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>

3 files changed, 146 insertions, 1 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 45cecc59d894..acc0e8bf043e 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -108,7 +108,7 @@ obj-$(CONFIG_MICROCODE)			+= microcode.o
 # 64 bit specific files
 ifeq ($(CONFIG_X86_64),y)
         obj-y                           += genapic_64.o genapic_flat_64.o genx2apic_uv_x.o tlb_uv.o
-        obj-y                           += bios_uv.o
+        obj-y                           += bios_uv.o uv_irq.o
         obj-y                           += genx2apic_cluster.o
         obj-y                           += genx2apic_phys.o
         obj-$(CONFIG_X86_PM_TIMER)      += pmtimer_64.o
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index 4ee270d30358..260c95a5e6dc 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -58,6 +58,8 @@
 #include <asm/setup.h>
 #include <asm/irq_remapping.h>
 #include <asm/hpet.h>
+#include <asm/uv/uv_hub.h>
+#include <asm/uv/uv_irq.h>
 
 #include <mach_ipi.h>
 #include <mach_apic.h>
@@ -3692,6 +3694,72 @@ int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
 }
 #endif /* CONFIG_HT_IRQ */
 
+#ifdef CONFIG_X86_64
+/*
+ * Re-target the irq to the specified CPU and enable the specified MMR located
+ * on the specified blade to allow the sending of MSIs to the specified CPU.
+ */
+int arch_enable_uv_irq(char *irq_name, unsigned int irq, int cpu, int mmr_blade,
+                       unsigned long mmr_offset)
+{
+        const cpumask_t *eligible_cpu = get_cpu_mask(cpu);
+        struct irq_cfg *cfg;
+        int mmr_pnode;
+        unsigned long mmr_value;
+        struct uv_IO_APIC_route_entry *entry;
+        unsigned long flags;
+        int err;
+
+        err = assign_irq_vector(irq, *eligible_cpu);
+        if (err != 0)
+                return err;
+
+        spin_lock_irqsave(&vector_lock, flags);
+        set_irq_chip_and_handler_name(irq, &uv_irq_chip, handle_percpu_irq,
+                                      irq_name);
+        spin_unlock_irqrestore(&vector_lock, flags);
+
+        cfg = irq_cfg(irq);
+
+        mmr_value = 0;
+        entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
+        BUG_ON(sizeof(struct uv_IO_APIC_route_entry) != sizeof(unsigned long));
+
+        entry->vector = cfg->vector;
+        entry->delivery_mode = INT_DELIVERY_MODE;
+        entry->dest_mode = INT_DEST_MODE;
+        entry->polarity = 0;
+        entry->trigger = 0;
+        entry->mask = 0;
+        entry->dest = cpu_mask_to_apicid(*eligible_cpu);
+
+        mmr_pnode = uv_blade_to_pnode(mmr_blade);
+        uv_write_global_mmr64(mmr_pnode, mmr_offset, mmr_value);
+
+        return irq;
+}
+
+/*
+ * Disable the specified MMR located on the specified blade so that MSIs are
+ * longer allowed to be sent.
+ */
+void arch_disable_uv_irq(int mmr_blade, unsigned long mmr_offset)
+{
+        unsigned long mmr_value;
+        struct uv_IO_APIC_route_entry *entry;
+        int mmr_pnode;
+
+        mmr_value = 0;
+        entry = (struct uv_IO_APIC_route_entry *)&mmr_value;
+        BUG_ON(sizeof(struct uv_IO_APIC_route_entry) != sizeof(unsigned long));
+
+        entry->mask = 1;
+
+        mmr_pnode = uv_blade_to_pnode(mmr_blade);
+        uv_write_global_mmr64(mmr_pnode, mmr_offset, mmr_value);
+}
+#endif /* CONFIG_X86_64 */
+
 int __init io_apic_get_redir_entries (int ioapic)
 {
         union IO_APIC_reg_01    reg_01;
diff --git a/arch/x86/kernel/uv_irq.c b/arch/x86/kernel/uv_irq.c
new file mode 100644
index 000000000000..6bd26c91c30b
--- /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);