| /* |
| * Based on arch/arm/mm/mmu.c |
| * |
| * Copyright (C) 1995-2005 Russell King |
| * Copyright (C) 2012 ARM Ltd. |
| * |
| * 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. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <linux/export.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/init.h> |
| #include <linux/mman.h> |
| #include <linux/nodemask.h> |
| #include <linux/memblock.h> |
| #include <linux/fs.h> |
| #include <linux/io.h> |
| |
| #include <asm/cputype.h> |
| #include <asm/sections.h> |
| #include <asm/setup.h> |
| #include <asm/sizes.h> |
| #include <asm/tlb.h> |
| #include <asm/mmu_context.h> |
| |
| #include "mm.h" |
| |
| /* |
| * 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); |
| |
| pgprot_t pgprot_default; |
| EXPORT_SYMBOL(pgprot_default); |
| |
| static pmdval_t prot_sect_kernel; |
| |
| 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); |
| |
| /* |
| * Adjust the PMD section entries according to the CPU in use. |
| */ |
| static void __init init_mem_pgprot(void) |
| { |
| pteval_t default_pgprot; |
| int i; |
| |
| default_pgprot = PTE_ATTRINDX(MT_NORMAL); |
| prot_sect_kernel = PMD_TYPE_SECT | PMD_SECT_AF | PMD_ATTRINDX(MT_NORMAL); |
| |
| #ifdef CONFIG_SMP |
| /* |
| * Mark memory with the "shared" attribute for SMP systems |
| */ |
| default_pgprot |= PTE_SHARED; |
| prot_sect_kernel |= PMD_SECT_S; |
| #endif |
| |
| for (i = 0; i < 16; i++) { |
| unsigned long v = pgprot_val(protection_map[i]); |
| protection_map[i] = __pgprot(v | default_pgprot); |
| } |
| |
| pgprot_default = __pgprot(PTE_TYPE_PAGE | PTE_AF | default_pgprot); |
| } |
| |
| 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); |
| |
| static void __init *early_alloc(unsigned long sz) |
| { |
| void *ptr = __va(memblock_alloc(sz, sz)); |
| memset(ptr, 0, sz); |
| return ptr; |
| } |
| |
| static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, |
| unsigned long end, unsigned long pfn) |
| { |
| pte_t *pte; |
| |
| if (pmd_none(*pmd)) { |
| pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t)); |
| __pmd_populate(pmd, __pa(pte), PMD_TYPE_TABLE); |
| } |
| BUG_ON(pmd_bad(*pmd)); |
| |
| pte = pte_offset_kernel(pmd, addr); |
| do { |
| set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); |
| pfn++; |
| } 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) |
| { |
| pmd_t *pmd; |
| unsigned long next; |
| |
| /* |
| * 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 = pmd_offset(pud, addr); |
| do { |
| next = pmd_addr_end(addr, end); |
| /* try section mapping first */ |
| if (((addr | next | phys) & ~SECTION_MASK) == 0) |
| set_pmd(pmd, __pmd(phys | prot_sect_kernel)); |
| else |
| alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys)); |
| phys += next - addr; |
| } while (pmd++, addr = next, addr != end); |
| } |
| |
| static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr, |
| unsigned long end, unsigned long phys) |
| { |
| pud_t *pud = pud_offset(pgd, addr); |
| unsigned long next; |
| |
| do { |
| next = pud_addr_end(addr, end); |
| alloc_init_pmd(pud, addr, next, phys); |
| phys += next - addr; |
| } while (pud++, addr = next, addr != end); |
| } |
| |
| /* |
| * Create the page directory entries and any necessary page tables for the |
| * mapping specified by 'md'. |
| */ |
| static void __init create_mapping(phys_addr_t phys, unsigned long virt, |
| phys_addr_t size) |
| { |
| unsigned long addr, length, end, next; |
| pgd_t *pgd; |
| |
| if (virt < VMALLOC_START) { |
| pr_warning("BUG: not creating mapping for 0x%016llx at 0x%016lx - outside kernel range\n", |
| phys, virt); |
| return; |
| } |
| |
| addr = virt & PAGE_MASK; |
| length = PAGE_ALIGN(size + (virt & ~PAGE_MASK)); |
| |
| pgd = pgd_offset_k(addr); |
| end = addr + length; |
| do { |
| next = pgd_addr_end(addr, end); |
| alloc_init_pud(pgd, addr, next, phys); |
| phys += next - addr; |
