[PATCH 0/5] powerpc: Get rid of redundant arch specific swab functions

David Gibson
2015-02-03T05:37:08Z

arch/powerpc/include/asm/swab.h includes some powerpc specific
byteswapping functions, which are implemented in terms of powerpc's
built in byte reversed load/store instructions. There are two problems with this:

1) They're not necessary - gcc is perfectly capable of generating the
byte-reversed load and store instructions when using the normal,
generic byteswapping functions (tested with gcc (GCC) 4.8.3
20140911 (Red Hat 4.8.3-9))

2) They've become poorly named. The ld_le*() and st_le*() functions
in fact *always* byteswap, even in a little-endian powerpc kernel
build, in which case they'll actually be performing BE accesses.

This series removes the existing users of these arch-specific
functions, replacing them with calls to the generic byteswappers. 5/5
then removes the function definitions.

I've compile tested this series with pmac32_defconfig,
mpc512x_defconfig and ppc64_defconfig, and also those configs tweaked
to explicitly enable the BT8XX and MXC MMC drivers where possible.

I've tested the KVM patch (4/5) with both BE and LE guests, however I
don't have hardware to do any real testing of the drivers affected in
1..3/5.

David Gibson (5):
powerpc: Move Power Macintosh drivers to generic byteswappers
powerpc: Remove powerpc specific byteswap from bt8xx DVB driver
powerpc: Remove arch specific byteswappers from the MXC MMC driver
powerpc: Cleanup KVM emulated load/store endian handling
powerpc: Remove unused st_le*() and ld_le* functions

arch/powerpc/include/asm/dbdma.h | 12 ++++----
arch/powerpc/include/asm/kvm_host.h | 2 +-
arch/powerpc/include/asm/swab.h | 26 -----------------
arch/powerpc/include/asm/vga.h | 4 +--
arch/powerpc/kvm/powerpc.c | 38 ++++++++++++------------
drivers/ata/pata_macio.c | 10 +++----
drivers/block/swim3.c | 12 ++++----
drivers/ide/pmac.c | 10 +++----
drivers/macintosh/rack-meter.c | 30 +++++++++----------
drivers/media/pci/bt8xx/bt878.h | 4 +--
drivers/mmc/host/mxcmmc.c | 2 +-
drivers/net/ethernet/apple/bmac.c | 30 +++++++++----------
drivers/net/ethernet/apple/mace.c | 44 ++++++++++++++--------------
drivers/scsi/mac53c94.c | 10 +++----
drivers/scsi/mesh.c | 14 ++++-----
drivers/video/fbdev/controlfb.c | 2 +-
drivers/video/fbdev/platinumfb.c | 2 +-
sound/ppc/pmac.c | 58 ++++++++++++++++++-------------------
18 files changed, 141 insertions(+), 169 deletions(-)

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2.1.0