With the definition of the unified vDSO library the implementations of update_vsyscall and update_vsyscall_tz became quite similar across architectures.
Define a unified implementation of this two functions in kernel/vdso and provide the bindings that can be implemented by every architecture that takes advantage of the unified vDSO library.
Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- include/asm-generic/vdso/vsyscall.h | 56 +++++++++++ include/linux/timekeeper_internal.h | 9 ++ include/vdso/vsyscall.h | 11 +++ kernel/Makefile | 1 + kernel/vdso/Makefile | 2 + kernel/vdso/vsyscall.c | 139 ++++++++++++++++++++++++++++ 6 files changed, 218 insertions(+) create mode 100644 include/asm-generic/vdso/vsyscall.h create mode 100644 include/vdso/vsyscall.h create mode 100644 kernel/vdso/Makefile create mode 100644 kernel/vdso/vsyscall.c
diff --git a/include/asm-generic/vdso/vsyscall.h b/include/asm-generic/vdso/vsyscall.h new file mode 100644 index 000000000000..9a4b9fbcc9b6 --- /dev/null +++ b/include/asm-generic/vdso/vsyscall.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_VSYSCALL_H +#define __ASM_GENERIC_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#ifndef __arch_get_k_vdso_data +static __always_inline +struct vdso_data *__arch_get_k_vdso_data(void) +{ + return NULL; +} +#endif /* __arch_get_k_vdso_data */ + +#ifndef __arch_update_vdso_data +static __always_inline +int __arch_update_vdso_data(void) +{ + return 0; +} +#endif /* __arch_update_vdso_data */ + +#ifndef __arch_get_clock_mode +static __always_inline +int __arch_get_clock_mode(struct timekeeper *tk) +{ + return 0; +} +#endif /* __arch_get_clock_mode */ + +#ifndef __arch_use_vsyscall +static __always_inline +int __arch_use_vsyscall(struct vdso_data *vdata) +{ + return 1; +} +#endif /* __arch_use_vsyscall */ + +#ifndef __arch_update_vsyscall +static __always_inline +void __arch_update_vsyscall(struct vdso_data *vdata, + struct timekeeper *tk) +{ +} +#endif /* __arch_update_vsyscall */ + +#ifndef __arch_sync_vdso_data +static __always_inline +void __arch_sync_vdso_data(struct vdso_data *vdata) +{ +} +#endif /* __arch_sync_vdso_data */ + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_GENERIC_VSYSCALL_H */ diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h index 7acb953298a7..8177e75a71eb 100644 --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -135,9 +135,18 @@ struct timekeeper {
#ifdef CONFIG_GENERIC_TIME_VSYSCALL
+#ifdef CONFIG_HAVE_GENERIC_VDSO + +void update_vsyscall(struct timekeeper *tk); +void update_vsyscall_tz(void); + +#else + extern void update_vsyscall(struct timekeeper *tk); extern void update_vsyscall_tz(void);
+#endif /* CONFIG_HAVE_GENERIC_VDSO */ + #else
static inline void update_vsyscall(struct timekeeper *tk) diff --git a/include/vdso/vsyscall.h b/include/vdso/vsyscall.h new file mode 100644 index 000000000000..2c6134e0c23d --- /dev/null +++ b/include/vdso/vsyscall.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_VSYSCALL_H +#define __VDSO_VSYSCALL_H + +#ifndef __ASSEMBLY__ + +#include <asm/vdso/vsyscall.h> + +#endif /* !__ASSEMBLY__ */ + +#endif /* __VDSO_VSYSCALL_H */ diff --git a/kernel/Makefile b/kernel/Makefile index 33824f0385b3..56a98ebb7772 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -48,6 +48,7 @@ obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_STACKTRACE) += stacktrace.o +obj-$(CONFIG_HAVE_GENERIC_VDSO) += vdso/ obj-y += time/ obj-$(CONFIG_FUTEX) += futex.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o diff --git a/kernel/vdso/Makefile b/kernel/vdso/Makefile new file mode 100644 index 000000000000..ad0d3b1a475c --- /dev/null +++ b/kernel/vdso/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_HAVE_GENERIC_VDSO) += vsyscall.o diff --git a/kernel/vdso/vsyscall.c b/kernel/vdso/vsyscall.c new file mode 100644 index 000000000000..49409eece728 --- /dev/null +++ b/kernel/vdso/vsyscall.