[PATCH v6 04/19] arm64: Substitute gettimeofday with C implementation

Vincenzo Frascino
2019-05-30T14:16:02Z

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.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
arch/arm64/Kconfig | 2 +
arch/arm64/include/asm/vdso/gettimeofday.h | 84 ++++++
arch/arm64/include/asm/vdso/vsyscall.h | 53 ++++
arch/arm64/include/asm/vdso_datapage.h | 48 ---
arch/arm64/kernel/asm-offsets.c | 33 +-
arch/arm64/kernel/vdso.c | 51 +---
arch/arm64/kernel/vdso/Makefile | 34 ++-
arch/arm64/kernel/vdso/gettimeofday.S | 334 ---------------------
arch/arm64/kernel/vdso/vgettimeofday.c | 28 ++
9 files changed, 221 insertions(+), 446 deletions(-)
create mode 100644 arch/arm64/include/asm/vdso/gettimeofday.h
create mode 100644 arch/arm64/include/asm/vdso/vsyscall.h
delete mode 100644 arch/arm64/include/asm/vdso_datapage.h
delete mode 100644 arch/arm64/kernel/vdso/gettimeofday.S
create mode 100644 arch/arm64/kernel/vdso/vgettimeofday.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 697ea0510729..952c9f8cf3b8 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -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
diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h
new file mode 100644
index 000000000000..dcfe408b9b11
--- /dev/null
+++ b/arch/arm64/include/asm/vdso/gettimeofday.h
@@ -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>
+
+static __always_inline notrace 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 notrace 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 notrace 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 notrace u64 __arch_get_hw_counter(s32 clock_mode)
+{
+ u64 res;
+
+ asm volatile("mrs %0, cntvct_el0" : "=r" (res) :: "memory");
+
+ return res;
+}
+
+static __always_inline
+notrace const struct vdso_data *__arch_get_vdso_data(void)
+{
+ return _vdso_data;
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_GETTIMEOFDAY_H */
diff --git a/arch/arm64/include/asm/vdso/vsyscall.h b/arch/arm64/include/asm/vdso/vsyscall.h
new file mode 100644
index 000000000000..0c731bfc7c8c
--- /dev/null
+++ b/arch/arm64/include/asm/vdso/vsyscall.h
@@ -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 */
diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h
deleted file mode 100644
index f89263c8e11a..000000000000
--- a/arch/arm64/include/asm/vdso_datapage.h
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright (C) 2012 ARM Limited
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_VDSO_DATAPAGE_H
-#define __ASM_VDSO_DATAPAGE_H
-
-#ifdef __KERNEL__
-
-#ifndef __ASSEMBLY__
-
-struct vdso_data {
- __u64 cs_cycle_last; /* Timebase at clocksource init */
- __u64 raw_time_sec; /* Raw time */
- __u64 raw_time_nsec;
- __u64 xtime_clock_sec; /* Kernel time */
- __u64 xtime_clock_nsec;
- __u64 xtime_coarse_sec; /* Coarse time */
- __u64 xtime_coarse_nsec;
- __u64 wtm_clock_sec; /* Wall to monotonic time */
- __u64 wtm_clock_nsec;
- __u32 tb_seq_count; /* Timebase sequence counter */
- /* cs_* members must be adjacent and in this order (ldp accesses) */
- __u32 cs_mono_mult; /* NTP-adjusted clocksource multiplier */
- __u32 cs_shift; /* Clocksource shift (mono = raw) */
- __u32 cs_raw_mult; /* Raw clocksource multiplier */
- __u32 tz_minuteswest; /* Whacky timezone stuff */
- __u32 tz_dsttime;
- __u32 use_syscall;
- __u32 hrtimer_res;
-};
-
-#endif /* !__ASSEMBLY__ */
-
-#endif /* __KERNEL__ */
-
-#endif /* __ASM_VDSO_DATAPAGE_H */
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 947e39896e28..9e4b7ccbab2f 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -25,13 +25,13 @@
#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>

@@ -100,17 +100,28 @@ 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));
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 8074cbd3a3a8..23c38303a52a 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -31,11 +31,13 @@
#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;
@@ -44,10 +46,10 @@ 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
/*
@@ -280,46 +282,3 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
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;
-}
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index fa230ff09aa1..00bcfd2672cf 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -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 $@
diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S
deleted file mode 100644
index 856fee6d3512..000000000000
--- a/arch/arm64/kernel/vdso/gettimeofday.S
+++ /dev/null
@@ -1,334 +0,0 @@
-/*
- * Userspace implementations of gettimeofday() and friends.
- *
- * Copyright (C) 2012 ARM Limited
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- * 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)
diff --git a/arch/arm64/kernel/vdso/vgettimeofday.c b/arch/arm64/kernel/vdso/vgettimeofday.c
new file mode 100644
index 000000000000..bbc83b6e2b1a
--- /dev/null
+++ b/arch/arm64/kernel/vdso/vgettimeofday.c
@@ -0,0 +1,28 @@
+// 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>
+
+notrace int __kernel_clock_gettime(clockid_t clock,
+ struct __kernel_timespec *ts)
+{
+ return __cvdso_clock_gettime(clock, ts);
+}
+
+notrace int __kernel_gettimeofday(struct __kernel_old_timeval *tv,
+ struct timezone *tz)
+{
+ return __cvdso_gettimeofday(tv, tz);
+}
+
+notrace int __kernel_clock_getres(clockid_t clock_id,
+ struct __kernel_timespec *res)
+{
+ return __cvdso_clock_getres(clock_id, res);
+}
+
--
2.21.0