x86: arch specific support for remapping HPET MSIs

x86 arch support for remapping HPET MSI's by associating the HPET timer block
with the interrupt-remapping HW unit and setting up appropriate irq_chip

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jay Fenlason <fenlason@redhat.com>
LKML-Reference: <20090804190729.630510000@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

4 files changed, 47 insertions, 11 deletions

diff --git a/arch/x86/include/asm/hpet.h b/arch/x86/include/asm/hpet.h
index 65847c578b70..5d89fd2a3690 100644
--- a/arch/x86/include/asm/hpet.h
+++ b/arch/x86/include/asm/hpet.h
@@ -65,6 +65,7 @@
 /* hpet memory map physical address */
 extern unsigned long hpet_address;
 extern unsigned long force_hpet_address;
+extern u8 hpet_blockid;
 extern int hpet_force_user;
 extern int is_hpet_enabled(void);
 extern int hpet_enable(void);
@@ -78,9 +79,9 @@ extern void hpet_msi_write(unsigned int irq, struct msi_msg *msg);
 extern void hpet_msi_read(unsigned int irq, struct msi_msg *msg);
 
 #ifdef CONFIG_PCI_MSI
-extern int arch_setup_hpet_msi(unsigned int irq);
+extern int arch_setup_hpet_msi(unsigned int irq, unsigned int id);
 #else
-static inline int arch_setup_hpet_msi(unsigned int irq)
+static inline int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
 {
         return -EINVAL;
 }
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6b8ca3a0285d..eae642b0f345 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -624,6 +624,7 @@ static int __init acpi_parse_hpet(struct acpi_table_header *table)
         }
 
         hpet_address = hpet_tbl->address.address;
+        hpet_blockid = hpet_tbl->sequence;
 
         /*
          * Some broken BIOSes advertise HPET at 0x0. We really do not
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index d2ed6c5ddc80..d9c6f14d3b32 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3254,7 +3254,8 @@ void destroy_irq(unsigned int irq)
  * MSI message composition
  */
 #ifdef CONFIG_PCI_MSI
-static int msi_compose_msg(struct pci_dev *pdev, unsigned int irq, struct msi_msg *msg)
+static int msi_compose_msg(struct pci_dev *pdev, unsigned int irq,
+                           struct msi_msg *msg, u8 hpet_id)
 {
         struct irq_cfg *cfg;
         int err;
@@ -3288,7 +3289,10 @@ static int msi_compose_msg(struct pci_dev *pdev, unsigned int irq, struct msi_ms
                 irte.dest_id = IRTE_DEST(dest);
 
                 /* Set source-id of interrupt request */
-                set_msi_sid(&irte, pdev);
+                if (pdev)
+                        set_msi_sid(&irte, pdev);
+                else
+                        set_hpet_sid(&irte, hpet_id);
 
                 modify_irte(irq, &irte);
 
@@ -3453,7 +3457,7 @@ static int setup_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int irq)
         int ret;
         struct msi_msg msg;
 
-        ret = msi_compose_msg(dev, irq, &msg);
+        ret = msi_compose_msg(dev, irq, &msg, -1);
         if (ret < 0)
                 return ret;
 
@@ -3586,7 +3590,7 @@ int arch_setup_dmar_msi(unsigned int irq)
         int ret;
         struct msi_msg msg;
 
-        ret = msi_compose_msg(NULL, irq, &msg);
+        ret = msi_compose_msg(NULL, irq, &msg, -1);
         if (ret < 0)
                 return ret;
         dmar_msi_write(irq, &msg);
@@ -3626,6 +3630,19 @@ static int hpet_msi_set_affinity(unsigned int irq, const struct cpumask *mask)
 
 #endif /* CONFIG_SMP */
 
+static struct irq_chip ir_hpet_msi_type = {
+        .name = "IR-HPET_MSI",
+        .unmask = hpet_msi_unmask,
+        .mask = hpet_msi_mask,
+#ifdef CONFIG_INTR_REMAP
+        .ack = ir_ack_apic_edge,
+#ifdef CONFIG_SMP
+        .set_affinity = ir_set_msi_irq_affinity,
+#endif
+#endif
+        .retrigger = ioapic_retrigger_irq,
+};
+
 static struct irq_chip hpet_msi_type = {
         .name = "HPET_MSI",
         .unmask = hpet_msi_unmask,
@@ -3637,20 +3654,36 @@ static struct irq_chip hpet_msi_type = {
         .retrigger = ioapic_retrigger_irq,
 };
 
-int arch_setup_hpet_msi(unsigned int irq)
+int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
 {
         int ret;
         struct msi_msg msg;
         struct irq_desc *desc = irq_to_desc(irq);
 
-        ret = msi_compose_msg(NULL, irq, &msg);
+        if (intr_remapping_enabled) {
+                struct intel_iommu *iommu = map_hpet_to_ir(id);
+                int index;
+
+                if (!iommu)
+                        return -1;
+
+                index = alloc_irte(iommu, irq, 1);
+                if (index < 0)
+                        return -1;
+        }
+
+        ret = msi_compose_msg(NULL, irq, &msg, id);
         if (ret < 0)
                 return ret;
 
         hpet_msi_write(irq, &msg);
         desc->status |= IRQ_MOVE_PCNTXT;
-        set_irq_chip_and_handler_name(irq, &hpet_msi_type, handle_edge_irq,
-                "edge");
+        if (irq_remapped(irq))
+                set_irq_chip_and_handler_name(irq, &ir_hpet_msi_type,
+                                              handle_edge_irq, "edge");
+        else
+                set_irq_chip_and_handler_name(irq, &hpet_msi_type,
+                                              handle_edge_irq, "edge");
 
         return 0;
 }
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ba575f0f2e34..7f024ff47d1d 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -33,6 +33,7 @@
  * HPET address is set in acpi/boot.c, when an ACPI entry exists
  */
 unsigned long                           hpet_address;
+u8                                      hpet_blockid; /* OS timer block num */
 #ifdef CONFIG_PCI_MSI
 static unsigned long                    hpet_num_timers;
 #endif
@@ -467,7 +468,7 @@ static int hpet_msi_next_event(unsigned long delta,
 
 static int hpet_setup_msi_irq(unsigned int irq)
 {
-        if (arch_setup_hpet_msi(irq)) {
+        if (arch_setup_hpet_msi(irq, hpet_blockid)) {
                 destroy_irq(irq);
                 return -EINVAL;
         }