kernel/linux.git/arch/powerpc/lib/copy_32.S, branch linux-4.4.y

powerpc32: memset: only use dcbz once cache is enabled

2015-09-17T00:36:53+00:00

memset() uses instruction dcbz to speed up clearing by not wasting time loading cache line with data that will be overwritten. Some platform like mpc52xx do no have cache active at startup and can therefore not use memset(). Allthough no part of the code explicitly uses memset(), GCC may make calls to it. This patch modifies memset() such that at startup, memset() unconditionally skip the optimised bloc that uses dcbz instruction. Once the initial MMU is set up, in machine_init() we patch memset() by replacing this inconditional jump by a NOP Tested-by: Thomas Gleixner Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc32: memcpy: only use dcbz once cache is enabled

2015-09-17T00:36:44+00:00

memcpy() uses instruction dcbz to speed up copy by not wasting time loading cache line with data that will be overwritten. Some platform like mpc52xx do no have cache active at startup and can therefore not use memcpy(). Allthough no part of the code explicitly uses memcpy(), GCC makes calls to it. This patch modifies memcpy() such that at startup, memcpy() unconditionally jumps to generic_memcpy() which doesn't use the dcbz instruction. Once the initial MMU is set up, in machine_init() we patch memcpy() by replacing this inconditional jump by a NOP Reported-by: Michal Sojka Tested-by: Thomas Gleixner Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/32: Few optimisations in memcpy

2015-08-08T03:59:29+00:00

This patch adds a few optimisations in memcpy functions by using lbzu/stbu instead of lxb/stb and by re-ordering insn inside a loop to reduce latency due to loading Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc/32: cacheable_memcpy becomes memcpy

2015-08-08T03:59:27+00:00

cacheable_memcpy uses dcbz instruction and is more efficient than memcpy when the destination is in RAM. If the destination is in an io area, memcpy_toio() is normally used, not memcpy This patch renames memcpy as generic_memcpy, and renames cacheable_memcpy as memcpy On MPC885, we get approximatly 7% increase of the transfer rate on an FTP reception Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc/32: Merge the new memset() with the old one

2015-08-08T03:59:24+00:00

cacheable_memzero() which has become the new memset() and the old memset() are quite similar, so just merge them. Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc/32: memset(0): use cacheable_memzero

2015-08-08T03:59:21+00:00

cacheable_memzero uses dcbz instruction and is more efficient than memset(0) when the destination is in RAM This patch renames memset as generic_memset, and defines memset as a prolog to cacheable_memzero. This prolog checks if the byte to set is 0. If not, it falls back to generic_memcpy() cacheable_memzero disappears as it is not referenced anywhere anymore Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

Partially revert "powerpc: Remove duplicate cacheable_memcpy/memzero functions"

2015-08-08T03:59:21+00:00

This partially reverts commit 'powerpc: Remove duplicate cacheable_memcpy/memzero functions ("b05ae4ee602b7dc90771408ccf0972e1b3801a35")' Functions cacheable_memcpy/memzero are more efficient than memcpy/memset as they use the dcbz instruction which avoids refill of the cacheline with the data that we will overwrite. Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood

powerpc: Remove duplicate cacheable_memcpy/memzero functions

2015-03-17T00:25:50+00:00

These functions are only used from one place each. If the cacheable_* versions really are more efficient, then those changes should be migrated into the common code instead. NOTE: The old routines are just flat buggy on kernels that support hardware with different cacheline sizes. Signed-off-by: Kyle Moffett Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix incorrect .stabs entry for copy_32.S

2010-09-02T04:07:34+00:00

Signed-off-by: Sean MacLennan Signed-off-by: Benjamin Herrenschmidt

powerpc/8xx: Start using dcbX instructions in various copy routines

2009-12-09T06:10:37+00:00

Now that 8xx can fixup dcbX instructions, start using them where possible like every other PowerPc arch do. Signed-off-by: Joakim Tjernlund Signed-off-by: Benjamin Herrenschmidt