Re: [RFC PATCH 1/8] arm64: add CPU field to struct thread_info

2021-09-21 Thread Ard Biesheuvel 
On Thu, 16 Sept 2021 at 16:41, Catalin Marinas  wrote:
>
> On Tue, Sep 14, 2021 at 02:10:29PM +0200, Ard Biesheuvel wrote:
> > The CPU field will be moved back into thread_info even when
> > THREAD_INFO_IN_TASK is enabled, so add it back to arm64's definition of
> > struct thread_info.
> >
> > Signed-off-by: Ard Biesheuvel 
>
> Acked-by: Catalin Marinas 

Thanks. I take it this applies to patch #5 as well?

Re: [RFC PATCH 1/8] arm64: add CPU field to struct thread_info

2021-09-16 Thread Catalin Marinas 
On Tue, Sep 14, 2021 at 02:10:29PM +0200, Ard Biesheuvel wrote:
> The CPU field will be moved back into thread_info even when
> THREAD_INFO_IN_TASK is enabled, so add it back to arm64's definition of
> struct thread_info.
> 
> Signed-off-by: Ard Biesheuvel 

Acked-by: Catalin Marinas

Re: [RFC PATCH 1/8] arm64: add CPU field to struct thread_info

2021-09-14 Thread Ard Biesheuvel 
On Tue, 14 Sept 2021 at 17:41, Linus Torvalds
 wrote:
>
> On Tue, Sep 14, 2021 at 5:10 AM Ard Biesheuvel  wrote:
> >
> > The CPU field will be moved back into thread_info even when
> > THREAD_INFO_IN_TASK is enabled, so add it back to arm64's definition of
> > struct thread_info.
>
> The series looks sane to me, but it strikes me that it's inconsistent
> - here for arm64, you make it unconditional, but for the other
> architectures you end up putting it inside a #ifdef CONFIG_SMP.
>
> Was there some reason for this odd behavior?
>

Yes. CONFIG_SMP is a 'def_bool y' on arm64.

Re: [RFC PATCH 1/8] arm64: add CPU field to struct thread_info

2021-09-14 Thread Linus Torvalds 
On Tue, Sep 14, 2021 at 5:10 AM Ard Biesheuvel  wrote:
>
> The CPU field will be moved back into thread_info even when
> THREAD_INFO_IN_TASK is enabled, so add it back to arm64's definition of
> struct thread_info.

The series looks sane to me, but it strikes me that it's inconsistent
- here for arm64, you make it unconditional, but for the other
architectures you end up putting it inside a #ifdef CONFIG_SMP.

Was there some reason for this odd behavior?

   Linus

[RFC PATCH 1/8] arm64: add CPU field to struct thread_info

2021-09-14 Thread Ard Biesheuvel 
The CPU field will be moved back into thread_info even when
THREAD_INFO_IN_TASK is enabled, so add it back to arm64's definition of
struct thread_info.

Signed-off-by: Ard Biesheuvel 
---
 arch/arm64/include/asm/thread_info.h | 1 +
 arch/arm64/kernel/asm-offsets.c  | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/thread_info.h 
b/arch/arm64/include/asm/thread_info.h
index 6623c99f0984..c02bc8c183c3 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -42,6 +42,7 @@ struct thread_info {
void*scs_base;
void*scs_sp;
 #endif
+   u32 cpu;
 };
 
 #define thread_saved_pc(tsk)   \
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 551427ae8cc5..cee9f3e9f906 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -29,6 +29,7 @@ int main(void)
   DEFINE(TSK_ACTIVE_MM,offsetof(struct task_struct, 
active_mm));
   DEFINE(TSK_CPU,  offsetof(struct task_struct, cpu));
   BLANK();
+  DEFINE(TSK_TI_CPU,   offsetof(struct task_struct, thread_info.cpu));
   DEFINE(TSK_TI_FLAGS, offsetof(struct task_struct, 
thread_info.flags));
   DEFINE(TSK_TI_PREEMPT,   offsetof(struct task_struct, 
thread_info.preempt_count));
 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
-- 
2.30.2