ARM/arm64: vdso: Use common vdso clock mode storage

Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de

3 files changed, 11 insertions, 27 deletions

diff --git a/arch/arm/include/asm/clocksource.h b/arch/arm/include/asm/clocksource.h
index 0b350a7e26f3..73beb7f131de 100644
--- a/arch/arm/include/asm/clocksource.h
+++ b/arch/arm/include/asm/clocksource.h
@@ -1,8 +1,7 @@
 #ifndef _ASM_CLOCKSOURCE_H
 #define _ASM_CLOCKSOURCE_H
 
-struct arch_clocksource_data {
-	bool vdso_direct;	/* Usable for direct VDSO access? */
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
 
 #endif
diff --git a/arch/arm/include/asm/vdso/gettimeofday.h b/arch/arm/include/asm/vdso/gettimeofday.h
index f4757d327f43..07d791c65cf7 100644
--- a/arch/arm/include/asm/vdso/gettimeofday.h
+++ b/arch/arm/include/asm/vdso/gettimeofday.h
@@ -117,15 +117,21 @@ static __always_inline u64 __arch_get_hw_counter(int clock_mode)
 #ifdef CONFIG_ARM_ARCH_TIMER
 	u64 cycle_now;
 
-	if (!clock_mode)
-		return -EINVAL;
+	/*
+	 * Core checks for mode already, so this raced against a concurrent
+	 * update. Return something. Core will do another round and then
+	 * see the mode change and fallback to the syscall.
+	 */
+	if (clock_mode == VDSO_CLOCKMODE_NONE)
+		return 0;
 
 	isb();
 	cycle_now = read_sysreg(CNTVCT);
 
 	return cycle_now;
 #else
-	return -EINVAL; /* use fallback */
+	/* Make GCC happy. This is compiled out anyway */
+	return 0;
 #endif
 }
 
diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
index 85a7e58b7228..002f9edd8a2b 100644
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -11,18 +11,6 @@
 extern struct vdso_data *vdso_data;
 extern bool cntvct_ok;
 
-static __always_inline
-bool tk_is_cntvct(const struct timekeeper *tk)
-{
-	if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
-		return false;
-
-	if (!tk->tkr_mono.clock->archdata.vdso_direct)
-		return false;
-
-	return true;
-}
-
 /*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
  */
@@ -41,15 +29,6 @@ bool __arm_update_vdso_data(void)
 #define __arch_update_vdso_data __arm_update_vdso_data
 
 static __always_inline
-int __arm_get_clock_mode(struct timekeeper *tk)
-{
-	u32 __tk_is_cntvct = tk_is_cntvct(tk);
-
-	return __tk_is_cntvct;
-}
-#define __arch_get_clock_mode __arm_get_clock_mode
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));