| } while (pgd++, addr = next, addr != end); |
| } |
| |
| #ifdef CONFIG_EARLY_PRINTK |
| /* |
| * Create an early I/O mapping using the pgd/pmd entries already populated |
| * in head.S as this function is called too early to allocated any memory. The |
| * mapping size is 2MB with 4KB pages or 64KB or 64KB pages. |
| */ |
| void __iomem * __init early_io_map(phys_addr_t phys, unsigned long virt) |
| { |
| unsigned long size, mask; |
| bool page64k = IS_ENABLED(ARM64_64K_PAGES); |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| |
| /* |
| * No early pte entries with !ARM64_64K_PAGES configuration, so using |
| * sections (pmd). |
| */ |
| size = page64k ? PAGE_SIZE : SECTION_SIZE; |
| mask = ~(size - 1); |
| |
| pgd = pgd_offset_k(virt); |
| pud = pud_offset(pgd, virt); |
| if (pud_none(*pud)) |
| return NULL; |
| pmd = pmd_offset(pud, virt); |
| |
| if (page64k) { |
| if (pmd_none(*pmd)) |
| return NULL; |
| pte = pte_offset_kernel(pmd, virt); |
| set_pte(pte, __pte((phys & mask) | PROT_DEVICE_nGnRE)); |
| } else { |
| set_pmd(pmd, __pmd((phys & mask) | PROT_SECT_DEVICE_nGnRE)); |
| } |
| |
| return (void __iomem *)((virt & mask) + (phys & ~mask)); |
| } |
| #endif |
| |
| static void __init map_mem(void) |
| { |
| struct memblock_region *reg; |
| |
| /* map all the memory banks */ |
| for_each_memblock(memory, reg) { |
| phys_addr_t start = reg->base; |
| phys_addr_t end = start + reg->size; |
| |
| if (start >= end) |
| break; |
| |
| create_mapping(start, __phys_to_virt(start), end - start); |
| } |
| } |
| |
| /* |
| * 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; |
| |
| /* |
| * Maximum PGDIR_SIZE addressable via the initial direct kernel |
| * mapping in swapper_pg_dir. |
| */ |
| memblock_set_current_limit((PHYS_OFFSET & PGDIR_MASK) + PGDIR_SIZE); |
| |
| init_mem_pgprot(); |
| 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); |
| |
| bootmem_init(); |
| |
| empty_zero_page = virt_to_page(zero_page); |
| __flush_dcache_page(empty_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(); |
| } |
| |
| /* |
| * Check whether a kernel address is valid (derived from arch/x86/). |
| */ |
| int kern_addr_valid(unsigned long addr) |
| { |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| |
| if ((((long)addr) >> VA_BITS) != -1UL) |
| return 0; |
| |
| pgd = pgd_offset_k(addr); |
| if (pgd_none(*pgd)) |
| return 0; |
| |
| pud = pud_offset(pgd, addr); |
| if (pud_none(*pud)) |
| return 0; |
| |
| pmd = pmd_offset(pud, addr); |
| if (pmd_none(*pmd)) |
| return 0; |
| |
| pte = pte_offset_kernel(pmd, addr); |
| if (pte_none(*pte)) |
| return 0; |
| |
| return pfn_valid(pte_pfn(*pte)); |
| } |
| #ifdef CONFIG_SPARSEMEM_VMEMMAP |
| #ifdef CONFIG_ARM64_64K_PAGES |
| int __meminit vmemmap_populate(struct page *start_page, |
| unsigned long size, int node) |
| { |
| return vmemmap_populate_basepages(start_page, size, node); |
| } |
| #else /* !CONFIG_ARM64_64K_PAGES */ |
| int __meminit vmemmap_populate(struct page *start_page, |
| unsigned long size, int node) |
| { |
| unsigned long addr = (unsigned long)start_page; |
| unsigned long end = (unsigned long)(start_page + size); |
| unsigned long next; |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| |
| do { |
| next = pmd_addr_end(addr, end); |
| |
| pgd = vmemmap_pgd_populate(addr, node); |
| if (!pgd) |
| return -ENOMEM; |
| |
| pud = vmemmap_pud_populate(pgd, addr, node); |
| if (!pud) |
| return -ENOMEM; |
| |
| pmd = pmd_offset(pud, addr); |
| if (pmd_none(*pmd)) { |
| void *p = NULL; |
| |
| p = vmemmap_alloc_block_buf(PMD_SIZE, node); |
| if (!p) |
| return -ENOMEM; |
| |
| set_pmd(pmd, __pmd(__pa(p) | prot_sect_kernel)); |
| } else |
| vmemmap_verify((pte_t *)pmd, node, addr, next); |
| } while (addr = next, addr != end); |
| |
| return 0; |
| } |
| #endif /* CONFIG_ARM64_64K_PAGES */ |
| #endif /* CONFIG_SPARSEMEM_VMEMMAP */ |