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authorJeremy Fitzhardinge2010-08-21 03:57:53 +0200
committerJeremy Fitzhardinge2010-08-24 20:13:28 +0200
commitaaca49642b92c8a57d3ca5029a5a94019c7af69f (patch)
treea86a88c11addd689a2903d21f1bb948f461c1a1d /drivers
parentLinux 2.6.36-rc2 (diff)
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xen: use percpu interrupts for IPIs and VIRQs
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/xen/events.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 72f91bff29c7..0923ccb26121 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -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;