We found these warnings in arch/powerpc/kernel/time.c as follows:
warning: symbol 'decrementer_max' was not declared. Should it be static?
warning: symbol 'rtc_lock' was not declared. Should it be static?
warning: symbol 'dtl_consumer' was not declared. Should it be static?
Declare 'decrementer_max' in powerpc asm/time.h.
Include linux/mc146818rtc.h in powerpc kernel/time.c where 'rtc_lock'
is declared. And remove duplicated declaration of 'rtc_lock' in powerpc
platforms/chrp/time.c because it has included linux/mc146818rtc.h.
Move 'dtl_consumer' definition behind "include <asm/dtl.h>" because it
is declared there.
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: He Ying <[email protected]>
---
V2:
- Instead of including linux/mc146818rtc.h in powerpc kernel/time.c, declare
rtc_lock in powerpc asm/time.h.
V3:
- Recover to V1, that is including linux/mc146818rtc.h in powerpc
kernel/time.c. And remove duplicated declaration of 'rtc_lock' in powerpc
platforms/chrp/time.c because it has included linux/mc146818rtc.h.
arch/powerpc/include/asm/time.h | 1 +
arch/powerpc/kernel/time.c | 9 ++++-----
arch/powerpc/platforms/chrp/time.c | 2 --
3 files changed, 5 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 8dd3cdb25338..2cd2b50bedda 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -22,6 +22,7 @@ extern unsigned long tb_ticks_per_jiffy;
extern unsigned long tb_ticks_per_usec;
extern unsigned long tb_ticks_per_sec;
extern struct clock_event_device decrementer_clockevent;
+extern u64 decrementer_max;
extern void generic_calibrate_decr(void);
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index b67d93a609a2..ac81f043bf49 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -55,8 +55,9 @@
#include <linux/sched/cputime.h>
#include <linux/sched/clock.h>
#include <linux/processor.h>
-#include <asm/trace.h>
+#include <linux/mc146818rtc.h>
+#include <asm/trace.h>
#include <asm/interrupt.h>
#include <asm/io.h>
#include <asm/nvram.h>
@@ -150,10 +151,6 @@ bool tb_invalid;
u64 __cputime_usec_factor;
EXPORT_SYMBOL(__cputime_usec_factor);
-#ifdef CONFIG_PPC_SPLPAR
-void (*dtl_consumer)(struct dtl_entry *, u64);
-#endif
-
static void calc_cputime_factors(void)
{
struct div_result res;
@@ -179,6 +176,8 @@ static inline unsigned long read_spurr(unsigned long tb)
#include <asm/dtl.h>
+void (*dtl_consumer)(struct dtl_entry *, u64);
+
/*
* Scan the dispatch trace log and count up the stolen time.
* Should be called with interrupts disabled.
diff --git a/arch/powerpc/platforms/chrp/time.c b/arch/powerpc/platforms/chrp/time.c
index acde7bbe0716..b94dfd5090d8 100644
--- a/arch/powerpc/platforms/chrp/time.c
+++ b/arch/powerpc/platforms/chrp/time.c
@@ -30,8 +30,6 @@
#include <platforms/chrp/chrp.h>
-extern spinlock_t rtc_lock;
-
#define NVRAM_AS0 0x74
#define NVRAM_AS1 0x75
#define NVRAM_DATA 0x77
--
2.17.1
On 24/03/2021 05:09:39-0400, He Ying wrote:
> We found these warnings in arch/powerpc/kernel/time.c as follows:
> warning: symbol 'decrementer_max' was not declared. Should it be static?
> warning: symbol 'rtc_lock' was not declared. Should it be static?
> warning: symbol 'dtl_consumer' was not declared. Should it be static?
>
> Declare 'decrementer_max' in powerpc asm/time.h.
> Include linux/mc146818rtc.h in powerpc kernel/time.c where 'rtc_lock'
> is declared. And remove duplicated declaration of 'rtc_lock' in powerpc
> platforms/chrp/time.c because it has included linux/mc146818rtc.h.
> Move 'dtl_consumer' definition behind "include <asm/dtl.h>" because it
> is declared there.
>
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: He Ying <[email protected]>
> ---
> V2:
> - Instead of including linux/mc146818rtc.h in powerpc kernel/time.c, declare
> rtc_lock in powerpc asm/time.h.
> V3:
> - Recover to V1, that is including linux/mc146818rtc.h in powerpc
> kernel/time.c. And remove duplicated declaration of 'rtc_lock' in powerpc
> platforms/chrp/time.c because it has included linux/mc146818rtc.h.
