[PATCH 3/3] timekeeping: remove arch_gettimeoffset

From: Arnd Bergmann
Date: Thu Oct 08 2020 - 11:47:27 EST

With Arm EBSA110 gone, nothing uses it any more, so the corresponding
code and the Kconfig option can be removed.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
.../time/modern-timekeeping/arch-support.txt | 33 -------------------
drivers/Makefile | 2 --
drivers/clocksource/Kconfig | 2 +-
include/linux/time.h | 13 --------
kernel/time/Kconfig | 9 -----
kernel/time/clocksource.c | 8 -----
kernel/time/timekeeping.c | 25 +-------------
kernel/trace/Kconfig | 2 --
8 files changed, 2 insertions(+), 92 deletions(-)
delete mode 100644 Documentation/features/time/modern-timekeeping/arch-support.txt

diff --git a/Documentation/features/time/modern-timekeeping/arch-support.txt b/Documentation/features/time/modern-timekeeping/arch-support.txt
deleted file mode 100644
index a84c3b9d9a94..000000000000
--- a/Documentation/features/time/modern-timekeeping/arch-support.txt
+++ /dev/null
@@ -1,33 +0,0 @@
-#
-# Feature name: modern-timekeeping
-# Kconfig: !ARCH_USES_GETTIMEOFFSET
-# description: arch does not use arch_gettimeoffset() anymore
-#
- -----------------------
- | arch |status|
- -----------------------
- | alpha: | ok |
- | arc: | ok |
- | arm: | TODO |
- | arm64: | ok |
- | c6x: | ok |
- | csky: | ok |
- | h8300: | ok |
- | hexagon: | ok |
- | ia64: | ok |
- | m68k: | ok |
- | microblaze: | ok |
- | mips: | ok |
- | nds32: | ok |
- | nios2: | ok |
- | openrisc: | ok |
- | parisc: | ok |
- | powerpc: | ok |
- | riscv: | ok |
- | s390: | ok |
- | sh: | ok |
- | sparc: | ok |
- | um: | ok |
- | x86: | ok |
- | xtensa: | ok |
- -----------------------
diff --git a/drivers/Makefile b/drivers/Makefile
index c0cd1b9075e3..4ff1e4459512 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -135,9 +135,7 @@ obj-$(CONFIG_INFINIBAND) += infiniband/
obj-y += firmware/
obj-$(CONFIG_CRYPTO) += crypto/
obj-$(CONFIG_SUPERH) += sh/
-ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
obj-y += clocksource/
-endif
obj-$(CONFIG_DCA) += dca/
obj-$(CONFIG_HID) += hid/
obj-$(CONFIG_PPC_PS3) += ps3/
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 68b087bff59c..764936bfcb2c 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -563,7 +563,7 @@ config CLKSRC_QCOM

config CLKSRC_VERSATILE
bool "ARM Versatile (Express) reference platforms clock source" if COMPILE_TEST
- depends on GENERIC_SCHED_CLOCK && !ARCH_USES_GETTIMEOFFSET
+ depends on GENERIC_SCHED_CLOCK
select TIMER_OF
default y if (ARCH_VEXPRESS || ARCH_VERSATILE) && ARM
help
diff --git a/include/linux/time.h b/include/linux/time.h
index b142cb5f5a53..16cf4522d6f3 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -21,19 +21,6 @@ extern time64_t mktime64(const unsigned int year, const unsigned int mon,
const unsigned int day, const unsigned int hour,
const unsigned int min, const unsigned int sec);

-/* Some architectures do not supply their own clocksource.
- * This is mainly the case in architectures that get their
- * inter-tick times by reading the counter on their interval
- * timer. Since these timers wrap every tick, they're not really
- * useful as clocksources. Wrapping them to act like one is possible
- * but not very efficient. So we provide a callout these arches
- * can implement for use with the jiffies clocksource to provide
- * finer then tick granular time.
- */
-#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-extern u32 (*arch_gettimeoffset)(void);
-#endif
-
#ifdef CONFIG_POSIX_TIMERS
extern void clear_itimer(void);
#else
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index a09b1d61df6a..51d298ccbe05 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -26,10 +26,6 @@ config CLOCKSOURCE_VALIDATE_LAST_CYCLE
config GENERIC_TIME_VSYSCALL
bool

