FROMLIST: [PATCH v5 08/12] arm: vdso: Add ARCH_CLOCK_FIXED_MASK

(cherry picked from url https://patchwork.kernel.org/patch/10044543/)

Take an effort to recode the arm64 vdso code from assembler to C
previously submitted by Andrew Pinski <apinski@cavium.com>, 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 ARCH_CLOCK_FIXED_MASK as an efficiency since arm64 has no
purpose for cs_mask vdso_data variable.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: James Morse <james.morse@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Andrew Pinski <apinski@cavium.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Bug: 63737556
Bug: 20057882
Change-Id: Iadf94bed6166d2ee43bb46bdf54636618e4b8854

diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
index a354586f8a659936357ac2886dcd1bd719594b32..3005479efbe8c2081c0fcd7c3103b3f99e8ce26b 100644 (file)
--- a/arch/arm/vdso/vgettimeofday.c
+++ b/arch/arm/vdso/vgettimeofday.c
@@ -128,7 +128,11 @@ static notrace int do_realtime(const struct vdso_data *vd, struct timespec *ts)
 {
        u32 seq, mult, shift;
        u64 nsec, cycle_last;
+#ifdef ARCH_CLOCK_FIXED_MASK
+       static const u64 mask = ARCH_CLOCK_FIXED_MASK;
+#else
        u64 mask;
+#endif
        vdso_xtime_clock_sec_t sec;
 
        do {
@@ -141,7 +145,9 @@ static notrace int do_realtime(const struct vdso_data *vd, struct timespec *ts)
 
                mult = vd->cs_mono_mult;
                shift = vd->cs_shift;
+#ifndef ARCH_CLOCK_FIXED_MASK
                mask = vd->cs_mask;
+#endif
 
                sec = vd->xtime_clock_sec;
                nsec = vd->xtime_clock_snsec;
@@ -161,7 +167,11 @@ static notrace int do_monotonic(const struct vdso_data *vd, struct timespec *ts)
 {
        u32 seq, mult, shift;
        u64 nsec, cycle_last;
+#ifdef ARCH_CLOCK_FIXED_MASK
+       static const u64 mask = ARCH_CLOCK_FIXED_MASK;
+#else
        u64 mask;
+#endif
        vdso_wtm_clock_nsec_t wtm_nsec;
        __kernel_time_t sec;
 
@@ -175,7 +185,9 @@ static notrace int do_monotonic(const struct vdso_data *vd, struct timespec *ts)
 
                mult = vd->cs_mono_mult;
                shift = vd->cs_shift;
+#ifndef ARCH_CLOCK_FIXED_MASK
                mask = vd->cs_mask;
+#endif
 
                sec = vd->xtime_clock_sec;
                nsec = vd->xtime_clock_snsec;
@@ -200,7 +212,11 @@ static notrace int do_monotonic_raw(const struct vdso_data *vd,
 {
        u32 seq, mult, shift;
        u64 nsec, cycle_last;
+#ifdef ARCH_CLOCK_FIXED_MASK
+       static const u64 mask = ARCH_CLOCK_FIXED_MASK;
+#else
        u64 mask;
+#endif
        vdso_raw_time_sec_t sec;
 
        do {
@@ -213,7 +229,9 @@ static notrace int do_monotonic_raw(const struct vdso_data *vd,
 
                mult = vd->cs_raw_mult;
                shift = vd->cs_shift;
+#ifndef ARCH_CLOCK_FIXED_MASK
                mask = vd->cs_mask;
+#endif
 
                sec = vd->raw_time_sec;
                nsec = vd->raw_time_nsec;