From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41612 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750743AbdAXIAd (ORCPT ); Tue, 24 Jan 2017 03:00:33 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benjamin Herrenschmidt , Michael Ellerman Subject: [PATCH 4.9 052/130] powerpc/icp-opal: Fix missing KVM case and harden replay Date: Tue, 24 Jan 2017 08:54:52 +0100 Message-Id: <20170124075537.061337831@linuxfoundation.org> In-Reply-To: <20170124075534.905042535@linuxfoundation.org> References: <20170124075534.905042535@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Herrenschmidt commit 9728a7c8ab2f7a1c8d5c95278d2e4f4ac1285385 upstream. The icp-opal call is missing the code from icp-native to recover interrupts snatched by KVM. Without that, when running KVM, we can get into a situation where an interrupt is lost and the CPU stuck with an elevated CPPR. Also harden replay by always checking the return from opal_int_eoi(). Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend") Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/sysdev/xics/icp-opal.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) --- a/arch/powerpc/sysdev/xics/icp-opal.c +++ b/arch/powerpc/sysdev/xics/icp-opal.c @@ -20,6 +20,7 @@ #include #include #include +#include static void icp_opal_teardown_cpu(void) { @@ -39,7 +40,26 @@ static void icp_opal_flush_ipi(void) * Should we be flagging idle loop instead? * Or creating some task to be scheduled? */ - opal_int_eoi((0x00 << 24) | XICS_IPI); + if (opal_int_eoi((0x00 << 24) | XICS_IPI) > 0) + force_external_irq_replay(); +} + +static unsigned int icp_opal_get_xirr(void) +{ + unsigned int kvm_xirr; + __be32 hw_xirr; + int64_t rc; + + /* Handle an interrupt latched by KVM first */ + kvm_xirr = kvmppc_get_xics_latch(); + if (kvm_xirr) + return kvm_xirr; + + /* Then ask OPAL */ + rc = opal_int_get_xirr(&hw_xirr, false); + if (rc < 0) + return 0; + return be32_to_cpu(hw_xirr); } static unsigned int icp_opal_get_irq(void) @@ -47,12 +67,8 @@ static unsigned int icp_opal_get_irq(voi unsigned int xirr; unsigned int vec; unsigned int irq; - int64_t rc; - rc = opal_int_get_xirr(&xirr, false); - if (rc < 0) - return 0; - xirr = be32_to_cpu(xirr); + xirr = icp_opal_get_xirr(); vec = xirr & 0x00ffffff; if (vec == XICS_IRQ_SPURIOUS) return 0; @@ -67,7 +83,8 @@ static unsigned int icp_opal_get_irq(voi xics_mask_unknown_vec(vec); /* We might learn about it later, so EOI it */ - opal_int_eoi(xirr); + if (opal_int_eoi(xirr) > 0) + force_external_irq_replay(); return 0; }