diff options
Diffstat (limited to 'arch/arm64/mm/mmu.c')
-rw-r--r-- | arch/arm64/mm/mmu.c | 455 |
1 files changed, 308 insertions, 147 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index f4f8b500f74c..6147b780f805 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -26,8 +26,11 @@ #include <linux/memblock.h> #include <linux/fs.h> #include <linux/io.h> +#include <linux/slab.h> +#include <linux/stop_machine.h> #include <asm/cputype.h> +#include <asm/fixmap.h> #include <asm/sections.h> #include <asm/setup.h> #include <asm/sizes.h> @@ -37,87 +40,15 @@ #include "mm.h" +u64 idmap_t0sz = TCR_T0SZ(VA_BITS); + /* * Empty_zero_page is a special page that is used for zero-initialized data * and COW. */ -struct page *empty_zero_page; +unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; EXPORT_SYMBOL(empty_zero_page); -struct cachepolicy { - const char policy[16]; - u64 mair; - u64 tcr; -}; - -static struct cachepolicy cache_policies[] __initdata = { - { - .policy = "uncached", - .mair = 0x44, /* inner, outer non-cacheable */ - .tcr = TCR_IRGN_NC | TCR_ORGN_NC, - }, { - .policy = "writethrough", - .mair = 0xaa, /* inner, outer write-through, read-allocate */ - .tcr = TCR_IRGN_WT | TCR_ORGN_WT, - }, { - .policy = "writeback", - .mair = 0xee, /* inner, outer write-back, read-allocate */ - .tcr = TCR_IRGN_WBnWA | TCR_ORGN_WBnWA, - } -}; - -/* - * These are useful for identifying cache coherency problems by allowing the - * cache or the cache and writebuffer to be turned off. It changes the Normal - * memory caching attributes in the MAIR_EL1 register. - */ -static int __init early_cachepolicy(char *p) -{ - int i; - u64 tmp; - - 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) - break; - } - if (i == ARRAY_SIZE(cache_policies)) { - pr_err("ERROR: unknown or unsupported cache policy: %s\n", p); - return 0; - } - - flush_cache_all(); - - /* - * Modify MT_NORMAL attributes in MAIR_EL1. - */ - asm volatile( - " mrs %0, mair_el1\n" - " bfi %0, %1, %2, #8\n" - " msr mair_el1, %0\n" - " isb\n" - : "=&r" (tmp) - : "r" (cache_policies[i].mair), "i" (MT_NORMAL * 8)); - - /* - * Modify TCR PTW cacheability attributes. - */ - asm volatile( - " mrs %0, tcr_el1\n" - " bic %0, %0, %2\n" - " orr %0, %0, %1\n" - " msr tcr_el1, %0\n" - " isb\n" - : "=&r" (tmp) - : "r" (cache_policies[i].tcr), "r" (TCR_IRGN_MASK | TCR_ORGN_MASK)); - - flush_cache_all(); - - return 0; -} -early_param("cachepolicy", early_cachepolicy); - pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot) { @@ -132,21 +63,43 @@ EXPORT_SYMBOL(phys_mem_access_prot); static void __init *early_alloc(unsigned long sz) { void *ptr = __va(memblock_alloc(sz, sz)); + BUG_ON(!ptr); memset(ptr, 0, sz); return ptr; } -static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, +/* + * remap a PMD into pages + */ +static void split_pmd(pmd_t *pmd, pte_t *pte) +{ + unsigned long pfn = pmd_pfn(*pmd); + int i = 0; + + do { + /* + * Need to have the least restrictive permissions available + * permissions will be fixed up later + */ + set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); + pfn++; + } while (pte++, i++, i < PTRS_PER_PTE); +} + +static void alloc_init_pte(pmd_t *pmd, unsigned long addr, unsigned long end, unsigned long pfn, - pgprot_t prot) + pgprot_t prot, + void *(*alloc)(unsigned long size)) { pte_t *pte; - if (pmd_none(*pmd)) { - pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t)); + if (pmd_none(*pmd) || pmd_bad(*pmd)) { + pte = alloc(PTRS_PER_PTE * sizeof(pte_t)); + if (pmd_sect(*pmd)) + split_pmd(pmd, pte); __pmd_populate(pmd, __pa(pte), PMD_TYPE_TABLE); + flush_tlb_all(); } - BUG_ON(pmd_bad(*pmd)); pte = pte_offset_kernel(pmd, addr); do { @@ -155,29 +108,40 @@ static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, } while (pte++, addr += PAGE_SIZE, addr != end); } -static void __init alloc_init_pmd(pud_t *pud, unsigned long addr, - unsigned long end, phys_addr_t phys, - int map_io) +void split_pud(pud_t *old_pud, pmd_t *pmd) +{ + unsigned long addr = pud_pfn(*old_pud) << PAGE_SHIFT; + pgprot_t prot = __pgprot(pud_val(*old_pud) ^ addr); + int i = 0; + + do { + set_pmd(pmd, __pmd(addr | prot)); + addr += PMD_SIZE; + } while (pmd++, i++, i < PTRS_PER_PMD); +} + +static void alloc_init_pmd(struct mm_struct *mm, pud_t *pud, + unsigned long addr, unsigned long end, + phys_addr_t phys, pgprot_t prot, + void *(*alloc)(unsigned long size)) { pmd_t *pmd; unsigned long next; - pmdval_t prot_sect; - pgprot_t prot_pte; - - if (map_io) { - prot_sect = PROT_SECT_DEVICE_nGnRE; - prot_pte = __pgprot(PROT_DEVICE_nGnRE); - } else { - prot_sect = PROT_SECT_NORMAL_EXEC; - prot_pte = PAGE_KERNEL_EXEC; - } /* * Check for initial section mappings in the pgd/pud and remove them. */ if (pud_none(*pud) || pud_bad(*pud)) { - pmd = early_alloc(PTRS_PER_PMD * sizeof(pmd_t)); - pud_populate(&init_mm, pud, pmd); + pmd = alloc(PTRS_PER_PMD * sizeof(pmd_t)); + if (pud_sect(*pud)) { + /* + * need to have the 1G of mappings continue to be + * present + */ + split_pud(pud, pmd); + } + pud_populate(mm, pud, pmd); + flush_tlb_all(); } pmd = pmd_offset(pud, addr); @@ -186,31 +150,51 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr, /* try section mapping first */ if (((addr | next | phys) & ~SECTION_MASK) == 0) { pmd_t old_pmd =*pmd; - set_pmd(pmd, __pmd(phys | prot_sect)); + set_pmd(pmd, __pmd(phys | + pgprot_val(mk_sect_prot(prot)))); /* * Check for previous table entries created during * boot (__create_page_tables) and flush them. */ - if (!pmd_none(old_pmd)) + if (!pmd_none(old_pmd)) { flush_tlb_all(); + if (pmd_table(old_pmd)) { + phys_addr_t table = __pa(pte_offset_map(&old_pmd, 0)); + if (!WARN_ON_ONCE(slab_is_available())) + memblock_free(table, PAGE_SIZE); + } + } } else { alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys), - prot_pte); + prot, alloc); } phys += next - addr; } while (pmd++, addr = next, addr != end); } -static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, - unsigned long end, phys_addr_t phys, - int map_io) +static inline bool use_1G_block(unsigned long addr, unsigned long next, + unsigned long phys) +{ + if (PAGE_SHIFT != 12) + return false; + + if (((addr | next | phys) & ~PUD_MASK) != 0) + return false; + + return true; +} + +static void alloc_init_pud(struct mm_struct *mm, pgd_t *pgd, + unsigned long addr, unsigned long end, + phys_addr_t phys, pgprot_t prot, + void *(*alloc)(unsigned long size)) { pud_t *pud; unsigned long next; if (pgd_none(*pgd)) { - pud = early_alloc(PTRS_PER_PUD * sizeof(pud_t)); - pgd_populate(&init_mm, pgd, pud); + pud = alloc(PTRS_PER_PUD * sizeof(pud_t)); + pgd_populate(mm, pgd, pud); } BUG_ON(pgd_bad(*pgd)); @@ -221,10 +205,10 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, /* * For 4K granule only, attempt to put down a 1GB block */ - if (!map_io && (PAGE_SHIFT == 12) && - ((addr | next | phys) & ~PUD_MASK) == 0) { + if (use_1G_block(addr, next, phys)) { pud_t old_pud = *pud; - set_pud(pud, __pud(phys | PROT_SECT_NORMAL_EXEC)); + set_pud(pud, __pud(phys | + pgprot_val(mk_sect_prot(prot)))); /* * If we have an old value for a pud, it will @@ -234,12 +218,15 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, * Look up the old pmd table and free it. */ if (!pud_none(old_pud)) { - phys_addr_t table = __pa(pmd_offset(&old_pud, 0)); - memblock_free(table, PAGE_SIZE); flush_tlb_all(); + if (pud_table(old_pud)) { + phys_addr_t table = __pa(pmd_offset(&old_pud, 0)); + if (!WARN_ON_ONCE(slab_is_available())) + memblock_free(table, PAGE_SIZE); + } } } else { - alloc_init_pmd(pud, addr, next, phys, map_io); + alloc_init_pmd(mm, pud, addr, next, phys, prot, alloc); } phys += next - addr; } while (pud++, addr = next, addr != end); @@ -249,9 +236,10 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, * Create the page directory entries and any necessary page tables for the * mapping specified by 'md'. */ -static void __init __create_mapping(pgd_t *pgd, phys_addr_t phys, - unsigned long virt, phys_addr_t size, - int map_io) +static void __create_mapping(struct mm_struct *mm, pgd_t *pgd, + phys_addr_t phys, unsigned long virt, + phys_addr_t size, pgprot_t prot, + void *(*alloc)(unsigned long size)) { unsigned long addr, length, end, next; @@ -261,31 +249,94 @@ static void __init __create_mapping(pgd_t *pgd, phys_addr_t phys, end = addr + length; do { next = pgd_addr_end(addr, end); - alloc_init_pud(pgd, addr, next, phys, map_io); + alloc_init_pud(mm, pgd, addr, next, phys, prot, alloc); phys += next - addr; } while (pgd++, addr = next, addr != end); } -static void __init create_mapping(phys_addr_t phys, unsigned long virt, - phys_addr_t size) +static void *late_alloc(unsigned long size) +{ + void *ptr; + + BUG_ON(size > PAGE_SIZE); + ptr = (void *)__get_free_page(PGALLOC_GFP); + BUG_ON(!ptr); + return ptr; +} + +static void __ref create_mapping(phys_addr_t phys, unsigned long virt, + phys_addr_t size, pgprot_t prot) { if (virt < VMALLOC_START) { pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", &phys, virt); return; } - __create_mapping(pgd_offset_k(virt & PAGE_MASK), phys, virt, size, 0); + __create_mapping(&init_mm, pgd_offset_k(virt & PAGE_MASK), phys, virt, + size, prot, early_alloc); +} + +void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, + unsigned long virt, phys_addr_t size, + pgprot_t prot) +{ + __create_mapping(mm, pgd_offset(mm, virt), phys, virt, size, prot, + late_alloc); } -void __init create_id_mapping(phys_addr_t addr, phys_addr_t size, int map_io) +static void create_mapping_late(phys_addr_t phys, unsigned long virt, + phys_addr_t size, pgprot_t prot) { - if ((addr >> PGDIR_SHIFT) >= ARRAY_SIZE(idmap_pg_dir)) { - pr_warn("BUG: not creating id mapping for %pa\n", &addr); + if (virt < VMALLOC_START) { + pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", + &phys, virt); return; } - __create_mapping(&idmap_pg_dir[pgd_index(addr)], - addr, addr, size, map_io); + + return __create_mapping(&init_mm, pgd_offset_k(virt & PAGE_MASK), + phys, virt, size, prot, late_alloc); +} + +#ifdef CONFIG_DEBUG_RODATA +static void __init __map_memblock(phys_addr_t start, phys_addr_t end) +{ + /* + * Set up the executable regions using the existing section mappings + * for now. This will get more fine grained later once all memory + * is mapped + */ + unsigned long kernel_x_start = round_down(__pa(_stext), SECTION_SIZE); + unsigned long kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE); + + if (end < kernel_x_start) { + create_mapping(start, __phys_to_virt(start), + end - start, PAGE_KERNEL); + } else if (start >= kernel_x_end) { + create_mapping(start, __phys_to_virt(start), + end - start, PAGE_KERNEL); + } else { + if (start < kernel_x_start) + create_mapping(start, __phys_to_virt(start), + kernel_x_start - start, + PAGE_KERNEL); + create_mapping(kernel_x_start, + __phys_to_virt(kernel_x_start), + kernel_x_end - kernel_x_start, + PAGE_KERNEL_EXEC); + if (kernel_x_end < end) + create_mapping(kernel_x_end, + __phys_to_virt(kernel_x_end), + end - kernel_x_end, + PAGE_KERNEL); + } +} +#else +static void __init __map_memblock(phys_addr_t start, phys_addr_t end) +{ + create_mapping(start, __phys_to_virt(start), end - start, + PAGE_KERNEL_EXEC); } +#endif static void __init map_mem(void) { @@ -331,53 +382,70 @@ static void __init map_mem(void) memblock_set_current_limit(limit); } #endif - - create_mapping(start, __phys_to_virt(start), end - start); + __map_memblock(start, end); } /* Limit no longer required. */ memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); } +void __init fixup_executable(void) +{ +#ifdef CONFIG_DEBUG_RODATA + /* now that we are actually fully mapped, make the start/end more fine grained */ + if (!IS_ALIGNED((unsigned long)_stext, SECTION_SIZE)) { + unsigned long aligned_start = round_down(__pa(_stext), + SECTION_SIZE); + + create_mapping(aligned_start, __phys_to_virt(aligned_start), + __pa(_stext) - aligned_start, + PAGE_KERNEL); + } + + if (!IS_ALIGNED((unsigned long)__init_end, SECTION_SIZE)) { + unsigned