6 files changed, 34 insertions, 0 deletions

diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index f5693c81a1db..19e22e3784d0 100644
--- a/arch/x86/include/asm/entry_arch.h
+++ b/arch/x86/include/asm/entry_arch.h
@@ -13,6 +13,7 @@
 BUILD_INTERRUPT(reschedule_interrupt,RESCHEDULE_VECTOR)
 BUILD_INTERRUPT(call_function_interrupt,CALL_FUNCTION_VECTOR)
 BUILD_INTERRUPT(call_function_single_interrupt,CALL_FUNCTION_SINGLE_VECTOR)
+BUILD_INTERRUPT(pull_timers_interrupt,PULL_TIMERS_VECTOR)
 BUILD_INTERRUPT(irq_move_cleanup_interrupt,IRQ_MOVE_CLEANUP_VECTOR)
 BUILD_INTERRUPT(reboot_interrupt,REBOOT_VECTOR)
 
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index ba180d93b08c..162e5f9646ed 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -53,6 +53,8 @@ extern void threshold_interrupt(void);
 extern void call_function_interrupt(void);
 extern void call_function_single_interrupt(void);
 
+extern void pull_timers_interrupt(void);
+
 /* PIC specific functions */
 extern void disable_8259A_irq(unsigned int irq);
 extern void enable_8259A_irq(unsigned int irq);
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 5b21f0ec3df2..28c3bf3f4c84 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -104,6 +104,11 @@
 #define LOCAL_TIMER_VECTOR              0xef
 
 /*
+ * LITMUS^RT pull timers IRQ vector
+ */
+#define PULL_TIMERS_VECTOR              0xee
+
+/*
  * Generic system vector for platform specific use
  */
 #define GENERIC_INTERRUPT_VECTOR        0xed
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index 40f30773fb29..f5fa64c0b37e 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -172,6 +172,9 @@ static void __init smp_intr_init(void)
         alloc_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,
                         call_function_single_interrupt);
 
+        /* IPI for hrtimer pulling on remote cpus */
+        alloc_intr_gate(PULL_TIMERS_VECTOR, pull_timers_interrupt);
+
         /* Low priority IPI to cleanup after moving an irq */
         set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
         set_bit(IRQ_MOVE_CLEANUP_VECTOR, used_vectors);
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 337ce0c44f92..e83f79de863c 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -150,6 +150,16 @@ void native_send_call_func_ipi(const struct cpumask *mask)
         free_cpumask_var(allbutself);
 }
 
+/* trigger timers on remote cpu */
+void smp_send_pull_timers(int cpu)
+{
+        if (unlikely(cpu_is_offline(cpu))) {
+                WARN_ON(1);
+                return;
+        }
+        apic->send_IPI_mask(cpumask_of(cpu), PULL_TIMERS_VECTOR);
+}
+
 /*
  * this function calls the 'stop' function on all other CPUs in the system.
  */
@@ -230,6 +240,14 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)
         irq_exit();
 }
 
+extern void hrtimer_pull(void);
+
+void smp_pull_timers_interrupt(struct pt_regs *regs)
+{
+        ack_APIC_irq();
+        TRACE("pull timer interrupt\n");
+}
+
 struct smp_ops smp_ops = {
         .smp_prepare_boot_cpu   = native_smp_prepare_boot_cpu,
         .smp_prepare_cpus       = native_smp_prepare_cpus,
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 39c64bae776d..76bb3e45351f 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -77,6 +77,11 @@ void __smp_call_function_single(int cpuid, struct call_single_data *data,
                                 int wait);
 
 /*
+ * sends a 'pull timer' event to a remote CPU
+ */
+extern void smp_send_pull_timers(int cpu);
+
+/*
  * Generic and arch helpers
  */
 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS