From: Sergei Shtylyov sergei.shtylyov@cogentembedded.com
[ Upstream commit 22627c6f3ed3d9d0df13eec3c831b08f8186c38e ]
When trying to use CMT for clockevents on R-Car gen3 SoCs, I noticed that 'max_delta_ns' for the broadcast timer (CMT) was shown as 1000 in /proc/timer_list. It turned out that when calculating it, the driver did 1 << 32 (causing what I think was undefined behavior) resulting in a zero delta, later clamped to 1000 by cev_delta2ns(). The root cause turned out to be that the driver abused *unsigned long* for the CMT register values (which are 16/32-bit), so that the calculation of 'ch->max_match_value' in sh_cmt_setup_channel() used the wrong branch. Using more proper 'u32' instead fixed 'max_delta_ns' and even fixed the switching an active clocksource to CMT (which caused the system to turn non-interactive before).
Signed-off-by: Sergei Shtylyov sergei.shtylyov@cogentembedded.com 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 | 72 +++++++++++++++++------------------- 1 file changed, 33 insertions(+), 39 deletions(-)
diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index e09e8bf0bb9bf..560541f53c8d9 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -75,18 +75,17 @@ struct sh_cmt_info { enum sh_cmt_model model;
unsigned long width; /* 16 or 32 bit version of hardware block */ - unsigned long overflow_bit; - unsigned long clear_bits; + u32 overflow_bit; + u32 clear_bits;
/* callbacks for CMSTR and CMCSR access */ - unsigned long (*read_control)(void __iomem *base, unsigned long offs); + u32 (*read_control)(void __iomem *base, unsigned long offs); void (*write_control)(void __iomem *base, unsigned long offs, - unsigned long value); + u32 value);
/* callbacks for CMCNT and CMCOR access */ - unsigned long (*read_count)(void __iomem *base, unsigned long offs); - void (*write_count)(void __iomem *base, unsigned long offs, - unsigned long value); + u32 (*read_count)(void __iomem *base, unsigned long offs); + void (*write_count)(void __iomem *base, unsigned long offs, u32 value); };
struct sh_cmt_channel { @@ -100,9 +99,9 @@ struct sh_cmt_channel {
unsigned int timer_bit; unsigned long flags; - unsigned long match_value; - unsigned long next_match_value; - unsigned long max_match_value; + u32 match_value; + u32 next_match_value; + u32 max_match_value; raw_spinlock_t lock; struct clock_event_device ced; struct clocksource cs; @@ -157,24 +156,22 @@ struct sh_cmt_device { #define SH_CMT32_CMCSR_CKS_RCLK1 (7 << 0) #define SH_CMT32_CMCSR_CKS_MASK (7 << 0)
-static unsigned long sh_cmt_read16(void __iomem *base, unsigned long offs) +static u32 sh_cmt_read16(void __iomem *base, unsigned long offs) { return ioread16(base + (offs << 1)); }
-static unsigned long sh_cmt_read32(void __iomem *base, unsigned long offs) +static u32 sh_cmt_read32(void __iomem *base, unsigned long offs) { return ioread32(base + (offs << 2)); }
-static void sh_cmt_write16(void __iomem *base, unsigned long offs, - unsigned long value) +static void sh_cmt_write16(void __iomem *base, unsigned long offs, u32 value) { iowrite16(value, base + (offs << 1)); }
-static void sh_cmt_write32(void __iomem *base, unsigned long offs, - unsigned long value) +static void sh_cmt_write32(void __iomem *base, unsigned long offs, u32 value) { iowrite32(value, base + (offs << 2)); } @@ -236,7 +233,7 @@ static const struct sh_cmt_info sh_cmt_info[] = { #define CMCNT 1 /* channel register */ #define CMCOR 2 /* channel register */
-static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_channel *ch) +static inline u32 sh_cmt_read_cmstr(struct sh_cmt_channel *ch) { if (ch->iostart) return ch->cmt->info->read_control(ch->iostart, 0); @@ -244,8 +241,7 @@ static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_channel *ch) return ch->cmt->info->read_control(ch->cmt->mapbase, 0); }
-static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, - unsigned long value) +static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, u32 value) { if (ch->iostart) ch->cmt->info->write_control(ch->iostart, 0, value); @@ -253,39 +249,35 @@ static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, ch->cmt->info->write_control(ch->cmt->mapbase, 0, value); }
-static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_channel *ch) +static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch) { return ch->cmt->info->read_control(ch->ioctrl, CMCSR); }
-static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, - unsigned long value) +static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, u32 value) { ch->cmt->info->write_control(ch->ioctrl, CMCSR, value); }
-static inline unsigned long sh_cmt_read_cmcnt(struct sh_cmt_channel *ch) +static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch) { return ch->cmt->info->read_count(ch->ioctrl, CMCNT); }
-static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, - unsigned long value) +static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value) { ch->cmt->info->write_count(ch->ioctrl, CMCNT, value); }
-static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, - unsigned long value) +static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, u32 value) { ch->cmt->info->write_count(ch->ioctrl, CMCOR, value); }
-static unsigned long sh_cmt_get_counter(struct sh_cmt_channel *ch, - int *has_wrapped) +static u32 sh_cmt_get_counter(struct sh_cmt_channel *ch, u32 *has_wrapped) { - unsigned long v1, v2, v3; - int o1, o2; + u32 v1, v2, v3; + u32 o1, o2;
o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit;
@@ -305,7 +297,8 @@ static unsigned long sh_cmt_get_counter(struct sh_cmt_channel *ch,
static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start) { - unsigned long flags, value; + unsigned long flags; + u32 value;
/* start stop register shared by multiple timer channels */ raw_spin_lock_irqsave(&ch->cmt->lock, flags); @@ -412,11 +405,11 @@ static void sh_cmt_disable(struct sh_cmt_channel *ch) static void sh_cmt_clock_event_program_verify(struct sh_cmt_channel *ch, int absolute) { - unsigned long new_match; - unsigned long value = ch->next_match_value; - unsigned long delay = 0; - unsigned long now = 0; - int has_wrapped; + u32 value = ch->next_match_value; + u32 new_match; + u32 delay = 0; + u32 now = 0; + u32 has_wrapped;
now = sh_cmt_get_counter(ch, &has_wrapped); ch->flags |= FLAG_REPROGRAM; /* force reprogram */ @@ -613,9 +606,10 @@ static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs) static u64 sh_cmt_clocksource_read(struct clocksource *cs) { struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); - unsigned long flags, raw; + unsigned long flags; unsigned long value; - int has_wrapped; + u32 has_wrapped; + u32 raw;
raw_spin_lock_irqsave(&ch->lock, flags); value = ch->total_cycles;