From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756527Ab3HZL7P (ORCPT ); Mon, 26 Aug 2013 07:59:15 -0400 Received: from terminus.zytor.com ([198.137.202.10]:50808 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751529Ab3HZL7N (ORCPT ); Mon, 26 Aug 2013 07:59:13 -0400 Date: Mon, 26 Aug 2013 04:58:37 -0700 From: tip-bot for Liu Ping Fan Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, yinghai@kernel.org, haokexin@gmail.com, pingfank@linux.vnet.ibm.com, kernelfans@gmail.com, tglx@linutronix.de, len.brown@intel.com Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, haokexin@gmail.com, yinghai@kernel.org, pingfank@linux.vnet.ibm.com, kernelfans@gmail.com, tglx@linutronix.de, len.brown@intel.com In-Reply-To: <1377248327-19633-1-git-send-email-pingfank@linux.vnet.ibm.com> References: <1377248327-19633-1-git-send-email-pingfank@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/apic] x86/ioapic: Check attr against the previous setting when programmed more than once Git-Commit-ID: 25aa2957973d361081ac6c8b6e5a0d9d7a83fef6 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Mon, 26 Aug 2013 04:58:45 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 25aa2957973d361081ac6c8b6e5a0d9d7a83fef6 Gitweb: http://git.kernel.org/tip/25aa2957973d361081ac6c8b6e5a0d9d7a83fef6 Author: Liu Ping Fan AuthorDate: Fri, 23 Aug 2013 16:58:47 +0800 Committer: Ingo Molnar CommitDate: Mon, 26 Aug 2013 12:58:00 +0200 x86/ioapic: Check attr against the previous setting when programmed more than once When programming ioapic pinX more than once, current code does not check whether the later attr (trigger & polarity) is the same as the former or not. This causes broken semantics which can be observed in a qemu q35 machine, where ioapic's ioredtbl[x] can never be set as low-active, even if the hpet driver registered it. And hpet driver may share a high-level active IRQ line with other devices. So in qemu, when hpet-dev asserts low-level as kernel expects, the kernel has no response. With this patch, we can observe an ioredtbl[x] set as low-active for hpet. Fix it by reporting -EBUSY to the caller, when attr is different. Signed-off-by: Liu Ping Fan Cc: Kevin Hao Cc: Len Brown Cc: Yinghai Lu Link: http://lkml.kernel.org/r/1377248327-19633-1-git-send-email-pingfank@linux.vnet.ibm.com [ Made small readability edits to both the changelog and the code. ] Signed-off-by: Ingo Molnar --- arch/x86/kernel/acpi/boot.c | 5 ++++- arch/x86/kernel/apic/io_apic.c | 9 ++++++--- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 872a2d2..81aa73b 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -1120,6 +1120,7 @@ int mp_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity) int ioapic; int ioapic_pin; struct io_apic_irq_attr irq_attr; + int ret; if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC) return gsi; @@ -1149,7 +1150,9 @@ int mp_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity) set_io_apic_irq_attr(&irq_attr, ioapic, ioapic_pin, trigger == ACPI_EDGE_SENSITIVE ? 0 : 1, polarity == ACPI_ACTIVE_HIGH ? 0 : 1); - io_apic_set_pci_routing(dev, gsi_to_irq(gsi), &irq_attr); + ret = io_apic_set_pci_routing(dev, gsi_to_irq(gsi), &irq_attr); + if (ret < 0) + gsi = INT_MIN; return gsi; } diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 260abc2..e63a5bd 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -3380,12 +3380,15 @@ int io_apic_setup_irq_pin_once(unsigned int irq, int node, { unsigned int ioapic_idx = attr->ioapic, pin = attr->ioapic_pin; int ret; + struct IO_APIC_route_entry orig_entry; /* Avoid redundant programming */ if (test_bit(pin, ioapics[ioapic_idx].pin_programmed)) { - pr_debug("Pin %d-%d already programmed\n", - mpc_ioapic_id(ioapic_idx), pin); - return 0; + pr_debug("Pin %d-%d already programmed\n", mpc_ioapic_id(ioapic_idx), pin); + orig_entry = ioapic_read_entry(attr->ioapic, pin); + if (attr->trigger == orig_entry.trigger && attr->polarity == orig_entry.polarity) + return 0; + return -EBUSY; } ret = io_apic_setup_irq_pin(irq, node, attr); if (!ret)