Haren Myneni <ha...@linux.vnet.ibm.com> wrote:
> [PATCH 4/6] powerpc: Define ppr in thread_struct
>
> ppr in thread_struct is used to save PPR and restore it before process exits
> from kernel.
>
> This patch sets the default priority to 3 when tasks are created such
> that users can use 4 for higher priority tasks.
>
> Signed-off-by: Haren Myneni <ha...@us.ibm.com>
> ---
> arch/powerpc/include/asm/processor.h | 6 ++++++
> arch/powerpc/kernel/asm-offsets.c | 1 +
> arch/powerpc/kernel/process.c | 2 ++
> 3 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/processor.h
> b/arch/powerpc/include/asm/processor.h
> index 8750204..7db5df4 100644
> --- a/arch/powerpc/include/asm/processor.h
> +++ b/arch/powerpc/include/asm/processor.h
> @@ -245,6 +245,7 @@ struct thread_struct {
> #ifdef CONFIG_PPC64
> unsigned long dscr;
> int dscr_inherit;
> + unsigned long ppr;
> #endif
> };
>
> @@ -270,6 +271,10 @@ struct thread_struct {
> SPEFSCR_INIT \
> }
> #else
> +/* Default SMT priority is 3. Use 11- 13bits to save priority. */
> +/* .ppr is used to save/restore only on P7 or later processors */
> +#define INIT_PPR (3ull << 50)
Can you split this into two macros so that we can use the '3' elsewhere.
Like in patch 5, you do this:
+ lis ra,0xc; /* default ppr=3 */ \
where you could reuse the '3' so that we don't have to change it in two
places later.
Mikey
> +
> #define INIT_THREAD { \
> .ksp = INIT_SP, \
> .ksp_limit = INIT_SP_LIMIT, \
> @@ -278,6 +283,7 @@ struct thread_struct {
> .fpr = {{0}}, \
> .fpscr = { .val = 0, }, \
> .fpexc_mode = 0, \
> + .ppr = INIT_PPR, \
> }
> #endif
>
> diff --git a/arch/powerpc/kernel/asm-offsets.c
> b/arch/powerpc/kernel/asm-offsets.c
> index 7523539..41f65ec 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -77,6 +77,7 @@ int main(void)
> DEFINE(NMI_MASK, NMI_MASK);
> DEFINE(THREAD_DSCR, offsetof(struct thread_struct, dscr));
> DEFINE(THREAD_DSCR_INHERIT, offsetof(struct thread_struct,
> dscr_inherit));
> + DEFINE(TASKTHREADPPR, offsetof(struct task_struct, thread.ppr));
> #else
> DEFINE(THREAD_INFO, offsetof(struct task_struct, stack));
> #endif /* CONFIG_PPC64 */
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index ba48233..2563acc 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -814,6 +814,8 @@ int copy_thread(unsigned long clone_flags, unsigned long
> usp,
> p->thread.dscr_inherit = current->thread.dscr_inherit;
> p->thread.dscr = current->thread.dscr;
> }
> + if (cpu_has_feature(CPU_FTR_HAS_PPR))
> + p->thread.ppr = INIT_PPR;
> #endif
> /*
> * The PPC64 ABI makes use of a TOC to contain function
> --
> 1.7.1
>
>
>
> _______________________________________________
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> Linuxppc-dev@lists.ozlabs.org
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>
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