diff options
author | Sven Schnelle <svens@linux.ibm.com> | 2020-04-28 09:52:23 +0200 |
---|---|---|
committer | Vasily Gorbik <gor@linux.ibm.com> | 2020-08-26 18:47:21 +0200 |
commit | 4bff8cb5450287e246d365b719148b2d9364c292 (patch) | |
tree | 4cc4c378f7541d4b8fd080663d2f0847a24c2cfc /arch/s390/kernel/vdso64 | |
parent | 98ad45fb58c14ebef6da27f91905e5b8fcff8686 (diff) | |
download | linux-4bff8cb5450287e246d365b719148b2d9364c292.tar.bz2 |
s390: convert to GENERIC_VDSO
Convert s390 to generic vDSO. There are a few special things on s390:
- vDSO can be called without a stack frame - glibc did this in the past.
So we need to allocate a stackframe on our own.
- The former assembly code used stcke to get the TOD clock and applied
time steering to it. We need to do the same in the new code. This is done
in the architecture specific __arch_get_hw_counter function. The steering
information is stored in an architecure specific area in the vDSO data.
- CPUCLOCK_VIRT is now handled with a syscall fallback, which might
be slower/less accurate than the old implementation.
The getcpu() function stays as an assembly function because there is no
generic implementation and the code is just a few lines.
Performance number from my system do 100 mio gettimeofday() calls:
Plain syscall: 8.6s
Generic VDSO: 1.3s
old ASM VDSO: 1s
So it's a bit slower but still much faster than syscalls.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/vdso64')
-rw-r--r-- | arch/s390/kernel/vdso64/Makefile | 19 | ||||
-rw-r--r-- | arch/s390/kernel/vdso64/clock_getres.S | 50 | ||||
-rw-r--r-- | arch/s390/kernel/vdso64/clock_gettime.S | 163 | ||||
-rw-r--r-- | arch/s390/kernel/vdso64/gettimeofday.S | 71 | ||||
-rw-r--r-- | arch/s390/kernel/vdso64/vdso64_generic.c | 18 | ||||
-rw-r--r-- | arch/s390/kernel/vdso64/vdso_user_wrapper.S | 38 |
6 files changed, 71 insertions, 288 deletions
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile index 4a66a1cb919b..f1c0570780d1 100644 --- a/arch/s390/kernel/vdso64/Makefile +++ b/arch/s390/kernel/vdso64/Makefile @@ -1,14 +1,20 @@ # SPDX-License-Identifier: GPL-2.0 -# List of files in the vdso, has to be asm only for now +# List of files in the vdso KCOV_INSTRUMENT := n +ARCH_REL_TYPE_ABS := R_390_COPY|R_390_GLOB_DAT|R_390_JMP_SLOT|R_390_RELATIVE +ARCH_REL_TYPE_ABS += R_390_GOT|R_390_PLT -obj-vdso64 = gettimeofday.o clock_getres.o clock_gettime.o note.o getcpu.o +include $(srctree)/lib/vdso/Makefile +obj-vdso64 = vdso_user_wrapper.o note.o getcpu.o +obj-cvdso64 = vdso64_generic.o +CFLAGS_REMOVE_vdso64_generic.o = -pg $(CC_FLAGS_FTRACE) $(CC_FLAGS_EXPOLINE) # Build rules -targets := $(obj-vdso64) vdso64.so vdso64.so.dbg +targets := $(obj-vdso64) $(obj-cvdso64) vdso64.so vdso64.so.dbg obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64)) +obj-cvdso64 := $(addprefix $(obj)/, $(obj-cvdso64)) KBUILD_AFLAGS += -DBUILD_VDSO KBUILD_CFLAGS += -DBUILD_VDSO @@ -37,7 +43,7 @@ KASAN_SANITIZE := n $(obj)/vdso64_wrapper.o : $(obj)/vdso64.so # link rule for the .so file, .lds has to be first -$(obj)/vdso64.so.dbg: $(obj)/vdso64.lds $(obj-vdso64) FORCE +$(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) $(obj-cvdso64) FORCE $(call if_changed,ld) # strip rule for the .so file @@ -49,9 +55,14 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE $(obj-vdso64): %.o: %.S FORCE $(call if_changed_dep,vdso64as) +$(obj-cvdso64): %.o: %.c FORCE + $(call if_changed_dep,vdso64cc) + # actual build commands quiet_cmd_vdso64as = VDSO64A $@ cmd_vdso64as = $(CC) $(a_flags) -c -o $@ $< +quiet_cmd_vdso64cc = VDSO64C $@ + cmd_vdso64cc = $(CC) $(c_flags) -c -o $@ $< # install commands for the unstripped file quiet_cmd_vdso_install = INSTALL $@ diff --git a/arch/s390/kernel/vdso64/clock_getres.S b/arch/s390/kernel/vdso64/clock_getres.S deleted file mode 100644 index 0c79caa32b59..000000000000 --- a/arch/s390/kernel/vdso64/clock_getres.S +++ /dev/null @@ -1,50 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Userland implementation of clock_getres() for 64 bits processes in a - * s390 kernel for use in the vDSO - * - * Copyright IBM Corp. 2008 - * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) - */ -#include <asm/vdso.h> -#include <asm/asm-offsets.h> -#include <asm/unistd.h> -#include <asm/dwarf.h> - - .text - .align 4 - .globl __kernel_clock_getres - .type __kernel_clock_getres,@function -__kernel_clock_getres: - CFI_STARTPROC - larl %r1,3f - lg %r0,0(%r1) - cghi %r2,__CLOCK_REALTIME_COARSE - je 0f - cghi %r2,__CLOCK_MONOTONIC_COARSE - je 0f - larl %r1,_vdso_data - llgf %r0,__VDSO_CLOCK_REALTIME_RES(%r1) - cghi %r2,__CLOCK_REALTIME - je 0f - cghi %r2,__CLOCK_MONOTONIC - je 0f - cghi %r2,__CLOCK_THREAD_CPUTIME_ID - je 0f - cghi %r2,-2 /* Per-thread CPUCLOCK with PID=0, VIRT=1 */ - jne 2f - larl %r5,_vdso_data - icm %r0,15,__LC_ECTG_OK(%r5) - jz 2f -0: ltgr %r3,%r3 - jz 1f /* res == NULL */ - xc 0(8,%r3),0(%r3) /* set tp->tv_sec to zero */ - stg %r0,8(%r3) /* store tp->tv_usec */ -1: lghi %r2,0 - br %r14 -2: lghi %r1,__NR_clock_getres /* fallback to svc */ - svc 0 - br %r14 - CFI_ENDPROC -3: .quad __CLOCK_COARSE_RES - .size __kernel_clock_getres,.-__kernel_clock_getres diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S deleted file mode 100644 index 9d2ee79b90f2..000000000000 --- a/arch/s390/kernel/vdso64/clock_gettime.S +++ /dev/null @@ -1,163 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Userland implementation of clock_gettime() for 64 bits processes in a - * s390 kernel for use in the vDSO - * - * Copyright IBM Corp. 2008 - * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) - */ -#include <asm/vdso.h> -#include <asm/asm-offsets.h> -#include <asm/unistd.h> -#include <asm/dwarf.h> -#include <asm/ptrace.h> - - .text - .align 4 - .globl __kernel_clock_gettime - .type __kernel_clock_gettime,@function -__kernel_clock_gettime: - CFI_STARTPROC - aghi %r15,-16 - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16 - CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD - larl %r5,_vdso_data - cghi %r2,__CLOCK_REALTIME_COARSE - je 4f - cghi %r2,__CLOCK_REALTIME - je 5f - cghi %r2,-3 /* Per-thread CPUCLOCK with PID=0, VIRT=1 */ - je 9f - cghi %r2,__CLOCK_MONOTONIC_COARSE - je 3f - cghi %r2,__CLOCK_MONOTONIC - jne 12f - - /* CLOCK_MONOTONIC */ -0: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ - tmll %r4,0x0001 /* pending update ? loop */ - jnz 0b - stcke 0(%r15) /* Store TOD clock */ - lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ - lg %r0,__VDSO_WTOM_SEC(%r5) - lg %r1,1(%r15) - sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ - msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ - alg %r1,__VDSO_WTOM_NSEC(%r5) - srlg %r1,%r1,0(%r2) /* >> tk->shift */ - clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ - jne 0b - larl %r5,13f -1: clg %r1,0(%r5) - jl 2f - slg %r1,0(%r5) - aghi %r0,1 - j 1b -2: stg %r0,0(%r3) /* store tp->tv_sec */ - stg %r1,8(%r3) /* store tp->tv_nsec */ - lghi %r2,0 - aghi %r15,16 - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD - CFI_RESTORE 15 - br %r14 - - /* CLOCK_MONOTONIC_COARSE */ - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16 - CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD -3: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ - tmll %r4,0x0001 /* pending update ? loop */ - jnz 3b - lg %r0,__VDSO_WTOM_CRS_SEC(%r5) - lg %r1,__VDSO_WTOM_CRS_NSEC(%r5) - clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ - jne 3b - j 2b - - /* CLOCK_REALTIME_COARSE */ -4: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ - tmll %r4,0x0001 /* pending update ? loop */ - jnz 4b - lg %r0,__VDSO_XTIME_CRS_SEC(%r5) - lg %r1,__VDSO_XTIME_CRS_NSEC(%r5) - clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ - jne 4b - j 7f - - /* CLOCK_REALTIME */ -5: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ - tmll %r4,0x0001 /* pending update ? loop */ - jnz 5b - stcke 0(%r15) /* Store TOD clock */ - lg %r1,1(%r15) - lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */ - slgr %r0,%r1 /* now - ts_steering_end */ - ltgr %r0,%r0 /* past end of steering ? */ - jm 17f - srlg %r0,%r0,15 /* 1 per 2^16 */ - tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ - jz 18f - lcgr %r0,%r0 /* negative TOD offset */ -18: algr %r1,%r0 /* add steering offset */ -17: lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ - sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ - msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ - alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ - srlg %r1,%r1,0(%r2) /* >> tk->shift */ - lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */ - clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ - jne 5b - larl %r5,13f -6: clg %r1,0(%r5) - jl 7f - slg %r1,0(%r5) - aghi %r0,1 - j 6b -7: stg %r0,0(%r3) /* store tp->tv_sec */ - stg %r1,8(%r3) /* store tp->tv_nsec */ - lghi %r2,0 - aghi %r15,16 - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD - CFI_RESTORE 15 - br %r14 - - /* CPUCLOCK_VIRT for this thread */ - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16 - CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD -9: lghi %r4,0 - icm %r0,15,__VDSO_ECTG_OK(%r5) - jz 12f - sacf 256 /* Magic ectg instruction */ - .insn ssf,0xc80100000000,__VDSO_ECTG_BASE(4),__VDSO_ECTG_USER(4),4 - sacf 0 - algr %r1,%r0 /* r1 = cputime as TOD value */ - mghi %r1,1000 /* convert to nanoseconds */ - srlg %r1,%r1,12 /* r1 = cputime in nanosec */ - lgr %r4,%r1 - larl %r5,13f - srlg %r1,%r1,9 /* divide by 1000000000 */ - mlg %r0,8(%r5) - srlg %r0,%r0,11 /* r0 = tv_sec */ - stg %r0,0(%r3) - msg %r0,0(%r5) /* calculate tv_nsec */ - slgr %r4,%r0 /* r4 = tv_nsec */ - stg %r4,8(%r3) - lghi %r2,0 - aghi %r15,16 - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD - CFI_RESTORE 15 - br %r14 - - /* Fallback to system call */ - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD+16 - CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD -12: lghi %r1,__NR_clock_gettime - svc 0 - aghi %r15,16 - CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD - CFI_RESTORE 15 - br %r14 - CFI_ENDPROC - -13: .quad 1000000000 -14: .quad 19342813113834067 - .size __kernel_clock_gettime,.-__kernel_clock_gettime diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S deleted file mode 100644 index aebe10dc7c99..000000000000 --- a/arch/s390/kernel/vdso64/gettimeofday.S +++ /dev/null @@ -1,71 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Userland implementation of gettimeofday() for 64 bits processes in a - * s390 kernel for use in the vDSO - * - * Copyright IBM Corp. 2008 - * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) - */ -#include <asm/vdso.h> -#include <asm/asm-offsets.h> -#include <asm/unistd.h> -#include <asm/dwarf.h> -#include <asm/ptrace.h> - - .text - .align 4 - .globl __kernel_gettimeofday - .type __kernel_gettimeofday,@function -__kernel_gettimeofday: - CFI_STARTPROC - aghi %r15,-16 - CFI_ADJUST_CFA_OFFSET 16 - CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD - larl %r5,_vdso_data -0: ltgr %r3,%r3 /* check if tz is NULL */ - je 1f - mvc 0(8,%r3),__VDSO_TIMEZONE(%r5) -1: ltgr %r2,%r2 /* check if tv is NULL */ - je 4f - lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ - tmll %r4,0x0001 /* pending update ? loop */ - jnz 0b - stcke 0(%r15) /* Store TOD clock */ - lg %r1,1(%r15) - lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */ - slgr %r0,%r1 /* now - ts_steering_end */ - ltgr %r0,%r0 /* past end of steering ? */ - jm 6f - srlg %r0,%r0,15 /* 1 per 2^16 */ - tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ - jz 7f - lcgr %r0,%r0 /* negative TOD offset */ -7: algr %r1,%r0 /* add steering offset */ -6: sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ - msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ - alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ - lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */ - clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ - jne 0b - lgf %r5,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ - srlg %r1,%r1,0(%r5) /* >> tk->shift */ - larl %r5,5f -2: clg %r1,0(%r5) - jl 3f - slg %r1,0(%r5) - aghi %r0,1 - j 2b -3: stg %r0,0(%r2) /* store tv->tv_sec */ - slgr %r0,%r0 /* tv_nsec -> tv_usec */ - ml %r0,8(%r5) - srlg %r0,%r0,6 - stg %r0,8(%r2) /* store tv->tv_usec */ -4: lghi %r2,0 - aghi %r15,16 - CFI_ADJUST_CFA_OFFSET -16 - CFI_RESTORE 15 - br %r14 - CFI_ENDPROC -5: .quad 1000000000 - .long 274877907 - .size __kernel_gettimeofday,.-__kernel_gettimeofday diff --git a/arch/s390/kernel/vdso64/vdso64_generic.c b/arch/s390/kernel/vdso64/vdso64_generic.c new file mode 100644 index 000000000000..a8cef7e4d137 --- /dev/null +++ b/arch/s390/kernel/vdso64/vdso64_generic.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "../../../../lib/vdso/gettimeofday.c" + +int __s390_vdso_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +int __s390_vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +int __s390_vdso_clock_getres(clockid_t clock, struct __kernel_timespec *ts) +{ + return __cvdso_clock_getres(clock, ts); +} diff --git a/arch/s390/kernel/vdso64/vdso_user_wrapper.S b/arch/s390/kernel/vdso64/vdso_user_wrapper.S new file mode 100644 index 000000000000..a775d7e52872 --- /dev/null +++ b/arch/s390/kernel/vdso64/vdso_user_wrapper.S @@ -0,0 +1,38 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <asm/vdso.h> +#include <asm/unistd.h> +#include <asm/asm-offsets.h> +#include <asm/dwarf.h> +#include <asm/ptrace.h> + +#define WRAPPER_FRAME_SIZE (STACK_FRAME_OVERHEAD+8) + +/* + * Older glibc version called vdso without allocating a stackframe. This wrapper + * is just used to allocate a stackframe. See + * https://sourceware.org/git/?p=glibc.git;a=commit;h=478593e6374f3818da39332260dc453cb19cfa1e + * for details. + */ +.macro vdso_func func + .globl __kernel_\func + .type __kernel_\func,@function + .align 8 +__kernel_\func: + CFI_STARTPROC + aghi %r15,-WRAPPER_FRAME_SIZE + CFI_DEF_CFA_OFFSET (STACK_FRAME_OVERHEAD + WRAPPER_FRAME_SIZE) + CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD + stg %r14,STACK_FRAME_OVERHEAD(%r15) + brasl %r14,__s390_vdso_\func + lg %r14,STACK_FRAME_OVERHEAD(%r15) + aghi %r15,WRAPPER_FRAME_SIZE + CFI_DEF_CFA_OFFSET STACK_FRAME_OVERHEAD + CFI_RESTORE 15 + br %r14 + CFI_ENDPROC + .size __kernel_\func,.-__kernel_\func +.endm + +vdso_func gettimeofday +vdso_func clock_getres +vdso_func clock_gettime |