kernel.git/arch/powerpc/lib/Makefile, branch linux-5.3.y

powerpc/lib: only build ldstfp.o when CONFIG_PPC_FPU is set

2019-05-28T02:08:11Z

The entire code in ldstfp.o is enclosed into #ifdef CONFIG_PPC_FPU, so there is no point in building it when this config is not selected. Fixes: cd64d1697cf0 ("powerpc: mtmsrd not defined") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib: fix redundant inclusion of quad.o

2019-05-28T02:08:11Z

quad.o is only for PPC64, and already included in obj64-y, so it doesn't have to be in obj-y Fixes: 31bfdb036f12 ("powerpc: Use instruction emulation infrastructure to handle alignment faults") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: disable KASAN instrumentation on early/critical files.

2019-05-02T15:20:26Z

All files containing functions run before kasan_early_init() is called must have KASAN instrumentation disabled. For those file, branch profiling also have to be disabled otherwise each if () generates a call to ftrace_likely_update(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: prepare string/mem functions for KASAN

2019-05-02T15:20:25Z

CONFIG_KASAN implements wrappers for memcpy() memmove() and memset() Those wrappers are doing the verification then call respectively __memcpy() __memmove() and __memset(). The arches are therefore expected to rename their optimised functions that way. For files on which KASAN is inhibited, #defines are used to allow them to directly call optimised versions of the functions without going through the KASAN wrappers. See commit 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") for details. Other string / mem functions do not (yet) have kasan wrappers, we therefore have to fallback to the generic versions when KASAN is active, otherwise KASAN checks will be skipped. Signed-off-by: Christophe Leroy [mpe: Fixups to keep selftests working] Signed-off-by: Michael Ellerman

powerpc: sstep: Add tests for compute type instructions

2019-02-23T10:04:31Z

This enhances the current selftest framework for validating the in-kernel instruction emulation infrastructure by adding support for compute type instructions i.e. integer ALU-based instructions. Originally, this framework was limited to only testing load and store instructions. While most of the GPRs can be validated, support for SPRs is limited to LR, CR and XER for now. When writing the test cases, one must ensure that the Stack Pointer (GPR1) or the Thread Pointer (GPR13) are not touched by any means as these are vital non-volatile registers. Signed-off-by: Sandipan Das [mpe: Use patch_site for the code patching] Signed-off-by: Michael Ellerman

powerpc: Add support for function error injection

2018-10-20T02:26:43Z

We implement regs_set_return_value() and override_function_with_return() for this purpose. On powerpc, a return from a function (blr) just branches to the location contained in the link register. So, we can just update pt_regs rather than redirecting execution to a dummy function that returns. Signed-off-by: Naveen N. Rao Reviewed-by: Samuel Mendoza-Jonas Signed-off-by: Michael Ellerman

powerpc: Add -Werror at arch/powerpc level

2018-10-18T13:56:17Z

Back when I added -Werror in commit ba55bd74360e ("powerpc: Add configurable -Werror for arch/powerpc") I did it by adding it to most of the arch Makefiles. At the time we excluded math-emu, because apparently it didn't build cleanly. But that seems to have been fixed somewhere in the interim. So move the -Werror addition to the top-level of the arch, this saves us from repeating it in every Makefile and means we won't forget to add it to any new sub-dirs. Signed-off-by: Michael Ellerman

powerpc/lib: Implement strlen() in assembly for PPC32

2018-08-07T11:49:30Z

The generic implementation of strlen() reads strings byte per byte. This patch implements strlen() in assembly based on a read of entire words, in the same spirit as what some other arches and glibc do. On a 8xx the time spent in strlen is reduced by 3/4 for long strings. strlen() selftest on an 8xx provides the following values: Before the patch (ie with the generic strlen() in lib/string.c): len 256 : time = 1.195055 len 016 : time = 0.083745 len 008 : time = 0.046828 len 004 : time = 0.028390 After the patch: len 256 : time = 0.272185 ==> 78% improvment len 016 : time = 0.040632 ==> 51% improvment len 008 : time = 0.033060 ==> 29% improvment len 004 : time = 0.029149 ==> 2% degradation On a 832x: Before the patch: len 256 : time = 0.236125 len 016 : time = 0.018136 len 008 : time = 0.011000 len 004 : time = 0.007229 After the patch: len 256 : time = 0.094950 ==> 60% improvment len 016 : time = 0.013357 ==> 26% improvment len 008 : time = 0.010586 ==> 4% improvment len 004 : time = 0.008784 Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib: optimise PPC32 memcmp

2018-06-03T14:39:21Z

At the time being, memcmp() compares two chunks of memory byte per byte. This patch optimises the comparison by comparing word by word. On the same way as commit 15c2d45d17418 ("powerpc: Add 64bit optimised memcmp"), this patch moves memcmp() into a dedicated file named memcmp_32.S A small benchmark performed on an 8xx comparing two chuncks of 512 bytes performed 100000 times gives: Before : 5852274 TB ticks After: 1488638 TB ticks This is almost 4 times faster Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib: optimise 32 bits __clear_user()

2018-06-03T14:39:21Z

Rewrite clear_user() on the same principle as memset(0), making use of dcbz to clear complete cache lines. This code is a copy/paste of memset(), with some modifications in order to retrieve remaining number of bytes to be cleared, as it needs to be returned in case of error. On the same way as done on PPC64 in commit 17968fbbd19f1 ("powerpc: 64bit optimised __clear_user"), the patch moves __clear_user() into a dedicated file string_32.S On a MPC885, throughput is almost doubled: Before: ~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 18.990779 seconds, 52.7MB/s After: ~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 9.611468 seconds, 104.0MB/s On a MPC8321, throughput is multiplied by 2.12: Before: root@vgoippro:~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 6.844352 seconds, 146.1MB/s After: root@vgoippro:~# dd if=/dev/zero of=/dev/null bs=1M count=1000 1048576000 bytes (1000.0MB) copied, 3.218854 seconds, 310.7MB/s Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman