/* * linux/arch/arm/mm/mmu.c * * Copyright (C) 1995-2005 Russell King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mm.h" DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); /* * empty_zero_page is a special page that is used for * zero-initialized data and COW. */ struct page *empty_zero_page; EXPORT_SYMBOL(empty_zero_page); /* * The pmd table for the upper-most set of pages. */ pmd_t *top_pmd; #define CPOLICY_UNCACHED 0 #define CPOLICY_BUFFERED 1 #define CPOLICY_WRITETHROUGH 2 #define CPOLICY_WRITEBACK 3 #define CPOLICY_WRITEALLOC 4 static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK; static unsigned int ecc_mask __initdata = 0; pgprot_t pgprot_user; pgprot_t pgprot_kernel; EXPORT_SYMBOL(pgprot_user); EXPORT_SYMBOL(pgprot_kernel); struct cachepolicy { const char policy[16]; unsigned int cr_mask; unsigned int pmd; unsigned int pte; }; static struct cachepolicy cache_policies[] __initdata = { { .policy = "uncached", .cr_mask = CR_W|CR_C, .pmd = PMD_SECT_UNCACHED, .pte = L_PTE_MT_UNCACHED, }, { .policy = "buffered", .cr_mask = CR_C, .pmd = PMD_SECT_BUFFERED, .pte = L_PTE_MT_BUFFERABLE, }, { .policy = "writethrough", .cr_mask = 0, .pmd = PMD_SECT_WT, .pte = L_PTE_MT_WRITETHROUGH, }, { .policy = "writeback", .cr_mask = 0, .pmd = PMD_SECT_WB, .pte = L_PTE_MT_WRITEBACK, }, { .policy = "writealloc", .cr_mask = 0, .pmd = PMD_SECT_WBWA, .pte = L_PTE_MT_WRITEALLOC, } }; /* * These are useful for identifying cache coherency * problems by allowing the cache or the cache and * writebuffer to be turned off. (Note: the write * buffer should not be on and the cache off). */ static int __init early_cachepolicy(char *p) { int i; for (i = 0; i < ARRAY_SIZE(cache_policies); i++) { int len = strlen(cache_policies[i].policy); if (memcmp(p, cache_policies[i].policy, len) == 0) { cachepolicy = i; cr_alignment &= ~cache_policies[i].cr_mask; cr_no_alignment &= ~cache_policies[i].cr_mask; break; } } if (i == ARRAY_SIZE(cache_policies)) printk(KERN_ERR "ERROR: unknown or unsupported cache policy\n"); /* * This restriction is partly to do with the way we boot; it is * unpredictable to have memory mapped using two different sets of * memory attributes (shared, type, and cache attribs). We can not * change these attributes once the initial assembly has setup the * page tables. */ if (cpu_architecture() >= CPU_ARCH_ARMv6) { printk(KERN_WARNING "Only cachepolicy=writeback supported on ARMv6 and later\n"); cachepolicy = CPOLICY_WRITEBACK; } flush_cache_all(); set_cr(cr_alignment); return 0; } early_param("cachepolicy", early_cachepolicy); static int __init early_nocache(char *__unused) { char *p = "buffered"; printk(KERN_WARNING "nocache is deprecated; use cachepolicy=%s\n", p); early_cachepolicy(p); return 0; } early_param("nocache", early_nocache); static int __init early_nowrite(char *__unused) { char *p = "uncached"; printk(KERN_WARNING "nowb is deprecated; use cachepolicy=%s\n", p); early_cachepolicy(p); return 0; } early_param("nowb", early_nowrite); static int __init early_ecc(char *p) { if (memcmp(p, "on", 2) == 0) ecc_mask = PMD_PROTECTION; else if (memcmp(p, "off", 3) == 0) ecc_mask = 0; return 0; } early_param("ecc", early_ecc); static int __init noalign_setup(char *__unused) { cr_alignment &= ~CR_A; cr_no_alignment &= ~CR_A; set_cr(cr_alignment); return 1; } __setup("noalign", noalign_setup); #ifndef CONFIG_SMP void adjust_cr(unsigned long mask, unsigned long set) { unsigned long flags; mask &= ~CR_A; set &= mask; local_irq_save(flags); cr_no_alignment = (cr_no_alignment & ~mask) | set; cr_alignment = (cr_alignment & ~mask) | set; set_cr((get_cr() & ~mask) | set); local_irq_restore(flags); } #endif #define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_WRITE #define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE static struct mem_type