>
> arch/powerpc/include/asm/time.h | 1 +
> arch/powerpc/kernel/time.c | 9 ++++-----
> arch/powerpc/platforms/chrp/time.c | 2 --
> 3 files changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
> index 8dd3cdb25338..2cd2b50bedda 100644
> --- a/arch/powerpc/include/asm/time.h
> +++ b/arch/powerpc/include/asm/time.h
> @@ -22,6 +22,7 @@ extern unsigned long tb_ticks_per_jiffy;
> extern unsigned long tb_ticks_per_usec;
> extern unsigned long tb_ticks_per_sec;
> extern struct clock_event_device decrementer_clockevent;
> +extern u64 decrementer_max;
>
>
> extern void generic_calibrate_decr(void);
> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
> index b67d93a609a2..ac81f043bf49 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -55,8 +55,9 @@
> #include <linux/sched/cputime.h>
> #include <linux/sched/clock.h>
> #include <linux/processor.h>
> -#include <asm/trace.h>
> +#include <linux/mc146818rtc.h>
I'm fine with that but I really think my suggestion to make the rtc_lock
local to the platforms was better because it is only used to synchronize
between concurrent invocations of chrp_set_rtc_time or
maple_set_rtc_time. The rtc core will never do that and the only case
would be concurrent calls to rtc_ops.set_time and
update_persistent_clock64 (which should also be removed at some point).
>
> +#include <asm/trace.h>
> #include <asm/interrupt.h>
> #include <asm/io.h>
> #include <asm/nvram.h>
> @@ -150,10 +151,6 @@ bool tb_invalid;
> u64 __cputime_usec_factor;
> EXPORT_SYMBOL(__cputime_usec_factor);
>
> -#ifdef CONFIG_PPC_SPLPAR
> -void (*dtl_consumer)(struct dtl_entry *, u64);
> -#endif
> -
> static void calc_cputime_factors(void)
> {
> struct div_result res;
> @@ -179,6 +176,8 @@ static inline unsigned long read_spurr(unsigned long tb)
>
> #include <asm/dtl.h>
>
> +void (*dtl_consumer)(struct dtl_entry *, u64);
> +
> /*
> * Scan the dispatch trace log and count up the stolen time.
> * Should be called with interrupts disabled.
> diff --git a/arch/powerpc/platforms/chrp/time.c b/arch/powerpc/platforms/chrp/time.c
> index acde7bbe0716..b94dfd5090d8 100644
> --- a/arch/powerpc/platforms/chrp/time.c
> +++ b/arch/powerpc/platforms/chrp/time.c
> @@ -30,8 +30,6 @@
>
> #include <platforms/chrp/chrp.h>
>
> -extern spinlock_t rtc_lock;
> -
> #define NVRAM_AS0 0x74
> #define NVRAM_AS1 0x75
> #define NVRAM_DATA 0x77
> --
> 2.17.1
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Le 24/03/2021 à 10:09, He Ying a écrit :
> We found these warnings in arch/powerpc/kernel/time.c as follows:
> warning: symbol 'decrementer_max' was not declared. Should it be static?
> warning: symbol 'rtc_lock' was not declared. Should it be static?
> warning: symbol 'dtl_consumer' was not declared. Should it be static?
>
> Declare 'decrementer_max' in powerpc asm/time.h.
> Include linux/mc146818rtc.h in powerpc kernel/time.c where 'rtc_lock'
> is declared. And remove duplicated declaration of 'rtc_lock' in powerpc
> platforms/chrp/time.c because it has included linux/mc146818rtc.h.
> Move 'dtl_consumer' definition behind "include <asm/dtl.h>" because it
> is declared there.
>
> Reported-by: Hulk Robot <[email protected]>
> Signed-off-by: He Ying <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
> ---
> V2:
> - Instead of including linux/mc146818rtc.h in powerpc kernel/time.c, declare
> rtc_lock in powerpc asm/time.h.
> V3:
> - Recover to V1, that is including linux/mc146818rtc.h in powerpc
> kernel/time.c. And remove duplicated declaration of 'rtc_lock' in powerpc
> platforms/chrp/time.c because it has included linux/mc146818rtc.h.
>
> arch/powerpc/include/asm/time.h | 1 +
> arch/powerpc/kernel/time.c | 9 ++++-----
> arch/powerpc/platforms/chrp/time.c | 2 --
> 3 files changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
> index 8dd3cdb25338..2cd2b50bedda 100644
> --- a/arch/powerpc/include/asm/time.h
> +++ b/arch/powerpc/include/asm/time.h
> @@ -22,6 +22,7 @@ extern unsigned long tb_ticks_per_jiffy;
> extern unsigned long tb_ticks_per_usec;
> extern unsigned long tb_ticks_per_sec;
> extern struct clock_event_device decrementer_clockevent;
> +extern u64 decrementer_max;
>
>
> extern void generic_calibrate_decr(void);
> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
> index b67d93a609a2..ac81f043bf49 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -55,8 +55,9 @@
> #include <linux/sched/cputime.h>
> #include <linux/sched/clock.h>
> #include <linux/processor.h>
> -#include <asm/trace.h>
> +#include <linux/mc146818rtc.h>
>
> +#include <asm/trace.h>
> #include <asm/interrupt.h>
> #include <asm/io.h>
> #include <asm/nvram.h>
> @@ -150,10 +151,6 @@ bool tb_invalid;
> u64 __cputime_usec_factor;
> EXPORT_SYMBOL(__cputime_usec_factor);
>
> -#ifdef CONFIG_PPC_SPLPAR
> -void (*dtl_consumer)(struct dtl_entry *, u64);
> -#endif
> -
> static void calc_cputime_factors(void)
> {
> struct div_result res;
> @@ -179,6 +176,8 @@ static inline unsigned long read_spurr(unsigned long tb)
>
> #include <asm/dtl.h>
>
> +void (*dtl_consumer)(struct dtl_entry *, u64);
> +
> /*
> * Scan the dispatch trace log and count up the stolen time.
