Thread (38 messages) 38 messages, 3 authors, 2012-11-05
STALE4968d
Revisions (3)
  1. v1 [diff vs current]
  2. v2 [diff vs current]
  3. v3 current

[PATCH v3 15/25] xen/arm: receive Xen events on ARM

From: Stefano Stabellini <hidden>
Date: 2012-08-16 15:57:06
Also in: lkml, xen-devel
Subsystem: arm port, the rest, x86 architecture (32-bit and 64-bit), xen hypervisor arm, xen hypervisor interface, xen hypervisor x86 · Maintainers: Russell King, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Stefano Stabellini, Juergen Gross

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 <redacted>
---
 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 2e65e8d..14af29d 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,
@@ -74,6 +79,9 @@ 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 %s support found, events_irq=%d gnttab_frame_pfn=%lx\n",
+			version, xen_events_irq, xen_hvm_resume_frames);
 	xen_domain_type = XEN_HVM_DOMAIN;
 
 	xen_setup_features();
@@ -115,3 +123,28 @@ 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 7da65d3..c3516d3 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
@@ -1377,7 +1382,9 @@ 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();
@@ -1786,9 +1793,9 @@ 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);
@@ -1804,6 +1811,7 @@ 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();
@@ -1811,6 +1819,7 @@ 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());
@@ -1826,4 +1835,6 @@ 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
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