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74 lines
1.9 KiB
74 lines
1.9 KiB
// 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/sched.h> |
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#include <linux/io.h> |
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#include <linux/export.h> |
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#include <asm/cacheflush.h> |
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#include "pgalloc-track.h" |
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#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP |
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static unsigned int __ro_after_init iomap_max_page_shift = BITS_PER_LONG - 1; |
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static int __init set_nohugeiomap(char *str) |
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{ |
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iomap_max_page_shift = PAGE_SHIFT; |
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return 0; |
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} |
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early_param("nohugeiomap", set_nohugeiomap); |
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#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */ |
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static const unsigned int iomap_max_page_shift = PAGE_SHIFT; |
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#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ |
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int ioremap_page_range(unsigned long addr, |
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unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
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{ |
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return vmap_range(addr, end, phys_addr, prot, iomap_max_page_shift); |
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} |
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#ifdef CONFIG_GENERIC_IOREMAP |
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void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long 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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/* Disallow wrap-around or zero size */ |
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last_addr = addr + size - 1; |
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if (!size || last_addr < addr) |
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return NULL; |
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/* Page-align mappings */ |
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offset = addr & (~PAGE_MASK); |
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addr -= offset; |
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size = PAGE_ALIGN(size + offset); |
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area = get_vm_area_caller(size, VM_IOREMAP, |
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__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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if (ioremap_page_range(vaddr, vaddr + size, addr, __pgprot(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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EXPORT_SYMBOL(ioremap_prot); |
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void iounmap(volatile void __iomem *addr) |
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{ |
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vunmap((void *)((unsigned long)addr & PAGE_MASK)); |
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} |
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EXPORT_SYMBOL(iounmap); |
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#endif /* CONFIG_GENERIC_IOREMAP */
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