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    SubjectRe: [PATCH] x86: use bitmap library functions
    From
    2011/2/17 Ingo Molnar <mingo@elte.hu>:
    >
    > * Akinobu Mita <akinobu.mita@gmail.com> wrote:
    >
    >> Use bitmap_set()/bitmap_clear() to fill/zero a region of a bitmap
    >> instead of doing set_bit()/clear_bit() each bit.
    >>
    >> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
    >> Cc: Thomas Gleixner <tglx@linutronix.de>
    >> Cc: Ingo Molnar <mingo@redhat.com>
    >> Cc: "H. Peter Anvin" <hpa@zytor.com>
    >> Cc: x86@kernel.org
    >> ---
    >>  arch/x86/kernel/ioport.c |   20 +++++---------------
    >>  1 files changed, 5 insertions(+), 15 deletions(-)
    >
    > Before we can merge this it would be nice to tested this using sys_ioperm(), to make
    > sure port IO still gets denied/allowed as expected. You can check /proc/ioperm to
    > see which ports are (probably) safe to read: 0x80/0xed is usually safe to
    > read/write.

    I have tested with this program and there is no difference in behavior
    with this patch.

    #include <sys/io.h>
    #include <stdio.h>
    #include <err.h>

    int main(void)
    {
    unsigned long from = 0xed;
    unsigned long num = 1;
    int ret;
    int i;

    ret = ioperm(from, num, 1);
    if (ret)
    err(1, "ioperm");

    for (i = 0; i < num; i++)
    ret = inb(from + i);

    printf("OK\n");

    ret = ioperm(from, num, 0);
    if (ret)
    err(1, "ioperm");

    printf("will receive a segmentation fault\n");

    ret = inb(from);
    errx(1, "Oops");
    }
    --
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