75 lines
1.7 KiB
C
75 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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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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* (C) Copyright 1995 1996 Linus Torvalds
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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 <linux/export.h>
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#include <linux/ioremap.h>
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void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
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pgprot_t prot)
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{
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unsigned long offset, vaddr;
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phys_addr_t last_addr;
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struct vm_struct *area;
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/* An early platform driver might end up here */
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if (WARN_ON_ONCE(!slab_is_available()))
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return NULL;
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/* Disallow wrap-around 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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/* Page-align mappings */
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offset = phys_addr & (~PAGE_MASK);
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phys_addr -= offset;
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size = PAGE_ALIGN(size + offset);
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area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START,
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IOREMAP_END, __builtin_return_address(0));
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if (!area)
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return NULL;
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vaddr = (unsigned long)area->addr;
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area->phys_addr = phys_addr;
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if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
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free_vm_area(area);
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return NULL;
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}
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return (void __iomem *)(vaddr + offset);
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}
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#ifndef ioremap_prot
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void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
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unsigned long prot)
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{
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return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
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}
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EXPORT_SYMBOL(ioremap_prot);
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#endif
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void generic_iounmap(volatile void __iomem *addr)
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{
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void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
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if (is_ioremap_addr(vaddr))
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vunmap(vaddr);
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}
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#ifndef iounmap
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void iounmap(volatile void __iomem *addr)
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{
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generic_iounmap(addr);
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}
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EXPORT_SYMBOL(iounmap);
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#endif
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