2022-06-23 09:17:14

by Jiri Slaby

[permalink] [raw]
Subject: [PATCH 1/2] clk: pistachio: Fix initconst confusion

From: Andi Kleen <[email protected]>

A variable pointing to const isn't const itself. It'd have to contain
"const" keyword after "*" too. Therefore, PNAME() cannot put the strings
to "rodata". Hence use __initdata instead of __initconst to fix this.

[js] more explanatory commit message.

Cc: Michael Turquette <[email protected]>
Cc: Stephen Boyd <[email protected]>
Cc: [email protected]
Signed-off-by: Andi Kleen <[email protected]>
Signed-off-by: Jiri Slaby <[email protected]>
---
drivers/clk/pistachio/clk.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
index f9c31e3a0e47..742e5fab00c0 100644
--- a/drivers/clk/pistachio/clk.h
+++ b/drivers/clk/pistachio/clk.h
@@ -34,7 +34,7 @@ struct pistachio_mux {
const char **parents;
};

-#define PNAME(x) static const char *x[] __initconst
+#define PNAME(x) static const char *x[] __initdata

#define MUX(_id, _name, _pnames, _reg, _shift) \
{ \
--
2.36.1


2022-06-24 00:52:55

by Stephen Boyd

[permalink] [raw]
Subject: Re: [PATCH 1/2] clk: pistachio: Fix initconst confusion

Quoting Jiri Slaby (2022-06-23 01:32:16)
> From: Andi Kleen <[email protected]>
>
> A variable pointing to const isn't const itself. It'd have to contain
> "const" keyword after "*" too. Therefore, PNAME() cannot put the strings
> to "rodata". Hence use __initdata instead of __initconst to fix this.
>
> [js] more explanatory commit message.
>
> Cc: Michael Turquette <[email protected]>
> Cc: Stephen Boyd <[email protected]>
> Cc: [email protected]
> Signed-off-by: Andi Kleen <[email protected]>
> Signed-off-by: Jiri Slaby <[email protected]>
> ---
> drivers/clk/pistachio/clk.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
> index f9c31e3a0e47..742e5fab00c0 100644
> --- a/drivers/clk/pistachio/clk.h
> +++ b/drivers/clk/pistachio/clk.h
> @@ -34,7 +34,7 @@ struct pistachio_mux {
> const char **parents;
> };
>
> -#define PNAME(x) static const char *x[] __initconst
> +#define PNAME(x) static const char *x[] __initdata

Can it be const char * const and left as __initconst?

2022-06-27 08:32:36

by Jiri Slaby

[permalink] [raw]
Subject: Re: [PATCH 1/2] clk: pistachio: Fix initconst confusion

On 24. 06. 22, 2:42, Stephen Boyd wrote:
> Quoting Jiri Slaby (2022-06-23 01:32:16)
>> From: Andi Kleen <[email protected]>
>>
>> A variable pointing to const isn't const itself. It'd have to contain
>> "const" keyword after "*" too. Therefore, PNAME() cannot put the strings
>> to "rodata". Hence use __initdata instead of __initconst to fix this.
>>
>> [js] more explanatory commit message.
>>
>> Cc: Michael Turquette <[email protected]>
>> Cc: Stephen Boyd <[email protected]>
>> Cc: [email protected]
>> Signed-off-by: Andi Kleen <[email protected]>
>> Signed-off-by: Jiri Slaby <[email protected]>
>> ---
>> drivers/clk/pistachio/clk.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
>> index f9c31e3a0e47..742e5fab00c0 100644
>> --- a/drivers/clk/pistachio/clk.h
>> +++ b/drivers/clk/pistachio/clk.h
>> @@ -34,7 +34,7 @@ struct pistachio_mux {
>> const char **parents;
>> };
>>
>> -#define PNAME(x) static const char *x[] __initconst
>> +#define PNAME(x) static const char *x[] __initdata
>
> Can it be const char * const and left as __initconst?

Let me check, IIRC the struct where this is assigned would need to be
updated too.

I will get into it only some time next week.

thanks,
--
js
suse labs

2022-06-29 08:45:37

by Stephen Boyd

[permalink] [raw]
Subject: Re: [PATCH 1/2] clk: pistachio: Fix initconst confusion

Quoting Jiri Slaby (2022-06-27 00:46:15)
> On 24. 06. 22, 2:42, Stephen Boyd wrote:
> > Quoting Jiri Slaby (2022-06-23 01:32:16)
> >> From: Andi Kleen <[email protected]>
> >>
> >> A variable pointing to const isn't const itself. It'd have to contain
> >> "const" keyword after "*" too. Therefore, PNAME() cannot put the strings
> >> to "rodata". Hence use __initdata instead of __initconst to fix this.
> >>
> >> [js] more explanatory commit message.
> >>
> >> Cc: Michael Turquette <[email protected]>
> >> Cc: Stephen Boyd <[email protected]>
> >> Cc: [email protected]
> >> Signed-off-by: Andi Kleen <[email protected]>
> >> Signed-off-by: Jiri Slaby <[email protected]>
> >> ---
> >> drivers/clk/pistachio/clk.h | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
> >> index f9c31e3a0e47..742e5fab00c0 100644
> >> --- a/drivers/clk/pistachio/clk.h
> >> +++ b/drivers/clk/pistachio/clk.h
> >> @@ -34,7 +34,7 @@ struct pistachio_mux {
> >> const char **parents;
> >> };
> >>
> >> -#define PNAME(x) static const char *x[] __initconst
> >> +#define PNAME(x) static const char *x[] __initdata
> >
> > Can it be const char * const and left as __initconst?
>
> Let me check, IIRC the struct where this is assigned would need to be
> updated too.
>
> I will get into it only some time next week.
>

Ok, sounds good. This seems to at least compile locally.

----8<---

diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
index f9c31e3a0e47..8be02ac2d909 100644
--- a/drivers/clk/pistachio/clk.h
+++ b/drivers/clk/pistachio/clk.h
@@ -31,10 +31,10 @@ struct pistachio_mux {
unsigned int shift;
unsigned int num_parents;
const char *name;
- const char **parents;
+ const char * const *parents;
};

-#define PNAME(x) static const char *x[] __initconst
+#define PNAME(x) static const char * const x[] __initconst

#define MUX(_id, _name, _pnames, _reg, _shift) \
{ \

2022-07-08 07:54:11

by Jiri Slaby

[permalink] [raw]
Subject: Re: [PATCH 1/2] clk: pistachio: Fix initconst confusion

On 29. 06. 22, 10:21, Stephen Boyd wrote:
> Quoting Jiri Slaby (2022-06-27 00:46:15)
>> On 24. 06. 22, 2:42, Stephen Boyd wrote:
>>> Quoting Jiri Slaby (2022-06-23 01:32:16)
>>>> From: Andi Kleen <[email protected]>
>>>>
>>>> A variable pointing to const isn't const itself. It'd have to contain
>>>> "const" keyword after "*" too. Therefore, PNAME() cannot put the strings
>>>> to "rodata". Hence use __initdata instead of __initconst to fix this.
>>>>
>>>> [js] more explanatory commit message.
>>>>
>>>> Cc: Michael Turquette <[email protected]>
>>>> Cc: Stephen Boyd <[email protected]>
>>>> Cc: [email protected]
>>>> Signed-off-by: Andi Kleen <[email protected]>
>>>> Signed-off-by: Jiri Slaby <[email protected]>
>>>> ---
>>>> drivers/clk/pistachio/clk.h | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
>>>> index f9c31e3a0e47..742e5fab00c0 100644
>>>> --- a/drivers/clk/pistachio/clk.h
>>>> +++ b/drivers/clk/pistachio/clk.h
>>>> @@ -34,7 +34,7 @@ struct pistachio_mux {
>>>> const char **parents;
>>>> };
>>>>
>>>> -#define PNAME(x) static const char *x[] __initconst
>>>> +#define PNAME(x) static const char *x[] __initdata
>>>
>>> Can it be const char * const and left as __initconst?
>>
>> Let me check, IIRC the struct where this is assigned would need to be
>> updated too.
>>
>> I will get into it only some time next week.
>>
>
> Ok, sounds good. This seems to at least compile locally.

