[tip: sched/core] arm64/arch_timer: Fix MMIO byteswap

From: tip-bot2 for Peter Zijlstra
Date: Fri Jun 09 2023 - 03:56:10 EST


The following commit has been merged into the sched/core branch of tip:

Commit-ID: 5416bf1cf5602ab3a38b4c0d15ccec1ca4199633
Gitweb: https://git.kernel.org/tip/5416bf1cf5602ab3a38b4c0d15ccec1ca4199633
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Tue, 06 Jun 2023 10:06:14 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 06 Jun 2023 10:19:51 +02:00

arm64/arch_timer: Fix MMIO byteswap

The readl_relaxed() to __raw_readl() change meant to loose the
instrumentation, but also (inadvertently) lost the byteswap.

Fixes: 24ee7607b286 ("arm64/arch_timer: Provide noinstr sched_clock_read() functions")
Reported-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Link: https://lkml.kernel.org/r/20230606080614.GB905437@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
---
drivers/clocksource/arm_arch_timer.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index b23d23b..e733a2a 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -776,9 +776,9 @@ static noinstr u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo)
u32 cnt_lo, cnt_hi, tmp_hi;

do {
- cnt_hi = __raw_readl(t->base + offset_lo + 4);
- cnt_lo = __raw_readl(t->base + offset_lo);
- tmp_hi = __raw_readl(t->base + offset_lo + 4);
+ cnt_hi = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo + 4));
+ cnt_lo = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo));
+ tmp_hi = __le32_to_cpu((__le32 __force)__raw_readl(t->base + offset_lo + 4));
} while (cnt_hi != tmp_hi);

return ((u64) cnt_hi << 32) | cnt_lo;