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2019 ARM Ltd. + * + * Generic implementation of update_vsyscall and update_vsyscall_tz. + */ + +#include <linux/hrtimer.h> +#include <linux/timekeeper_internal.h> +#include <vdso/datapage.h> +#include <vdso/helpers.h> +#include <vdso/vsyscall.h> + +void update_vsyscall(struct timekeeper *tk) +{ + struct vdso_data *vdata = __arch_get_k_vdso_data(); + struct vdso_timestamp *vdso_ts; + u64 nsec; + + if (__arch_update_vdso_data()) { + /* + * Some architectures might want to skip the update of the + * data page. + */ + return; + } + + /* copy vsyscall data */ + vdso_write_begin(vdata); + + vdata[CS_HRES_COARSE].clock_mode = __arch_get_clock_mode(tk); + vdata[CS_RAW].clock_mode = __arch_get_clock_mode(tk); + + /* CLOCK_REALTIME_COARSE */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE]; + vdso_ts->sec = tk->xtime_sec; + vdso_ts->nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; + /* CLOCK_MONOTONIC_COARSE */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE]; + vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; + nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; + nsec = nsec + tk->wall_to_monotonic.tv_nsec; + while (nsec >= NSEC_PER_SEC) { + nsec = nsec - NSEC_PER_SEC; + vdso_ts->sec++; + } + vdso_ts->nsec = nsec; + + if (__arch_use_vsyscall(vdata)) { + vdata[CS_HRES_COARSE].cycle_last = + tk->tkr_mono.cycle_last; + vdata[CS_HRES_COARSE].mask = + tk->tkr_mono.mask; + vdata[CS_HRES_COARSE].mult = + tk->tkr_mono.mult; + vdata[CS_HRES_COARSE].shift = + tk->tkr_mono.shift; + vdata[CS_RAW].cycle_last = + tk->tkr_raw.cycle_last; + vdata[CS_RAW].mask = + tk->tkr_raw.mask; + vdata[CS_RAW].mult = + tk->tkr_raw.mult; + vdata[CS_RAW].shift = + tk->tkr_raw.shift; + /* CLOCK_REALTIME */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME]; + vdso_ts->sec = tk->xtime_sec; + vdso_ts->nsec = tk->tkr_mono.xtime_nsec; + /* CLOCK_MONOTONIC */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC]; + vdso_ts->sec = tk->xtime_sec + + tk->wall_to_monotonic.tv_sec; + nsec = tk->tkr_mono.xtime_nsec; + nsec = nsec + + ((u64)tk->wall_to_monotonic.tv_nsec << + tk->tkr_mono.shift); + while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { + nsec = nsec - + (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift); + vdso_ts->sec++; + } + vdso_ts->nsec = nsec; + /* CLOCK_MONOTONIC_RAW */ + vdso_ts = + &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW]; + vdso_ts->sec = tk->raw_sec; + vdso_ts->nsec = tk->tkr_raw.xtime_nsec; + /* CLOCK_BOOTTIME */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME]; + vdso_ts->sec = tk->xtime_sec + + tk->wall_to_monotonic.tv_sec; + nsec = tk->tkr_mono.xtime_nsec; + nsec = nsec + + ((u64)(tk->wall_to_monotonic.tv_nsec + + ktime_to_ns(tk->offs_boot)) << + tk->tkr_mono.shift); + while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { + nsec = nsec - + (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift); + vdso_ts->sec++; + } + vdso_ts->nsec = nsec; + /* CLOCK_TAI */ + vdso_ts = + &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI]; + vdso_ts->sec = tk->xtime_sec + (s64)tk->tai_offset; + vdso_ts->nsec = tk->tkr_mono.xtime_nsec; + + /* + * Read without the seqlock held by clock_getres(). + * Note: No need to have a second copy. + */ + WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution); + } + + __arch_update_vsyscall(vdata, tk); + + vdso_write_end(vdata); + + __arch_sync_vdso_data(vdata); +} + +void update_vsyscall_tz(void) +{ + struct vdso_data *vdata = __arch_get_k_vdso_data(); + + if (__arch_use_vsyscall(vdata)) { + vdata[CS_HRES_COARSE].tz_minuteswest = sys_tz.tz_minuteswest; + vdata[CS_HRES_COARSE].tz_dsttime = sys_tz.tz_dsttime; + } + + __arch_sync_vdso_data(vdata); +}