> * Should be called with interrupts disabled.
> diff --git a/arch/powerpc/platforms/chrp/time.c b/arch/powerpc/platforms/chrp/time.c
> index acde7bbe0716..b94dfd5090d8 100644
> --- a/arch/powerpc/platforms/chrp/time.c
> +++ b/arch/powerpc/platforms/chrp/time.c
> @@ -30,8 +30,6 @@
>
> #include <platforms/chrp/chrp.h>
>
> -extern spinlock_t rtc_lock;
> -
> #define NVRAM_AS0 0x74
> #define NVRAM_AS1 0x75
> #define NVRAM_DATA 0x77
>
Le 24/03/2021 à 10:29, Alexandre Belloni a écrit :
> On 24/03/2021 05:09:39-0400, He Ying wrote:
>> We found these warnings in arch/powerpc/kernel/time.c as follows:
>> warning: symbol 'decrementer_max' was not declared. Should it be static?
>> warning: symbol 'rtc_lock' was not declared. Should it be static?
>> warning: symbol 'dtl_consumer' was not declared. Should it be static?
>>
>> Declare 'decrementer_max' in powerpc asm/time.h.
>> Include linux/mc146818rtc.h in powerpc kernel/time.c where 'rtc_lock'
>> is declared. And remove duplicated declaration of 'rtc_lock' in powerpc
>> platforms/chrp/time.c because it has included linux/mc146818rtc.h.
>> Move 'dtl_consumer' definition behind "include <asm/dtl.h>" because it
>> is declared there.
>>
>> Reported-by: Hulk Robot <[email protected]>
>> Signed-off-by: He Ying <[email protected]>
>> ---
>> V2:
>> - Instead of including linux/mc146818rtc.h in powerpc kernel/time.c, declare
>> rtc_lock in powerpc asm/time.h.
>> V3:
>> - Recover to V1, that is including linux/mc146818rtc.h in powerpc
>> kernel/time.c. And remove duplicated declaration of 'rtc_lock' in powerpc
>> platforms/chrp/time.c because it has included linux/mc146818rtc.h.
>>
>> arch/powerpc/include/asm/time.h | 1 +
>> arch/powerpc/kernel/time.c | 9 ++++-----
>> arch/powerpc/platforms/chrp/time.c | 2 --
>> 3 files changed, 5 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
>> index 8dd3cdb25338..2cd2b50bedda 100644
>> --- a/arch/powerpc/include/asm/time.h
>> +++ b/arch/powerpc/include/asm/time.h
>> @@ -22,6 +22,7 @@ extern unsigned long tb_ticks_per_jiffy;
>> extern unsigned long tb_ticks_per_usec;
>> extern unsigned long tb_ticks_per_sec;
>> extern struct clock_event_device decrementer_clockevent;
>> +extern u64 decrementer_max;
>>
>>
>> extern void generic_calibrate_decr(void);
>> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
>> index b67d93a609a2..ac81f043bf49 100644
>> --- a/arch/powerpc/kernel/time.c
>> +++ b/arch/powerpc/kernel/time.c
>> @@ -55,8 +55,9 @@
>> #include <linux/sched/cputime.h>
>> #include <linux/sched/clock.h>
>> #include <linux/processor.h>
>> -#include <asm/trace.h>
>> +#include <linux/mc146818rtc.h>
>
> I'm fine with that but I really think my suggestion to make the rtc_lock
> local to the platforms was better because it is only used to synchronize
> between concurrent invocations of chrp_set_rtc_time or
> maple_set_rtc_time. The rtc core will never do that and the only case
> would be concurrent calls to rtc_ops.set_time and
> update_persistent_clock64 (which should also be removed at some point).
I agree but I think it must be done carefully. If the lock is local to the driver really and without
a link with the RTC core, then the lock var should probably be static. But then we'll have name
conflict with the global rtc_lock which is declared in <linux/mc146818rtc.h>
All this is not easy, and I like your idea in the other mail to really clean up the rtc core and
remove this global rtc_lock completely.
For the time being I guess the fix provided by this patch is just semantic and is just fine as is,
as there is no real bug behind the messages from sparse.
Christophe