* [PATCH] powerpc/64s: Mark 'dummy_copy_buffer' as used
@ 2019-03-12 20:29 Mathieu Malaterre
2019-03-12 21:06 ` Christophe Leroy
2019-03-13 20:00 ` [PATCH v2] powerpc/64s: Remove 'dummy_copy_buffer' Mathieu Malaterre
0 siblings, 2 replies; 5+ messages in thread
From: Mathieu Malaterre @ 2019-03-12 20:29 UTC (permalink / raw)
To: Michael Ellerman
Cc: Mathieu Malaterre, linux-kernel, Nicholas Piggin, Paul Mackerras,
linuxppc-dev
In commit 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch
when possible") a buffer 'dummy_copy_buffer' was introduced. gcc does
not see this buffer being used in the inline assembly within function
'__switch_to', explicitly marked this variable as being used.
Prefer using '__aligned' to get passed line over 80 characters warning
in checkpatch.
This remove the following warning:
arch/powerpc/kernel/process.c:1156:17: error: 'dummy_copy_buffer' defined but not used [-Werror=unused-const-variable=]
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
---
arch/powerpc/kernel/process.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 77e44275d025..5acf63d45802 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1153,7 +1153,7 @@ static inline void restore_sprs(struct thread_struct *old_thread,
#ifdef CONFIG_PPC_BOOK3S_64
#define CP_SIZE 128
-static const u8 dummy_copy_buffer[CP_SIZE] __attribute__((aligned(CP_SIZE)));
+static const u8 dummy_copy_buffer[CP_SIZE] __aligned(CP_SIZE) __used;
#endif
struct task_struct *__switch_to(struct task_struct *prev,
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/64s: Mark 'dummy_copy_buffer' as used
2019-03-12 20:29 [PATCH] powerpc/64s: Mark 'dummy_copy_buffer' as used Mathieu Malaterre
@ 2019-03-12 21:06 ` Christophe Leroy
2019-03-13 4:05 ` Michael Ellerman
2019-03-13 20:00 ` [PATCH v2] powerpc/64s: Remove 'dummy_copy_buffer' Mathieu Malaterre
1 sibling, 1 reply; 5+ messages in thread
From: Christophe Leroy @ 2019-03-12 21:06 UTC (permalink / raw)
To: Mathieu Malaterre, Michael Ellerman
Cc: linuxppc-dev, Paul Mackerras, linux-kernel, Nicholas Piggin
On 03/12/2019 08:29 PM, Mathieu Malaterre wrote:
> In commit 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch
> when possible") a buffer 'dummy_copy_buffer' was introduced. gcc does
> not see this buffer being used in the inline assembly within function
> '__switch_to', explicitly marked this variable as being used.
>
> Prefer using '__aligned' to get passed line over 80 characters warning
> in checkpatch.
Powerpc accepts 90 characters, use arch/powerpc/tools/checkpatch.sh
>
> This remove the following warning:
>
> arch/powerpc/kernel/process.c:1156:17: error: 'dummy_copy_buffer' defined but not used [-Werror=unused-const-variable=]
commit 2bf1071a8d50 ("powerpc/64s: Remove POWER9 DD1 support") has
removed the fonction using 'dummy_copy_buffer' so you should remove it
completely.
Christophe
>
> Cc: Nicholas Piggin <npiggin@gmail.com>
> Signed-off-by: Mathieu Malaterre <malat@debian.org>
> ---
> arch/powerpc/kernel/process.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index 77e44275d025..5acf63d45802 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -1153,7 +1153,7 @@ static inline void restore_sprs(struct thread_struct *old_thread,
>
> #ifdef CONFIG_PPC_BOOK3S_64
> #define CP_SIZE 128
> -static const u8 dummy_copy_buffer[CP_SIZE] __attribute__((aligned(CP_SIZE)));
> +static const u8 dummy_copy_buffer[CP_SIZE] __aligned(CP_SIZE) __used;
> #endif
>
> struct task_struct *__switch_to(struct task_struct *prev,
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] powerpc/64s: Mark 'dummy_copy_buffer' as used
2019-03-12 21:06 ` Christophe Leroy
@ 2019-03-13 4:05 ` Michael Ellerman
0 siblings, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2019-03-13 4:05 UTC (permalink / raw)
To: Christophe Leroy, Mathieu Malaterre
Cc: linuxppc-dev, Paul Mackerras, linux-kernel, Nicholas Piggin
Christophe Leroy <christophe.leroy@c-s.fr> writes:
> On 03/12/2019 08:29 PM, Mathieu Malaterre wrote:
>> In commit 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch
>> when possible") a buffer 'dummy_copy_buffer' was introduced. gcc does
>> not see this buffer being used in the inline assembly within function
>> '__switch_to', explicitly marked this variable as being used.
>>
>> Prefer using '__aligned' to get passed line over 80 characters warning
>> in checkpatch.
>
> Powerpc accepts 90 characters, use arch/powerpc/tools/checkpatch.sh
>
>>
>> This remove the following warning:
>>
>> arch/powerpc/kernel/process.c:1156:17: error: 'dummy_copy_buffer' defined but not used [-Werror=unused-const-variable=]
>
> commit 2bf1071a8d50 ("powerpc/64s: Remove POWER9 DD1 support") has
> removed the fonction using 'dummy_copy_buffer' so you should remove it
> completely.
Yes that would be better, thanks.
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v2] powerpc/64s: Remove 'dummy_copy_buffer'
2019-03-12 20:29 [PATCH] powerpc/64s: Mark 'dummy_copy_buffer' as used Mathieu Malaterre
2019-03-12 21:06 ` Christophe Leroy
@ 2019-03-13 20:00 ` Mathieu Malaterre
2019-05-03 6:59 ` Michael Ellerman
1 sibling, 1 reply; 5+ messages in thread
From: Mathieu Malaterre @ 2019-03-13 20:00 UTC (permalink / raw)
To: Michael Ellerman
Cc: Mathieu Malaterre, linux-kernel, Nicholas Piggin, Paul Mackerras,
linuxppc-dev
In commit 2bf1071a8d50 ("powerpc/64s: Remove POWER9 DD1 support") the
function __switch_to remove usage for 'dummy_copy_buffer'. Since it is
not used anywhere else, remove it completely.
This remove the following warning:
arch/powerpc/kernel/process.c:1156:17: error: 'dummy_copy_buffer' defined but not used [-Werror=unused-const-variable=]
Cc: Nicholas Piggin <npiggin@gmail.com>
Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
---
v2: complely remove dummy_copy_buffer instead of marking it as used (since not anymore)
arch/powerpc/kernel/process.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 77e44275d025..b2f0daa2fcf1 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1151,11 +1151,6 @@ static inline void restore_sprs(struct thread_struct *old_thread,
thread_pkey_regs_restore(new_thread, old_thread);
}
-#ifdef CONFIG_PPC_BOOK3S_64
-#define CP_SIZE 128
-static const u8 dummy_copy_buffer[CP_SIZE] __attribute__((aligned(CP_SIZE)));
-#endif
-
struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *new)
{
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-05-03 7:13 UTC | newest]
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2019-03-12 20:29 [PATCH] powerpc/64s: Mark 'dummy_copy_buffer' as used Mathieu Malaterre
2019-03-12 21:06 ` Christophe Leroy
2019-03-13 4:05 ` Michael Ellerman
2019-03-13 20:00 ` [PATCH v2] powerpc/64s: Remove 'dummy_copy_buffer' Mathieu Malaterre
2019-05-03 6:59 ` Michael Ellerman
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