[PATCH AUTOSEL 4.19 031/244] ARM: vdso: Remove dependency with the arch_timer driver internals

Sasha Levin
2019-05-22T19:27:28Z

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 a9dd619c6c290..7bdbf5d5c47d3 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;

--
2.20.1