long aligned_end = round_up(__pa(__init_end), + SECTION_SIZE); + create_mapping(__pa(__init_end), (unsigned long)__init_end, + aligned_end - __pa(__init_end), + PAGE_KERNEL); + } +#endif +} + +#ifdef CONFIG_DEBUG_RODATA +void mark_rodata_ro(void) +{ + create_mapping_late(__pa(_stext), (unsigned long)_stext, + (unsigned long)__init_begin - (unsigned long)_stext, + PAGE_KERNEL_EXEC | PTE_RDONLY); +} +#endif + +void fixup_init(void) +{ + create_mapping_late(__pa(__init_begin), (unsigned long)__init_begin, + (unsigned long)__init_end - (unsigned long)__init_begin, + PAGE_KERNEL); +} + /* * paging_init() sets up the page tables, initialises the zone memory * maps and sets up the zero page. */ void __init paging_init(void) { - void *zero_page; - map_mem(); - - /* - * Finally flush the caches and tlb to ensure that we're in a - * consistent state. - */ - flush_cache_all(); - flush_tlb_all(); - - /* allocate the zero page. */ - zero_page = early_alloc(PAGE_SIZE); + fixup_executable(); bootmem_init(); - empty_zero_page = virt_to_page(zero_page); - /* * TTBR0 is only used for the identity mapping at this stage. Make it * point to zero page to avoid speculatively fetching new entries. */ cpu_set_reserved_ttbr0(); - flush_tlb_all(); -} - -/* - * Enable the identity mapping to allow the MMU disabling. - */ -void setup_mm_for_reboot(void) -{ - cpu_switch_mm(idmap_pg_dir, &init_mm); - flush_tlb_all(); + local_flush_tlb_all(); + cpu_set_default_tcr_t0sz(); } /* @@ -463,3 +531,96 @@ void vmemmap_free(unsigned long start, unsigned long end) { } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ + +static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss; +#if CONFIG_PGTABLE_LEVELS > 2 +static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss; +#endif +#if CONFIG_PGTABLE_LEVELS > 3 +static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss; +#endif + +static inline pud_t * fixmap_pud(unsigned long addr) +{ + pgd_t *pgd = pgd_offset_k(addr); + + BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd)); + + return pud_offset(pgd, addr); +} + +static inline pmd_t * fixmap_pmd(unsigned long addr) +{ + pud_t *pud = fixmap_pud(addr); + + BUG_ON(pud_none(*pud) || pud_bad(*pud)); + + return pmd_offset(pud, addr); +} + +static inline pte_t * fixmap_pte(unsigned long addr) +{ + pmd_t *pmd = fixmap_pmd(addr); + + BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd)); + + return pte_offset_kernel(pmd, addr); +} + +void __init early_fixmap_init(void) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + unsigned long addr = FIXADDR_START; + + pgd = pgd_offset_k(addr); + pgd_populate(&init_mm, pgd, bm_pud); + pud = pud_offset(pgd, addr); + pud_populate(&init_mm, pud, bm_pmd); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, bm_pte); + + /* + * The boot-ioremap range spans multiple pmds, for which + * we are not preparted: + */ + BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) + != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); + + if ((pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN))) + || pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) { + WARN_ON(1); + pr_warn("pmd %p != %p, %p\n", + pmd, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)), + fixmap_pmd(fix_to_virt(FIX_BTMAP_END))); + pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", + fix_to_virt(FIX_BTMAP_BEGIN)); + pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", + fix_to_virt(FIX_BTMAP_END)); + + pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); + pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); + } +} + +void __set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t flags) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *pte; + + if (idx >= __end_of_fixed_addresses) { + BUG(); + return; + } + + pte = fixmap_pte(addr); + + if (pgprot_val(flags)) { + set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); + } else { + pte_clear(&init_mm, addr, pte); + flush_tlb_kernel_range(addr, addr+PAGE_SIZE); + } +} |