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xen: use percpu interrupts for IPIs and VIRQs

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IPIs and VIRQs are inherently per-cpu event types, so treat them as such:
 - use a specific percpu irq_chip implementation, and
 - handle them with handle_percpu_irq

This makes the path for delivering these interrupts more efficient
(no masking/unmasking, no locks), and it avoid problems with attempts
to migrate them.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
This commit is contained in:
Jeremy Fitzhardinge 2010-08-20 18:57:53 -07:00
parent 76be97c1fc
commit aaca49642b
1 changed files with 15 additions and 4 deletions
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19
drivers/xen/events.c
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@ -112,6 +112,7 @@ static inline unsigned long *cpu_evtchn_mask(int cpu)
#define VALID_EVTCHN(chn) ((chn) != 0)
static struct irq_chip xen_dynamic_chip;
static struct irq_chip xen_percpu_chip;
/* Constructor for packed IRQ information. */
static struct irq_info mk_unbound_info(void)
@ -403,8 +404,8 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
if (irq < 0)
goto out;
set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_level_irq, "ipi");
set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
handle_percpu_irq, "ipi");
bind_ipi.vcpu = cpu;
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
@ -444,8 +445,8 @@ static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
irq = find_unbound_irq();
set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_level_irq, "virq");
set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
handle_percpu_irq, "virq");
evtchn_to_irq[evtchn] = irq;
irq_info[irq] = mk_virq_info(evtchn, virq);
@ -964,6 +965,16 @@ static struct irq_chip xen_dynamic_chip __read_mostly = {
.retrigger = retrigger_dynirq,
};
static struct irq_chip xen_percpu_chip __read_mostly = {
.name = "xen-percpu",
.disable = disable_dynirq,
.mask = disable_dynirq,
.unmask = enable_dynirq,
.ack = ack_dynirq,
};
int xen_set_callback_via(uint64_t via)
{
struct xen_hvm_param a;