| /* |
| * linux/arch/unicore32/mm/mmu.c |
| * |
| * Code specific to PKUnity SoC and UniCore ISA |
| * |
| * Copyright (C) 2001-2010 GUAN Xue-tao |
| * |
| * 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 <linux/module.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/bootmem.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 <mach/map.h> |
| |
| #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; |
| |
| pgprot_t pgprot_user; |
| EXPORT_SYMBOL(pgprot_user); |
| |
| pgprot_t pgprot_kernel; |
| EXPORT_SYMBOL(pgprot_kernel); |
| |
| 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); |
| |
| 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); |
| } |
| |
| struct map_desc { |
| unsigned long virtual; |
| unsigned long pfn; |
| unsigned long length; |
| unsigned int type; |
| }; |
| |
| #define PROT_PTE_DEVICE (PTE_PRESENT | PTE_YOUNG | \ |
| PTE_DIRTY | PTE_READ | PTE_WRITE) |
| #define PROT_SECT_DEVICE (PMD_TYPE_SECT | PMD_PRESENT | \ |
| PMD_SECT_READ | PMD_SECT_WRITE) |
| |
| static struct mem_type mem_types[] = { |
| [MT_DEVICE] = { /* Strongly ordered */ |
| .prot_pte = PROT_PTE_DEVICE, |
| .prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT, |
| .prot_sect = PROT_SECT_DEVICE, |
| }, |
| /* |
| * MT_KUSER: pte for vecpage -- cacheable, |
| * and sect for unigfx mmap -- noncacheable |
| */ |
| [MT_KUSER] = { |
| .prot_pte = PTE_PRESENT | PTE_YOUNG | PTE_DIRTY | |
| PTE_CACHEABLE | PTE_READ | PTE_EXEC, |
| .prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT, |
| .prot_sect = PROT_SECT_DEVICE, |
| }, |
| [MT_HIGH_VECTORS] = { |
| .prot_pte = PTE_PRESENT | PTE_YOUNG | PTE_DIRTY | |
| PTE_CACHEABLE | PTE_READ | PTE_WRITE | |
| PTE_EXEC, |
| .prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT, |
| }, |
| [MT_MEMORY] = { |
| .prot_pte = PTE_PRESENT | PTE_YOUNG | PTE_DIRTY | |
| PTE_WRITE | PTE_EXEC, |
| .prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT, |
| .prot_sect = PMD_TYPE_SECT | PMD_PRESENT | PMD_SECT_CACHEABLE | |
| PMD_SECT_READ | PMD_SECT_WRITE | PMD_SECT_EXEC, |
| }, |
| [MT_ROM] = { |
| .prot_sect = PMD_TYPE_SECT | PMD_PRESENT | PMD_SECT_CACHEABLE | |
| PMD_SECT_READ, |
| }, |
| }; |
| |
| 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) |
| { |
| pgprot_user = __pgprot(PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE); |
| pgprot_kernel = __pgprot(PTE_PRESENT | PTE_YOUNG | |
| PTE_DIRTY | PTE_READ | PTE_WRITE | |
| PTE_EXEC | PTE_CACHEABLE); |
| } |
| |
| #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(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(pte, pfn_pte(pfn, __pgprot(type->prot_pte))); |
| pfn++; |
| } while (pte++, addr += PAGE_SIZE, addr != end); |
| } |
| |
| static void __init alloc_init_section(pgd_t *pgd, unsigned long addr, |
| unsigned long end, unsigned long phys, |
| const struct mem_type *type) |
| { |
| pmd_t *pmd = pmd_offset((pud_t *)pgd, addr); |
| |
| /* |
| * Try a section mapping - end, addr and phys must all be aligned |
| * to a section boundary. |
| */ |
| if (((addr | end | phys) & ~SECTION_MASK) == 0) { |
| pmd_t *p = pmd; |
| |
| do { |
| set_pmd(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); |
| } |
| } |
| |
| /* |
| * 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. |
| */ |
| 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]; |
| |
| 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); |
| } |
| |
| 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 = SZ_1G; |
| |
| static void __init sanity_check_meminfo(void) |
| { |
| int i, j; |
| |
| 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]; |
| j++; |
| } |
| 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)); |
| |
| 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 uc32_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_PUV3_UNIGFX |
| /* |
| * These should likewise go elsewhere. They pre-reserve the |
| * screen/video memory region at the 48M~64M of main system memory. |
| */ |
| memblock_reserve(PKUNITY_UNIGFX_MMAP_BASE, PKUNITY_UNIGFX_MMAP_SIZE); |
| memblock_reserve(PKUNITY_UVC_MMAP_BASE, PKUNITY_UVC_MMAP_SIZE); |
| #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(void) |
| { |
| 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)); |
| |
| /* |
| * Create a mapping for UniGFX VRAM |
| */ |
| #ifdef CONFIG_PUV3_UNIGFX |
| map.pfn = __phys_to_pfn(PKUNITY_UNIGFX_MMAP_BASE); |
| map.virtual = KUSER_UNIGFX_BASE; |
| map.length = PKUNITY_UNIGFX_MMAP_SIZE; |
| map.type = MT_KUSER; |
| 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 = VECTORS_BASE; |
| map.length = PAGE_SIZE; |
| map.type = MT_HIGH_VECTORS; |
| create_mapping(&map); |
| |
| /* |
| * Create a mapping for the kuser page at the special |
| * location (0xbfff0000) to the same vectors location. |
| */ |
| map.pfn = __phys_to_pfn(virt_to_phys(vectors)); |
| map.virtual = KUSER_VECPAGE_BASE; |
| map.length = PAGE_SIZE; |
| map.type = MT_KUSER; |
| create_mapping(&map); |
| |
| /* |
| * 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 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(void) |
| { |
| void *zero_page; |
| |
| build_mem_type_table(); |
| sanity_check_meminfo(); |
| prepare_page_table(); |
| map_lowmem(); |
| devicemaps_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_WRITE | PMD_SECT_READ | PMD_TYPE_SECT; |
| |
| 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); |
| set_pmd(pmd, __pmd(pmdval)); |
| flush_pmd_entry(pmd); |
| } |
| |
| local_flush_tlb_all(); |
| } |
| |
| /* |
| * Take care of architecture specific things when placing a new PTE into |
| * a page table, or changing an existing PTE. Basically, there are two |
| * things that we need to take care of: |
| * |
| * 1. If PG_dcache_clean is not set for the page, we need to ensure |
| * that any cache entries for the kernels virtual memory |
| * range are written back to the page. |
| * 2. If we have multiple shared mappings of the same space in |
| * an object, we need to deal with the cache aliasing issues. |
| * |
| * Note that the pte lock will be held. |
| */ |
| void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, |
| pte_t *ptep) |
| { |
| unsigned long pfn = pte_pfn(*ptep); |
| struct address_space *mapping; |
| struct page *page; |
| |
| if (!pfn_valid(pfn)) |
| return; |
| |
| /* |
| * The zero page is never written to, so never has any dirty |
| * cache lines, and therefore never needs to be flushed. |
| */ |
| page = pfn_to_page(pfn); |
| if (page == ZERO_PAGE(0)) |
| return; |
| |
| mapping = page_mapping(page); |
| if (!test_and_set_bit(PG_dcache_clean, &page->flags)) |
| __flush_dcache_page(mapping, page); |
| if (mapping) |
| if (vma->vm_flags & VM_EXEC) |
| __flush_icache_all(); |
| } |