x86: UV, SGI RTC: add generic system vector

This patch allocates a system interrupt vector for various platform
specific uses.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: john stultz <johnstul@us.ibm.com>
LKML-Reference: <20090304185605.GA24419@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 42 insertions, 0 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 83d1836b9467..7ba4621c0dfa 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -984,6 +984,8 @@ apicinterrupt UV_BAU_MESSAGE \
 #endif
 apicinterrupt LOCAL_TIMER_VECTOR \
         apic_timer_interrupt smp_apic_timer_interrupt
+apicinterrupt GENERIC_INTERRUPT_VECTOR \
+        generic_interrupt smp_generic_interrupt
 
 #ifdef CONFIG_SMP
 apicinterrupt INVALIDATE_TLB_VECTOR_START+0 \
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index f13ca1650aaf..b864341dcc45 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -15,6 +15,9 @@
 
 atomic_t irq_err_count;
 
+/* Function pointer for generic interrupt vector handling */
+void (*generic_interrupt_extension)(void) = NULL;
+
 /*
  * 'what should we do if we get a hw irq event on an illegal vector'.
  * each architecture has to answer this themselves.
@@ -56,6 +59,12 @@ static int show_other_interrupts(struct seq_file *p)
                 seq_printf(p, "%10u ", irq_stats(j)->apic_timer_irqs);
         seq_printf(p, "  Local timer interrupts\n");
 #endif
+        if (generic_interrupt_extension) {
+                seq_printf(p, "PLT: ");
+                for_each_online_cpu(j)
+                        seq_printf(p, "%10u ", irq_stats(j)->generic_irqs);
+                seq_printf(p, "  Platform interrupts\n");
+        }
 #ifdef CONFIG_SMP
         seq_printf(p, "RES: ");
         for_each_online_cpu(j)
@@ -163,6 +172,8 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
 #ifdef CONFIG_X86_LOCAL_APIC
         sum += irq_stats(cpu)->apic_timer_irqs;
 #endif
+        if (generic_interrupt_extension)
+                sum += irq_stats(cpu)->generic_irqs;
 #ifdef CONFIG_SMP
         sum += irq_stats(cpu)->irq_resched_count;
         sum += irq_stats(cpu)->irq_call_count;
@@ -226,4 +237,27 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
         return 1;
 }
 
+/*
+ * Handler for GENERIC_INTERRUPT_VECTOR.
+ */
+void smp_generic_interrupt(struct pt_regs *regs)
+{
+        struct pt_regs *old_regs = set_irq_regs(regs);
+
+        ack_APIC_irq();
+
+        exit_idle();
+
+        irq_enter();
+
+        inc_irq_stat(generic_irqs);
+
+        if (generic_interrupt_extension)
+                generic_interrupt_extension();
+
+        irq_exit();
+
+        set_irq_regs(old_regs);
+}
+
 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
diff --git a/arch/x86/kernel/irqinit_32.c b/arch/x86/kernel/irqinit_32.c
index 50b8c3a3006c..bc1326105448 100644
--- a/arch/x86/kernel/irqinit_32.c
+++ b/arch/x86/kernel/irqinit_32.c
@@ -175,6 +175,9 @@ void __init native_init_IRQ(void)
         /* self generated IPI for local APIC timer */
         alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
 
+        /* generic IPI for platform specific use */
+        alloc_intr_gate(GENERIC_INTERRUPT_VECTOR, generic_interrupt);
+
         /* IPI vectors for APIC spurious and error interrupts */
         alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
         alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
diff --git a/arch/x86/kernel/irqinit_64.c b/arch/x86/kernel/irqinit_64.c
index da481a1e3f30..c7a49e0ffbfb 100644
--- a/arch/x86/kernel/irqinit_64.c
+++ b/arch/x86/kernel/irqinit_64.c
@@ -147,6 +147,9 @@ static void __init apic_intr_init(void)
         /* self generated IPI for local APIC timer */
         alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
 
+        /* generic IPI for platform specific use */
+        alloc_intr_gate(GENERIC_INTERRUPT_VECTOR, generic_interrupt);
+
         /* IPI vectors for APIC spurious and error interrupts */
         alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
         alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);