[PATCH v3 5/8] clocksource: Replace vread with generic arch data

From: Andy Lutomirski
Date: Wed Jul 13 2011 - 09:24:45 EST


The vread field was bloating struct clocksource everywhere except
x86_64, and I want to change the way this works on x86_64, so let's
split it out into per-arch data.

Cc: x86@xxxxxxxxxx
Cc: Clemens Ladisch <clemens@xxxxxxxxxx>
Cc: linux-ia64@xxxxxxxxxxxxxxx
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: John Stultz <johnstul@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andy Lutomirski <luto@xxxxxxx>
---
arch/x86/include/asm/clocksource.h | 16 ++++++++++++++++
arch/x86/kernel/hpet.c | 2 +-
arch/x86/kernel/tsc.c | 2 +-
arch/x86/kernel/vsyscall_64.c | 2 +-
include/asm-generic/clocksource.h | 4 ++++
include/linux/clocksource.h | 10 ++++++++--
6 files changed, 31 insertions(+), 5 deletions(-)
create mode 100644 arch/x86/include/asm/clocksource.h
create mode 100644 include/asm-generic/clocksource.h

diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h
new file mode 100644
index 0000000..a5df33f
--- /dev/null
+++ b/arch/x86/include/asm/clocksource.h
@@ -0,0 +1,16 @@
+/* x86-specific clocksource additions */
+
+#ifndef _ASM_X86_CLOCKSOURCE_H
+#define _ASM_X86_CLOCKSOURCE_H
+
+#ifdef CONFIG_X86_64
+
+#define __ARCH_HAS_CLOCKSOURCE_DATA
+
+struct arch_clocksource_data {
+ cycle_t (*vread)(void);
+};
+
+#endif /* CONFIG_X86_64 */
+
+#endif /* _ASM_X86_CLOCKSOURCE_H */
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index e9f5605..0e07257 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -753,7 +753,7 @@ static struct clocksource clocksource_hpet = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.resume = hpet_resume_counter,
#ifdef CONFIG_X86_64
- .vread = vread_hpet,
+ .archdata = { .vread = vread_hpet },
#endif
};

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 6cc6922..e7a74b8 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -777,7 +777,7 @@ static struct clocksource clocksource_tsc = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS |
CLOCK_SOURCE_MUST_VERIFY,
#ifdef CONFIG_X86_64
- .vread = vread_tsc,
+ .archdata = { .vread = vread_tsc },
#endif
};

diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index a262400..12d488f 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -74,7 +74,7 @@ void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);

/* copy vsyscall data */
- vsyscall_gtod_data.clock.vread = clock->vread;
+ vsyscall_gtod_data.clock.vread = clock->archdata.vread;
vsyscall_gtod_data.clock.cycle_last = clock->cycle_last;
vsyscall_gtod_data.clock.mask = clock->mask;
vsyscall_gtod_data.clock.mult = mult;
diff --git a/include/asm-generic/clocksource.h b/include/asm-generic/clocksource.h
new file mode 100644
index 0000000..0a462d3
--- /dev/null
+++ b/include/asm-generic/clocksource.h
@@ -0,0 +1,4 @@
+/*
+ * Architectures should override this file to add private userspace
+ * clock magic if needed.
+ */
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 18a1baf..9ab6b6a 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -22,6 +22,8 @@
typedef u64 cycle_t;
struct clocksource;

+#include <asm/clocksource.h>
+
/**
* struct cyclecounter - hardware abstraction for a free running counter
* Provides completely state-free accessors to the underlying hardware.
@@ -153,7 +155,7 @@ extern u64 timecounter_cyc2time(struct timecounter *tc,
* @shift: cycle to nanosecond divisor (power of two)
* @max_idle_ns: max idle time permitted by the clocksource (nsecs)
* @flags: flags describing special properties
- * @vread: vsyscall based read
+ * @archdata: arch-specific data
* @suspend: suspend function for the clocksource, if necessary
* @resume: resume function for the clocksource, if necessary
*/
@@ -175,10 +177,14 @@ struct clocksource {
#else
#define CLKSRC_FSYS_MMIO_SET(mmio, addr) do { } while (0)
#endif
+
+#ifdef __ARCH_HAS_CLOCKSOURCE_DATA
+ struct arch_clocksource_data archdata;
+#endif
+
const char *name;
struct list_head list;
int rating;
- cycle_t (*vread)(void);
int (*enable)(struct clocksource *cs);
void (*disable)(struct clocksource *cs);
unsigned long flags;
--
1.7.6

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