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/*

 * 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;

}