diff options
Diffstat (limited to 'lib/ioremap.c')
-rw-r--r-- | lib/ioremap.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/lib/ioremap.c b/lib/ioremap.c new file mode 100644 index 00000000..da4e2ad7 --- /dev/null +++ b/lib/ioremap.c @@ -0,0 +1,94 @@ +/* + * Re-map IO memory to kernel address space so that we can access it. + * This is needed for high PCI addresses that aren't mapped in the + * 640k-1MB IO memory area on PC's + * + * (C) Copyright 1995 1996 Linus Torvalds + */ +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/io.h> +#include <linux/module.h> +#include <asm/cacheflush.h> +#include <asm/pgtable.h> + +static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, + unsigned long end, phys_addr_t phys_addr, pgprot_t prot) +{ + pte_t *pte; + u64 pfn; + + pfn = phys_addr >> PAGE_SHIFT; + pte = pte_alloc_kernel(pmd, addr); + if (!pte) + return -ENOMEM; + do { + BUG_ON(!pte_none(*pte)); + set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); + pfn++; + } while (pte++, addr += PAGE_SIZE, addr != end); + return 0; +} + +static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr, + unsigned long end, phys_addr_t phys_addr, pgprot_t prot) +{ + pmd_t *pmd; + unsigned long next; + + phys_addr -= addr; + pmd = pmd_alloc(&init_mm, pud, addr); + if (!pmd) + return -ENOMEM; + do { + next = pmd_addr_end(addr, end); + if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot)) + return -ENOMEM; + } while (pmd++, addr = next, addr != end); + return 0; +} + +static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr, + unsigned long end, phys_addr_t phys_addr, pgprot_t prot) +{ + pud_t *pud; + unsigned long next; + + phys_addr -= addr; + pud = pud_alloc(&init_mm, pgd, addr); + if (!pud) + return -ENOMEM; + do { + next = pud_addr_end(addr, end); + if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot)) + return -ENOMEM; + } while (pud++, addr = next, addr != end); + return 0; +} + +int ioremap_page_range(unsigned long addr, + unsigned long end, phys_addr_t phys_addr, pgprot_t prot) +{ + pgd_t *pgd; + unsigned long start; + unsigned long next; + int err; + + BUG_ON(addr >= end); + + start = addr; + phys_addr -= addr; + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, end); + err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot); + if (err) + break; + } while (pgd++, addr = next, addr != end); + + flush_cache_vmap(start, end); + + return err; +} +EXPORT_SYMBOL_GPL(ioremap_page_range); |