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* xen: explicitly initialise the cpu field of irq_infoIan Campbell2009-02-091-5/+6
| | | | | | | | | | | | | | | | | | I was seeing a very odd crash on 64 bit in bind_evtchn_to_cpu because cpu_from_irq(irq) was coming out as -1. I found this was coming direct from the mk_ipi_info call. It's not clear to me that this isn't a compiler bug (implicit initialisation to zero of unsigned shorts in a struct not handled correctly?). On the other hand is it true that all event channels start of bound to CPU 0? If not then -1 might be correct and the various other functions should cope with this. Signed-off-by: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: make sure that softirqs get handled at the end of event processingJeremy Fitzhardinge2009-02-091-20/+9
| | | | | | | | | | Make sure that irq_enter()/irq_exit() wrap the entire event processing loop, rather than each individual event invokation. This makes sure that softirq processing is deferred until the end of event processing, rather than in the middle with interrupts disabled. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: remove irq bindcountJeremy Fitzhardinge2009-02-091-19/+7
| | | | | | | | | There should be no need for us to maintain our own bind count for irqs, since the surrounding irq system should keep track of shared irqs for us. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: pack all irq-related info togetherJeremy Fitzhardinge2009-02-091-49/+135
| | | | | | | | | Put all irq info into one struct. Also, use a union to keep event channel type-specific information, rather than overloading the index field. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: use our own eventchannel->irq pathJeremy Fitzhardinge2009-02-091-2/+20
| | | | | | | | | | | | | Rather than overloading vectors for event channels, take full responsibility for mapping an event channel to irq directly. With this patch Xen has its own irq allocator. When the kernel gets an event channel upcall, it maps the event channel number to an irq and injects it into the normal interrupt path. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: set irq_chip disableJeremy Fitzhardinge2009-02-091-0/+3
| | | | | | | | By default, the irq_chip.disable operation is a no-op. Explicitly set it to disable the Xen event channel. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: fix too early kmalloc callChristophe Saout2009-01-121-2/+3
| | | | | | | | | | | | Impact: fix bootup crash on xen guests SLAB is not yet up, with earlyprintk it is giving me an Oops in __kmalloc. Replace call to kmalloc() with alloc_bootmem(). Reported-by: Christophe Saout <christophe@saout.de> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Xen: reduce memory required for cpu_evtchn_maskMike Travis2009-01-111-5/+16
| | | | | | | | | | | | | | | | Impact: reduce memory usage. Reduce this significant gain in the amount of memory used when NR_CPUS bumped from 128 to 4096 by allocating the array based on nr_cpu_ids: 65536 +2031616 2097152 +3100% cpu_evtchn_mask(.bss) Signed-off-by: Mike Travis <travis@sgi.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: virtualization@lists.osdl.org Cc: xen-devel@lists.xensource.com
* cpumask: update irq_desc to use cpumask_var_tMike Travis2009-01-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: reduce memory usage, use new cpumask API. Replace the affinity and pending_masks with cpumask_var_t's. This adds to the significant size reduction done with the SPARSE_IRQS changes. The added functions (init_alloc_desc_masks & init_copy_desc_masks) are in the include file so they can be inlined (and optimized out for the !CONFIG_CPUMASKS_OFFSTACK case.) [Naming chosen to be consistent with the other init*irq functions, as well as the backwards arg declaration of "from, to" instead of the more common "to, from" standard.] Includes a slight change to the declaration of struct irq_desc to embed the pending_mask within ifdef(CONFIG_SMP) to be consistent with other references, and some small changes to Xen. Tested: sparse/non-sparse/cpumask_offstack/non-cpumask_offstack/nonuma/nosmp on x86_64 Signed-off-by: Mike Travis <travis@sgi.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: virtualization@lists.osdl.org Cc: xen-devel@lists.xensource.com Cc: Yinghai Lu <yhlu.kernel@gmail.com>
* Merge branch 'cpus4096-for-linus-2' of ↵Linus Torvalds2009-01-021-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits) x86: export vector_used_by_percpu_irq x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and() sched: nominate preferred wakeup cpu, fix x86: fix lguest used_vectors breakage, -v2 x86: fix warning in arch/x86/kernel/io_apic.c sched: fix warning in kernel/sched.c sched: move test_sd_parent() to an SMP section of sched.h sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0 sched: activate active load balancing in new idle cpus sched: bias task wakeups to preferred semi-idle packages sched: nominate preferred wakeup cpu sched: favour lower logical cpu number for sched_mc balance sched: framework for sched_mc/smt_power_savings=N sched: convert BALANCE_FOR_xx_POWER to inline functions x86: use possible_cpus=NUM to extend the possible cpus allowed x86: fix cpu_mask_to_apicid_and to include cpu_online_mask x86: update io_apic.c to the new cpumask code x86: Introduce topology_core_cpumask()/topology_thread_cpumask() x86: xen: use smp_call_function_many() x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c ... Fixed up trivial conflict in kernel/time/tick-sched.c manually
