[PATCH AUTOSEL 4.19 065/209] clocksource/drivers/sh_cmt: Fix clocksource width for 32-bit machines

Sasha Levin
2019-11-13T02:24:42Z

From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

[ Upstream commit 37e7742c55ba856eaec7e35673ee370f36eb17f3 ]

The driver seems to abuse *unsigned long* not only for the (32-bit)
register values but also for the 'sh_cmt_channel::total_cycles' which
needs to always be 64-bit -- as a result, the clocksource's mask is
needlessly clamped down to 32-bits on the 32-bit machines...

Fixes: 19bdc9d061bc ("clocksource: sh_cmt clocksource support")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clocksource/sh_cmt.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index 49302086f36fd..cec90a4c79b34 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -108,7 +108,7 @@ struct sh_cmt_channel {
raw_spinlock_t lock;
struct clock_event_device ced;
struct clocksource cs;
- unsigned long total_cycles;
+ u64 total_cycles;
bool cs_enabled;
};

@@ -613,8 +613,8 @@ static u64 sh_cmt_clocksource_read(struct clocksource *cs)
{
struct sh_cmt_channel *ch = cs_to_sh_cmt(cs);
unsigned long flags;
- unsigned long value;
u32 has_wrapped;
+ u64 value;
u32 raw;

raw_spin_lock_irqsave(&ch->lock, flags);
@@ -688,7 +688,7 @@ static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch,
cs->disable = sh_cmt_clocksource_disable;
cs->suspend = sh_cmt_clocksource_suspend;
cs->resume = sh_cmt_clocksource_resume;
- cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
+ cs->mask = CLOCKSOURCE_MASK(sizeof(u64) * 8);
cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;

dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n",
--
2.20.1