lkml.org 
[lkml]   [2009]   [Jan]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    SubjectRe: [PATCH 14/23] arm: introduce asm/swab.h
    On Tue, Jan 06, 2009 at 11:12:35PM +0000, Russell King wrote:
    > Thanks for bypassing me.
    >
    > We've had this patch in the kernel before, then it got reverted.

    Correction - we've had something similar to this before.

    > Application: ae82cbfc8beaa69007aa09966d3983ac938c3577
    > Reversion: b35de672e74ceea6482b4f690ad053aec8465c5d
    >
    > Revert "[ARM] use the new byteorder headers"
    >
    > This reverts commit ae82cbfc8beaa69007aa09966d3983ac938c3577. It
    > needs the new byteorder headers to be exported to userspace, and
    > they aren't yet -- and probably shouldn't be, at this point in the
    > 2.6.27 release cycle (or ever, for that matter).
    >
    > Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
    > Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
    >
    > Please explain what's changed to make this acceptable now.
    >
    > On Tue, Jan 06, 2009 at 01:30:52PM -0800, Harvey Harrison wrote:
    > > Convert to the new-style arch overrides as well.
    > >
    > > Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
    > > ---
    > > arch/arm/include/asm/Kbuild | 1 +
    > > arch/arm/include/asm/byteorder.h | 33 +------------------------
    > > arch/arm/include/asm/swab.h | 50 ++++++++++++++++++++++++++++++++++++++
    > > 3 files changed, 52 insertions(+), 32 deletions(-)
    > >
    > > diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild
    > > index 73237bd..43b0b2b 100644
    > > --- a/arch/arm/include/asm/Kbuild
    > > +++ b/arch/arm/include/asm/Kbuild
    > > @@ -1,3 +1,4 @@
    > > include include/asm-generic/Kbuild.asm
    > >
    > > unifdef-y += hwcap.h
    > > +unifdef-y += swab.h
    > > diff --git a/arch/arm/include/asm/byteorder.h b/arch/arm/include/asm/byteorder.h
    > > index 4fbfb22..c02b6fc 100644
    > > --- a/arch/arm/include/asm/byteorder.h
    > > +++ b/arch/arm/include/asm/byteorder.h
    > > @@ -15,38 +15,7 @@
    > > #ifndef __ASM_ARM_BYTEORDER_H
    > > #define __ASM_ARM_BYTEORDER_H
    > >
    > > -#include <linux/compiler.h>
    > > -#include <asm/types.h>
    > > -
    > > -static inline __attribute_const__ __u32 ___arch__swab32(__u32 x)
    > > -{
    > > - __u32 t;
    > > -
    > > -#ifndef __thumb__
    > > - if (!__builtin_constant_p(x)) {
    > > - /*
    > > - * The compiler needs a bit of a hint here to always do the
    > > - * right thing and not screw it up to different degrees
    > > - * depending on the gcc version.
    > > - */
    > > - asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
    > > - } else
    > > -#endif
    > > - t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
    > > -
    > > - x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
    > > - t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
    > > - x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
    > > -
    > > - return x;
    > > -}
    > > -
    > > -#define __arch__swab32(x) ___arch__swab32(x)
    > > -
    > > -#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
    > > -# define __BYTEORDER_HAS_U64__
    > > -# define __SWAB_64_THRU_32__
    > > -#endif
    > > +#include <asm/swab.h>
    > >
    > > #ifdef __ARMEB__
    > > #include <linux/byteorder/big_endian.h>
    > > diff --git a/arch/arm/include/asm/swab.h b/arch/arm/include/asm/swab.h
    > > new file mode 100644
    > > index 0000000..27a689b
    > > --- /dev/null
    > > +++ b/arch/arm/include/asm/swab.h
    > > @@ -0,0 +1,50 @@
    > > +/*
    > > + * arch/arm/include/asm/byteorder.h
    > > + *
    > > + * ARM Endian-ness. In little endian mode, the data bus is connected such
    > > + * that byte accesses appear as:
    > > + * 0 = d0...d7, 1 = d8...d15, 2 = d16...d23, 3 = d24...d31
    > > + * and word accesses (data or instruction) appear as:
    > > + * d0...d31
    > > + *
    > > + * When in big endian mode, byte accesses appear as:
    > > + * 0 = d24...d31, 1 = d16...d23, 2 = d8...d15, 3 = d0...d7
    > > + * and word accesses (data or instruction) appear as:
    > > + * d0...d31
    > > + */
    > > +#ifndef __ASM_ARM_SWAB_H
    > > +#define __ASM_ARM_SWAB_H
    > > +
    > > +#include <linux/compiler.h>
    > > +#include <asm/types.h>
    > > +
    > > +#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
    > > +# define __SWAB_64_THRU_32__
    > > +#endif
    > > +
    > > +static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
    > > +{
    > > + __u32 t;
    > > +
    > > +#ifndef __thumb__
    > > + if (!__builtin_constant_p(x)) {
    > > + /*
    > > + * The compiler needs a bit of a hint here to always do the
    > > + * right thing and not screw it up to different degrees
    > > + * depending on the gcc version.
    > > + */
    > > + asm ("eor\t%0, %1, %1, ror #16" : "=r" (t) : "r" (x));
    > > + } else
    > > +#endif
    > > + t = x ^ ((x << 16) | (x >> 16)); /* eor r1,r0,r0,ror #16 */
    > > +
    > > + x = (x << 24) | (x >> 8); /* mov r0,r0,ror #8 */
    > > + t &= ~0x00FF0000; /* bic r1,r1,#0x00FF0000 */
    > > + x ^= (t >> 8); /* eor r0,r0,r1,lsr #8 */
    > > +
    > > + return x;
    > > +}
    > > +#define __arch_swab32 __arch_swab32
    > > +
    > > +#endif
    > > +
    > > --
    > > 1.6.1.94.g9388
    > >
    >
    > --
    > Russell King
    > Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
    > maintainer of:

    --
    Russell King
    Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
    maintainer of:


    \
     
     \ /
      Last update: 2009-01-07 00:19    [W:0.053 / U:0.120 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site