| * Merge ../linux-2.6-x86Rusty Russell2008-12-131-4/+8
| |\ | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/io_apic.c kernel/sched.c kernel/sched_stats.h
| * | cpumask: make irq_set_affinity() take a const struct cpumaskRusty Russell2008-12-131-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: change existing irq_chip API Not much point with gentle transition here: the struct irq_chip's setaffinity method signature needs to change. Fortunately, not widely used code, but hits a few architectures. Note: In irq_select_affinity() I save a temporary in by mangling irq_desc[irq].affinity directly. Ingo, does this break anything? (Folded in fix from KOSAKI Motohiro) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Grant Grundler <grundler@parisc-linux.org> Acked-by: Ingo Molnar <mingo@redhat.com> Cc: ralf@linux-mips.org Cc: grundler@parisc-linux.org Cc: jeremy@xensource.com Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
* | | irq: simplify for_each_irq_desc() usageKOSAKI Motohiro2008-12-261-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup all for_each_irq_desc() usage point have !desc check. then its check can move into for_each_irq_desc() macro. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | sparseirq, xen: make sure irq_desc is allocated for interruptsJeremy Fitzhardinge2008-12-181-0/+5
| |/ |/| | | | | | | | | | | | | | | Impact: fix crash Make sure all Xen irqs have an irq_desc. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | sparse irq_desc[] array: core kernel and x86 changesYinghai Lu2008-12-081-4/+8
|/ | | | | | | | | | | | | | | | | | | | | Impact: new feature Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with NR_CPUS set to large values. The goal is to be able to scale up to much larger NR_IRQS value without impacting the (important) common case. To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of irq_desc pointers. When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc, this also makes the IRQ descriptors NUMA-local (to the site that calls request_irq()). This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now uses desc->chip_data for x86 to store irq_cfg. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: compilation fix of drivers/xen/events.c on IA64Isaku Yamahata2008-10-231-1/+1
| | | | | | | | | | | | | use set_xen_guest_handle() instead of direct assigning. > linux-2.6/drivers/xen/events.c: In function 'xen_poll_irq': > linux-2.6/drivers/xen/events.c:757: error: incompatible types in assignment > make[4]: *** [drivers/xen/events.o] Error 1 Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* genirq: use iterators for irq_desc loopsThomas Gleixner2008-10-161-8/+6
| | | | | | Use for_each_irq_desc[_reverse] for all the iteration loops. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* xen: fix memory access violation bug when CONFIG_HAVE_SPARSE_IRQ is enabledAlex Nixon2008-10-161-0/+2
| | | | | | | | | | When sparse IRQs are enabled, it is not safe to assume an IRQ descriptor exists for every possible IRQ. This patch causes init_evtchn_cpu_bindings to skip initialisation of IRQ descriptors which don't exist. Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* generic: sparse irqs: use irq_desc() together with dyn_array, instead of ↵Yinghai Lu2008-10-161-3/+5
| | | | | | | | | | | | | | | | | | irq_desc[] add CONFIG_HAVE_SPARSE_IRQ to for use condensed array. Get rid of irq_desc[] array assumptions. Preallocate 32 irq_desc, and irq_desc() will try to get more. ( No change in functionality is expected anywhere, except the odd build failure where we missed a code site or where a crossing commit itroduces new irq_desc[] usage. ) v2: according to Eric, change get_irq_desc() to irq_desc() Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* drivers/xen: use nr_irqsYinghai Lu2008-10-161-6/+6
| | | | | Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: implement CPU hotpluggingAlex Nixon2008-08-251-0/+4
| | | | | | | | | | | | | | | | | Note the changes from 2.6.18-xen CPU hotplugging: A vcpu_down request from the remote admin via Xenbus both hotunplugs the CPU, and disables it by removing it from the cpu_present map, and removing its entry in /sys. A vcpu_up request from the remote admin only re-enables the CPU, and does not immediately bring the CPU up. A udev event is emitted, which can be caught by the user if he wishes to automatically re-up CPUs when available, or implement a more complex policy. Signed-off-by: Alex Nixon <alex.nixon@citrix.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: save previous spinlock when blockingJeremy Fitzhardinge2008-08-211-0/+25
| | | | | | | | | | | | | | | | | | A spinlock can be interrupted while spinning, so make sure we preserve the previous lock of interest if we're taking a lock from within an interrupt handler. We also need to deal with the case where the blocking path gets interrupted between testing to see if the lock is free and actually blocking. If we get interrupted there and end up in the state where the lock is free but the irq isn't pending, then we'll block indefinitely in the hypervisor. This fix is to make sure that any nested lock-takers will always leave the irq pending if there's any chance the outer lock became free. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: compile irq functions without -pg for ftraceJeremy Fitzhardinge2008-07-311-11/+0
