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linux/arch/s390/lib/tishift.S

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s390: select ARCH_SUPPORTS_INT128 s390 has instructions to support 128 bit arithmetics, e.g. a 64 bit multiply instruction with a 128 bit result. Also 128 bit integer artithmetics are already used in s390 specific architecture code (see e.g. read_persistent_clock64()). Therefore select ARCH_SUPPORTS_INT128. However limit this to clang for now, since gcc generates inefficient code, which may lead to stack overflows, when compiling lib/crypto/curve25519-hacl64.c which depends on ARCH_SUPPORTS_INT128. The gcc generated functions have 6kb stack frames, compared to only 1kb of the code generated with clang. If the kernel is compiled with -Os library calls for __ashlti3(), __ashrti3(), and __lshrti3() may be generated. Similar to arm64 and riscv provide assembler implementations for these functions. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-04-25 04:42:11 -07:00
/* SPDX-License-Identifier: GPL-2.0 */
s390: replace #include <asm/export.h> with #include <linux/export.h> Commit ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost") deprecated <asm/export.h>, which is now a wrapper of <linux/export.h>. Replace #include <asm/export.h> with #include <linux/export.h>. After all the <asm/export.h> lines are converted, <asm/export.h> and <asm-generic/export.h> will be removed. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20230806151641.394720-2-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-06 08:16:39 -07:00
#include <linux/export.h>
s390: select ARCH_SUPPORTS_INT128 s390 has instructions to support 128 bit arithmetics, e.g. a 64 bit multiply instruction with a 128 bit result. Also 128 bit integer artithmetics are already used in s390 specific architecture code (see e.g. read_persistent_clock64()). Therefore select ARCH_SUPPORTS_INT128. However limit this to clang for now, since gcc generates inefficient code, which may lead to stack overflows, when compiling lib/crypto/curve25519-hacl64.c which depends on ARCH_SUPPORTS_INT128. The gcc generated functions have 6kb stack frames, compared to only 1kb of the code generated with clang. If the kernel is compiled with -Os library calls for __ashlti3(), __ashrti3(), and __lshrti3() may be generated. Similar to arm64 and riscv provide assembler implementations for these functions. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-04-25 04:42:11 -07:00
#include <linux/linkage.h>
#include <asm/nospec-insn.h>
.section .noinstr.text, "ax"
GEN_BR_THUNK %r14
SYM_FUNC_START(__ashlti3)
lmg %r0,%r1,0(%r3)
cije %r4,0,1f
lhi %r3,64
sr %r3,%r4
jnh 0f
srlg %r3,%r1,0(%r3)
sllg %r0,%r0,0(%r4)
sllg %r1,%r1,0(%r4)
ogr %r0,%r3
j 1f
0: sllg %r0,%r1,-64(%r4)
lghi %r1,0
1: stmg %r0,%r1,0(%r2)
BR_EX %r14
SYM_FUNC_END(__ashlti3)
EXPORT_SYMBOL(__ashlti3)
SYM_FUNC_START(__ashrti3)
lmg %r0,%r1,0(%r3)
cije %r4,0,1f
lhi %r3,64
sr %r3,%r4
jnh 0f
sllg %r3,%r0,0(%r3)
srlg %r1,%r1,0(%r4)
srag %r0,%r0,0(%r4)
ogr %r1,%r3
j 1f
0: srag %r1,%r0,-64(%r4)
srag %r0,%r0,63
1: stmg %r0,%r1,0(%r2)
BR_EX %r14
SYM_FUNC_END(__ashrti3)
EXPORT_SYMBOL(__ashrti3)
SYM_FUNC_START(__lshrti3)
lmg %r0,%r1,0(%r3)
cije %r4,0,1f
lhi %r3,64
sr %r3,%r4
jnh 0f
sllg %r3,%r0,0(%r3)
srlg %r1,%r1,0(%r4)
srlg %r0,%r0,0(%r4)
ogr %r1,%r3
j 1f
0: srlg %r1,%r0,-64(%r4)
lghi %r0,0
1: stmg %r0,%r1,0(%r2)
BR_EX %r14
SYM_FUNC_END(__lshrti3)
EXPORT_SYMBOL(__lshrti3)
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