mem_types[] = { [MT_DEVICE] = { /* Strongly ordered / ARMv6 shared device */ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED | L_PTE_SHARED, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PROT_SECT_DEVICE | PMD_SECT_S, .domain = DOMAIN_IO, }, [MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PROT_SECT_DEVICE, .domain = DOMAIN_IO, }, [MT_DEVICE_CACHED] = { /* ioremap_cached */ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PROT_SECT_DEVICE | PMD_SECT_WB, .domain = DOMAIN_IO, }, [MT_DEVICE_WC] = { /* ioremap_wc */ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PROT_SECT_DEVICE, .domain = DOMAIN_IO, }, [MT_UNCACHED] = { .prot_pte = PROT_PTE_DEVICE, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, .domain = DOMAIN_IO, }, [MT_CACHECLEAN] = { .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, .domain = DOMAIN_KERNEL, }, [MT_MINICLEAN] = { .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE, .domain = DOMAIN_KERNEL, }, [MT_LOW_VECTORS] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_EXEC, .prot_l1 = PMD_TYPE_TABLE, .domain = DOMAIN_USER, }, [MT_HIGH_VECTORS] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_USER | L_PTE_EXEC, .prot_l1 = PMD_TYPE_TABLE, .domain = DOMAIN_USER, }, [MT_MEMORY] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_WRITE | L_PTE_EXEC, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE, .domain = DOMAIN_KERNEL, }, [MT_ROM] = { .prot_sect = PMD_TYPE_SECT, .domain = DOMAIN_KERNEL, }, [MT_MEMORY_NONCACHED] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_WRITE | L_PTE_EXEC | L_PTE_MT_BUFFERABLE, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE, .domain = DOMAIN_KERNEL, }, [MT_MEMORY_DTCM] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_WRITE, .prot_l1 = PMD_TYPE_TABLE, .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN, .domain = DOMAIN_KERNEL, }, [MT_MEMORY_ITCM] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_WRITE | L_PTE_EXEC, .prot_l1 = PMD_TYPE_TABLE, .domain = DOMAIN_KERNEL, }, }; const struct mem_type *get_mem_type(unsigned int type) { return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL; } EXPORT_SYMBOL(get_mem_type); /* * Adjust the PMD section entries according to the CPU in use. */ static void __init build_mem_type_table(void) { struct cachepolicy *cp; unsigned int cr = get_cr(); unsigned int user_pgprot, kern_pgprot, vecs_pgprot; int cpu_arch = cpu_architecture(); int i; if (cpu_arch < CPU_ARCH_ARMv6) { #if defined(CONFIG_CPU_DCACHE_DISABLE) if (cachepolicy > CPOLICY_BUFFERED) cachepolicy = CPOLICY_BUFFERED; #elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH) if (cachepolicy > CPOLICY_WRITETHROUGH) cachepolicy = CPOLICY_WRITETHROUGH; #endif } if (cpu_arch < CPU_ARCH_ARMv5) { if (cachepolicy >= CPOLICY_WRITEALLOC) cachepolicy = CPOLICY_WRITEBACK; ecc_mask = 0; } if (is_smp()) cachepolicy = CPOLICY_WRITEALLOC; /* * Strip out features not present on earlier architectures. * Pre-ARMv5 CPUs don't have TEX bits. Pre-ARMv6 CPUs or those * without extended page tables don't have the 'Shared' bit. */ if (cpu_arch < CPU_ARCH_ARMv5) for (i = 0; i < ARRAY_SIZE(mem_types); i++) mem_types[i].prot_sect &= ~PMD_SECT_TEX(7); if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3()) for (i = 0; i < ARRAY_SIZE(mem_types); i++) mem_types[i].prot_sect &= ~PMD_SECT_S; /* * ARMv5 and lower, bit 4 must be set for page tables (was: cache * "update-able on write" bit on ARM610). However, Xscale and * Xscale3 require this bit to be cleared. */ if (cpu_is_xscale() || cpu_is_xsc3()) { for (i = 0; i < ARRAY_SIZE(mem_types); i++) { mem_types[i].prot_sect &= ~PMD_BIT4; mem_types[i].prot_l1 &= ~PMD_BIT4; } } else if (cpu_arch < CPU_ARCH_ARMv6) { for (i = 0; i < ARRAY_SIZE(mem_types); i++) { if (mem_types[i].prot_l1) mem_types[i].prot_l1 |= PMD_BIT4; if (mem_types[i].prot_sect) mem_types[i].prot_sect |= PMD_BIT4; } } /* * Mark the device areas according to the CPU/architecture. */ if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) { if (!cpu_is_xsc3()) { /* * Mark device regions on ARMv6+ as execute-never * to prevent speculative instruction fetches. */ mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN; mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN; mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN; mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN; } if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) { /* * For ARMv7 with TEX remapping, * - shared device is SXCB=1100 * - nonshared device is SXCB=0100 * - write combine device mem is SXCB=0001 * (Uncached Normal memory) */ mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1); mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1); mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE; } else if (cpu_is_xsc3()) { /* * For Xscale3, * - shared device is TEXCB=00101 * - nonshared device is TEXCB=01000 * - write combine device mem is TEXCB=00100 * (Inner/Outer Uncacheable in xsc3 parlance) */ mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED; mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2); mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1); } else { /* * For ARMv6 and ARMv7 without TEX remapping, * - shared device is TEXCB=00001 * - nonshared device is TEXCB=01000 * - write combine device mem is TEXCB=00100 * (Uncached Normal in ARMv6 parlance). */ mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED; mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2); mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1); } } else { /* * On others, write combining is "Uncached/Buffered" */ mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE; } /* * Now deal with the memory-type mappings */ cp = &cache_policies[cachepolicy]; vecs_pgprot = kern_pgprot = user_pgprot = cp->pte; /* * Only use write-through for non-SMP systems */ if (!is_smp() && cpu_arch >= CPU_ARCH_ARMv5 && cachepolicy > CPOLICY_WRITETHROUGH) vecs_pgprot = cache_policies[CPOLICY_WRITETHROUGH].pte; /* * Enable CPU-specific coherency if supported. * (Only available on XSC3 at the moment.) */ if (arch_is_coherent() && cpu_is_xsc3()) { mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S; mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED; mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S; mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED; } /* * ARMv6 and above have extended page tables. */ if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) { /* * Mark cache clean areas and XIP ROM read only * from SVC mode and no access from userspace. */ mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE; if (is_smp()) { /* * Mark memory with the "shared" attribute * for SMP systems */ user_pgprot |= L_PTE_SHARED; kern_pgprot |= L_PTE_SHARED; vecs_pgprot |= L_PTE_SHARED; mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S; mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED; mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S; mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED; mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S; mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED; mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S; mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED; } } /* * Non-cacheable Normal - intended for memory areas that must * not cause dirty cache line writebacks when used */ if (cpu_arch >= CPU_ARCH_ARMv6) { if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) { /* Non-cacheable Normal is XCB = 001 */ mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERED; } else { /* For both ARMv6 and non-TEX-remapping ARMv7 */ mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_TEX(1); } } else { mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE; } for (i = 0; i < 16; i++) { unsigned long v = pgprot_val(protection_map[i]); protection_map[i] = __pgprot(v | user_pgprot); } mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot; mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot; pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot); pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_WRITE | kern_pgprot); mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask; mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask; mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd; mem_types[MT_MEMORY].prot_pte |= kern_pgprot; mem_types[MT_MEMORY_NONCACHED].prot_sect |= ecc_mask; mem_types[MT_ROM].prot_sect |= cp->pmd; switch (cp->pmd) { case PMD_SECT_WT: mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT; break; case PMD_SECT_WB: case PMD_SECT_WBWA: mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB; break; } printk("Memory policy: ECC %sabled, Data cache %s\n", ecc_mask ? "en" : "dis", cp->policy); for (i = 0; i < ARRAY_SIZE(mem_types); i++) { struct mem_type *t = &mem_types[i]; if (t->prot_l1) t->prot_l1 |= PMD_DOMAIN(t->domain); if (t->prot_sect) t->prot_sect |= PMD_DOMAIN(t->domain); } } #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot) { if (!pfn_valid(pfn)) return pgprot_noncached(vma_prot); else if (file->f_flags & O_SYNC) return pgprot_writecombine(vma_prot); return vma_prot; } EXPORT_SYMBOL(phys_mem_access_prot); #endif #define vectors_base() (vectors_high() ? 0xffff0000 : 0) static void __init *early_alloc(unsigned long sz) { void *ptr = __va(memblock_alloc(sz, sz)); memset(ptr, 0, sz); return ptr; } static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot) { if (pmd_none(*pmd)) { pte_t *pte = early_alloc(2 * PTRS_PER_PTE * sizeof(pte_t)); __pmd_populate(pmd, __pa(pte), prot); } BUG_ON(pmd_bad(*pmd)); return pte_offset_kernel(pmd, addr); } static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, unsigned long end, unsigned long pfn, const struct mem_type *type) { pte_t *pte = early_pte_alloc(pmd, addr, type->prot_l1); do { set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0); pfn++; } while (pte++, addr += PAGE_SIZE, addr != end); } static void __init alloc_init_section(pgd_t *pgd, unsigned long addr, unsigned long end, phys_addr_t phys, const struct mem_type *type) { pmd_t *pmd = pmd_offset(pgd, addr); /* * Try a section mapping - end, addr and phys must all be aligned * to a section boundary. Note that PMDs refer to the individual * L1 entries, whereas PGDs refer to a group of L1 entries making * up one logical pointer to an L2 table. */ if (((addr | end | phys) & ~SECTION_MASK) == 0) { pmd_t *p = pmd; if (addr & SECTION_SIZE) pmd++; do { *pmd = __pmd(phys | type->prot_sect); phys += SECTION_SIZE; } while (pmd++, addr += SECTION_SIZE, addr != end); flush_pmd_entry(p); } else { /* * No need to loop; pte's aren't interested in the * individual L1 entries. */ alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type); } } static void __init create_36bit_mapping(struct map_desc *md, const struct mem_type *type) { unsigned long addr, length, end; phys_addr_t phys; pgd_t *pgd; addr = md->virtual; phys = (unsigned long)__pfn_to_phys(md->pfn); length = PAGE_ALIGN(md->length); if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) { printk(KERN_ERR "MM: CPU does not support supersection " "mapping for 0x%08llx at 0x%08lx\n", __pfn_to_phys((u64)md->pfn), addr); return; } /* N.B. ARMv6 supersections are only defined to work with domain 0. * Since domain assignments can in fact be arbitrary, the * 'domain == 0' check below is required to insure that ARMv6 * supersections are only allocated for domain 0 regardless * of the actual domain assignments in use. */ if (type->domain) { printk(KERN_ERR "MM: invalid domain in supersection " "mapping for 0x%08llx at 0x%08lx\n", __pfn_to_phys((u64)md->pfn), addr); return; } if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) { printk(KERN_ERR "MM: cannot create mapping for " "0x%08llx at 0x%08lx invalid alignment\n", __pfn_to_phys((u64)md->pfn), addr); return; } /* * Shift bits [35:32] of address into bits [23:20] of PMD * (See ARMv6 spec). */ phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20); pgd = pgd_offset_k(addr); end = addr + length; do { pmd_t *pmd = pmd_offset(pgd, addr); int i; for (i = 0; i < 16; i++) *pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER); addr += SUPERSECTION_SIZE; phys += SUPERSECTION_SIZE; pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT; } while (addr != end); } /* * Create the page directory entries and any necessary * page tables for the mapping specified by `md'. We * are able to cope here with varying sizes and address * offsets, and we take full advantage of sections and * supersections. */ static void __init create_mapping(struct map_desc *md) { unsigned long phys, addr, length, end; const struct mem_type *type; pgd_t *pgd; if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) { printk(KERN_WARNING "BUG: not creating mapping for " "0x%08llx at 0x%08lx in user region\n", __pfn_to_phys((u64)md->pfn), md->virtual); return; } if ((md->type == MT_DEVICE || md->type == MT_ROM) && md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) { printk(KERN_WARNING "BUG: mapping for 0x%08llx at 0x%08lx " "overlaps vmalloc space\n", __pfn_to_phys((u64)md->pfn), md->virtual); } type = &mem_types[md->type]; /* * Catch 36-bit addresses */ if (md->pfn >= 0x100000) { create_36bit_mapping(md, type); return; } addr = md->virtual & PAGE_MASK; phys = (unsigned long)__pfn_to_phys(md->pfn); length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK)); if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) { printk(KERN_WARNING "BUG: map for 0x%08lx at 0x%08lx can not " "be mapped using pages, ignoring.\n", __pfn_to_phys(md->pfn), addr); return; } pgd = pgd_offset_k(addr); end = addr + length; do { unsigned long next = pgd_addr_end(addr, end); alloc_init_section(pgd, addr, next, phys, type); phys += next - addr; addr = next; } while (pgd++, addr != end); } /* * Create the architecture specific mappings */ void __init iotable_init(struct map_desc *io_desc, int nr) { int i; for (i = 0; i < nr; i++) create_mapping(io_desc + i); } static void * __initdata vmalloc_min = (void *)(VMALLOC_END - SZ_128M); /* * vmalloc=size forces the vmalloc area to be exactly 'size' * bytes. This can be used to increase (or decrease) the vmalloc * area - the default is 128m. */ static int __init early_vmalloc(char *arg) { unsigned long vmalloc_reserve = memparse(arg, NULL); if (vmalloc_reserve < SZ_16M) { vmalloc_reserve = SZ_16M; printk(KERN_WARNING "vmalloc area too small, limiting to %luMB\n", vmalloc_reserve >> 20); } if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) { vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M); printk(KERN_WARNING "vmalloc area is too big, limiting to %luMB\n", vmalloc_reserve >> 20); } vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve); return 0; } early_param("vmalloc", early_vmalloc); static phys_addr_t lowmem_limit __initdata = 0; static void __init sanity_check_meminfo(void) { int i, j, highmem = 0; lowmem_limit = __pa(vmalloc_min - 1) + 1; memblock_set_current_limit(lowmem_limit); for (i = 0, j = 0; i < meminfo.nr_banks; i++) { struct membank *bank = &meminfo.bank[j]; *bank = meminfo.bank[i]; #ifdef CONFIG_HIGHMEM if (__va(bank->start) > vmalloc_min || __va(bank->start) < (void *)PAGE_OFFSET) highmem = 1; bank->highmem = highmem; /* * Split those memory banks which