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

4 files changed, 12 insertions, 24 deletions

diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h
index 0ece64a26c8c..eb82e9d95c5d 100644
--- a/arch/arm64/include/asm/clocksource.h
+++ b/arch/arm64/include/asm/clocksource.h
@@ -2,8 +2,7 @@
 #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/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
index 537b1e695365..81b0c394f1d8 100644
--- a/arch/arm64/include/asm/vdso/compat_gettimeofday.h
+++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
@@ -12,8 +12,6 @@
 
 #include <asm/vdso/compat_barrier.h>
 
-#define __VDSO_USE_SYSCALL		ULLONG_MAX
-
 #define VDSO_HAS_CLOCK_GETRES		1
 
 #define BUILD_VDSO32			1
@@ -117,11 +115,12 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 	u64 res;
 
 	/*
-	 * clock_mode == 0 implies that vDSO are enabled otherwise
-	 * fallback on syscall.
+	 * 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)
-		return __VDSO_USE_SYSCALL;
+	if (clock_mode == VDSO_CLOCKMODE_NONE)
+		return 0;
 
 	/*
 	 * This isb() is required to prevent that the counter value
diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h
index b08f476b72b4..5a534432aa5d 100644
--- a/arch/arm64/include/asm/vdso/gettimeofday.h
+++ b/arch/arm64/include/asm/vdso/gettimeofday.h
@@ -10,8 +10,6 @@
 #include <asm/unistd.h>
 #include <uapi/linux/time.h>
 
-#define __VDSO_USE_SYSCALL		ULLONG_MAX
-
 #define VDSO_HAS_CLOCK_GETRES		1
 
 static __always_inline
@@ -71,11 +69,12 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 	u64 res;
 
 	/*
-	 * clock_mode == 0 implies that vDSO are enabled otherwise
-	 * fallback on syscall.
+	 * 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)
-		return __VDSO_USE_SYSCALL;
+	if (clock_mode == VDSO_CLOCKMODE_NONE)
+		return 0;
 
 	/*
 	 * This isb() is required to prevent that the counter value
diff --git a/arch/arm64/include/asm/vdso/vsyscall.h b/arch/arm64/include/asm/vdso/vsyscall.h
index 0c20a7c1bee5..f94b1457c117 100644
--- a/arch/arm64/include/asm/vdso/vsyscall.h
+++ b/arch/arm64/include/asm/vdso/vsyscall.h
@@ -22,15 +22,6 @@ struct vdso_data *__arm64_get_k_vdso_data(void)
 #define __arch_get_k_vdso_data __arm64_get_k_vdso_data
 
 static __always_inline
-int __arm64_get_clock_mode(struct timekeeper *tk)
-{
-	u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
-
-	return use_syscall;
-}
-#define __arch_get_clock_mode __arm64_get_clock_mode
-
-static __always_inline
 void __arm64_update_vsyscall(struct vdso_data *vdata, struct timekeeper *tk)
 {
 	vdata[CS_HRES_COARSE].mask	= VDSO_PRECISION_MASK;