mirror of https://gitee.com/openkylin/linux.git
59 lines
1.4 KiB
C
59 lines
1.4 KiB
C
/*
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* arch/s390/mm/ioremap.c
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*
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* S390 version
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* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
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* Author(s): Hartmut Penner (hp@de.ibm.com)
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*
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* Derived from "arch/i386/mm/extable.c"
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* (C) Copyright 1995 1996 Linus Torvalds
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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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* This is needed for high PCI addresses that aren't mapped in the
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* 640k-1MB IO memory area on PC's
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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/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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void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
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{
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void * addr;
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struct vm_struct * area;
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if (phys_addr < virt_to_phys(high_memory))
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return phys_to_virt(phys_addr);
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if (phys_addr & ~PAGE_MASK)
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return NULL;
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size = PAGE_ALIGN(size);
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if (!size || size > phys_addr + size)
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return NULL;
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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 = area->addr;
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if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
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phys_addr, __pgprot(flags))) {
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vfree(addr);
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return NULL;
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}
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return addr;
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}
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void iounmap(void *addr)
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{
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if (addr > high_memory)
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vfree(addr);
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}
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