101 строка
2.4 KiB
C
101 строка
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* arch/parisc/mm/ioremap.c
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*
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* (C) Copyright 1995 1996 Linus Torvalds
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* (C) Copyright 2001-2006 Helge Deller <deller@gmx.de>
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* (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
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*/
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#include <linux/vmalloc.h>
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#include <linux/errno.h>
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#include <linux/module.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.
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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(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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#ifdef CONFIG_EISA
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unsigned long end = phys_addr + size - 1;
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/* Support EISA addresses */
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if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
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(phys_addr >= 0x00500000 && end < 0x03bfffff)) {
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phys_addr |= F_EXTEND(0xfc000000);
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flags |= _PAGE_NO_CACHE;
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}
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#endif
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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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* 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);
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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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}
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pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
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_PAGE_ACCESSED | 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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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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vfree(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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EXPORT_SYMBOL(__ioremap);
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void iounmap(const 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 __force) addr));
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}
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EXPORT_SYMBOL(iounmap);
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