94 строки
2.3 KiB
C
94 строки
2.3 KiB
C
/*
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* Copyright (C) 2004-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/vmalloc.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <asm/pgtable.h>
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#include <asm/addrspace.h>
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/*
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* Re-map an arbitrary physical address space into the kernel virtual
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* address space. Needed when the kernel wants to access physical
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* memory directly.
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*/
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void __iomem *__ioremap(unsigned long phys_addr, size_t size,
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unsigned long flags)
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{
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unsigned long addr;
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struct vm_struct *area;
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unsigned long offset, last_addr;
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pgprot_t prot;
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/*
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* Check if we can simply use the P4 segment. This area is
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* uncacheable, so if caching/buffering is requested, we can't
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* use it.
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*/
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if ((phys_addr >= P4SEG) && (flags == 0))
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return (void __iomem *)phys_addr;
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/* Don't allow wraparound or zero size */
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last_addr = phys_addr + size - 1;
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if (!size || last_addr < phys_addr)
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return NULL;
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/*
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* XXX: When mapping regular RAM, we'd better make damn sure
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* it's never used for anything else. But this is really the
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* caller's responsibility...
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*/
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if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr)
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return (void __iomem *)P2SEGADDR(phys_addr);
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/* Mappings have to be page-aligned */
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offset = phys_addr & ~PAGE_MASK;
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phys_addr &= PAGE_MASK;
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size = PAGE_ALIGN(last_addr + 1) - phys_addr;
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prot = __pgprot(_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_RW | _PAGE_DIRTY
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| _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags);
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/*
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* Ok, go for it..
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*/
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area = get_vm_area(size, VM_IOREMAP);
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if (!area)
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return NULL;
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area->phys_addr = phys_addr;
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addr = (unsigned long )area->addr;
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if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
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vunmap((void *)addr);
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return NULL;
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}
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return (void __iomem *)(offset + (char *)addr);
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}
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EXPORT_SYMBOL(__ioremap);
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void __iounmap(void __iomem *addr)
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{
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struct vm_struct *p;
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if ((unsigned long)addr >= P4SEG)
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return;
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if (PXSEG(addr) == P2SEG)
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return;
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p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
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if (unlikely(!p)) {
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printk (KERN_ERR "iounmap: bad address %p\n", addr);
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return;
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}
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kfree (p);
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}
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EXPORT_SYMBOL(__iounmap);
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