Commit 5416bf1c authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

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: 24ee7607 ("arm64/arch_timer: Provide noinstr sched_clock_read() functions")
Reported-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20230606080614.GB905437@hirez.programming.kicks-ass.net
parent 7d0583cf

drivers/clocksource/arm_arch_timer.c

+3 −3
Original line number Diff line number Diff line
@@ -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;