x86, UV: add uv_setup_irq() and uv_teardown_irq() functions, v3

Provide a means for UV interrupt MMRs to be setup with the message to be sent
when an MSI is raised.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 77 insertions, 0 deletions

diff --git a/arch/x86/kernel/uv_irq.c b/arch/x86/kernel/uv_irq.c
new file mode 100644
index 00000000000..6bd26c91c30
--- /dev/null
+++ b/arch/x86/kernel/uv_irq.c
@@ -0,0 +1,77 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * SGI UV IRQ functions
+ *
+ * Copyright (C) 2008 Silicon Graphics, Inc. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <asm/uv/uv_irq.h>
+
+static void uv_noop(unsigned int irq)
+{
+}
+
+static unsigned int uv_noop_ret(unsigned int irq)
+{
+	return 0;
+}
+
+static void uv_ack_apic(unsigned int irq)
+{
+	ack_APIC_irq();
+}
+
+struct irq_chip uv_irq_chip = {
+	.name		= "UV-CORE",
+	.startup	= uv_noop_ret,
+	.shutdown	= uv_noop,
+	.enable		= uv_noop,
+	.disable	= uv_noop,
+	.ack		= uv_noop,
+	.mask		= uv_noop,
+	.unmask		= uv_noop,
+	.eoi		= uv_ack_apic,
+	.end		= uv_noop,
+};
+
+/*
+ * Set up a mapping of an available irq and vector, and enable the specified
+ * MMR that defines the MSI that is to be sent to the specified CPU when an
+ * interrupt is raised.
+ */
+int uv_setup_irq(char *irq_name, int cpu, int mmr_blade,
+		 unsigned long mmr_offset)
+{
+	int irq;
+	int ret;
+
+	irq = create_irq();
+	if (irq <= 0)
+		return -EBUSY;
+
+	ret = arch_enable_uv_irq(irq_name, irq, cpu, mmr_blade, mmr_offset);
+	if (ret != irq)
+		destroy_irq(irq);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(uv_setup_irq);
+
+/*
+ * Tear down a mapping of an irq and vector, and disable the specified MMR that
+ * defined the MSI that was to be sent to the specified CPU when an interrupt
+ * was raised.
+ *
+ * Set mmr_blade and mmr_offset to what was passed in on uv_setup_irq().
+ */
+void uv_teardown_irq(unsigned int irq, int mmr_blade, unsigned long mmr_offset)
+{
+	arch_disable_uv_irq(mmr_blade, mmr_offset);
+	destroy_irq(irq);
+}
+EXPORT_SYMBOL_GPL(uv_teardown_irq);