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arm: vdso: Add support for CLOCK_MONOTONIC_RAW

PATCH New Mark Salyzyn 1 participant 1 message Nov 9, 2017 Arm (32-bit)

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Mark Salyzyn

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PATCH v6 5/12 arm: vdso: Add support for CLOCK_MONOTONIC_RAW

Take an effort to recode the arm64 vdso code from assembler to C previously submitted by Andrew Pinski <[email protected]>, rework it for use in both arm and arm64, overlapping any optimizations for each architecture. But instead of landing it in arm64, land the result into lib/vdso and unify both implementations to simplify future maintenance.

Add a case for CLOCK_MONOTONIC_RAW to match up with support that is available in arm64's vdso.

Signed-off-by Mark Salyzyn <[email protected]>
Cc James Morse <[email protected]>
Cc Russell King <[email protected]>
Cc Catalin Marinas <[email protected]>
Cc Will Deacon <[email protected]>
Cc Andy Lutomirski <[email protected]>
Cc Dmitry Safonov <[email protected]>
Cc John Stultz <[email protected]>
Cc Mark Rutland <[email protected]>
Cc Laura Abbott <[email protected]>
Cc Kees Cook <[email protected]>
Cc Ard Biesheuvel <[email protected]>
Cc Andy Gross <[email protected]>
Cc Kevin Brodsky <[email protected]>
Cc Andrew Pinski <[email protected]>
Cc Thomas Gleixner <[email protected]>
Cc linux-kernel at vger.kernel.org
Cc linux-arm-kernel at lists.infradead.org

v2:
- split first CL into 6 of 7 pieces

v4:
- Move out ARCH_CLOCK_FIXED_MASK to later adjustment.
- update commit message to reflect overall reasoning.
- replace typeof() with type vdso_raw_time_sec_t.

v5:
- replace erroneous tk->raw_time.shift with tk->tkr_raw.shift

v6:
- fixup raw_time_sec and raw_time_nsec in vdso.c

---
 arch/arm/include/asm/vdso_datapage.h | 11 +++++++++
 arch/arm/kernel/vdso.c               |  3 +++
 arch/arm/vdso/vgettimeofday.c        | 44 ++++++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+)
arch/arm/include/asm/vdso_datapage.h +11 -0
index 8dd7303db4ec..1c6e6a5d5d9d 100644
@@ -34,6 +34,11 @@ typedef u32 vdso_wtm_clock_nsec_t;
 typedef u32 vdso_xtime_clock_sec_t;
 #endif
 
+#ifndef _VDSO_RAW_TIME_SEC_T
+#define _VDSO_RAW_TIME_SEC_T
+typedef u32 vdso_raw_time_sec_t;
+#endif
+
 /* Try to be cache-friendly on systems that don't implement the
  * generic timer: fit the unconditionally updated fields in the first
  * 32 bytes.

@@ -58,6 +63,12 @@ struct vdso_data {
 	u64 xtime_clock_snsec;	/* CLOCK_REALTIME sub-ns base */
 	u32 tz_minuteswest;	/* timezone info for gettimeofday(2) */
 	u32 tz_dsttime;
+
+	/* Raw clocksource multipler */
+	u32 cs_raw_mult;
+	/* Raw time */
+	vdso_raw_time_sec_t raw_time_sec;
+	u32 raw_time_nsec;
 };
 
 union vdso_data_store {
arch/arm/kernel/vdso.c +3 -0
index aed84b659cc5..898420579ae9 100644
@@ -335,9 +335,12 @@ void update_vsyscall(struct timekeeper *tk)
 
 	if (!vdso_data->use_syscall) {
 		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_snsec	= 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;
 		vdso_data->cs_mask		= tk->tkr_mono.mask;
arch/arm/vdso/vgettimeofday.c +44 -0

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