[PATCH 2/2] xen: implement IRQ_WORK_VECTOR handler

From: Lin Ming
Date: Sun Apr 15 2012 - 02:09:28 EST


Signed-off-by: Lin Ming <mlin@xxxxxxxxxxxxx>
---
arch/x86/include/asm/xen/events.h | 1 +
arch/x86/xen/smp.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h
index 1df3541..cc146d5 100644
--- a/arch/x86/include/asm/xen/events.h
+++ b/arch/x86/include/asm/xen/events.h
@@ -6,6 +6,7 @@ enum ipi_vector {
XEN_CALL_FUNCTION_VECTOR,
XEN_CALL_FUNCTION_SINGLE_VECTOR,
XEN_SPIN_UNLOCK_VECTOR,
+ XEN_IRQ_WORK_VECTOR,

XEN_NR_IPIS,
};
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 2dc6628..92ad12d 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -16,6 +16,7 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/smp.h>
+#include <linux/irq_work.h>

#include <asm/paravirt.h>
#include <asm/desc.h>
@@ -41,10 +42,12 @@ cpumask_var_t xen_cpu_initialized_map;
static DEFINE_PER_CPU(int, xen_resched_irq);
static DEFINE_PER_CPU(int, xen_callfunc_irq);
static DEFINE_PER_CPU(int, xen_callfuncsingle_irq);
+static DEFINE_PER_CPU(int, xen_irq_work);
static DEFINE_PER_CPU(int, xen_debug_irq) = -1;

static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
+static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);

/*
* Reschedule call back.
@@ -143,6 +146,17 @@ static int xen_smp_intr_init(unsigned int cpu)
goto fail;
per_cpu(xen_callfuncsingle_irq, cpu) = rc;

+ callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
+ rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
+ cpu,
+ xen_irq_work_interrupt,
+ IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
+ callfunc_name,
+ NULL);
+ if (rc < 0)
+ goto fail;
+ per_cpu(xen_irq_work, cpu) = rc;
+
return 0;

fail:
@@ -155,6 +169,8 @@ static int xen_smp_intr_init(unsigned int cpu)
if (per_cpu(xen_callfuncsingle_irq, cpu) >= 0)
unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu),
NULL);
+ if (per_cpu(xen_irq_work, cpu) >= 0)
+ unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);

return rc;
}
@@ -509,6 +525,9 @@ static inline int xen_map_vector(int vector)
case CALL_FUNCTION_SINGLE_VECTOR:
xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
break;
+ case IRQ_WORK_VECTOR:
+ xen_vector = XEN_IRQ_WORK_VECTOR;
+ break;
default:
xen_vector = -1;
printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
@@ -588,6 +607,16 @@ static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

+static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
+{
+ irq_enter();
+ inc_irq_stat(apic_irq_work_irqs);
+ irq_work_run();
+ irq_exit();
+
+ return IRQ_HANDLED;
+}
+
static const struct smp_ops xen_smp_ops __initconst = {
.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
.smp_prepare_cpus = xen_smp_prepare_cpus,
@@ -634,6 +663,7 @@ static void xen_hvm_cpu_die(unsigned int cpu)
unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
+ unbind_from_irqhandler(per_cpu(xen_irq_work, cpu), NULL);
native_cpu_die(cpu);
}

--
1.7.2.5

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