From: Marc Zyngier marc.zyngier@arm.com
[ Upstream commit 1f5b62f09f6b314c8d70b9de5182dae4de1f94da ]
The VDSO code uses the kernel helper that was originally designed to abstract the access between 32 and 64bit systems. It worked so far because this function is declared as 'inline'.
As we're about to revamp that part of the code, the VDSO would break. Let's fix it by doing what should have been done from the start, a proper system register access.
Reviewed-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/include/asm/cp15.h | 2 ++ arch/arm/vdso/vgettimeofday.c | 5 +++-- 2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h index 07e27f212dc75..d2453e2d3f1f3 100644 --- a/arch/arm/include/asm/cp15.h +++ b/arch/arm/include/asm/cp15.h @@ -68,6 +68,8 @@ #define BPIALL __ACCESS_CP15(c7, 0, c5, 6) #define ICIALLU __ACCESS_CP15(c7, 0, c5, 0)
+#define CNTVCT __ACCESS_CP15_64(1, c14) + extern unsigned long cr_alignment; /* defined in entry-armv.S */
static inline unsigned long get_cr(void) diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c index 79214d5ff0970..3af02d2a0b7f2 100644 --- a/arch/arm/vdso/vgettimeofday.c +++ b/arch/arm/vdso/vgettimeofday.c @@ -18,9 +18,9 @@ #include <linux/compiler.h> #include <linux/hrtimer.h> #include <linux/time.h> -#include <asm/arch_timer.h> #include <asm/barrier.h> #include <asm/bug.h> +#include <asm/cp15.h> #include <asm/page.h> #include <asm/unistd.h> #include <asm/vdso_datapage.h> @@ -123,7 +123,8 @@ static notrace u64 get_ns(struct vdso_data *vdata) u64 cycle_now; u64 nsec;
- cycle_now = arch_counter_get_cntvct(); + isb(); + cycle_now = read_sysreg(CNTVCT);
cycle_delta = (cycle_now - vdata->cs_cycle_last) & vdata->cs_mask;