root/lib/ioremap.c

DEFINITIONS

1. ioremap_pte_range
2. ioremap_pmd_range
3. ioremap_pud_range
4. ioremap_page_range

/*
 * 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 <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;
}