kernel.git/arch/x86/kernel/irq.c, branch linux-3.17.y

Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-06-13T03:03:47Z

Pull x86 irq fixes from Ingo Molnar: "Two changes: a cpu-hotplug/irq race fix, plus a HyperV related fix" * 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/irq: Fix fixup_irqs() error handling x86, irq, pic: Probe for legacy PIC and set legacy_pic appropriately

x86: irq: Get correct available vectors for cpu disable

2014-06-04T12:18:34Z

check_irq_vectors_for_cpu_disable() can overestimate the number of available interrupt vectors, so the check for cpu down succeeds, but the actual cpu removal fails. It iterates from FIRST_EXTERNAL_VECTOR to NR_VECTORS, which is wrong because the systems vectors are not taken into account. Limit the search to first_system_vector instead of NR_VECTORS. The second indicator for vector availability the used_vectors bitmap is not taken into account at all. So system vectors, e.g. IA32_SYSCALL_VECTOR (0x80) and IRQ_MOVE_CLEANUP_VECTOR (0x20), are accounted as available. Add a check for the used_vectors bitmap and do not account vectors which are marked there. [ tglx: Simplified code. Rewrote changelog and code comments. ] Signed-off-by: Yinghai Lu Acked-by: Prarit Bhargava Cc: Seiji Aguchi Cc: Andi Kleen Cc: K. Y. Srinivasan Cc: Steven Rostedt (Red Hat) Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: "Elliott, Robert (Server Storage)" Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1400160305-17774-2-git-send-email-prarit@redhat.com Signed-off-by: Thomas Gleixner

x86/irq: Fix fixup_irqs() error handling

2014-04-16T11:30:49Z

Several patches to fix cpu hotplug and the down'd cpu's irq relocations have been submitted in the past month or so. The patches should resolve the problems with cpu hotplug and irq relocation, however, there is always a possibility that a bug still exists. The big problem with debugging these irq reassignments is that the cpu down completes and then we get random stack traces from drivers for which irqs have not been properly assigned to a new cpu. The stack traces are a mix of storage, network, and other kernel subsystem (I once saw the serial port stop working ...) warnings and failures. The problem with these failures is that they are difficult to diagnose. There is no warning in the cpu hotplug down path to indicate that an IRQ has failed to be assigned to a new cpu, and all we are left with is a stack trace from a driver, or a non-functional device. If we had some information on the console debugging these situations would be much easier; after all we can map an IRQ to a device by simply using lspci or /proc/interrupts. The current code, fixup_irqs(), which migrates IRQs from the down'd cpu and is called close to the end of the cpu down path, calls chip->set_irq_affinity which eventually calls __assign_irq_vector(). Errors are not propogated back from this function call and this results in silent irq relocation failures. This patch fixes this issue by returning the error codes up the call stack and prints out a warning if there is a relocation failure. Signed-off-by: Prarit Bhargava Acked-by: Thomas Gleixner Cc: Rui Wang Cc: Liu Ping Fan Cc: Bjorn Helgaas Cc: Yoshihiro YUNOMAE Cc: Lv Zheng Cc: Seiji Aguchi Cc: Yang Zhang Cc: Andi Kleen Cc: Steven Rostedt (Red Hat) Cc: Li Fei Cc: gong.chen@linux.intel.com Link: http://lkml.kernel.org/r/1396440673-18286-1-git-send-email-prarit@redhat.com [ Made small cleanliness tweaks. ] Signed-off-by: Ingo Molnar

x86/platform/hyperv: Handle VMBUS driver being a module

2014-04-02T07:49:47Z

Hyper-V VMBUS driver can be a module; handle this case correctly. Please apply. Signed-off-by: K. Y. Srinivasan Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Link: http://lkml.kernel.org/r/1396421502-23222-1-git-send-email-kys@microsoft.com Signed-off-by: Ingo Molnar

x86: Add proper vector accounting for HYPERVISOR_CALLBACK_VECTOR

2014-03-04T16:37:54Z

HyperV abuses a device interrupt to account for the HYPERVISOR_CALLBACK_VECTOR. Provide proper accounting as we have for the other vectors as well. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Konrad Rzeszutek Wilk Cc: K. Y. Srinivasan Cc: x86 Link: http://lkml.kernel.org/r/20140223212738.681855582@linutronix.de Signed-off-by: Thomas Gleixner

x86, cpu hotplug: Fix stack frame warning in check_irq_vectors_for_cpu_disable()