| | | | | | | | | | | | | For some reason I managed to miss a bunch of irq-related functions which also need to be compiled without -pg when using ftrace. This patch moves them into their own file, and starts a cleanup process I've been meaning to do anyway. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: "Alex Nixon (Intern)" <Alex.Nixon@eu.citrix.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: implement Xen-specific spinlocksJeremy Fitzhardinge2008-07-161-0/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The standard ticket spinlocks are very expensive in a virtual environment, because their performance depends on Xen's scheduler giving vcpus time in the order that they're supposed to take the spinlock. This implements a Xen-specific spinlock, which should be much more efficient. The fast-path is essentially the old Linux-x86 locks, using a single lock byte. The locker decrements the byte; if the result is 0, then they have the lock. If the lock is negative, then locker must spin until the lock is positive again. When there's contention, the locker spin for 2^16[*] iterations waiting to get the lock. If it fails to get the lock in that time, it adds itself to the contention count in the lock and blocks on a per-cpu event channel. When unlocking the spinlock, the locker looks to see if there's anyone blocked waiting for the lock by checking for a non-zero waiter count. If there's a waiter, it traverses the per-cpu "lock_spinners" variable, which contains which lock each CPU is waiting on. It picks one CPU waiting on the lock and sends it an event to wake it up. This allows efficient fast-path spinlock operation, while allowing spinning vcpus to give up their processor time while waiting for a contended lock. [*] 2^16 iterations is threshold at which 98% locks have been taken according to Thomas Friebel's Xen Summit talk "Preventing Guests from Spinning Around". Therefore, we'd expect the lock and unlock slow paths will only be entered 2% of the time. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <clameter@linux-foundation.org> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Virtualization <virtualization@lists.linux-foundation.org> Cc: Xen devel <xen-devel@lists.xensource.com> Cc: Thomas Friebel <thomas.friebel@amd.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: Use wmb instead of rmb in xen_evtchn_do_upcall().Isaku Yamahata2008-06-201-1/+1
| | | | | | | | | | | | | This patch is ported one from 534:77db69c38249 of linux-2.6.18-xen.hg. Use wmb instead of rmb to enforce ordering between evtchn_upcall_pending and evtchn_pending_sel stores in xen_evtchn_do_upcall(). Cc: Samuel Thibault <samuel.thibault@eu.citrix.com> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: the arch/x86 maintainers <x86@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* xen: implement save/restoreJeremy Fitzhardinge2008-05-271-0/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements Xen save/restore and migration. Saving is triggered via xenbus, which is polled in drivers/xen/manage.c. When a suspend request comes in, the kernel prepares itself for saving by: 1 - Freeze all processes. This is primarily to prevent any partially-completed pagetable updates from confusing the suspend process. If CONFIG_PREEMPT isn't defined, then this isn't necessary. 2 - Suspend xenbus and other devices 3 - Stop_machine, to make sure all the other vcpus are quiescent. The Xen tools require the domain to run its save off vcpu0. 4 - Within the stop_machine state, it pins any unpinned pgds (under construction or destruction), performs canonicalizes various other pieces of state (mostly converting mfns to pfns), and finally 5 - Suspend the domain Restore reverses the steps used to save the domain, ending when all the frozen processes are thawed. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* xen: fix unbind_from_irq()Jeremy Fitzhardinge2008-05-271-2/+2
| | | | | | | | | | Rearrange the tests in unbind_from_irq() so that we can still unbind an irq even if the underlying event channel is bad. This allows a device driver to shuffle its irqs on save/restore before the underlying event channels have been fixed up. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* xen: add rebind_evtchn_irqJeremy Fitzhardinge2008-05-271-0/+27
| | | | | | | | | | Add rebind_evtchn_irq(), which will rebind an device driver's existing irq to a new event channel on restore. Since the new event channel will be masked and bound to vcpu0, we update the state accordingly and unmask the irq once everything is set up. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* xen: add resend_irq_on_evtchn() definition into events.cIsaku Yamahata2008-04-241-0/+16
| | | | | | | | | | | Define resend_irq_on_evtchn() which ia64/xen uses. Although it isn't used by current x86/xen code, it's arch generic so that put it into common code. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Xen: make events.c portable for ia64/xen supportIsaku Yamahata2008-04-241-6/+7
| | | | | | | | | | | | | | Remove x86 dependency in drivers/xen/events.c for ia64/xen support introducing include/asm/xen/events.h. Introduce xen_irqs_disabled() to hide regs->flags Introduce xen_do_IRQ() to hide regs->orig_ax. make enum ipi_vector definition arch specific. ia64/xen needs four vectors. Add one rmb() because on ia64 xchg() isn't barrier. Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* xen: move events.c to drivers/xen for IA64/Xen supportIsaku Yamahata2008-04-241-0/+657
move arch/x86/xen/events.c undedr drivers/xen to share codes with x86 and ia64. And minor adjustment to compile. ia64/xen also uses events.c Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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