mm_struct *mm)
 333{
 334        void *pte_frag, *ret;
 335
 336        spin_lock(&mm->page_table_lock);
 337        ret = mm->context.pte_frag;
 338        if (ret) {
 339                pte_frag = ret + PTE_FRAG_SIZE;
 340                /*
 341                 * If we have taken up all the fragments mark PTE page NULL
 342                 */
 343                if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
 344                        pte_frag = NULL;
 345                mm->context.pte_frag = pte_frag;
 346        }
 347        spin_unlock(&mm->page_table_lock);
 348        return (pte_t *)ret;
 349}
 350
 351static pte_t *__alloc_for_cache(struct mm_struct *mm, int kernel)
 352{
 353        void *ret = NULL;
 354        struct page *page = alloc_page(GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO);
 355        if (!page)
 356                return NULL;
 357        if (!kernel && !pgtable_page_ctor(page)) {
 358                __free_page(page);
 359                return NULL;
 360        }
 361
 362        ret = page_address(page);
 363        spin_lock(&mm->page_table_lock);
 364        /*
 365         * If we find pgtable_page set, we return
 366         * the allocated page with single fragement
 367         * count.
 368         */
 369        if (likely(!mm->context.pte_frag)) {
 370                set_page_count(page, PTE_FRAG_NR);
 371                mm->context.pte_frag = ret + PTE_FRAG_SIZE;
 372        }
 373        spin_unlock(&mm->page_table_lock);
 374
 375        return (pte_t *)ret;
 376}
 377
 378pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
 379{
 380        pte_t *pte;
 381
 382        pte = get_from_cache(mm);
 383        if (pte)
 384                return pte;
 385
 386        return __alloc_for_cache(mm, kernel);
 387}
 388#endif /* CONFIG_PPC_64K_PAGES */
 389
 390void pte_fragment_free(unsigned long *table, int kernel)
 391{
 392        struct page *page = virt_to_page(table);
 393        if (put_page_testzero(page)) {
 394                if (!kernel)
 395                        pgtable_page_dtor(page);
 396                free_hot_cold_page(page, 0);
 397        }
 398}
 399
 400#ifdef CONFIG_SMP
 401void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 402{
 403        unsigned long pgf = (unsigned long)table;
 404
 405        BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 406        pgf |= shift;
 407        tlb_remove_table(tlb, (void *)pgf);
 408}
 409
 410void __tlb_remove_table(void *_table)
 411{
 412        void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
 413        unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
 414
 415        if (!shift)
 416                /* PTE page needs special handling */
 417                pte_fragment_free(table, 0);
 418        else {
 419                BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 420                kmem_cache_free(PGT_CACHE(shift), table);
 421        }
 422}
 423#else
 424void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 425{
 426        if (!shift) {
 427                /* PTE page needs special handling */
 428                pte_fragment_free(table, 0);
 429        } else {
 430                BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 431                kmem_cache_free(PGT_CACHE(shift), table);
 432        }
 433}
 434#endif
 435
 436#ifdef CONFIG_PPC_BOOK3S_64
 437void __init mmu_partition_table_init(void)
 438{
 439        unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
 440        unsigned long ptcr;
 441
 442        BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
 443        partition_tb = __va(memblock_alloc_base(patb_size, patb_size,
 444                                                MEMBLOCK_ALLOC_ANYWHERE));
 445
 446        /* Initialize the Partition Table with no entries */
 447        memset((void *)partition_tb, 0, patb_size);
 448
 449        /*
 450         * update partition table control register,
 451         * 64 K size.
 452         */
 453        ptcr = __pa(partition_tb) | (PATB_SIZE_SHIFT - 12);
 454        mtspr(SPRN_PTCR, ptcr);
 455        powernv_set_nmmu_ptcr(ptcr);
 456}
 457
 458void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
 459                                   unsigned long dw1)
 460{
 461        unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
 462
 463        partition_tb[lpid].patb0 = cpu_to_be64(dw0);
 464        partition_tb[lpid].patb1 = cpu_to_be64(dw1);
 465
 466        /*
 467         * Global flush of TLBs and partition table caches for this lpid.
 468         * The type of flush (hash or radix) depends on what the previous
 469         * use of this partition ID was, not the new use.
 470         */
 471        asm volatile("ptesync" : : : "memory");
 472        if (old & PATB_HR)
 473                asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
 474                             "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
 475        else
 476                asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
 477                             "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
 478        asm volatile("eieio; tlbsync; ptesync" : : : "memory");
 479}
 480EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
 481#endif /* CONFIG_PPC_BOOK3S_64 */
 482