io.c

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/*
 * arch/sh/kernel/io.c - Machine independent I/O functions.
 *
 * Copyright (C) 2000 - 2009  Stuart Menefy
 * Copyright (C) 2005  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/module.h>
#include <linux/pci.h>
#include <asm/machvec.h>
#include <asm/io.h>

/*
 * Copy data from IO memory space to "real" memory space.
 */
void memcpy_fromio(void *to, const volatile void __iomem *from, unsigned long count)
{
    /*
     * Would it be worthwhile doing byte and long transfers first
     * to try and get aligned?
     */
#ifdef CONFIG_CPU_SH4
    if ((count >= 0x20) &&
         (((u32)to & 0x1f) == 0) && (((u32)from & 0x3) == 0)) {
        int tmp2, tmp3, tmp4, tmp5, tmp6;

        __asm__ __volatile__(
            "1:         \n\t"
            "mov.l  @%7+, r0    \n\t"
            "mov.l  @%7+, %2    \n\t"
            "movca.l r0, @%0    \n\t"
            "mov.l  @%7+, %3    \n\t"
            "mov.l  @%7+, %4    \n\t"
            "mov.l  @%7+, %5    \n\t"
            "mov.l  @%7+, %6    \n\t"
            "mov.l  @%7+, r7    \n\t"
            "mov.l  @%7+, r0    \n\t"
            "mov.l  %2, @(0x04,%0)  \n\t"
            "mov    #0x20, %2   \n\t"
            "mov.l  %3, @(0x08,%0)  \n\t"
            "sub    %2, %1      \n\t"
            "mov.l  %4, @(0x0c,%0)  \n\t"
            "cmp/hi %1, %2      ! T if 32 > count   \n\t"
            "mov.l  %5, @(0x10,%0)  \n\t"
            "mov.l  %6, @(0x14,%0)  \n\t"
            "mov.l  r7, @(0x18,%0)  \n\t"
            "mov.l  r0, @(0x1c,%0)  \n\t"
            "bf.s   1b      \n\t"
            " add   #0x20, %0   \n\t"
            : "=&r" (to), "=&r" (count),
              "=&r" (tmp2), "=&r" (tmp3), "=&r" (tmp4),
              "=&r" (tmp5), "=&r" (tmp6), "=&r" (from)
            : "7"(from), "0" (to), "1" (count)
            : "r0", "r7", "t", "memory");
    }
#endif

    if ((((u32)to | (u32)from) & 0x3) == 0) {
        for (; count > 3; count -= 4) {
            *(u32 *)to = *(volatile u32 *)from;
            to += 4;
            from += 4;
        }
    }

    for (; count > 0; count--) {
        *(u8 *)to = *(volatile u8 *)from;
        to++;
        from++;
    }

    mb();
}
EXPORT_SYMBOL(memcpy_fromio);

/*
 * Copy data from "real" memory space to IO memory space.
 */
void memcpy_toio(volatile void __iomem *to, const void *from, unsigned long count)
{
    if ((((u32)to | (u32)from) & 0x3) == 0) {
        for ( ; count > 3; count -= 4) {
            *(volatile u32 *)to = *(u32 *)from;
            to += 4;
            from += 4;
        }
    }

    for (; count > 0; count--) {
        *(volatile u8 *)to = *(u8 *)from;
        to++;
        from++;
    }

    mb();
}
EXPORT_SYMBOL(memcpy_toio);

/*
 * "memset" on IO memory space.
 * This needs to be optimized.
 */
void memset_io(volatile void __iomem *dst, int c, unsigned long count)
{
        while (count) {
                count--;
                writeb(c, dst);
                dst++;
        }
}
EXPORT_SYMBOL(memset_io);