2014-01-31T00:40:13Z

Further discussion here: http://marc.info/?l=linux-kernel&m=139073901101034&w=2 kbuild, 0day kernel build service, outputs the warning: arch/x86/kernel/irq.c:333:1: warning: the frame size of 2056 bytes is larger than 2048 bytes [-Wframe-larger-than=] because check_irq_vectors_for_cpu_disable() allocates two cpumasks on the stack. Fix this by moving the two cpumasks to a global file context. Reported-by: Fengguang Wu Tested-by: David Rientjes Signed-off-by: Prarit Bhargava Link: http://lkml.kernel.org/r/1390915331-27375-1-git-send-email-prarit@redhat.com Cc: Andi Kleen Cc: Michel Lespinasse Cc: Seiji Aguchi Cc: Yang Zhang Cc: Paul Gortmaker Cc: Janet Morgan Cc: Tony Luck Cc: Ruiv Wang Cc: Gong Chen Cc: Yinghai Lu Signed-off-by: H. Peter Anvin

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-01-20T20:11:41Z

Pull leftover x86 fixes from Ingo Molnar: "Two leftover fixes that did not make it into v3.13" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Add check for number of available vectors before CPU down x86, cpu, amd: Add workaround for family 16h, erratum 793

x86: Add check for number of available vectors before CPU down

2014-01-16T06:24:02Z

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=64791 When a cpu is downed on a system, the irqs on the cpu are assigned to other cpus. It is possible, however, that when a cpu is downed there aren't enough free vectors on the remaining cpus to account for the vectors from the cpu that is being downed. This results in an interesting "overflow" condition where irqs are "assigned" to a CPU but are not handled. For example, when downing cpus on a 1-64 logical processor system: [ 232.021745] smpboot: CPU 61 is now offline [ 238.480275] smpboot: CPU 62 is now offline [ 245.991080] ------------[ cut here ]------------ [ 245.996270] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:264 dev_watchdog+0x246/0x250() [ 246.005688] NETDEV WATCHDOG: p786p1 (ixgbe): transmit queue 0 timed out [ 246.013070] Modules linked in: lockd sunrpc iTCO_wdt iTCO_vendor_support sb_edac ixgbe microcode e1000e pcspkr joydev edac_core lpc_ich ioatdma ptp mdio mfd_core i2c_i801 dca pps_core i2c_core wmi acpi_cpufreq isci libsas scsi_transport_sas [ 246.037633] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.12.0+ #14 [ 246.044451] Hardware name: Intel Corporation S4600LH ........../SVRBD-ROW_T, BIOS SE5C600.86B.01.08.0003.022620131521 02/26/2013 [ 246.057371] 0000000000000009 ffff88081fa03d40 ffffffff8164fbf6 ffff88081fa0ee48 [ 246.065728] ffff88081fa03d90 ffff88081fa03d80 ffffffff81054ecc ffff88081fa13040 [ 246.074073] 0000000000000000 ffff88200cce0000 0000000000000040 0000000000000000 [ 246.082430] Call Trace: [ 246.085174] [] dump_stack+0x46/0x58 [ 246.091633] [] warn_slowpath_common+0x8c/0xc0 [ 246.098352] [] warn_slowpath_fmt+0x46/0x50 [ 246.104786] [] dev_watchdog+0x246/0x250 [ 246.110923] [] ? dev_deactivate_queue.constprop.31+0x80/0x80 [ 246.119097] [] call_timer_fn+0x3a/0x110 [ 246.125224] [] ? update_process_times+0x6f/0x80 [ 246.132137] [] ? dev_deactivate_queue.constprop.31+0x80/0x80 [ 246.140308] [] run_timer_softirq+0x1f0/0x2a0 [ 246.146933] [] __do_softirq+0xe0/0x220 [ 246.152976] [] call_softirq+0x1c/0x30 [ 246.158920] [] do_softirq+0x55/0x90 [ 246.164670] [] irq_exit+0xa5/0xb0 [ 246.170227] [] smp_apic_timer_interrupt+0x4a/0x60 [ 246.177324] [] apic_timer_interrupt+0x6a/0x70 [ 246.184041] [] ? cpuidle_enter_state+0x5b/0xe0 [ 246.191559] [] ? cpuidle_enter_state+0x57/0xe0 [ 246.198374] [] cpuidle_idle_call+0xbd/0x200 [ 246.204900] [] arch_cpu_idle+0xe/0x30 [ 246.210846] [] cpu_startup_entry+0xd0/0x250 [ 246.217371] [] rest_init+0x77/0x80 [ 246.223028] [] start_kernel+0x3ee/0x3fb [ 246.229165] [] ? repair_env_string+0x5e/0x5e [ 246.235787] [] x86_64_start_reservations+0x2a/0x2c [ 246.242990] [] x86_64_start_kernel+0xf8/0xfc [ 246.249610] ---[ end trace fb74fdef54d79039 ]--- [ 246.254807] ixgbe 0000:c2:00.0 p786p1: initiating reset due to tx timeout [ 246.262489] ixgbe 0000:c2:00.0 p786p1: Reset adapter Last login: Mon Nov 11 08:35:14 from 10.18.17.119 [root@(none) ~]# [ 246.792676] ixgbe 0000:c2:00.0 p786p1: detected SFP+: 5 [ 249.231598] ixgbe 0000:c2:00.0 p786p1: NIC Link is Up 10 Gbps, Flow Control: RX/TX [ 246.792676] ixgbe 0000:c2:00.0 p786p1: detected SFP+: 5 [ 249.231598] ixgbe 0000:c2:00.0 p786p1: NIC Link is Up 10 Gbps, Flow Control: RX/TX (last lines keep repeating. ixgbe driver is dead until module reload.) If the downed cpu has more vectors than are free on the remaining cpus on the system, it is possible that some vectors are "orphaned" even though they are assigned to a cpu. In this case, since the ixgbe driver had a watchdog, the watchdog fired and notified that something was wrong. This patch adds a function, check_vectors(), to compare the number of vectors on the CPU going down and compares it to the number of vectors available on the system. If there aren't enough vectors for the CPU to go down, an error is returned and propogated back to userspace. v2: Do not need to look at percpu irqs v3: Need to check affinity to prevent counting of MSIs in IOAPIC Lowest Priority Mode v4: Additional changes suggested by Gong Chen. v5/v6/v7/v8: Updated comment text Signed-off-by: Prarit Bhargava Link: http://lkml.kernel.org/r/1389613861-3853-1-git-send-email-prarit@redhat.com Reviewed-by: Gong Chen Cc: Andi Kleen Cc: Michel Lespinasse Cc: Seiji Aguchi Cc: Yang Zhang Cc: Paul Gortmaker Cc: Janet Morgan Cc: Tony Luck Cc: Ruiv Wang Cc: Gong Chen Signed-off-by: H. Peter Anvin Cc:

