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-rw-r--r--include/linux/clocksource.h12
-rw-r--r--kernel/time/clocksource.c9
-rw-r--r--kernel/time/vsyscall.c10
-rw-r--r--lib/vdso/Kconfig3
-rw-r--r--lib/vdso/gettimeofday.c13
5 files changed, 42 insertions, 5 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 2c4574b517d2..6d5ed1b4d24d 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -23,10 +23,19 @@
struct clocksource;
struct module;
-#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
+#if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \
+ defined(CONFIG_GENERIC_VDSO_CLOCK_MODE)
#include <asm/clocksource.h>
#endif
+enum vdso_clock_mode {
+ VDSO_CLOCKMODE_NONE,
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+ VDSO_ARCH_CLOCKMODES,
+#endif
+ VDSO_CLOCKMODE_MAX,
+};
+
/**
* struct clocksource - hardware abstraction for a free running counter
* Provides mostly state-free accessors to the underlying hardware.
@@ -97,6 +106,7 @@ struct clocksource {
const char *name;
struct list_head list;
int rating;
+ enum vdso_clock_mode vdso_clock_mode;
unsigned long flags;
int (*enable)(struct clocksource *cs);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 428beb69426a..7cb09c4cf21c 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -928,6 +928,15 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
clocksource_arch_init(cs);
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+ if (cs->vdso_clock_mode < 0 ||
+ cs->vdso_clock_mode >= VDSO_CLOCKMODE_MAX) {
+ pr_warn("clocksource %s registered with invalid VDSO mode %d. Disabling VDSO support.\n",
+ cs->name, cs->vdso_clock_mode);
+ cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
+ }
+#endif
+
/* Initialize mult/shift and max_idle_ns */
__clocksource_update_freq_scale(cs, scale, freq);
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index 9577c89179cd..f9a5178c69bb 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -71,13 +71,19 @@ void update_vsyscall(struct timekeeper *tk)
{
struct vdso_data *vdata = __arch_get_k_vdso_data();
struct vdso_timestamp *vdso_ts;
+ s32 clock_mode;
u64 nsec;
/* 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);
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+ clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
+#else
+ clock_mode = __arch_get_clock_mode(tk);
+#endif
+ vdata[CS_HRES_COARSE].clock_mode = clock_mode;
+ vdata[CS_RAW].clock_mode = clock_mode;
/* CLOCK_REALTIME also required for time() */
vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
index d883ac299508..d9f43c84fcc6 100644
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -30,4 +30,7 @@ config GENERIC_VDSO_TIME_NS
Selected by architectures which support time namespaces in the
VDSO
+config GENERIC_VDSO_CLOCK_MODE
+ bool
+
endif
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 5804e4e168e7..3f2d8b859130 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -7,6 +7,7 @@
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/hrtimer_defs.h>
+#include <linux/clocksource.h>
#include <vdso/datapage.h>
#include <vdso/helpers.h>
@@ -64,10 +65,14 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
do {
seq = vdso_read_begin(vd);
+ if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ vd->clock_mode == VDSO_CLOCKMODE_NONE)
+ return -1;
cycles = __arch_get_hw_counter(vd->clock_mode);
ns = vdso_ts->nsec;
last = vd->cycle_last;
- if (unlikely((s64)cycles < 0))
+ if (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ unlikely((s64)cycles < 0))
return -1;
ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
@@ -132,10 +137,14 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
}
smp_rmb();
+ if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ vd->clock_mode == VDSO_CLOCKMODE_NONE)
+ return -1;
cycles = __arch_get_hw_counter(vd->clock_mode);
ns = vdso_ts->nsec;
last = vd->cycle_last;
- if (unlikely((s64)cycles < 0))
+ if (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ unlikely((s64)cycles < 0))
return -1;
ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);