diff options
Diffstat (limited to 'arch/sh/mm/ioremap_fixed.c')
-rw-r--r-- | arch/sh/mm/ioremap_fixed.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap_fixed.c b/arch/sh/mm/ioremap_fixed.c new file mode 100644 index 00000000000..7f682e5dafc --- /dev/null +++ b/arch/sh/mm/ioremap_fixed.c @@ -0,0 +1,135 @@ +/* + * Re-map IO memory to kernel address space so that we can access it. + * + * These functions should only be used when it is necessary to map a + * physical address space into the kernel address space before ioremap() + * can be used, e.g. early in boot before paging_init(). + * + * Copyright (C) 2009 Matt Fleming + */ + +#include <linux/vmalloc.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/io.h> +#include <linux/bootmem.h> +#include <linux/proc_fs.h> +#include <linux/slab.h> +#include <asm/fixmap.h> +#include <asm/page.h> +#include <asm/pgalloc.h> +#include <asm/addrspace.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/mmu.h> +#include <asm/mmu_context.h> + +struct ioremap_map { + void __iomem *addr; + unsigned long size; + unsigned long fixmap_addr; +}; + +static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS]; + +void __init ioremap_fixed_init(void) +{ + struct ioremap_map *map; + int i; + + for (i = 0; i < FIX_N_IOREMAPS; i++) { + map = &ioremap_maps[i]; + map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i); + } +} + +void __init __iomem * +ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot) +{ + enum fixed_addresses idx0, idx; + struct ioremap_map *map; + unsigned int nrpages; + unsigned long offset; + int i, slot; + + /* + * Mappings have to be page-aligned + */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(phys_addr + size) - phys_addr; + + slot = -1; + for (i = 0; i < FIX_N_IOREMAPS; i++) { + map = &ioremap_maps[i]; + if (!map->addr) { + map->size = size; + slot = i; + break; + } + } + + if (slot < 0) + return NULL; + + /* + * Mappings have to fit in the FIX_IOREMAP area. + */ + nrpages = size >> PAGE_SHIFT; + if (nrpages > FIX_N_IOREMAPS) + return NULL; + + /* + * Ok, go for it.. + */ + idx0 = FIX_IOREMAP_BEGIN + slot; + idx = idx0; + while (nrpages > 0) { + pgprot_val(prot) |= _PAGE_WIRED; + __set_fixmap(idx, phys_addr, prot); + phys_addr += PAGE_SIZE; + idx++; + --nrpages; + } + + map->addr = (void __iomem *)(offset + map->fixmap_addr); + return map->addr; +} + +int iounmap_fixed(void __iomem *addr) +{ + enum fixed_addresses idx; + struct ioremap_map *map; + unsigned int nrpages; + int i, slot; + + slot = -1; + for (i = 0; i < FIX_N_IOREMAPS; i++) { + map = &ioremap_maps[i]; + if (map->addr == addr) { + slot = i; + break; + } + } + + /* + * If we don't match, it's not for us. + */ + if (slot < 0) + return -EINVAL; + + nrpages = map->size >> PAGE_SHIFT; + + idx = FIX_IOREMAP_BEGIN + slot + nrpages - 1; + while (nrpages > 0) { + __clear_fixmap(idx, __pgprot(_PAGE_WIRED)); + --idx; + --nrpages; + } + + map->size = 0; + map->addr = NULL; + + return 0; +} |