diff options
| -rw-r--r-- | include/linux/io.h | 4 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/ioremap.c | 94 |
3 files changed, 99 insertions, 0 deletions
diff --git a/include/linux/io.h b/include/linux/io.h index 420e2fdf26f6..aa3f5af670b5 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -19,8 +19,12 @@ #define _LINUX_IO_H #include <asm/io.h> +#include <asm/page.h> void __iowrite32_copy(void __iomem *to, const void *from, size_t count); void __iowrite64_copy(void __iomem *to, const void *from, size_t count); +int ioremap_page_range(unsigned long addr, unsigned long end, + unsigned long phys_addr, pgprot_t prot); + #endif /* _LINUX_IO_H */ diff --git a/lib/Makefile b/lib/Makefile index 402762fead70..ddf3e676e1f4 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -7,6 +7,7 @@ lib-y := errno.o ctype.o string.o vsprintf.o cmdline.o \ idr.o div64.o int_sqrt.o bitmap.o extable.o prio_tree.o \ sha1.o +lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o kref.o kobject_uevent.o klist.o diff --git a/lib/ioremap.c b/lib/ioremap.c new file mode 100644 index 000000000000..29c810ec9813 --- /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/io.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> + +#include <asm/cacheflush.h> +#include <asm/pgtable.h> + +static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, + unsigned long end, unsigned long phys_addr, pgprot_t prot) +{ + pte_t *pte; + unsigned long 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, unsigned long 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, unsigned long 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, unsigned long phys_addr, pgprot_t prot) +{ + pgd_t *pgd; + unsigned long start; + unsigned long next; + int err; + + BUG_ON(addr >= end); + + flush_cache_all(); + + 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_tlb_all(); + + return err; +} |