Hi Marc, On Mon, Apr 08, 2019 at 04:49:01PM +0100, Marc Zyngier wrote: > 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. > > Signed-off-by: Marc Zyngier <[email protected]> > --- > arch/arm/include/asm/cp15.h | 2 ++ > arch/arm/vdso/vgettimeofday.c | 5 +++-- > 2 files changed, 5 insertions(+), 2 deletions(-)
This looks ok to me and I'd like to take the series via arm64, but I could do with an Ack from Russell on these 32-bit ARM parts first. Will > diff --git a/arch/arm/include/asm/cp15.h b/arch/arm/include/asm/cp15.h > index 07e27f212dc7..d2453e2d3f1f 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 a9dd619c6c29..7bdbf5d5c47d 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 >
