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125 lines
2.9 KiB
125 lines
2.9 KiB
/*
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* arch/sh/mm/mmap.c
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*
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* Copyright (C) 2008 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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#ifdef CONFIG_MMU
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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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/*
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* To avoid cache aliases, we map the shared page with same color.
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*/
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#define COLOUR_ALIGN(addr, pgoff) \
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((((addr) + shm_align_mask) & ~shm_align_mask) + \
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(((pgoff) << PAGE_SHIFT) & shm_align_mask))
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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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#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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