Revision 8155469341a60ba7064d64b62bb32af5a901ccaf authored by Linus Torvalds on 28 July 2017, 20:36:56 UTC, committed by Linus Torvalds on 28 July 2017, 20:36:56 UTC
Pull KVM fixes from Paolo Bonzini: "s390: - SRCU fix PPC: - host crash fixes x86: - bugfixes, including making nested posted interrupts really work Generic: - tweaks to kvm_stat and to uevents" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: LAPIC: Fix reentrancy issues with preempt notifiers tools/kvm_stat: add '-f help' to get the available event list tools/kvm_stat: use variables instead of hard paths in help output KVM: nVMX: Fix loss of L2's NMI blocking state KVM: nVMX: Fix posted intr delivery when vcpu is in guest mode x86: irq: Define a global vector for nested posted interrupts KVM: x86: do mask out upper bits of PAE CR3 KVM: make pid available for uevents without debugfs KVM: s390: take srcu lock when getting/setting storage keys KVM: VMX: remove unused field KVM: PPC: Book3S HV: Fix host crash on changing HPT size KVM: PPC: Book3S HV: Enable TM before accessing TM registers
once.c
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/once.h>
#include <linux/random.h>
struct once_work {
struct work_struct work;
struct static_key *key;
};
static void once_deferred(struct work_struct *w)
{
struct once_work *work;
work = container_of(w, struct once_work, work);
BUG_ON(!static_key_enabled(work->key));
static_key_slow_dec(work->key);
kfree(work);
}
static void once_disable_jump(struct static_key *key)
{
struct once_work *w;
w = kmalloc(sizeof(*w), GFP_ATOMIC);
if (!w)
return;
INIT_WORK(&w->work, once_deferred);
w->key = key;
schedule_work(&w->work);
}
static DEFINE_SPINLOCK(once_lock);
bool __do_once_start(bool *done, unsigned long *flags)
__acquires(once_lock)
{
spin_lock_irqsave(&once_lock, *flags);
if (*done) {
spin_unlock_irqrestore(&once_lock, *flags);
/* Keep sparse happy by restoring an even lock count on
* this lock. In case we return here, we don't call into
* __do_once_done but return early in the DO_ONCE() macro.
*/
__acquire(once_lock);
return false;
}
return true;
}
EXPORT_SYMBOL(__do_once_start);
void __do_once_done(bool *done, struct static_key *once_key,
unsigned long *flags)
__releases(once_lock)
{
*done = true;
spin_unlock_irqrestore(&once_lock, *flags);
once_disable_jump(once_key);
}
EXPORT_SYMBOL(__do_once_done);
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