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135 lines
2.6 KiB
135 lines
2.6 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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* |
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* These functions should only be used when it is necessary to map a |
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* physical address space into the kernel address space before ioremap() |
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* can be used, e.g. early in boot before paging_init(). |
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* |
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* Copyright (C) 2009 Matt Fleming |
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*/ |
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#include <linux/vmalloc.h> |
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#include <linux/ioport.h> |
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#include <linux/module.h> |
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#include <linux/mm.h> |
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#include <linux/io.h> |
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#include <linux/memblock.h> |
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#include <linux/proc_fs.h> |
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#include <asm/fixmap.h> |
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#include <asm/page.h> |
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#include <asm/addrspace.h> |
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#include <asm/cacheflush.h> |
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#include <asm/tlbflush.h> |
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#include <asm/mmu.h> |
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#include <asm/mmu_context.h> |
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#include "ioremap.h" |
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struct ioremap_map { |
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void __iomem *addr; |
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unsigned long size; |
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unsigned long fixmap_addr; |
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}; |
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static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS]; |
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void __init ioremap_fixed_init(void) |
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{ |
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struct ioremap_map *map; |
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int i; |
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for (i = 0; i < FIX_N_IOREMAPS; i++) { |
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map = &ioremap_maps[i]; |
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map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i); |
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} |
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} |
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void __init __iomem * |
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ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot) |
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{ |
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enum fixed_addresses idx0, idx; |
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struct ioremap_map *map; |
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unsigned int nrpages; |
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unsigned long offset; |
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int i, slot; |
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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(phys_addr + size) - phys_addr; |
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slot = -1; |
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for (i = 0; i < FIX_N_IOREMAPS; i++) { |
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map = &ioremap_maps[i]; |
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if (!map->addr) { |
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map->size = size; |
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slot = i; |
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break; |
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} |
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} |
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if (slot < 0) |
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return NULL; |
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/* |
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* Mappings have to fit in the FIX_IOREMAP area. |
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*/ |
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nrpages = size >> PAGE_SHIFT; |
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if (nrpages > FIX_N_IOREMAPS) |
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return NULL; |
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/* |
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* Ok, go for it.. |
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*/ |
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idx0 = FIX_IOREMAP_BEGIN + slot; |
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idx = idx0; |
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while (nrpages > 0) { |
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pgprot_val(prot) |= _PAGE_WIRED; |
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__set_fixmap(idx, phys_addr, prot); |
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phys_addr += PAGE_SIZE; |
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idx++; |
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--nrpages; |
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} |
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map->addr = (void __iomem *)(offset + map->fixmap_addr); |
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return map->addr; |
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} |
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int iounmap_fixed(void __iomem *addr) |
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{ |
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enum fixed_addresses idx; |
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struct ioremap_map *map; |
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unsigned int nrpages; |
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int i, slot; |
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slot = -1; |
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for (i = 0; i < FIX_N_IOREMAPS; i++) { |
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map = &ioremap_maps[i]; |
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if (map->addr == addr) { |
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slot = i; |
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break; |
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} |
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} |
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/* |
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* If we don't match, it's not for us. |
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*/ |
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if (slot < 0) |
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return -EINVAL; |
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nrpages = map->size >> PAGE_SHIFT; |
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idx = FIX_IOREMAP_BEGIN + slot + nrpages - 1; |
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while (nrpages > 0) { |
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__clear_fixmap(idx, __pgprot(_PAGE_WIRED)); |
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--idx; |
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--nrpages; |
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} |
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map->size = 0; |
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map->addr = NULL; |
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return 0; |
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}
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