diff options
| author | Heiko Carstens <hca@linux.ibm.com> | 2020-11-16 08:06:41 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2020-11-23 12:01:13 +0100 |
| commit | 80f06306240e0ad1c75116111be11950474dfda7 (patch) | |
| tree | 99ed304a1c6d26ad408145ba98b83d9fbf807b7f /arch/s390/kernel/vdso64 | |
| parent | 062e527956d05fae02f143c0d5ff9e8525c6799f (diff) | |
| download | linux-80f06306240e0ad1c75116111be11950474dfda7.tar.gz | |
s390/vdso: reimplement getcpu vdso syscall
Implement the previously removed getcpu vdso syscall by using the
TOD programmable field to pass the cpu number to user space.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/vdso64')
| -rw-r--r-- | arch/s390/kernel/vdso64/Makefile | 3 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso64/getcpu.c | 20 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso64/vdso64.lds.S | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/vdso64/vdso_user_wrapper.S | 1 |
4 files changed, 24 insertions, 2 deletions
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile index b0cf58ae82fe..a6e0fb6b91d6 100644 --- a/arch/s390/kernel/vdso64/Makefile +++ b/arch/s390/kernel/vdso64/Makefile @@ -7,7 +7,8 @@ ARCH_REL_TYPE_ABS += R_390_GOT|R_390_PLT include $(srctree)/lib/vdso/Makefile obj-vdso64 = vdso_user_wrapper.o note.o -obj-cvdso64 = vdso64_generic.o +obj-cvdso64 = vdso64_generic.o getcpu.o +CFLAGS_REMOVE_getcpu.o = -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE) CFLAGS_REMOVE_vdso64_generic.o = -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE) # Build rules diff --git a/arch/s390/kernel/vdso64/getcpu.c b/arch/s390/kernel/vdso64/getcpu.c new file mode 100644 index 000000000000..a5da7a9eb43d --- /dev/null +++ b/arch/s390/kernel/vdso64/getcpu.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright IBM Corp. 2020 */ + +#include <linux/compiler.h> +#include <linux/getcpu.h> +#include <asm/timex.h> + +int __s390_vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused) +{ + __u16 todval[8]; + + /* CPU number is stored in the programmable field of the TOD clock */ + get_tod_clock_ext((char *)todval); + if (cpu) + *cpu = todval[7]; + /* NUMA node is always zero */ + if (node) + *node = 0; + return 0; +} diff --git a/arch/s390/kernel/vdso64/vdso64.lds.S b/arch/s390/kernel/vdso64/vdso64.lds.S index b59006584a9d..7bde3909290f 100644 --- a/arch/s390/kernel/vdso64/vdso64.lds.S +++ b/arch/s390/kernel/vdso64/vdso64.lds.S @@ -135,7 +135,7 @@ VERSION __kernel_gettimeofday; __kernel_clock_gettime; __kernel_clock_getres; - + __kernel_getcpu; local: *; }; } diff --git a/arch/s390/kernel/vdso64/vdso_user_wrapper.S b/arch/s390/kernel/vdso64/vdso_user_wrapper.S index a775d7e52872..f773505c7e63 100644 --- a/arch/s390/kernel/vdso64/vdso_user_wrapper.S +++ b/arch/s390/kernel/vdso64/vdso_user_wrapper.S @@ -36,3 +36,4 @@ __kernel_\func: vdso_func gettimeofday vdso_func clock_getres vdso_func clock_gettime +vdso_func getcpu |