forked from Minki/linux
920efaabcb
iounmap_fixed() had a couple of bugs in it that caused it to effectively fail at life. The total number of pages to unmap factored in the mapping offset and aligned up to the next page boundary, which doesn't match the ioremap_fixed() behaviour. When ioremap_fixed() pegs a slot, the address in the mapping data already contains the offset displacement, and the size is recorded verbatim given that we're only interested in total number of pages required. As such, we need to calculate the total number from the original size in the unmap path as well. At the same time, there was also an off-by-1 problem in the fixmap index calculation which has also been corrected. Previously subsequent remaps of an identical fixmap index would trigger the pte_ERROR() in set_pte_phys(): arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506). arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506). arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506). arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506). arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506). arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506). With this patch in place, the iounmap-driven fixmap teardown actually does what it's supposed to do. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
129 lines
2.4 KiB
C
129 lines
2.4 KiB
C
/*
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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/bootmem.h>
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#include <linux/proc_fs.h>
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#include <linux/slab.h>
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#include <asm/fixmap.h>
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#include <asm/page.h>
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#include <asm/pgalloc.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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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(resource_size_t phys_addr, unsigned long offset,
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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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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) {
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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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