/* * 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 <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); 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; }