Initial suspend/resume support for amd64.

This code is heavily inspired by Takanori Watanabe's experimental SMP patch
for i386 and large portion was shamelessly cut and pasted from Peter Wemm's
AP boot code.

1 files changed, 40 insertions, 0 deletions

diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index c65f6f8..b7c03d9 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -58,6 +58,7 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/apicreg.h>
 #include <machine/cputypes.h>
+#include <machine/cpufunc.h>
 #include <machine/md_var.h>
 #include <machine/mp_watchdog.h>
 #include <machine/pcb.h>
@@ -103,6 +104,7 @@ extern pt_entry_t *SMPpt;
 extern int  _udatasel;
 
 struct pcb stoppcbs[MAXCPU];
+struct xpcb *stopxpcbs = NULL;
 
 /* Variables needed for SMP tlb shootdown. */
 vm_offset_t smp_tlb_addr1;
@@ -344,6 +346,9 @@ cpu_mp_start(void)
 	/* Install an inter-CPU IPI for CPU stop/restart */
 	setidt(IPI_STOP, IDTVEC(cpustop), SDT_SYSIGT, SEL_KPL, 0);
 
+	/* Install an inter-CPU IPI for CPU suspend/resume */
+	setidt(IPI_SUSPEND, IDTVEC(cpususpend), SDT_SYSIGT, SEL_KPL, 0);
+
 	/* Set boot_cpu_id if needed. */
 	if (boot_cpu_id == -1) {
 		boot_cpu_id = PCPU_GET(apic_id);
@@ -1145,6 +1150,41 @@ cpustop_handler(void)
 }
 
 /*
+ * Handle an IPI_SUSPEND by saving our current context and spinning until we
+ * are resumed.
+ */
+void
+cpususpend_handler(void)
+{
+	struct savefpu *stopfpu;
+	register_t cr3, rf;
+	int cpu = PCPU_GET(cpuid);
+	int cpumask = PCPU_GET(cpumask);
+
+	rf = intr_disable();
+	cr3 = rcr3();
+	stopfpu = &stopxpcbs[cpu].xpcb_pcb.pcb_save;
+	if (savectx2(&stopxpcbs[cpu])) {
+		fpugetregs(curthread, stopfpu);
+		wbinvd();
+		atomic_set_int(&stopped_cpus, cpumask);
+	} else
+		fpusetregs(curthread, stopfpu);
+
+	/* Wait for resume */
+	while (!(started_cpus & cpumask))
+		ia32_pause();
+
+	atomic_clear_int(&started_cpus, cpumask);
+	atomic_clear_int(&stopped_cpus, cpumask);
+
+	/* Restore CR3 and enable interrupts */
+	load_cr3(cr3);
+	lapic_setup(0);
+	intr_restore(rf);
+}
+
+/*
  * This is called once the rest of the system is up and running and we're
  * ready to let the AP's out of the pen.
  */