linux/arch/s390/lib/Makefile
Heiko Carstens fbac266f09 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>
2023-05-15 14:12:14 +02:00

26 lines
831 B
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# Makefile for s390-specific library files..
#
lib-y += delay.o string.o uaccess.o find.o spinlock.o tishift.o
obj-y += mem.o xor.o
lib-$(CONFIG_KPROBES) += probes.o
lib-$(CONFIG_UPROBES) += probes.o
obj-$(CONFIG_S390_KPROBES_SANITY_TEST) += test_kprobes_s390.o
test_kprobes_s390-objs += test_kprobes_asm.o test_kprobes.o
# Instrumenting memory accesses to __user data (in different address space)
# produce false positives
KASAN_SANITIZE_uaccess.o := n
obj-$(CONFIG_S390_UNWIND_SELFTEST) += test_unwind.o
CFLAGS_test_unwind.o += -fno-optimize-sibling-calls
obj-$(CONFIG_S390_MODULES_SANITY_TEST) += test_modules.o
obj-$(CONFIG_S390_MODULES_SANITY_TEST_HELPERS) += test_modules_helpers.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
obj-$(CONFIG_EXPOLINE_EXTERN) += expoline/