From: Heiko Carstens Date: Tue, 9 Jun 2026 10:33:41 +0000 (+0200) Subject: s390/string: Convert memset(16|32|64)() to C X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=90d7412cd1ca82528adaf79abffaf12c36ba1b19;p=thirdparty%2Flinux.git s390/string: Convert memset(16|32|64)() to C Convert memset(16|32|64)() from assembler to C, which should make it easier to read and change, if required. And it allows the compiler to optimize the code, and use different instructions, except for the used inline assemblies. Reviewed-by: Juergen Christ Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev --- diff --git a/arch/s390/boot/Makefile b/arch/s390/boot/Makefile index e1f82d118bc95..10b75e053a6f6 100644 --- a/arch/s390/boot/Makefile +++ b/arch/s390/boot/Makefile @@ -31,7 +31,7 @@ CFLAGS_sclp_early_core.o += -I$(srctree)/drivers/s390/char CFLAGS_string.o = -ffreestanding obj-y := head.o als.o startup.o physmem_info.o ipl_parm.o ipl_report.o vmem.o -obj-y += string.o ebcdic.o sclp_early_core.o mem.o ipl_vmparm.o cmdline.o +obj-y += string.o ebcdic.o sclp_early_core.o ipl_vmparm.o cmdline.o obj-y += version.o pgm_check.o ctype.o ipl_data.o relocs.o alternative.o obj-y += uv.o printk.o trampoline.o obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o diff --git a/arch/s390/boot/mem.S b/arch/s390/boot/mem.S deleted file mode 100644 index b33463633f03e..0000000000000 --- a/arch/s390/boot/mem.S +++ /dev/null @@ -1,2 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#include "../lib/mem.S" diff --git a/arch/s390/boot/string.c b/arch/s390/boot/string.c index bd68161434a60..e4ad196cb7200 100644 --- a/arch/s390/boot/string.c +++ b/arch/s390/boot/string.c @@ -43,11 +43,7 @@ ssize_t sized_strscpy(char *dst, const char *src, size_t count) void *memset64(uint64_t *s, uint64_t v, size_t count) { - uint64_t *xs = s; - - while (count--) - *xs++ = v; - return s; + return __memset64(s, v, count * sizeof(v)); } char *skip_spaces(const char *str) diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile index c82aedef02728..aa6cc6a1fe881 100644 --- a/arch/s390/lib/Makefile +++ b/arch/s390/lib/Makefile @@ -10,7 +10,6 @@ CFLAGS_string.o = -ffreestanding lib-y += delay.o string.o uaccess.o find.o spinlock.o tishift.o lib-y += csum-partial.o -obj-y += mem.o lib-$(CONFIG_KPROBES) += probes.o lib-$(CONFIG_UPROBES) += probes.o obj-$(CONFIG_S390_KPROBES_SANITY_TEST) += test_kprobes_s390.o diff --git a/arch/s390/lib/mem.S b/arch/s390/lib/mem.S deleted file mode 100644 index d2e1ca87a5680..0000000000000 --- a/arch/s390/lib/mem.S +++ /dev/null @@ -1,57 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * String handling functions. - * - * Copyright IBM Corp. 2012 - */ - -#include -#include -#include - - GEN_BR_THUNK %r14 - -/* - * __memset16/32/64 - * - * void *__memset16(uint16_t *s, uint16_t v, size_t count) - * void *__memset32(uint32_t *s, uint32_t v, size_t count) - * void *__memset64(uint64_t *s, uint64_t v, size_t count) - */ -.macro __MEMSET bits,bytes,insn -SYM_FUNC_START(__memset\bits) - ltgr %r4,%r4 - jz .L__memset_exit\bits - cghi %r4,\bytes - je .L__memset_store\bits - aghi %r4,-(\bytes+1) - srlg %r5,%r4,8 - ltgr %r5,%r5 - lgr %r1,%r2 - jz .L__memset_remainder\bits -.L__memset_loop\bits: - \insn %r3,0(%r1) - mvc \bytes(256-\bytes,%r1),0(%r1) - la %r1,256(%r1) - brctg %r5,.L__memset_loop\bits -.L__memset_remainder\bits: - \insn %r3,0(%r1) - exrl %r4,.L__memset_mvc\bits - BR_EX %r14 -.L__memset_store\bits: - \insn %r3,0(%r2) -.L__memset_exit\bits: - BR_EX %r14 -.L__memset_mvc\bits: - mvc \bytes(1,%r1),0(%r1) -SYM_FUNC_END(__memset\bits) -.endm - -__MEMSET 16,2,sth -EXPORT_SYMBOL(__memset16) - -__MEMSET 32,4,st -EXPORT_SYMBOL(__memset32) - -__MEMSET 64,8,stg -EXPORT_SYMBOL(__memset64) diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c index 056ea2027ddd2..cb65b8f5392a9 100644 --- a/arch/s390/lib/string.c +++ b/arch/s390/lib/string.c @@ -158,6 +158,53 @@ EXPORT_SYMBOL(__memcpy); EXPORT_SYMBOL(memcpy); #endif +#define DEFINE_MEMSET(_bits, _bytes, _type) \ +void *__memset##_bits(_type *s, _type v, size_t n) \ +{ \ + _type *xs = s; \ + \ + if (!n) \ + return s; \ + while (n >= 256) { \ + *xs = v; \ + asm volatile( \ + " mvc %[_b](256-%[_b],%[xs]),0(%[xs])\n" \ + : \ + : [xs] "a" (xs), [_b] "i" (_bytes) \ + : "memory"); \ + xs = (_type *)((char *)xs + 256); \ + n -= 256; \ + } \ + if (!n) \ + return s; \ + *xs = v; \ + if (n == _bytes) \ + return s; \ + n -= _bytes + 1; \ + asm volatile( \ + " exrl %[n],1f\n" \ + " j 2f\n" \ + "1: mvc %[_b](1,%[xs]),0(%[xs])\n" \ + "2:" \ + : \ + : [n] "a" (n), [xs] "a" (xs), [_b] "i" (_bytes) \ + : "memory"); \ + return s; \ +} \ +EXPORT_SYMBOL(__memset##_bits) + +#ifdef __HAVE_ARCH_MEMSET16 +DEFINE_MEMSET(16, 2, uint16_t); +#endif + +#ifdef __HAVE_ARCH_MEMSET32 +DEFINE_MEMSET(32, 4, uint32_t); +#endif + +#ifdef __HAVE_ARCH_MEMSET64 +DEFINE_MEMSET(64, 8, uint64_t); +#endif + /* * Helper functions to find the end of a string */ diff --git a/arch/s390/purgatory/Makefile b/arch/s390/purgatory/Makefile index f55764d0c49e4..e74410bb1b884 100644 --- a/arch/s390/purgatory/Makefile +++ b/arch/s390/purgatory/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -purgatory-y := head.o purgatory.o string.o sha256.o mem.o +purgatory-y := head.o purgatory.o string.o sha256.o targets += $(purgatory-y) purgatory.lds purgatory purgatory.chk purgatory.ro PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y)) @@ -10,9 +10,6 @@ $(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE CFLAGS_sha256.o := -D__NO_FORTIFY -$(obj)/mem.o: $(srctree)/arch/s390/lib/mem.S FORCE - $(call if_changed_rule,as_o_S) - CC_FLAGS_MARCH_MINIMUM := -march=z10 KBUILD_CFLAGS := $(CC_FLAGS_DIALECT) -fno-strict-aliasing -Wall -Wstrict-prototypes