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90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
/*
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* arch/cris/mm/ioremap.c
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*
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* Re-map IO memory to kernel address space so that we can access it.
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* Needed for memory-mapped I/O devices mapped outside our normal DRAM
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* window (that is, all memory-mapped I/O devices).
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*
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* (C) Copyright 1995 1996 Linus Torvalds
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* CRIS-port by Axis Communications AB
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*/
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#include <linux/vmalloc.h>
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#include <linux/io.h>
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#include <asm/pgalloc.h>
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#include <arch/memmap.h>
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/*
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* Generic mapping function (not visible outside):
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*/
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/*
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* Remap an arbitrary physical address space into the kernel virtual
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* address space. Needed when the kernel wants to access high addresses
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* directly.
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*
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* NOTE! We need to allow non-page-aligned mappings too: we will obviously
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* have to convert them into an offset in a page-aligned mapping, but the
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* caller shouldn't need to know that small detail.
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*/
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void __iomem * __ioremap_prot(unsigned long phys_addr, unsigned long size, pgprot_t prot)
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{
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void __iomem * addr;
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struct vm_struct * area;
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unsigned long offset, last_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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* Mappings have to be page-aligned
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*/
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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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/*
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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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addr = (void __iomem *)area->addr;
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if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
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phys_addr, prot)) {
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vfree((void __force *)addr);
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return NULL;
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}
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return (void __iomem *) (offset + (char __iomem *)addr);
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}
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void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
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{
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return __ioremap_prot(phys_addr, size,
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__pgprot(_PAGE_PRESENT | __READABLE |
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__WRITEABLE | _PAGE_GLOBAL |
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_PAGE_KERNEL | flags));
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}
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/**
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* ioremap_nocache - map bus memory into CPU space
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* @offset: bus address of the memory
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* @size: size of the resource to map
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*
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* Must be freed with iounmap.
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*/
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void __iomem *ioremap_nocache(unsigned long phys_addr, unsigned long size)
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{
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return __ioremap(phys_addr | MEM_NON_CACHEABLE, size, 0);
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}
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EXPORT_SYMBOL(ioremap_nocache);
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void iounmap(volatile void __iomem *addr)
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{
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if (addr > high_memory)
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return vfree((void *) (PAGE_MASK & (unsigned long) addr));
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}
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