are partially overlapping * the vmalloc area greatly simplifying things later. */ if (__va(bank->start) < vmalloc_min && bank->size > vmalloc_min - __va(bank->start)) { if (meminfo.nr_banks >= NR_BANKS) { printk(KERN_CRIT "NR_BANKS too low, " "ignoring high memory\n"); } else { memmove(bank + 1, bank, (meminfo.nr_banks - i) * sizeof(*bank)); meminfo.nr_banks++; i++; bank[1].size -= vmalloc_min - __va(bank->start); bank[1].start = __pa(vmalloc_min - 1) + 1; bank[1].highmem = highmem = 1; j++; } bank->size = vmalloc_min - __va(bank->start); } #else bank->highmem = highmem; /* * Check whether this memory bank would entirely overlap * the vmalloc area. */ if (__va(bank->start) >= vmalloc_min || __va(bank->start) < (void *)PAGE_OFFSET) { printk(KERN_NOTICE "Ignoring RAM at %.8lx-%.8lx " "(vmalloc region overlap).\n", bank->start, bank->start + bank->size - 1); continue; } /* * Check whether this memory bank would partially overlap * the vmalloc area. */ if (__va(bank->start + bank->size) > vmalloc_min || __va(bank->start + bank->size) < __va(bank->start)) { unsigned long newsize = vmalloc_min - __va(bank->start); printk(KERN_NOTICE "Truncating RAM at %.8lx-%.8lx " "to -%.8lx (vmalloc region overlap).\n", bank->start, bank->start + bank->size - 1, bank->start + newsize - 1); bank->size = newsize; } #endif j++; } #ifdef CONFIG_HIGHMEM if (highmem) { const char *reason = NULL; if (cache_is_vipt_aliasing()) { /* * Interactions between kmap and other mappings * make highmem support with aliasing VIPT caches * rather difficult. */ reason = "with VIPT aliasing cache"; } else if (is_smp() && tlb_ops_need_broadcast()) { /* * kmap_high needs to occasionally flush TLB entries, * however, if the TLB entries need to be broadcast * we may deadlock: * kmap_high(irqs off)->flush_all_zero_pkmaps-> * flush_tlb_kernel_range->smp_call_function_many * (must not be called with irqs off) */ reason = "without hardware TLB ops broadcasting"; } if (reason) { printk(KERN_CRIT "HIGHMEM is not supported %s, ignoring high memory\n", reason); while (j > 0 && meminfo.bank[j - 1].highmem) j--; } } #endif meminfo.nr_banks = j; } static inline void prepare_page_table(void) { unsigned long addr; phys_addr_t end; /* * Clear out all the mappings below the kernel image. */ for (addr = 0; addr < MODULES_VADDR; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); #ifdef CONFIG_XIP_KERNEL /* The XIP kernel is mapped in the module area -- skip over it */ addr = ((unsigned long)_etext + PGDIR_SIZE - 1) & PGDIR_MASK; #endif for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); /* * Find the end of the first block of lowmem. */ end = memblock.memory.regions[0].base + memblock.memory.regions[0].size; if (end >= lowmem_limit) end = lowmem_limit; /* * Clear out all the kernel space mappings, except for the first * memory bank, up to the end of the vmalloc region. */ for (addr = __phys_to_virt(end); addr < VMALLOC_END; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); } /* * Reserve the special regions of memory */ void __init arm_mm_memblock_reserve(void) { /* * Reserve the page tables. These are already in use, * and can only be in node 0. */ memblock_reserve(__pa(swapper_pg_dir), PTRS_PER_PGD * sizeof(pgd_t)); #ifdef CONFIG_SA1111 /* * Because of the SA1111 DMA bug, we want to preserve our * precious DMA-able memory... */ memblock_reserve(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET); #endif } /* * Set up device the mappings. Since we clear out the page tables for all * mappings above VMALLOC_END, we will remove any debug device mappings. * This means you have to be careful how you debug this function, or any * called function. This means you can't use any function or debugging * method which may touch any device, otherwise the kernel _will_ crash. */ static void __init