linux-stable.git/arch/powerpc/lib, branch linux-4.3.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: put csum_tcpudp_magic inline

2015-08-08T03:59:19+00:00

csum_tcpudp_magic() is only a few instructions, and does modify
really few registers. So it is not worth having it as a separate
function and suffer function branching and saving of volatile
registers.

This patch makes it inline by use of the already existing
csum_tcpudp_nofold() function.

Signed-off-by: Christophe Leroy 
Signed-off-by: Scott Wood

Merge tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

2015-06-24T15:46:32+00:00

Pull powerpc updates from Michael Ellerman:

- disable the 32-bit vdso when building LE, so we can build with a
64-bit only toolchain.

- EEH fixes from Gavin & Richard.

- enable the sys_kcmp syscall from Laurent.

- sysfs control for fastsleep workaround from Shreyas.

- expose OPAL events as an irq chip by Alistair.

- MSI ops moved to pci_controller_ops by Daniel.

- fix for kernel to userspace backtraces for perf from Anton.

- merge pseries and pseries_le defconfigs from Cyril.

- CXL in-kernel API from Mikey.

- OPAL prd driver from Jeremy.

- fix for DSCR handling & tests from Anshuman.

- Powernv flash mtd driver from Cyril.

- dynamic DMA Window support on powernv from Alexey.

- LLVM clang fixes & workarounds from Anton.

- reworked version of the patch to abort syscalls when transactional.

- fix the swap encoding to support 4TB, from Aneesh.

- various fixes as usual.

- Freescale updates from Scott: Highlights include more 8xx
optimizations, an e6500 hugetlb optimization, QMan device tree nodes,
t1024/t1023 support, and various fixes and cleanup.

* tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (180 commits)
cxl: Fix typo in debug print
cxl: Add CXL_KERNEL_API config option
powerpc/powernv: Fix wrong IOMMU table in pnv_ioda_setup_bus_dma()
powerpc/mm: Change the swap encoding in pte.
powerpc/mm: PTE_RPN_MAX is not used, remove the same
powerpc/tm: Abort syscalls in active transactions
powerpc/iommu/ioda2: Enable compile with IOV=on and IOMMU_API=off
powerpc/include: Add opal-prd to installed uapi headers
powerpc/powernv: fix construction of opal PRD messages
powerpc/powernv: Increase opal-irqchip initcall priority
powerpc: Make doorbell check preemption safe
powerpc/powernv: pnv_init_idle_states() should only run on powernv
macintosh/nvram: Remove as unused
powerpc: Don't use gcc specific options on clang
powerpc: Don't use -mno-strict-align on clang
powerpc: Only use -mtraceback=no, -mno-string and -msoft-float if toolchain supports it
powerpc: Only use -mabi=altivec if toolchain supports it
powerpc: Fix duplicate const clang warning in user access code
vfio: powerpc/spapr: Support Dynamic DMA windows
vfio: powerpc/spapr: Register memory and define IOMMU v2
...

powerpc: Only use -mabi=altivec if toolchain supports it

2015-06-11T07:33:05+00:00

The -mabi=altivec option is not recognised on LLVM, so use call cc-option
to check for support.

Signed-off-by: Anton Blanchard 
Signed-off-by: Michael Ellerman