On Sun, 10 Jun 2018 23:30:27 +1000
Nicholas Piggin <npig...@gmail.com> wrote:
> POWER9 DD1 was never a product. It is no longer supported by upstream
> firmware, and it is not effectively supported in Linux due to lack of
> testing.
>
> diff --git a/arch/powerpc/kvm/book3s_xive_template.c
> b/arch/powerpc/kvm/book3s_xive_template.c index
> 99c3620b40d9..487f1f6650cc 100644 ---
> a/arch/powerpc/kvm/book3s_xive_template.c +++
> b/arch/powerpc/kvm/book3s_xive_template.c @@ -25,18 +25,6 @@ static
> void GLUE(X_PFX,ack_pending)(struct kvmppc_xive_vcpu *xc) */
> eieio();
>
> - /*
> - * DD1 bug workaround: If PIPR is less favored than CPPR
> - * ignore the interrupt or we might incorrectly lose an IPB
> - * bit.
> - */
> - if (cpu_has_feature(CPU_FTR_POWER9_DD1)) {
> - __be64 qw1 = __x_readq(__x_tima + TM_QW1_OS);
> - u8 pipr = be64_to_cpu(qw1) & 0xff;
> - if (pipr >= xc->hw_cppr)
> - return;
> - }
> -
> /* Perform the acknowledge OS to register cycle. */
> ack = be16_to_cpu(__x_readw(__x_tima + TM_SPC_ACK_OS_REG));
>
> @@ -105,7 +93,7 @@ static void GLUE(X_PFX,source_eoi)(u32 hw_irq,
> struct xive_irq_data *xd) *
> * For LSIs, using the HW EOI cycle works around a
> problem
> * on P9 DD1 PHBs where the other ESB accesses don't
> work
> - * properly.
> + * properly. XXX: can this be removed?
> */
> if (xd->flags & XIVE_IRQ_FLAG_LSI)
> __x_readq(__x_eoi_page(xd) +
Maybe this should be really removed or the comment changed to why it is
still useful?
Thanks
Michal