x86/irq: Fix do_IRQ() interrupt warning for cpu hotplug retriggered irqs

2014-01-12T12:13:02Z

During heavy CPU-hotplug operations the following spurious kernel warnings can trigger: do_IRQ: No ... irq handler for vector (irq -1) [ See: https://bugzilla.kernel.org/show_bug.cgi?id=64831 ] When downing a cpu it is possible that there are unhandled irqs left in the APIC IRR register. The following code path shows how the problem can occur: 1. CPU 5 is to go down. 2. cpu_disable() on CPU 5 executes with interrupt flag cleared by local_irq_save() via stop_machine(). 3. IRQ 12 asserts on CPU 5, setting IRR but not ISR because interrupt flag is cleared (CPU unabled to handle the irq) 4. IRQs are migrated off of CPU 5, and the vectors' irqs are set to -1. 5. stop_machine() finishes cpu_disable() 6. cpu_die() for CPU 5 executes in normal context. 7. CPU 5 attempts to handle IRQ 12 because the IRR is set for IRQ 12. The code attempts to find the vector's IRQ and cannot because it has been set to -1. 8. do_IRQ() warning displays warning about CPU 5 IRQ 12. I added a debug printk to output which CPU & vector was retriggered and discovered that that we are getting bogus events. I see a 100% correlation between this debug printk in fixup_irqs() and the do_IRQ() warning. This patchset resolves this by adding definitions for VECTOR_UNDEFINED(-1) and VECTOR_RETRIGGERED(-2) and modifying the code to use them. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=64831 Signed-off-by: Prarit Bhargava Reviewed-by: Rui Wang Cc: Michel Lespinasse Cc: Seiji Aguchi Cc: Yang Zhang Cc: Paul Gortmaker Cc: janet.morgan@Intel.com Cc: tony.luck@Intel.com Cc: ruiv.wang@gmail.com Link: http://lkml.kernel.org/r/1388938252-16627-1-git-send-email-prarit@redhat.com [ Cleaned up the code a bit. ] Signed-off-by: Ingo Molnar

x86, asmlinkage: Make all interrupt handlers asmlinkage / __visible

2013-08-06T21:18:23Z

These handlers are all referenced from assembler stubs, so need to be visible. The handlers without arguments become asmlinkage, the others __visible to not force regparms(0) on x86-32. I put it all into a single patch, please let me know if you want it it split up. Signed-off-by: Andi Kleen Link: http://lkml.kernel.org/r/1375740170-7446-4-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin