Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-14 16:12:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

arm64: vdso: Substitute gettimeofday() with C implementation

Browse Source 
To take advantage of the commonly defined vdso interface for gettimeofday()
the architectural code requires an adaptation.

Re-implement the gettimeofday VDSO in C in order to use lib/vdso.

With the new implementation arm64 gains support for CLOCK_BOOTTIME
and CLOCK_TAI.

[ tglx: Reformatted the function line breaks ]

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shijith Thotton <sthotton@marvell.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Huw Davies <huw@codeweavers.com>
Link: https://lkml.kernel.org/r/20190621095252.32307-5-vincenzo.frascino@arm.com
This commit is contained in:
Vincenzo Frascino 2019-06-21 10:52:31 +01:00 committed by Thomas Gleixner
parent 44f57d788e
commit 28b1a824a4
8 changed files with 220 additions and 387 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm64/Kconfig
View File

@ -107,6 +107,7 @@ config ARM64
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select GENERIC_TIME_VSYSCALL
select GENERIC_GETTIMEOFDAY
select HANDLE_DOMAIN_IRQ
select HARDIRQS_SW_RESEND
select HAVE_PCI
@ -160,6 +161,7 @@ config ARM64
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_KPROBES
select HAVE_KRETPROBES
select HAVE_GENERIC_VDSO
select IOMMU_DMA if IOMMU_SUPPORT
select IRQ_DOMAIN
select IRQ_FORCED_THREADING

84
arch/arm64/include/asm/vdso/gettimeofday.h Normal file
View File

@ -0,0 +1,84 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2018 ARM Limited
*/
#ifndef __ASM_VDSO_GETTIMEOFDAY_H
#define __ASM_VDSO_GETTIMEOFDAY_H
#ifndef __ASSEMBLY__
#include <asm/unistd.h>
#include <uapi/linux/time.h>
#define VDSO_HAS_CLOCK_GETRES 1
static __always_inline
int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
struct timezone *_tz)
{
register struct timezone *tz asm("x1") = _tz;
register struct __kernel_old_timeval *tv asm("x0") = _tv;
register long ret asm ("x0");
register long nr asm("x8") = __NR_gettimeofday;
asm volatile(
" svc #0\n"
: "=r" (ret)
: "r" (tv), "r" (tz), "r" (nr)
: "memory");
return ret;
}
static __always_inline
long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
{
register struct __kernel_timespec *ts asm("x1") = _ts;
register clockid_t clkid asm("x0") = _clkid;
register long ret asm ("x0");
register long nr asm("x8") = __NR_clock_gettime;
asm volatile(
" svc #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline
int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
{
register struct __kernel_timespec *ts asm("x1") = _ts;
register clockid_t clkid asm("x0") = _clkid;
register long ret asm ("x0");
register long nr asm("x8") = __NR_clock_getres;
asm volatile(
" svc #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
{
u64 res;
asm volatile("mrs %0, cntvct_el0" : "=r" (res) :: "memory");
return res;
}
static __always_inline
const struct vdso_data *__arch_get_vdso_data(void)
{
return _vdso_data;
}
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_GETTIMEOFDAY_H */

53
arch/arm64/include/asm/vdso/vsyscall.h Normal file
View File

@ -0,0 +1,53 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_VDSO_VSYSCALL_H
#define __ASM_VDSO_VSYSCALL_H
#ifndef __ASSEMBLY__
#include <linux/timekeeper_internal.h>
#include <vdso/datapage.h>
#define VDSO_PRECISION_MASK ~(0xFF00ULL<<48)
extern struct vdso_data *vdso_data;
/*
* Update the vDSO data page to keep in sync with kernel timekeeping.
*/
static __always_inline
struct vdso_data *__arm64_get_k_vdso_data(void)
{
return vdso_data;
}
#define __arch_get_k_vdso_data __arm64_get_k_vdso_data
static __always_inline
int __arm64_get_clock_mode(struct timekeeper *tk)
{
u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
return use_syscall;
}
#define __arch_get_clock_mode __arm64_get_clock_mode
static __always_inline
int __arm64_use_vsyscall(struct vdso_data *vdata)
{
return !vdata[CS_HRES_COARSE].clock_mode;
}
#define __arch_use_vsyscall __arm64_use_vsyscall
static __always_inline
void __arm64_update_vsyscall(struct vdso_data *vdata, struct timekeeper *tk)
{
vdata[CS_HRES_COARSE].mask = VDSO_PRECISION_MASK;
vdata[CS_RAW].mask = VDSO_PRECISION_MASK;
}
#define __arch_update_vsyscall __arm64_update_vsyscall
/* The asm-generic header needs to be included after the definitions above */
#include <asm-generic/vdso/vsyscall.h>
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_VSYSCALL_H */

33
arch/arm64/kernel/asm-offsets.c
View File

@ -14,13 +14,13 @@
#include <linux/kvm_host.h>
#include <linux/preempt.h>
#include <linux/suspend.h>
#include <vdso/datapage.h>
#include <asm/cpufeature.h>
#include <asm/fixmap.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/smp_plat.h>
#include <asm/suspend.h>
#include <asm/vdso_datapage.h>
#include <linux/kbuild.h>
#include <linux/arm-smccc.h>
@ -89,17 +89,28 @@ int main(void)
DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC);
DEFINE(NSEC_PER_SEC, NSEC_PER_SEC);
BLANK();
DEFINE(VDSO_CS_CYCLE_LAST, offsetof(struct vdso_data, cs_cycle_last));
DEFINE(VDSO_RAW_TIME_SEC, offsetof(struct vdso_data, raw_time_sec));
DEFINE(VDSO_XTIME_CLK_SEC, offsetof(struct vdso_data, xtime_clock_sec));
DEFINE(VDSO_XTIME_CRS_SEC, offsetof(struct vdso_data, xtime_coarse_sec));
DEFINE(VDSO_XTIME_CRS_NSEC, offsetof(struct vdso_data, xtime_coarse_nsec));
DEFINE(VDSO_WTM_CLK_SEC, offsetof(struct vdso_data, wtm_clock_sec));
DEFINE(VDSO_TB_SEQ_COUNT, offsetof(struct vdso_data, tb_seq_count));
DEFINE(VDSO_CS_MONO_MULT, offsetof(struct vdso_data, cs_mono_mult));
DEFINE(VDSO_CS_SHIFT, offsetof(struct vdso_data, cs_shift));
DEFINE(VDSO_SEQ, offsetof(struct vdso_data, seq));
DEFINE(VDSO_CLK_MODE, offsetof(struct vdso_data, clock_mode));
DEFINE(VDSO_CYCLE_LAST, offsetof(struct vdso_data, cycle_last));
DEFINE(VDSO_MASK, offsetof(struct vdso_data, mask));
DEFINE(VDSO_MULT, offsetof(struct vdso_data, mult));
DEFINE(VDSO_SHIFT, offsetof(struct vdso_data, shift));
DEFINE(VDSO_REALTIME_SEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME].sec));
DEFINE(VDSO_REALTIME_NSEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME].nsec));
DEFINE(VDSO_MONO_SEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC].sec));
DEFINE(VDSO_MONO_NSEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC].nsec));
DEFINE(VDSO_MONO_RAW_SEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_RAW].sec));
DEFINE(VDSO_MONO_RAW_NSEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_RAW].nsec));
DEFINE(VDSO_BOOTTIME_SEC, offsetof(struct vdso_data, basetime[CLOCK_BOOTTIME].sec));
DEFINE(VDSO_BOOTTIME_NSEC, offsetof(struct vdso_data, basetime[CLOCK_BOOTTIME].nsec));
DEFINE(VDSO_TAI_SEC, offsetof(struct vdso_data, basetime[CLOCK_TAI].sec));
DEFINE(VDSO_TAI_NSEC, offsetof(struct vdso_data, basetime[CLOCK_TAI].nsec));
DEFINE(VDSO_RT_COARSE_SEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME_COARSE].sec));
DEFINE(VDSO_RT_COARSE_NSEC, offsetof(struct vdso_data, basetime[CLOCK_REALTIME_COARSE].nsec));
DEFINE(VDSO_MONO_COARSE_SEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_COARSE].sec));
DEFINE(VDSO_MONO_COARSE_NSEC, offsetof(struct vdso_data, basetime[CLOCK_MONOTONIC_COARSE].nsec));
DEFINE(VDSO_TZ_MINWEST, offsetof(struct vdso_data, tz_minuteswest));
DEFINE(VDSO_USE_SYSCALL, offsetof(struct vdso_data, use_syscall));
DEFINE(VDSO_TZ_DSTTIME, offsetof(struct vdso_data, tz_dsttime));
BLANK();
DEFINE(TVAL_TV_SEC, offsetof(struct timeval, tv_sec));
DEFINE(TSPEC_TV_SEC, offsetof(struct timespec, tv_sec));

51
arch/arm64/kernel/vdso.c
View File

@ -20,11 +20,13 @@
#include <linux/slab.h>
#include <linux/timekeeper_internal.h>
#include <linux/vmalloc.h>
#include <vdso/datapage.h>
#include <vdso/helpers.h>
#include <vdso/vsyscall.h>
#include <asm/cacheflush.h>
#include <asm/signal32.h>
#include <asm/vdso.h>
#include <asm/vdso_datapage.h>
extern char vdso_start[], vdso_end[];
static unsigned long vdso_pages __ro_after_init;
@ -33,10 +35,10 @@ static unsigned long vdso_pages __ro_after_init;
* The vDSO data page.
*/
static union {
struct vdso_data data;
struct vdso_data data[CS_BASES];
u8 page[PAGE_SIZE];
} vdso_data_store __page_aligned_data;
struct vdso_data *vdso_data = &vdso_data_store.data;
struct vdso_data *vdso_data = vdso_data_store.data;
#ifdef CONFIG_COMPAT
/*
@ -269,46 +271,3 @@ up_fail:
up_write(&mm->mmap_sem);
return PTR_ERR(ret);
}
/*
* Update the vDSO data page to keep in sync with kernel timekeeping.
*/
void update_vsyscall(struct timekeeper *tk)
{
u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
++vdso_data->tb_seq_count;
smp_wmb();
vdso_data->use_syscall = use_syscall;
vdso_data->xtime_coarse_sec = tk->xtime_sec;
vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
tk->tkr_mono.shift;
vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec;
vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec;
/* Read without the seqlock held by clock_getres() */
WRITE_ONCE(vdso_data->hrtimer_res, hrtimer_resolution);
if (!use_syscall) {
/* tkr_mono.cycle_last == tkr_raw.cycle_last */
vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last;
vdso_data->raw_time_sec = tk->raw_sec;
vdso_data->raw_time_nsec = tk->tkr_raw.xtime_nsec;
vdso_data->xtime_clock_sec = tk->xtime_sec;
vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
vdso_data->cs_mono_mult = tk->tkr_mono.mult;
vdso_data->cs_raw_mult = tk->tkr_raw.mult;
/* tkr_mono.shift == tkr_raw.shift */
vdso_data->cs_shift = tk->tkr_mono.shift;
}
smp_wmb();
++vdso_data->tb_seq_count;
}
void update_vsyscall_tz(void)
{
vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
vdso_data->tz_dsttime = sys_tz.tz_dsttime;
}

34
arch/arm64/kernel/vdso/Makefile
View File

@ -6,7 +6,12 @@
# Heavily based on the vDSO Makefiles for other archs.
#
obj-vdso := gettimeofday.o note.o sigreturn.o
# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
# the inclusion of generic Makefile.
ARCH_REL_TYPE_ABS := R_AARCH64_JUMP_SLOT|R_AARCH64_GLOB_DAT|R_AARCH64_ABS64
include $(srctree)/lib/vdso/Makefile
obj-vdso := vgettimeofday.o note.o sigreturn.o
# Build rules
targets := $(obj-vdso) vdso.so vdso.so.dbg
@ -15,6 +20,24 @@ obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \
--build-id -n -T
ccflags-y := -fno-common -fno-builtin -fno-stack-protector
ccflags-y += -DDISABLE_BRANCH_PROFILING
VDSO_LDFLAGS := -Bsymbolic
CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
KBUILD_CFLAGS += $(DISABLE_LTO)
KASAN_SANITIZE := n
UBSAN_SANITIZE := n
OBJECT_FILES_NON_STANDARD := y
KCOV_INSTRUMENT := n
ifeq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny
else
CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -include $(c-gettimeofday-y)
endif
# Disable gcov profiling for VDSO code
GCOV_PROFILE := n
@ -28,6 +51,7 @@ $(obj)/vdso.o : $(obj)/vdso.so
# Link rule for the .so file, .lds has to be first
$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,ld)
$(call if_changed,vdso_check)
# Strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
@ -42,13 +66,9 @@ quiet_cmd_vdsosym = VDSOSYM $@
include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
$(call if_changed,vdsosym)
# Assembly rules for the .S files
$(obj-vdso): %.o: %.S FORCE
$(call if_changed_dep,vdsoas)
# Actual build commands
quiet_cmd_vdsoas = VDSOA $@
cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $<
quiet_cmd_vdsocc = VDSOCC $@
cmd_vdsocc = $(CC) $(a_flags) $(c_flags) -c -o $@ $<
# Install commands for the unstripped file
quiet_cmd_vdso_install = INSTALL $@

