112 lines
2.7 KiB
C
112 lines
2.7 KiB
C
/*
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* linux/arch/m32r/mm/ioremap.c
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*
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* Copyright (c) 2001, 2002 Hiroyuki Kondo
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*
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* Taken from mips version.
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* (C) Copyright 1995 1996 Linus Torvalds
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* (C) Copyright 2001 Ralf Baechle
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*/
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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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*/
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#include <linux/module.h>
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#include <asm/addrspace.h>
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#include <asm/byteorder.h>
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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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/*
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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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#define IS_LOW512(addr) (!((unsigned long)(addr) & ~0x1fffffffUL))
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void __iomem *
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__ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
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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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pgprot_t pgprot;
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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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* Map objects in the low 512mb of address space using KSEG1, otherwise
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* map using page tables.
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*/
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if (IS_LOW512(phys_addr) && IS_LOW512(phys_addr + size - 1))
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return (void *) KSEG1ADDR(phys_addr);
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/*
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* Don't allow anybody to remap normal RAM that we're using..
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*/
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if (phys_addr < virt_to_phys(high_memory)) {
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char *t_addr, *t_end;
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struct page *page;
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t_addr = __va(phys_addr);
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t_end = t_addr + (size - 1);
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for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
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if(!PageReserved(page))
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return NULL;
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}
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pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_READ
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| _PAGE_WRITE | flags);
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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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area->phys_addr = phys_addr;
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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, pgprot)) {
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vunmap((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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#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1)
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void iounmap(volatile void __iomem *addr)
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{
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if (!IS_KSEG1(addr))
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vfree((void *) (PAGE_MASK & (unsigned long) addr));
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}
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