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dde5e3ffb7
This does a bit of reorganizing for allowing nommu to use the new and generic cache.c, no functional changes. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
254 lines
6.1 KiB
C
254 lines
6.1 KiB
C
/*
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* arch/sh/mm/mmap.c
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*
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* Copyright (C) 2008 - 2009 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/io.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/module.h>
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#include <asm/page.h>
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#include <asm/processor.h>
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unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
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EXPORT_SYMBOL(shm_align_mask);
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#ifdef CONFIG_MMU
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/*
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* To avoid cache aliases, we map the shared page with same color.
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*/
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static inline unsigned long COLOUR_ALIGN(unsigned long addr,
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unsigned long pgoff)
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{
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unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;
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unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
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return base + off;
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}
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static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
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unsigned long pgoff)
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{
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unsigned long base = addr & ~shm_align_mask;
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unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
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if (base + off <= addr)
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return base + off;
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return base - off;
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}
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unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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unsigned long start_addr;
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int do_colour_align;
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if (flags & MAP_FIXED) {
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/* We do not accept a shared mapping if it would violate
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* cache aliasing constraints.
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*/
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if ((flags & MAP_SHARED) && (addr & shm_align_mask))
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return -EINVAL;
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return addr;
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}
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if (unlikely(len > TASK_SIZE))
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return -ENOMEM;
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do_colour_align = 0;
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if (filp || (flags & MAP_SHARED))
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do_colour_align = 1;
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if (addr) {
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if (do_colour_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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if (len > mm->cached_hole_size) {
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start_addr = addr = mm->free_area_cache;
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} else {
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mm->cached_hole_size = 0;
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start_addr = addr = TASK_UNMAPPED_BASE;
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}
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full_search:
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if (do_colour_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(mm->free_area_cache);
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for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
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/* At this point: (!vma || addr < vma->vm_end). */
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if (unlikely(TASK_SIZE - len < addr)) {
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/*
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* Start a new search - just in case we missed
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* some holes.
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*/
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if (start_addr != TASK_UNMAPPED_BASE) {
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start_addr = addr = TASK_UNMAPPED_BASE;
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mm->cached_hole_size = 0;
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goto full_search;
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}
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return -ENOMEM;
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}
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if (likely(!vma || addr + len <= vma->vm_start)) {
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/*
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* Remember the place where we stopped the search:
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*/
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mm->free_area_cache = addr + len;
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return addr;
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}
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if (addr + mm->cached_hole_size < vma->vm_start)
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mm->cached_hole_size = vma->vm_start - addr;
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addr = vma->vm_end;
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if (do_colour_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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}
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}
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unsigned long
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arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
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const unsigned long len, const unsigned long pgoff,
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const unsigned long flags)
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{
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struct vm_area_struct *vma;
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struct mm_struct *mm = current->mm;
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unsigned long addr = addr0;
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int do_colour_align;
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if (flags & MAP_FIXED) {
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/* We do not accept a shared mapping if it would violate
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* cache aliasing constraints.
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*/
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if ((flags & MAP_SHARED) &&
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((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
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return -EINVAL;
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return addr;
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}
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if (unlikely(len > TASK_SIZE))
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return -ENOMEM;
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do_colour_align = 0;
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if (filp || (flags & MAP_SHARED))
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do_colour_align = 1;
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/* requesting a specific address */
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if (addr) {
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if (do_colour_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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/* check if free_area_cache is useful for us */
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if (len <= mm->cached_hole_size) {
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mm->cached_hole_size = 0;
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mm->free_area_cache = mm->mmap_base;
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}
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/* either no address requested or can't fit in requested address hole */
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addr = mm->free_area_cache;
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if (do_colour_align) {
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unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);
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addr = base + len;
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}
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/* make sure it can fit in the remaining address space */
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if (likely(addr > len)) {
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vma = find_vma(mm, addr-len);
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if (!vma || addr <= vma->vm_start) {
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/* remember the address as a hint for next time */
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return (mm->free_area_cache = addr-len);
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}
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}
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if (unlikely(mm->mmap_base < len))
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goto bottomup;
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addr = mm->mmap_base-len;
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if (do_colour_align)
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addr = COLOUR_ALIGN_DOWN(addr, pgoff);
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do {
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/*
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* Lookup failure means no vma is above this address,
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* else if new region fits below vma->vm_start,
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* return with success:
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*/
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vma = find_vma(mm, addr);
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if (likely(!vma || addr+len <= vma->vm_start)) {
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/* remember the address as a hint for next time */
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return (mm->free_area_cache = addr);
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}
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/* remember the largest hole we saw so far */
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if (addr + mm->cached_hole_size < vma->vm_start)
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mm->cached_hole_size = vma->vm_start - addr;
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/* try just below the current vma->vm_start */
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addr = vma->vm_start-len;
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if (do_colour_align)
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addr = COLOUR_ALIGN_DOWN(addr, pgoff);
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} while (likely(len < vma->vm_start));
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bottomup:
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/*
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* A failed mmap() very likely causes application failure,
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* so fall back to the bottom-up function here. This scenario
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* can happen with large stack limits and large mmap()
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* allocations.
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*/
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mm->cached_hole_size = ~0UL;
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mm->free_area_cache = TASK_UNMAPPED_BASE;
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addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
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/*
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* Restore the topdown base:
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*/
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mm->free_area_cache = mm->mmap_base;
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mm->cached_hole_size = ~0UL;
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return addr;
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}
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#endif /* CONFIG_MMU */
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/*
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* You really shouldn't be using read() or write() on /dev/mem. This
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* might go away in the future.
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*/
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int valid_phys_addr_range(unsigned long addr, size_t count)
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{
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if (addr < __MEMORY_START)
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return 0;
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if (addr + count > __pa(high_memory))
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return 0;
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return 1;
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}
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int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
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{
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return 1;
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}
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