bee8ce809f
While ioremap() will happily map a physical address through the P2 (uncached) segment when appropriate, iounmap() doesn't know how to handle those mappings. This patch makes iounmap() do the right thing, i.e. nothing, for such mappings. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
92 lines
2.2 KiB
C
92 lines
2.2 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/module.h>
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#include <linux/io.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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