[PATCH v2 15/23] xen/arm: receive Xen events on ARM

Stefano Stabellini
2012-08-06T14:56:25Z

Compile events.c on ARM.
Parse, map and enable the IRQ to get event notifications from the device
tree (node "/xen").

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
arch/arm/include/asm/xen/events.h | 18 ++++++++++++++++++
arch/arm/xen/enlighten.c | 33 +++++++++++++++++++++++++++++++++
arch/x86/xen/enlighten.c | 1 +
arch/x86/xen/irq.c | 1 +
arch/x86/xen/xen-ops.h | 1 -
drivers/xen/events.c | 17 ++++++++++++++---
include/xen/events.h | 2 ++
7 files changed, 69 insertions(+), 4 deletions(-)
create mode 100644 arch/arm/include/asm/xen/events.h

diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h
new file mode 100644
index 0000000..94b4e90
--- /dev/null
+++ b/arch/arm/include/asm/xen/events.h
@@ -0,0 +1,18 @@
+#ifndef _ASM_ARM_XEN_EVENTS_H
+#define _ASM_ARM_XEN_EVENTS_H
+
+#include <asm/ptrace.h>
+
+enum ipi_vector {
+ XEN_PLACEHOLDER_VECTOR,
+
+ /* Xen IPIs go here */
+ XEN_NR_IPIS,
+};
+
+static inline int xen_irqs_disabled(struct pt_regs *regs)
+{
+ return raw_irqs_disabled_flags(regs->ARM_cpsr);
+}
+
+#endif /* _ASM_ARM_XEN_EVENTS_H */
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index e5e92d5..87b17f0 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -1,4 +1,5 @@
#include <xen/xen.h>
+#include <xen/events.h>
#include <xen/grant_table.h>
#include <xen/hvm.h>
#include <xen/interface/xen.h>
@@ -9,6 +10,8 @@
#include <xen/xenbus.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
@@ -33,6 +36,8 @@ EXPORT_SYMBOL_GPL(xen_have_vector_callback);
int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);

+static __read_mostly int xen_events_irq = -1;
+
int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
unsigned long addr,
unsigned long mfn, int nr,
@@ -66,6 +71,9 @@ static int __init xen_guest_init(void)
if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res))
return 0;
xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
+ xen_events_irq = irq_of_parse_and_map(node, 0);
+ pr_info("Xen support found, events_irq=%d gnttab_frame_pfn=%lx\n",
+ xen_events_irq, xen_hvm_resume_frames);
xen_domain_type = XEN_HVM_DOMAIN;

xen_setup_features();
@@ -107,3 +115,28 @@ static int __init xen_guest_init(void)
return 0;
}
core_initcall(xen_guest_init);
+
+static irqreturn_t xen_arm_callback(int irq, void *arg)
+{
+ xen_hvm_evtchn_do_upcall();
+ return IRQ_HANDLED;
+}
+
+static int __init xen_init_events(void)
+{
+ if (!xen_domain() || xen_events_irq < 0)
+ return -ENODEV;
+
+ xen_init_IRQ();
+
+ if (request_percpu_irq(xen_events_irq, xen_arm_callback,
+ "events", xen_vcpu)) {
+ pr_err("Error requesting IRQ %d\n", xen_events_irq);
+ return -EINVAL;
+ }
+
+ enable_percpu_irq(xen_events_irq, 0);
+
+ return 0;
+}
+postcore_initcall(xen_init_events);
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index ff962d4..9f8b0ef 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -33,6 +33,7 @@
#include <linux/memblock.h>

#include <xen/xen.h>
+#include <xen/events.h>
#include <xen/interface/xen.h>
#include <xen/interface/version.h>
#include <xen/interface/physdev.h>
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 1573376..01a4dc0 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -5,6 +5,7 @@
#include <xen/interface/xen.h>
#include <xen/interface/sched.h>
#include <xen/interface/vcpu.h>
+#include <xen/events.h>

#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 202d4c1..2368295 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -35,7 +35,6 @@ void xen_set_pat(u64);

char * __init xen_memory_setup(void);
void __init xen_arch_setup(void);
-void __init xen_init_IRQ(void);
void xen_enable_sysenter(void);
void xen_enable_syscall(void);
void xen_vcpu_restore(void);
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 7595581..5ecb596 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -31,14 +31,16 @@
#include <linux/irqnr.h>
#include <linux/pci.h>

+#ifdef CONFIG_X86
#include <asm/desc.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/io_apic.h>
-#include <asm/sync_bitops.h>
#include <asm/xen/page.h>
#include <asm/xen/pci.h>
+#endif
+#include <asm/sync_bitops.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>

@@ -50,6 +52,9 @@
#include <xen/interface/event_channel.h>
#include <xen/interface/hvm/hvm_op.h>
#include <xen/interface/hvm/params.h>
+#include <xen/interface/physdev.h>
+#include <xen/interface/sched.h>
+#include <asm/hw_irq.h>

/*
* This lock protects updates to the following mapping and reference-count
@@ -1374,7 +1379,9 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);

+#ifdef CONFIG_X86
exit_idle();
+#endif
irq_enter();

__xen_evtchn_do_upcall();
@@ -1783,9 +1790,9 @@ void xen_callback_vector(void)
void xen_callback_vector(void) {}
#endif

-void __init xen_init_IRQ(void)
+void xen_init_IRQ(void)
{
- int i, rc;
+ int i;

evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
GFP_KERNEL);
@@ -1801,6 +1808,7 @@ void __init xen_init_IRQ(void)

pirq_needs_eoi = pirq_needs_eoi_flag;

+#ifdef CONFIG_X86
if (xen_hvm_domain()) {
xen_callback_vector();
native_init_IRQ();
@@ -1808,6 +1816,7 @@ void __init xen_init_IRQ(void)
* __acpi_register_gsi can point at the right function */
pci_xen_hvm_init();
} else {
+ int rc;
struct physdev_pirq_eoi_gmfn eoi_gmfn;

irq_ctx_init(smp_processor_id());
@@ -1823,4 +1832,6 @@ void __init xen_init_IRQ(void)
} else
pirq_needs_eoi = pirq_check_eoi_map;
}
+#endif
}
+EXPORT_SYMBOL_GPL(xen_init_IRQ);
diff --git a/include/xen/events.h b/include/xen/events.h
index 04399b2..c6bfe01 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -109,4 +109,6 @@ int xen_irq_from_gsi(unsigned gsi);
/* Determine whether to ignore this IRQ if it is passed to a guest. */
int xen_test_irq_shared(int irq);

+/* initialize Xen IRQ subsystem */
+void xen_init_IRQ(void);
#endif /* _XEN_EVENTS_H */
--
1.7.2.5