devicemaps_init(struct machine_desc *mdesc) { struct map_desc map; unsigned long addr; void *vectors; /* * Allocate the vector page early. */ vectors = early_alloc(PAGE_SIZE); for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); /* * Map the kernel if it is XIP. * It is always first in the modulearea. */ #ifdef CONFIG_XIP_KERNEL map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK); map.virtual = MODULES_VADDR; map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK; map.type = MT_ROM; create_mapping(&map); #endif /* * Map the cache flushing regions. */ #ifdef FLUSH_BASE map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS); map.virtual = FLUSH_BASE; map.length = SZ_1M; map.type = MT_CACHECLEAN; create_mapping(&map); #endif #ifdef FLUSH_BASE_MINICACHE map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M); map.virtual = FLUSH_BASE_MINICACHE; map.length = SZ_1M; map.type = MT_MINICLEAN; create_mapping(&map); #endif /* * Create a mapping for the machine vectors at the high-vectors * location (0xffff0000). If we aren't using high-vectors, also * create a mapping at the low-vectors virtual address. */ map.pfn = __phys_to_pfn(virt_to_phys(vectors)); map.virtual = 0xffff0000; map.length = PAGE_SIZE; map.type = MT_HIGH_VECTORS; create_mapping(&map); if (!vectors_high()) { map.virtual = 0; map.type = MT_LOW_VECTORS; create_mapping(&map); } /* * Ask the machine support to map in the statically mapped devices. */ if (mdesc->map_io) mdesc->map_io(); /* * Finally flush the caches and tlb to ensure that we're in a * consistent state wrt the writebuffer. This also ensures that * any write-allocated cache lines in the vector page are written * back. After this point, we can start to touch devices again. */ local_flush_tlb_all(); flush_cache_all(); } static void __init kmap_init(void) { #ifdef CONFIG_HIGHMEM pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE), PKMAP_BASE, _PAGE_KERNEL_TABLE); #endif } static void __init map_lowmem(void) { struct memblock_region *reg; /* Map all the lowmem memory banks. */ for_each_memblock(memory, reg) { phys_addr_t start = reg->base; phys_addr_t end = start + reg->size; struct map_desc map; if (end > lowmem_limit) end = lowmem_limit; if (start >= end) break; map.pfn = __phys_to_pfn(start); map.virtual = __phys_to_virt(start); map.length = end - start; map.type = MT_MEMORY; create_mapping(&map); } } /* * paging_init() sets up the page tables, initialises the zone memory * maps, and sets up the zero page, bad page and bad page tables. */ void __init paging_init(struct machine_desc *mdesc) { void *zero_page; build_mem_type_table(); sanity_check_meminfo(); prepare_page_table(); map_lowmem(); devicemaps_init(mdesc); kmap_init(); top_pmd = pmd_off_k(0xffff0000); /* allocate the zero page. */ zero_page = early_alloc(PAGE_SIZE); bootmem_init(); empty_zero_page = virt_to_page(zero_page); __flush_dcache_page(NULL, empty_zero_page); } /* * In order to soft-boot, we need to insert a 1:1 mapping in place of * the user-mode pages. This will then ensure that we have predictable * results when turning the mmu off */ void setup_mm_for_reboot(char mode) { unsigned long base_pmdval; pgd_t *pgd; int i; /* * We need to access to user-mode page tables here. For kernel threads * we don't have any user-mode mappings so we use the context that we * "borrowed". */ pgd = current->active_mm->pgd; base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT; if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) base_pmdval |= PMD_BIT4; for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) { unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval; pmd_t *pmd; pmd = pmd_off(pgd, i << PGDIR_SHIFT); pmd[0] = __pmd(pmdval); pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1))); flush_pmd_entry(pmd); } local_flush_tlb_all(); }