-# Old style timekeeping
-config ARCH_USES_GETTIMEOFFSET
- bool
-
# The generic clock events infrastructure
config GENERIC_CLOCKEVENTS
bool
@@ -72,7 +68,6 @@ config TICK_ONESHOT

config NO_HZ_COMMON
bool
- depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
select TICK_ONESHOT

choice
@@ -87,7 +82,6 @@ config HZ_PERIODIC

config NO_HZ_IDLE
bool "Idle dynticks system (tickless idle)"
- depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
select NO_HZ_COMMON
help
This option enables a tickless idle system: timer interrupts
@@ -99,7 +93,6 @@ config NO_HZ_IDLE
config NO_HZ_FULL
bool "Full dynticks system (tickless)"
# NO_HZ_COMMON dependency
- depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
# We need at least one periodic CPU for timekeeping
depends on SMP
depends on HAVE_CONTEXT_TRACKING
@@ -158,7 +151,6 @@ config CONTEXT_TRACKING_FORCE

config NO_HZ
bool "Old Idle dynticks config"
- depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
help
This is the old config entry that enables dynticks idle.
We keep it around for a little while to enforce backward
@@ -166,7 +158,6 @@ config NO_HZ

config HIGH_RES_TIMERS
bool "High Resolution Timer Support"
- depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS
select TICK_ONESHOT
help
This option enables high resolution timer support. If your
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 02441ead3c3b..cce484a2cc7c 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -705,8 +705,6 @@ static inline void clocksource_update_max_deferment(struct clocksource *cs)
&cs->max_cycles);
}

-#ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
-
static struct clocksource *clocksource_find_best(bool oneshot, bool skipcur)
{
struct clocksource *cs;
@@ -798,12 +796,6 @@ static void clocksource_select_fallback(void)
__clocksource_select(true);
}

-#else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */
-static inline void clocksource_select(void) { }
-static inline void clocksource_select_fallback(void) { }
-
-#endif
-
/*
* clocksource_done_booting - Called near the end of core bootup
*
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 4c47f388a83f..cf99a9a00716 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -352,13 +352,6 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)

/* Timekeeper helper functions. */

-#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-static u32 default_arch_gettimeoffset(void) { return 0; }
-u32 (*arch_gettimeoffset)(void) = default_arch_gettimeoffset;
-#else
-static inline u32 arch_gettimeoffset(void) { return 0; }
-#endif
-
static inline u64 timekeeping_delta_to_ns(const struct tk_read_base *tkr, u64 delta)
{
u64 nsec;
@@ -366,8 +359,7 @@ static inline u64 timekeeping_delta_to_ns(const struct tk_read_base *tkr, u64 de
nsec = delta * tkr->mult + tkr->xtime_nsec;
nsec >>= tkr->shift;

- /* If arch requires, add in get_arch_timeoffset() */
- return nsec + arch_gettimeoffset();
+ return nsec;
}

static inline u64 timekeeping_get_ns(const struct tk_read_base *tkr)
@@ -707,16 +699,8 @@ static void timekeeping_forward_now(struct timekeeper *tk)
tk->tkr_raw.cycle_last = cycle_now;

tk->tkr_mono.xtime_nsec += delta * tk->tkr_mono.mult;
-
- /* If arch requires, add in get_arch_timeoffset() */
- tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift;
-
-
tk->tkr_raw.xtime_nsec += delta * tk->tkr_raw.mult;

- /* If arch requires, add in get_arch_timeoffset() */
- tk->tkr_raw.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_raw.shift;
-
tk_normalize_xtime(tk);
}

@@ -2062,19 +2046,12 @@ static void timekeeping_advance(enum timekeeping_adv_mode mode)
if (unlikely(timekeeping_suspended))
goto out;

-#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
- offset = real_tk->cycle_interval;
-
- if (mode != TK_ADV_TICK)
- goto out;
-#else
offset = clocksource_delta(tk_clock_read(&tk->tkr_mono),
tk->tkr_mono.cycle_last, tk->tkr_mono.mask);

/* Check if there's really nothing to do */
if (offset < real_tk->cycle_interval && mode == TK_ADV_TICK)
goto out;
-#endif

/* Do some additional sanity checking */
timekeeping_check_update(tk, offset);
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index a4020c0b4508..b74099f990bf 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -253,7 +253,6 @@ config IRQSOFF_TRACER
bool "Interrupts-off Latency Tracer"
default n
depends on TRACE_IRQFLAGS_SUPPORT
- depends on !ARCH_USES_GETTIMEOFFSET
select TRACE_IRQFLAGS
select GENERIC_TRACER
select TRACER_MAX_TRACE
@@ -277,7 +276,6 @@ config IRQSOFF_TRACER
config PREEMPT_TRACER
bool "Preemption-off Latency Tracer"
default n
- depends on !ARCH_USES_GETTIMEOFFSET
depends on PREEMPTION
select GENERIC_TRACER
select TRACER_MAX_TRACE
--
2.27.0