/* * Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra * * Provides a framework for enqueueing and running callbacks from hardirq * context. The enqueueing is NMI-safe. */ #include #include #include #include #include #include #include #include #include #include #include #include #include static DEFINE_PER_CPU(struct llist_head, raised_list); static DEFINE_PER_CPU(struct llist_head, lazy_list); /* * Claim the entry so that no one else will poke at it. */ static bool irq_work_claim(struct irq_work *work) { unsigned long flags, oflags, nflags; /* * Start with our best wish as a premise but only trust any * flag value after cmpxchg() result. */ flags = work->flags & ~IRQ_WORK_PENDING; for (;;) { nflags = flags | IRQ_WORK_FLAGS; oflags = cmpxchg(&work->flags, flags, nflags); if (oflags == flags) break; if (oflags & IRQ_WORK_PENDING) return false; flags = oflags; cpu_relax(); } return true; } void __weak arch_irq_work_raise(void) { /* * Lame architectures will get the timer tick callback */ } #ifdef CONFIG_SMP /* * Enqueue the irq_work @work on @cpu unless it's already pending * somewhere. * * Can be re-enqueued while the callback is still in progress. */ bool irq_work_queue_on(struct irq_work *work, int cpu) { /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(cpu)); /* Arch remote IPI send/receive backend aren't NMI safe */ WARN_ON_ONCE(in_nmi()); /* Only queue if not already pending */ if (!irq_work_claim(work)) return false; if (llist_add(&work->llnode, &per_cpu(raised_list, cpu))) arch_send_call_function_single_ipi(cpu); return true; } EXPORT_SYMBOL_GPL(irq_work_queue_on); #endif /* Enqueue the irq work @work on the current CPU */ bool irq_work_queue(struct irq_work *work) { /* Only queue if not already pending */ if (!irq_work_claim(work)) return false; /* Queue the entry and raise the IPI if needed. */ preempt_disable(); /* If the work is "lazy", handle it from next tick if any */ if (work->flags & IRQ_WORK_LAZY) { if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) && tick_nohz_tick_stopped()) arch_irq_work_raise(); } else { if (llist_add(&work->llnode, this_cpu_ptr(&raised_list))) arch_irq_work_raise(); } preempt_enable(); return true; } EXPORT_SYMBOL_GPL(irq_work_queue); bool irq_work_needs_cpu(void) { struct llist_head *raised, *lazy; raised = this_cpu_ptr(&raised_list); lazy = this_cpu_ptr(&lazy_list); if (llist_empty(raised) || arch_irq_work_has_interrupt()) if (llist_empty(lazy)) return false; /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); return true; } static void irq_work_run_list(struct llist_head *list) { unsigned long flags; struct irq_work *work; struct llist_node *llnode; BUG_ON(!irqs_disabled()); if (llist_empty(list)) return; llnode = llist_del_all(list); while (llnode != NULL) { work = llist_entry(llnode, struct irq_work, llnode); llnode = llist_next(llnode); /* * Clear the PENDING bit, after this point the @work * can be re-used. * Make it immediately visible so that other CPUs trying * to claim that work don't rely on us to handle their data * while we are in the middle of the func. */ flags = work->flags & ~IRQ_WORK_PENDING; xchg(&work->flags, flags); work->func(work); /* * Clear the BUSY bit and return to the free state if * no-one else claimed it meanwhile. */ (void)cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY); } } /* * hotplug calls this through: * hotplug_cfd() -> flush_smp_call_function_queue() */ void irq_work_run(void) { irq_work_run_list(this_cpu_ptr(&raised_list)); irq_work_run_list(this_cpu_ptr(&lazy_list)); } EXPORT_SYMBOL_GPL(irq_work_run); void irq_work_tick(void) { struct llist_head *raised = this_cpu_ptr(&raised_list); if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) irq_work_run_list(raised); irq_work_run_list(this_cpu_ptr(&lazy_list)); } /* * Synchronize against the irq_work @entry, ensures the entry is not * currently in use. */ void irq_work_sync(struct irq_work *work) { WARN_ON_ONCE(irqs_disabled()); while (work->flags & IRQ_WORK_BUSY) cpu_relax(); } EXPORT_SYMBOL_GPL(irq_work_sync); e>
authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-15 12:40:53 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-15 12:40:53 -0800
commitc92816275674c1491ce228ee49aa030a5fa1be04 (patch)
tree97deb97f282c6b9f4f58e45a60ea78d1fe31df4e /include/crypto/mcryptd.h
parent2d5a7101a140adcf7a5d8677649847fbb2dd5a2f (diff)
parentc8a6a09c1c617402cc9254b2bc8da359a0347d75 (diff)
Merge tag 'char-misc-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH: "Here are some small char/misc driver fixes for 4.10-rc4 that resolve some reported issues. The MEI driver issue resolves a lot of problems that people have been having, as does the mem driver fix. The other minor fixes resolve other reported issues. All of these have been in linux-next for a while" * tag 'char-misc-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: vme: Fix wrong pointer utilization in ca91cx42_slave_get auxdisplay: fix new ht16k33 build errors ppdev: don't print a free'd string extcon: return error code on failure drivers: char: mem: Fix thinkos in kmem address checks mei: bus: enable OS version only for SPT and newer
Diffstat (limited to 'include/crypto/mcryptd.h')