8 files changed, 44 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4f412167b95d..411536b9c975 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2249,5 +2249,8 @@ source "arch/arm/kvm/Kconfig"
 config ARCH_HAS_FEATHER_TRACE
         def_bool n
 
+config ARCH_HAS_SEND_PULL_TIMERS
+        def_bool n
+
 source "litmus/Kconfig"
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 171cdc9cc5db..b0695266a4cb 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2350,4 +2350,7 @@ source "lib/Kconfig"
 config ARCH_HAS_FEATHER_TRACE
         def_bool y
 
+config ARCH_HAS_SEND_PULL_TIMERS
+        def_bool y
+
 source "litmus/Kconfig"
diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index 9bd4ecac72be..3a3c2f1ac1c4 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)
 #endif
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 1da97efad08a..672de9367d27 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -77,6 +77,8 @@ extern void threshold_interrupt(void);
 extern void call_function_interrupt(void);
 extern void call_function_single_interrupt(void);
 
+extern void pull_timers_interrupt(void);
+
 /* IOAPIC */
 #define IO_APIC_IRQ(x) (((x) >= NR_IRQS_LEGACY) || ((1<<(x)) & io_apic_irqs))
 extern unsigned long io_apic_irqs;
@@ -166,6 +168,7 @@ extern asmlinkage void smp_irq_move_cleanup_interrupt(void);
 extern void smp_reschedule_interrupt(struct pt_regs *);
 extern void smp_call_function_interrupt(struct pt_regs *);
 extern void smp_call_function_single_interrupt(struct pt_regs *);
+extern void smp_pull_timers_interrupt(struct pt_regs *);
 #ifdef CONFIG_X86_32
 extern void smp_invalidate_interrupt(struct pt_regs *);
 #else
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 5702d7e3111d..224116be0e22 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -124,6 +124,12 @@
  */
 #define LOCAL_TIMER_VECTOR              0xef
 
+/*
+ * LITMUS^RT pull timers IRQ vector.
+ * Make sure it's not used by Linux.
+ */
+#define PULL_TIMERS_VECTOR              0xdf
+
 #define NR_VECTORS                       256
 
 #define FPU_IRQ                           13
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 727208941030..a48b3ea137cd 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1183,6 +1183,8 @@ apicinterrupt CALL_FUNCTION_VECTOR \
         call_function_interrupt smp_call_function_interrupt
 apicinterrupt RESCHEDULE_VECTOR \
         reschedule_interrupt smp_reschedule_interrupt
+apicinterrupt PULL_TIMERS_VECTOR \
+        pull_timers_interrupt smp_pull_timers_interrupt
 #endif
 
 apicinterrupt ERROR_APIC_VECTOR \
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index a2a1fbc594ff..77979d9bd90d 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -145,6 +145,9 @@ 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 48d2b7ded422..a52ef7fd6862 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -24,6 +24,8 @@
 #include <linux/cpu.h>
 #include <linux/gfp.h>
 
+#include <litmus/debug_trace.h>
+
 #include <asm/mtrr.h>
 #include <asm/tlbflush.h>
 #include <asm/mmu_context.h>
@@ -163,6 +165,16 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
         return NMI_HANDLED;
 }
 
+/* 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.
  */
@@ -285,6 +297,17 @@ static int __init nonmi_ipi_setup(char *str)
 
 __setup("nonmi_ipi", nonmi_ipi_setup);
 
+extern void hrtimer_pull(void);
+
+void smp_pull_timers_interrupt(struct pt_regs *regs)
+{
+        ack_APIC_irq();
+        irq_enter();
+        TRACE("pull timer interrupt\n");
+        hrtimer_pull();
+        irq_exit();
+}
+
 struct smp_ops smp_ops = {
         .smp_prepare_boot_cpu   = native_smp_prepare_boot_cpu,
         .smp_prepare_cpus       = native_smp_prepare_cpus,