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author | Michal Simek <monstr@monstr.eu> | 2009-05-26 16:30:15 +0200 |
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committer | Michal Simek <monstr@monstr.eu> | 2009-05-26 16:45:16 +0200 |
commit | 15902bf63c8332946e5a1f48a72e3ae22874b11b (patch) | |
tree | 5a8aa78716a7176ea9df52f87ca0c0176f4ce955 /arch/microblaze/mm/pgtable.c | |
parent | microblaze_mmu_v2: Context handling - mmu_context.c/h (diff) | |
download | linux-15902bf63c8332946e5a1f48a72e3ae22874b11b.tar.xz linux-15902bf63c8332946e5a1f48a72e3ae22874b11b.zip |
microblaze_mmu_v2: Page table - ioremap - pgtable.c/h, section update
Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/mm/pgtable.c')
-rw-r--r-- | arch/microblaze/mm/pgtable.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c new file mode 100644 index 000000000000..46c4ca5d15c5 --- /dev/null +++ b/arch/microblaze/mm/pgtable.c @@ -0,0 +1,286 @@ +/* + * 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/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/vmalloc.h> +#include <linux/init.h> + +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <linux/io.h> +#include <asm/mmu.h> +#include <asm/sections.h> + +#define flush_HPTE(X, va, pg) _tlbie(va) + +unsigned long ioremap_base; +unsigned long ioremap_bot; + +/* The maximum lowmem defaults to 768Mb, but this can be configured to + * another value. + */ +#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE + +#ifndef CONFIG_SMP +struct pgtable_cache_struct quicklists; +#endif + +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((unsigned long)&__bss_stop) && + p < virt_to_phys((unsigned long)__bss_stop))) { + printk(KERN_WARNING "__ioremap(): phys addr "PTE_FMT + " is RAM lr %p\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 = VMALLOC_VMADDR(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(void *addr) +{ + if (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) +{ + pmd_t *pd; + pte_t *pg; + int err = -ENOMEM; + /* spin_lock(&init_mm.page_table_lock); */ + /* Use upper 10 bits of VA to index the first level map */ + pd = pmd_offset(pgd_offset_k(va), 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 (mem_init_done) + flush_HPTE(0, va, pmd_val(*pd)); + /* flush_HPTE(0, va, pg); */ + + } + /* spin_unlock(&init_mm.page_table_lock); */ + return err; +} + +void __init adjust_total_lowmem(void) +{ +/* TBD */ +#if 0 + unsigned long max_low_mem = MAX_LOW_MEM; + + if (total_lowmem > max_low_mem) { + total_lowmem = max_low_mem; +#ifndef CONFIG_HIGHMEM + printk(KERN_INFO "Warning, memory limited to %ld Mb, use " + "CONFIG_HIGHMEM to reach %ld Mb\n", + max_low_mem >> 20, total_memory >> 20); + total_memory = total_lowmem; +#endif /* CONFIG_HIGHMEM */ + } +#endif +} + +static void show_tmem(unsigned long tmem) +{ + volatile unsigned long a; + a = a + tmem; +} + +/* + * 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; + show_tmem(memory_size); + for (s = 0; s < memory_size; s += PAGE_SIZE) { + f = _PAGE_PRESENT | _PAGE_ACCESSED | + _PAGE_SHARED | _PAGE_HWEXEC; + if ((char *) v < _stext || (char *) v >= _etext) + 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)) + +/* + * Set up a mapping for a block of I/O. + * virt, phys, size must all be page-aligned. + * This should only be called before ioremap is called. + */ +void __init io_block_mapping(unsigned long virt, phys_addr_t phys, + unsigned int size, int flags) +{ + int i; + + if (virt > CONFIG_KERNEL_START && virt < ioremap_bot) + ioremap_bot = ioremap_base = virt; + + /* Put it in the page tables. */ + for (i = 0; i < size; i += PAGE_SIZE) + map_page(virt + i, phys + i, flags); +} + +/* 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; + pmd_t *pmd; + pte_t *pte; + int retval = 0; + + pgd = pgd_offset(mm, addr & PAGE_MASK); + if (pgd) { + pmd = pmd_offset(pgd, 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; +} |