x86/{tcb,trap}: implement rescheduling IPIs

5 files changed, 31 insertions, 0 deletions

diff --git a/arch/x86/machine/tcb.c b/arch/x86/machine/tcb.c
index c1f2500..90f08b5 100644
--- a/arch/x86/machine/tcb.c
+++ b/arch/x86/machine/tcb.c
@@ -47,3 +47,13 @@ tcb_load(struct tcb *tcb)
     tcb_set_current(tcb);
     tcb_context_load(tcb);
 }
+
+void
+tcb_reschedule_intr(struct trap_frame *frame)
+{
+    (void)frame;
+
+    lapic_eoi();
+
+    /* Let the return from interrupt code handle rescheduling */
+}
diff --git a/arch/x86/machine/tcb.h b/arch/x86/machine/tcb.h
index 8bf6a00..886237e 100644
--- a/arch/x86/machine/tcb.h
+++ b/arch/x86/machine/tcb.h
@@ -24,6 +24,7 @@
 #include <kern/assert.h>
 #include <kern/macros.h>
 #include <machine/cpu.h>
+#include <machine/lapic.h>
 #include <machine/trap.h>
 
 /*
@@ -80,4 +81,18 @@ tcb_switch(struct tcb *prev, struct tcb *next)
     tcb_context_switch(prev, next);
 }
 
+/*
+ * Send a rescheduling interrupt to a remote processor.
+ */
+static inline void
+tcb_send_reschedule(unsigned int cpu)
+{
+    lapic_ipi_send(cpu, TRAP_RESCHEDULE);
+}
+
+/*
+ * Interrupt handler for rescheduling requests.
+ */
+void tcb_reschedule_intr(struct trap_frame *frame);
+
 #endif /* _X86_TCB_H */
diff --git a/arch/x86/machine/trap.c b/arch/x86/machine/trap.c
index 8591aa5..254f5ed 100644
--- a/arch/x86/machine/trap.c
+++ b/arch/x86/machine/trap.c
@@ -30,6 +30,7 @@
 #include <machine/pic.h>
 #include <machine/pmap.h>
 #include <machine/strace.h>
+#include <machine/tcb.h>
 #include <machine/trap.h>
 
 /*
@@ -75,6 +76,7 @@ void trap_isr_machine_check(void);
 void trap_isr_simd_fp_exception(void);
 void trap_isr_pic_int7(void);
 void trap_isr_pic_int15(void);
+void trap_isr_reschedule(void);
 void trap_isr_pmap_update(void);
 void trap_isr_cpu_halt(void);
 void trap_isr_lapic_timer(void);
@@ -201,6 +203,8 @@ trap_setup(void)
                  trap_isr_pic_int15, pic_intr_spurious);
 
     /* System defined traps */
+    trap_install(TRAP_RESCHEDULE, TRAP_HF_NOPREEMPT,
+                 trap_isr_reschedule, tcb_reschedule_intr);
     trap_install(TRAP_PMAP_UPDATE, TRAP_HF_NOPREEMPT,
                  trap_isr_pmap_update, pmap_update_intr);
     trap_install(TRAP_CPU_HALT, TRAP_HF_NOPREEMPT,
diff --git a/arch/x86/machine/trap.h b/arch/x86/machine/trap.h
index cc805de..8952024 100644
--- a/arch/x86/machine/trap.h
+++ b/arch/x86/machine/trap.h
@@ -53,6 +53,7 @@
  *
  * The local APIC assigns one priority every 16 vectors.
  */
+#define TRAP_RESCHEDULE     238
 #define TRAP_PMAP_UPDATE    239
 #define TRAP_CPU_HALT       240
 #define TRAP_LAPIC_TIMER    253
diff --git a/arch/x86/machine/trap_asm.S b/arch/x86/machine/trap_asm.S
index cf51b38..535ede3 100644
--- a/arch/x86/machine/trap_asm.S
+++ b/arch/x86/machine/trap_asm.S
@@ -157,6 +157,7 @@ TRAP(TRAP_PIC_BASE + 7, pic_int7)
 TRAP(TRAP_PIC_BASE + 15, pic_int15)
 
 /* System defined traps */
+TRAP(TRAP_RESCHEDULE, reschedule)
 TRAP(TRAP_PMAP_UPDATE, pmap_update)
 TRAP(TRAP_CPU_HALT, cpu_halt)
 TRAP(TRAP_LAPIC_TIMER, lapic_timer)