Re: [RFC PATCH] powerpc/64s: remove POWER9 DD1 support
From: Michal Suchánek <hidden>
Date: 2018-06-10 20:58:20
On Sun, 10 Jun 2018 23:30:27 +1000 Nicholas Piggin [off-list ref] 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.
quoted hunk ↗ jump to hunk
diff --git a/arch/powerpc/kvm/book3s_xive_template.cb/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