Yeah, that works. I've sent a v2.

BTW is the code intended to put the actual strings to .init.rodata? As
that was never the case. Only those PNAME defined arrays (pointers to
strings) end up in .init.rodata now and the strings are in .rodata.

> ----8<---
>
> diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
> index f9c31e3a0e47..8be02ac2d909 100644
> --- a/drivers/clk/pistachio/clk.h
> +++ b/drivers/clk/pistachio/clk.h
> @@ -31,10 +31,10 @@ struct pistachio_mux {
> unsigned int shift;
> unsigned int num_parents;
> const char *name;
> - const char **parents;
> + const char * const *parents;
> };
>
> -#define PNAME(x) static const char *x[] __initconst
> +#define PNAME(x) static const char * const x[] __initconst
>
> #define MUX(_id, _name, _pnames, _reg, _shift) \
> { \


--
js
suse labs

2022-07-11 21:10:38

by Stephen Boyd

[permalink] [raw]
Subject: Re: [PATCH 1/2] clk: pistachio: Fix initconst confusion

Quoting Jiri Slaby (2022-07-08 00:16:12)
> On 29. 06. 22, 10:21, Stephen Boyd wrote:
> > Quoting Jiri Slaby (2022-06-27 00:46:15)
> >> On 24. 06. 22, 2:42, Stephen Boyd wrote:
> >>> Quoting Jiri Slaby (2022-06-23 01:32:16)
> >>>> From: Andi Kleen <[email protected]>
> >>>>
> >>>> A variable pointing to const isn't const itself. It'd have to contain
> >>>> "const" keyword after "*" too. Therefore, PNAME() cannot put the strings
> >>>> to "rodata". Hence use __initdata instead of __initconst to fix this.
> >>>>
> >>>> [js] more explanatory commit message.
> >>>>
> >>>> Cc: Michael Turquette <[email protected]>
> >>>> Cc: Stephen Boyd <[email protected]>
> >>>> Cc: [email protected]
> >>>> Signed-off-by: Andi Kleen <[email protected]>
> >>>> Signed-off-by: Jiri Slaby <[email protected]>
> >>>> ---
> >>>> drivers/clk/pistachio/clk.h | 2 +-
> >>>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/drivers/clk/pistachio/clk.h b/drivers/clk/pistachio/clk.h
> >>>> index f9c31e3a0e47..742e5fab00c0 100644
> >>>> --- a/drivers/clk/pistachio/clk.h
> >>>> +++ b/drivers/clk/pistachio/clk.h
> >>>> @@ -34,7 +34,7 @@ struct pistachio_mux {
> >>>> const char **parents;
> >>>> };
> >>>>
> >>>> -#define PNAME(x) static const char *x[] __initconst
> >>>> +#define PNAME(x) static const char *x[] __initdata
> >>>
> >>> Can it be const char * const and left as __initconst?
> >>
> >> Let me check, IIRC the struct where this is assigned would need to be
> >> updated too.
> >>
> >> I will get into it only some time next week.
> >>
> >
> > Ok, sounds good. This seems to at least compile locally.
>
> Yeah, that works. I've sent a v2.
>
> BTW is the code intended to put the actual strings to .init.rodata? As
> that was never the case. Only those PNAME defined arrays (pointers to
> strings) end up in .init.rodata now and the strings are in .rodata.

I think both the strings and the array should be in .init.rodata. The
clk framework deep copies data like parent names.