+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * linux/arch/unicore32/mm/mmu.c
- *
- * Code specific to PKUnity SoC and UniCore ISA
- *
- * Copyright (C) 2001-2010 GUAN Xue-tao
- */
-#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/io.h>
-
-#include <asm/cputype.h>
-#include <asm/sections.h>
-#include <asm/setup.h>
-#include <linux/sizes.h>
-#include <asm/tlb.h>
-#include <asm/memblock.h>
-
-#include <mach/map.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);
-
-/*
- * 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 pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr,
- unsigned long prot)
-{
- if (pmd_none(*pmd)) {
- size_t size = PTRS_PER_PTE * sizeof(pte_t);
- pte_t *pte = memblock_alloc(size, size);
-
- if (!pte)
- panic("%s: Failed to allocate %zu bytes align=%zx\n",
- __func__, size, size);
-
- __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));
-}
-
-/*
- * 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 = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
- if (!vectors)
- panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
- __func__, PAGE_SIZE, PAGE_SIZE);
-
- for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE)
- pmd_clear(pmd_off_k(addr));
-
- /*
- * 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 = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
- if (!zero_page)
- panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
- __func__, PAGE_SIZE, 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(void)
-{
- 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_file(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();
-}
projects / linux-2.6-block.git / blobdiff