323
arch/arm64/kernel/vdso/gettimeofday.S
View File

@ -1,323 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Userspace implementations of gettimeofday() and friends.
*
* Copyright (C) 2012 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#define NSEC_PER_SEC_LO16 0xca00
#define NSEC_PER_SEC_HI16 0x3b9a
vdso_data .req x6
seqcnt .req w7
w_tmp .req w8
x_tmp .req x8
/*
* Conventions for macro arguments:
* - An argument is write-only if its name starts with "res".
* - All other arguments are read-only, unless otherwise specified.
*/
.macro seqcnt_acquire
9999: ldr seqcnt, [vdso_data, #VDSO_TB_SEQ_COUNT]
tbnz seqcnt, #0, 9999b
dmb ishld
.endm
.macro seqcnt_check fail
dmb ishld
ldr w_tmp, [vdso_data, #VDSO_TB_SEQ_COUNT]
cmp w_tmp, seqcnt
b.ne \fail
.endm
.macro syscall_check fail
ldr w_tmp, [vdso_data, #VDSO_USE_SYSCALL]
cbnz w_tmp, \fail
.endm
.macro get_nsec_per_sec res
mov \res, #NSEC_PER_SEC_LO16
movk \res, #NSEC_PER_SEC_HI16, lsl #16
.endm
/*
* Returns the clock delta, in nanoseconds left-shifted by the clock
* shift.
*/
.macro get_clock_shifted_nsec res, cycle_last, mult
/* Read the virtual counter. */
isb
mrs x_tmp, cntvct_el0
/* Calculate cycle delta and convert to ns. */
sub \res, x_tmp, \cycle_last
/* We can only guarantee 56 bits of precision. */
movn x_tmp, #0xff00, lsl #48
and \res, x_tmp, \res
mul \res, \res, \mult
/*
* Fake address dependency from the value computed from the counter
* register to subsequent data page accesses so that the sequence
* locking also orders the read of the counter.
*/
and x_tmp, \res, xzr
add vdso_data, vdso_data, x_tmp
.endm
/*
* Returns in res_{sec,nsec} the REALTIME timespec, based on the
* "wall time" (xtime) and the clock_mono delta.
*/
.macro get_ts_realtime res_sec, res_nsec, \
clock_nsec, xtime_sec, xtime_nsec, nsec_to_sec
add \res_nsec, \clock_nsec, \xtime_nsec
udiv x_tmp, \res_nsec, \nsec_to_sec
add \res_sec, \xtime_sec, x_tmp
msub \res_nsec, x_tmp, \nsec_to_sec, \res_nsec
.endm
/*
* Returns in res_{sec,nsec} the timespec based on the clock_raw delta,
* used for CLOCK_MONOTONIC_RAW.
*/
.macro get_ts_clock_raw res_sec, res_nsec, clock_nsec, nsec_to_sec
udiv \res_sec, \clock_nsec, \nsec_to_sec
msub \res_nsec, \res_sec, \nsec_to_sec, \clock_nsec
.endm
/* sec and nsec are modified in place. */
.macro add_ts sec, nsec, ts_sec, ts_nsec, nsec_to_sec
/* Add timespec. */
add \sec, \sec, \ts_sec
add \nsec, \nsec, \ts_nsec
/* Normalise the new timespec. */
cmp \nsec, \nsec_to_sec
b.lt 9999f
sub \nsec, \nsec, \nsec_to_sec
add \sec, \sec, #1
9999:
cmp \nsec, #0
b.ge 9998f
add \nsec, \nsec, \nsec_to_sec
sub \sec, \sec, #1
9998:
.endm
.macro clock_gettime_return, shift=0
.if \shift == 1
lsr x11, x11, x12
.endif
stp x10, x11, [x1, #TSPEC_TV_SEC]
mov x0, xzr
ret
.endm
.macro jump_slot jumptable, index, label
.if (. - \jumptable) != 4 * (\index)
.error "Jump slot index mismatch"
.endif
b \label
.endm
.text
/* int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); */
ENTRY(__kernel_gettimeofday)
.cfi_startproc
adr vdso_data, _vdso_data
/* If tv is NULL, skip to the timezone code. */
cbz x0, 2f
/* Compute the time of day. */
1: seqcnt_acquire
syscall_check fail=4f
ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST]
/* w11 = cs_mono_mult, w12 = cs_shift */
ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT]
ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC]
get_nsec_per_sec res=x9
lsl x9, x9, x12
get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11
seqcnt_check fail=1b
get_ts_realtime res_sec=x10, res_nsec=x11, \
clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9
/* Convert ns to us. */
mov x13, #1000
lsl x13, x13, x12
udiv x11, x11, x13
stp x10, x11, [x0, #TVAL_TV_SEC]
2:
/* If tz is NULL, return 0. */
cbz x1, 3f
ldp w4, w5, [vdso_data, #VDSO_TZ_MINWEST]
stp w4, w5, [x1, #TZ_MINWEST]
3:
mov x0, xzr
ret
4:
/* Syscall fallback. */
mov x8, #__NR_gettimeofday
svc #0
ret
.cfi_endproc
ENDPROC(__kernel_gettimeofday)
#define JUMPSLOT_MAX CLOCK_MONOTONIC_COARSE
/* int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); */
ENTRY(__kernel_clock_gettime)
.cfi_startproc
cmp w0, #JUMPSLOT_MAX
b.hi syscall
adr vdso_data, _vdso_data
adr x_tmp, jumptable
