lkml.org 
[lkml]   [2006]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[PATCH] [RFC] Generic 32-bit MMIO copy, out of line
    From
    Date
    On Tue, 2006-01-10 at 08:07 -0800, Bryan O'Sullivan wrote:

    > The only problem with this is that it's an unusual approach, so I don't
    > have any obvious examples to copy.

    It was easy to hack up a quick patch to try the idea out.

    This single-arch patch is for review purposes only; I compile-tested it
    on i386, and it has no obvious problems at compile- or link-time.

    If it looks OK, I have a complete patch set that affects all arches.
    The parts that affect arch/*/lib/Makefile and include/asm-*/io.h are
    essentially identical in all cases.

    <b

    diff -r 48616306e7bd include/asm-generic/raw_memcpy_toio32.h
    --- /dev/null Thu Jan 1 00:00:00 1970 +0000
    +++ b/include/asm-generic/raw_memcpy_toio32.h Tue Jan 10 08:44:30 2006 -0800
    @@ -0,0 +1,16 @@
    +#ifndef _ASM_GENERIC_RAW_MEMCPYTOIO32_H
    +#define _ASM_GENERIC_RAW_MEMCPYTOIO32_H
    +
    +/*
    + * __raw_memcpy_toio32 - copy data to MMIO space, in 32-bit units
    + *
    + * Order of access is not guaranteed, nor is a memory barrier performed
    + * afterwards. This is an arch-independent generic implementation.
    + *
    + * @to: destination, in MMIO space (must be 32-bit aligned)
    + * @from: source (must be 32-bit aligned)
    + * @count: number of 32-bit quantities to copy
    + */
    +void __raw_memcpy_toio32(void __iomem *to, const void *from, size_t count);
    +
    +#endif // _ASM_GENERIC_RAW_MEMCPYTOIO32_H
    --- /dev/null Thu Jan 1 00:00:00 1970 +0000
    +++ b/lib/raw_memcpy_toio32.c Tue Jan 10 08:44:30 2006 -0800
    @@ -0,0 +1,13 @@
    +#include <linux/types.h>
    +#include <asm/io.h>
    +#include <asm-generic/raw_memcpy_toio32.h>
    +
    +void __raw_memcpy_toio32(void __iomem *to, const void *from, size_t count)
    +{
    + u32 __iomem *dst = to;
    + const u32 *src = from;
    + size_t i;
    +
    + for (i = 0; i < count; i++)
    + __raw_writel(*src++, dst++);
    +}
    --- a/arch/i386/lib/Makefile Tue Jan 10 08:44:35 2006 -0800
    +++ b/arch/i386/lib/Makefile Tue Jan 10 08:44:44 2006 -0800
    @@ -5,5 +5,6 @@

    lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \
    bitops.o
    +lib-y += ../../../lib/raw_memcpy_toio32.o

    lib-$(CONFIG_X86_USE_3DNOW) += mmx.o
    --- a/include/asm-i386/io.h Tue Jan 10 08:44:35 2006 -0800
    +++ b/include/asm-i386/io.h Tue Jan 10 08:44:44 2006 -0800
    @@ -203,6 +203,8 @@
    {
    __memcpy((void __force *) dst, src, count);
    }
    +
    +#include <asm-generic/raw_memcpy_toio32.h>

    /*
    * ISA space is 'always mapped' on a typical x86 system, no need to

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-01-10 17:58    [W:0.024 / U:89.168 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site