Hi Nick,
On Tue, Mar 14, 2017 at 07:23:46PM +1000, Nicholas Piggin wrote:
> POWER9 does not use this field, so it should be moved into the POWER8
> code. Update the documentation in the paca struct too.
>
> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
> ---
> arch/powerpc/include/asm/paca.h | 12 ++++++++++--
> arch/powerpc/kernel/idle_book3s.S | 13 +++++++------
> 2 files changed, 17 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
> index 708c3e592eeb..bbb59e226a9f 100644
> --- a/arch/powerpc/include/asm/paca.h
> +++ b/arch/powerpc/include/asm/paca.h
> @@ -165,11 +165,19 @@ struct paca_struct {
> #endif
>
> #ifdef CONFIG_PPC_POWERNV
> - /* Per-core mask tracking idle threads and a lock bit-[L][TTTTTTTT] */
> + /* CPU idle fields */
> +
> + /*
> + * Per-core word used to synchronize between threads. See
> + * asm/cpuidle.h, PNV_CORE_IDLE_*
> + */
> u32 *core_idle_state_ptr;
> - u8 thread_idle_state; /* PNV_THREAD_RUNNING/NAP/SLEEP */
> /* Mask to indicate thread id in core */
> u8 thread_mask;
> +
> + /* POWER8 specific fields */
> + /* PNV_THREAD_RUNNING/NAP/SLEEP */
> + u8 thread_idle_state;
I am planning to use this in POWER9 DD1 to distinguish between a
SRESET received when the thread was running vs when it was in stop.
Unfortunately the SRR1[46:47] are not cleared in the former case. So
we need a way in software to distinguish between the two.
> /* Mask to denote subcore sibling threads */
> u8 subcore_sibling_mask;
> #endif
> diff --git a/arch/powerpc/kernel/idle_book3s.S
> b/arch/powerpc/kernel/idle_book3s.S
> index 9284ea0762b1..9bdfba75a5e7 100644
> --- a/arch/powerpc/kernel/idle_book3s.S
> +++ b/arch/powerpc/kernel/idle_book3s.S
> @@ -389,9 +389,6 @@ FTR_SECTION_ELSE
> bl pnv_restore_hyp_resource_arch207
> ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
>
> - li r0,PNV_THREAD_RUNNING
> - stb r0,PACA_THREAD_IDLE_STATE(r13) /* Clear thread state */
> -
> #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> li r0,KVM_HWTHREAD_IN_KERNEL
> stb r0,HSTATE_HWTHREAD_STATE(r13)
> @@ -445,9 +442,13 @@ pnv_restore_hyp_resource_arch207:
> ld r2,PACATOC(r13);
>
> lbz r0,PACA_THREAD_IDLE_STATE(r13)
> - cmpwi cr2,r0,PNV_THREAD_NAP
> - cmpwi cr4,r0,PNV_THREAD_WINKLE
> - bgt cr2,pnv_wakeup_tb_loss /* Either sleep or Winkle */
> + cmpwi cr2,r0,PNV_THREAD_NAP
> + cmpwi cr4,r0,PNV_THREAD_WINKLE
> + li r0,PNV_THREAD_RUNNING
> + stb r0,PACA_THREAD_IDLE_STATE(r13) /* Clear thread state */
> +
> + bgt cr2,pnv_wakeup_tb_loss /* Either sleep or Winkle */
> +
>
> /*
> * We fall through here if PACA_THREAD_IDLE_STATE shows we are waking
> --
> 2.11.0
>
