[PATCH v5 06/12] arm: vdso: add support for clock_getres
From: Mark Salyzyn <hidden>
Date: 2017-11-06 21:02:34
Also in:
lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
Take an effort to recode the arm64 vdso code from assembler to C previously submitted by Andrew Pinski [off-list ref], 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 clock_getres vdso support to match up with existing support in the arm64's vdso. Signed-off-by: Mark Salyzyn <redacted> Cc: James Morse <james.morse@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <redacted> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dmitry Safonov <redacted> Cc: John Stultz <redacted> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Laura Abbott <redacted> Cc: Kees Cook <redacted> Cc: Ard Biesheuvel <redacted> Cc: Andy Gross <redacted> Cc: Kevin Brodsky <redacted> Cc: Andrew Pinski <redacted> Cc: Thomas Gleixner <redacted> Cc: linux-kernel at vger.kernel.org Cc: linux-arm-kernel at lists.infradead.org v2: - split first CL into 7 of 7 pieces v4: - update commit message to reflect overall reasoning. - replace typeof() with long for nsec - replace clock_id with clock to match usage elsewhere. v5: - add linux/hrtimer.h to compiler.h to supply for LOW_RES_NSEC and MONOTONIC_RES_NSEC. --- arch/arm/kernel/vdso.c | 1 + arch/arm/vdso/compiler.h | 1 + arch/arm/vdso/vdso.lds.S | 1 + arch/arm/vdso/vgettimeofday.c | 23 +++++++++++++++++++++++ 4 files changed, 26 insertions(+)
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index b7c93fce2f59..a80c58805699 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c@@ -189,6 +189,7 @@ static void __init patch_vdso(void *ehdr) if (!cntvct_ok) { vdso_nullpatch_one(&einfo, "__vdso_gettimeofday"); vdso_nullpatch_one(&einfo, "__vdso_clock_gettime"); + vdso_nullpatch_one(&einfo, "__vdso_clock_getres"); } }
diff --git a/arch/arm/vdso/compiler.h b/arch/arm/vdso/compiler.h
index 3edddb705a1b..c7751019246a 100644
--- a/arch/arm/vdso/compiler.h
+++ b/arch/arm/vdso/compiler.h@@ -27,6 +27,7 @@ #include <asm/processor.h> /* for cpu_relax() */ #include <asm/unistd.h> #include <linux/compiler.h> +#include <linux/hrtimer.h> /* for LOW_RES_NSEC and MONOTONIC_RES_NSEC */ #include <linux/time.h> /* for NSEC_PER_SEC */ #ifndef CONFIG_AEABI
diff --git a/arch/arm/vdso/vdso.lds.S b/arch/arm/vdso/vdso.lds.S
index 89ca89f12d23..1d81e8c3acf6 100644
--- a/arch/arm/vdso/vdso.lds.S
+++ b/arch/arm/vdso/vdso.lds.S@@ -82,6 +82,7 @@ VERSION global: __vdso_clock_gettime; __vdso_gettimeofday; + __vdso_clock_getres; local: *; }; }
diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
index a2c4db83edc4..a354586f8a65 100644
--- a/arch/arm/vdso/vgettimeofday.c
+++ b/arch/arm/vdso/vgettimeofday.c@@ -32,6 +32,7 @@ DEFINE_FALLBACK(gettimeofday, struct timeval *, tv, struct timezone *, tz) DEFINE_FALLBACK(clock_gettime, clockid_t, clock, struct timespec *, ts) +DEFINE_FALLBACK(clock_getres, clockid_t, clock, struct timespec *, ts) static notrace u32 vdso_read_begin(const struct vdso_data *vd) {
@@ -301,3 +302,25 @@ notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz) return 0; } + +int __vdso_clock_getres(clockid_t clock, struct timespec *res) +{ + long nsec; + + if (clock == CLOCK_REALTIME || + clock == CLOCK_MONOTONIC || + clock == CLOCK_MONOTONIC_RAW) + nsec = MONOTONIC_RES_NSEC; + else if (clock == CLOCK_REALTIME_COARSE || + clock == CLOCK_MONOTONIC_COARSE) + nsec = LOW_RES_NSEC; + else + return clock_getres_fallback(clock, res); + + if (likely(res != NULL)) { + res->tv_sec = 0; + res->tv_nsec = nsec; + } + + return 0; +}
--
2.15.0.403.gc27cc4dac6-goog