add x_tmp, x_tmp, w0, uxtw #2
br x_tmp
ALIGN
jumptable:
jump_slot jumptable, CLOCK_REALTIME, realtime
jump_slot jumptable, CLOCK_MONOTONIC, monotonic
b syscall
b syscall
jump_slot jumptable, CLOCK_MONOTONIC_RAW, monotonic_raw
jump_slot jumptable, CLOCK_REALTIME_COARSE, realtime_coarse
jump_slot jumptable, CLOCK_MONOTONIC_COARSE, monotonic_coarse
.if (. - jumptable) != 4 * (JUMPSLOT_MAX + 1)
.error "Wrong jumptable size"
.endif
ALIGN
realtime:
seqcnt_acquire
syscall_check fail=syscall
ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST]
/* w11 = cs_mono_mult, w12 = cs_shift */
ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT]
ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC]
/* All computations are done with left-shifted nsecs. */
get_nsec_per_sec res=x9
lsl x9, x9, x12
get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11
seqcnt_check fail=realtime
get_ts_realtime res_sec=x10, res_nsec=x11, \
clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9
clock_gettime_return, shift=1
ALIGN
monotonic:
seqcnt_acquire
syscall_check fail=syscall
ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST]
/* w11 = cs_mono_mult, w12 = cs_shift */
ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT]
ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC]
ldp x3, x4, [vdso_data, #VDSO_WTM_CLK_SEC]
/* All computations are done with left-shifted nsecs. */
lsl x4, x4, x12
get_nsec_per_sec res=x9
lsl x9, x9, x12
get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11
seqcnt_check fail=monotonic
get_ts_realtime res_sec=x10, res_nsec=x11, \
clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9
add_ts sec=x10, nsec=x11, ts_sec=x3, ts_nsec=x4, nsec_to_sec=x9
clock_gettime_return, shift=1
ALIGN
monotonic_raw:
seqcnt_acquire
syscall_check fail=syscall
ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST]
/* w11 = cs_raw_mult, w12 = cs_shift */
ldp w12, w11, [vdso_data, #VDSO_CS_SHIFT]
ldp x13, x14, [vdso_data, #VDSO_RAW_TIME_SEC]
/* All computations are done with left-shifted nsecs. */
get_nsec_per_sec res=x9
lsl x9, x9, x12
get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11
seqcnt_check fail=monotonic_raw
get_ts_clock_raw res_sec=x10, res_nsec=x11, \
clock_nsec=x15, nsec_to_sec=x9
add_ts sec=x10, nsec=x11, ts_sec=x13, ts_nsec=x14, nsec_to_sec=x9
clock_gettime_return, shift=1
ALIGN
realtime_coarse:
seqcnt_acquire
ldp x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC]
seqcnt_check fail=realtime_coarse
clock_gettime_return
ALIGN
monotonic_coarse:
seqcnt_acquire
ldp x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC]
ldp x13, x14, [vdso_data, #VDSO_WTM_CLK_SEC]
seqcnt_check fail=monotonic_coarse
/* Computations are done in (non-shifted) nsecs. */
get_nsec_per_sec res=x9
add_ts sec=x10, nsec=x11, ts_sec=x13, ts_nsec=x14, nsec_to_sec=x9
clock_gettime_return
ALIGN
syscall: /* Syscall fallback. */
mov x8, #__NR_clock_gettime
svc #0
ret
.cfi_endproc
ENDPROC(__kernel_clock_gettime)
/* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */
ENTRY(__kernel_clock_getres)
.cfi_startproc
cmp w0, #CLOCK_REALTIME
ccmp w0, #CLOCK_MONOTONIC, #0x4, ne
ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne
b.ne 1f
adr vdso_data, _vdso_data
ldr w2, [vdso_data, #CLOCK_REALTIME_RES]
b 2f
1:
cmp w0, #CLOCK_REALTIME_COARSE
ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne
b.ne 4f
ldr x2, 5f
2:
cbz x1, 3f
stp xzr, x2, [x1]
3: /* res == NULL. */
mov w0, wzr
ret
4: /* Syscall fallback. */
mov x8, #__NR_clock_getres
svc #0
ret
5:
.quad CLOCK_COARSE_RES
.cfi_endproc
ENDPROC(__kernel_clock_getres)

27
arch/arm64/kernel/vdso/vgettimeofday.c Normal file
View File

@ -0,0 +1,27 @@
// SPDX-License-Identifier: GPL-2.0
/*
* ARM64 userspace implementations of gettimeofday() and similar.
*
* Copyright (C) 2018 ARM Limited
*
*/
#include <linux/time.h>
#include <linux/types.h>
int __kernel_clock_gettime(clockid_t clock,
struct __kernel_timespec *ts)
{
return __cvdso_clock_gettime(clock, ts);
}
int __kernel_gettimeofday(struct __kernel_old_timeval *tv,
struct timezone *tz)
{
return __cvdso_gettimeofday(tv, tz);
}
int __kernel_clock_getres(clockid_t clock_id,
struct __kernel_timespec *res)
{
return __cvdso_clock_getres(clock_id, res);
}