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Diffstat (limited to 'arch/microblaze/mm/pgtable.c')
| -rw-r--r-- | arch/microblaze/mm/pgtable.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c new file mode 100644 index 0000000000..9f73265aad --- /dev/null +++ b/arch/microblaze/mm/pgtable.c @@ -0,0 +1,264 @@ +/* + * This file contains the routines setting up the linux page tables. + * + * Copyright (C) 2008 Michal Simek + * Copyright (C) 2008 PetaLogix + * + * Copyright (C) 2007 Xilinx, Inc. All rights reserved. + * + * Derived from arch/ppc/mm/pgtable.c: + * -- paulus + * + * Derived from arch/ppc/mm/init.c: + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) + * and Cort Dougan (PReP) (cort@cs.nmt.edu) + * Copyright (C) 1996 Paul Mackerras + * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). + * + * Derived from "arch/i386/mm/init.c" + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + * + */ + +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/vmalloc.h> +#include <linux/init.h> +#include <linux/mm_types.h> +#include <linux/pgtable.h> +#include <linux/memblock.h> +#include <linux/kallsyms.h> + +#include <asm/pgalloc.h> +#include <linux/io.h> +#include <asm/mmu.h> +#include <asm/sections.h> +#include <asm/fixmap.h> + +unsigned long ioremap_base; +unsigned long ioremap_bot; +EXPORT_SYMBOL(ioremap_bot); + +static void __iomem *__ioremap(phys_addr_t addr, unsigned long size, + unsigned long flags) +{ + unsigned long v, i; + phys_addr_t p; + int err; + + /* + * Choose an address to map it to. + * Once the vmalloc system is running, we use it. + * Before then, we use space going down from ioremap_base + * (ioremap_bot records where we're up to). + */ + p = addr & PAGE_MASK; + size = PAGE_ALIGN(addr + size) - p; + + /* + * Don't allow anybody to remap normal RAM that we're using. + * mem_init() sets high_memory so only do the check after that. + * + * However, allow remap of rootfs: TBD + */ + + if (mem_init_done && + p >= memory_start && p < virt_to_phys(high_memory) && + !(p >= __virt_to_phys((phys_addr_t)__bss_stop) && + p < __virt_to_phys((phys_addr_t)__bss_stop))) { + pr_warn("__ioremap(): phys addr "PTE_FMT" is RAM lr %ps\n", + (unsigned long)p, __builtin_return_address(0)); + return NULL; + } + + if (size == 0) + return NULL; + + /* + * Is it already mapped? If the whole area is mapped then we're + * done, otherwise remap it since we want to keep the virt addrs for + * each request contiguous. + * + * We make the assumption here that if the bottom and top + * of the range we want are mapped then it's mapped to the + * same virt address (and this is contiguous). + * -- Cort + */ + + if (mem_init_done) { + struct vm_struct *area; + area = get_vm_area(size, VM_IOREMAP); + if (area == NULL) + return NULL; + v = (unsigned long) area->addr; + } else { + v = (ioremap_bot -= size); + } + + if ((flags & _PAGE_PRESENT) == 0) + flags |= _PAGE_KERNEL; + if (flags & _PAGE_NO_CACHE) + flags |= _PAGE_GUARDED; + + err = 0; + for (i = 0; i < size && err == 0; i += PAGE_SIZE) + err = map_page(v + i, p + i, flags); + if (err) { + if (mem_init_done) + vfree((void *)v); + return NULL; + } + + return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); +} + +void __iomem *ioremap(phys_addr_t addr, unsigned long size) +{ + return __ioremap(addr, size, _PAGE_NO_CACHE); +} +EXPORT_SYMBOL(ioremap); + +void iounmap(volatile void __iomem *addr) +{ + if ((__force void *)addr > high_memory && + (unsigned long) addr < ioremap_bot) + vfree((void *) (PAGE_MASK & (unsigned long) addr)); +} +EXPORT_SYMBOL(iounmap); + + +int map_page(unsigned long va, phys_addr_t pa, int flags) +{ + p4d_t *p4d; + pud_t *pud; + pmd_t *pd; + pte_t *pg; + int err = -ENOMEM; + + /* Use upper 10 bits of VA to index the first level map */ + p4d = p4d_offset(pgd_offset_k(va), va); + pud = pud_offset(p4d, va); + pd = pmd_offset(pud, va); + /* Use middle 10 bits of VA to index the second-level map */ + pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */ + /* pg = pte_alloc_kernel(&init_mm, pd, va); */ + + if (pg != NULL) { + err = 0; + set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, + __pgprot(flags))); + if (unlikely(mem_init_done)) + _tlbie(va); + } + return err; +} + +/* + * Map in all of physical memory starting at CONFIG_KERNEL_START. + */ +void __init mapin_ram(void) +{ + unsigned long v, p, s, f; + + v = CONFIG_KERNEL_START; + p = memory_start; + for (s = 0; s < lowmem_size; s += PAGE_SIZE) { + f = _PAGE_PRESENT | _PAGE_ACCESSED | + _PAGE_SHARED | _PAGE_HWEXEC; + if (!is_kernel_text(v)) + f |= _PAGE_WRENABLE; + else + /* On the MicroBlaze, no user access + forces R/W kernel access */ + f |= _PAGE_USER; + map_page(v, p, f); + v += PAGE_SIZE; + p += PAGE_SIZE; + } +} + +/* is x a power of 2? */ +#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) + +/* Scan the real Linux page tables and return a PTE pointer for + * a virtual address in a context. + * Returns true (1) if PTE was found, zero otherwise. The pointer to + * the PTE pointer is unmodified if PTE is not found. + */ +static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + int retval = 0; + + pgd = pgd_offset(mm, addr & PAGE_MASK); + if (pgd) { + p4d = p4d_offset(pgd, addr & PAGE_MASK); + pud = pud_offset(p4d, addr & PAGE_MASK); + pmd = pmd_offset(pud, addr & PAGE_MASK); + if (pmd_present(*pmd)) { + pte = pte_offset_kernel(pmd, addr & PAGE_MASK); + if (pte) { + retval = 1; + *ptep = pte; + } + } + } + return retval; +} + +/* Find physical address for this virtual address. Normally used by + * I/O functions, but anyone can call it. + */ +unsigned long iopa(unsigned long addr) +{ + unsigned long pa; + + pte_t *pte; + struct mm_struct *mm; + + /* Allow mapping of user addresses (within the thread) + * for DMA if necessary. + */ + if (addr < TASK_SIZE) + mm = current->mm; + else + mm = &init_mm; + + pa = 0; + if (get_pteptr(mm, addr, &pte)) + pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); + + return pa; +} + +__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm) +{ + if (mem_init_done) + return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); + else + return memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE, + MEMBLOCK_LOW_LIMIT, + memory_start + kernel_tlb, + NUMA_NO_NODE); +} + +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) +{ + unsigned long address = __fix_to_virt(idx); + + if (idx >= __end_of_fixed_addresses) + BUG(); + + map_page(address, phys, pgprot_val(flags)); +} |