For AIM, have cpu_idle() set MSR_POW when the powerpc_pow_enabled

variable is set. On my Mac Mini this puts the CPU in NAP mode when
the kernel is idle and, any technical or environmental reasons
aside, avoids that I have to listen to the fan all day :-)

4 files changed, 16 insertions, 11 deletions

diff --git a/sys/powerpc/aim/locore.S b/sys/powerpc/aim/locore.S
index e566e4d..ab6aade 100644
--- a/sys/powerpc/aim/locore.S
+++ b/sys/powerpc/aim/locore.S
@@ -89,9 +89,6 @@ GLOBAL(esym)
 GLOBAL(ofmsr)
 	.long	0, 0, 0, 0, 0		/* msr/sprg0-3 used in Open Firmware */
 
-GLOBAL(powersave)
-	.long	0
-
 #define	INTSTK		16384		/* 16K interrupt stack */
 #define	INTRCNT_COUNT	256		/* max(HROWPIC_IRQMAX,OPENPIC_IRQMAX) */
 GLOBAL(intrnames)
diff --git a/sys/powerpc/aim/machdep.c b/sys/powerpc/aim/machdep.c
index 23c6eb2..4a70556 100644
--- a/sys/powerpc/aim/machdep.c
+++ b/sys/powerpc/aim/machdep.c
@@ -107,6 +107,7 @@ __FBSDID("$FreeBSD$");
 #include <machine/cpu.h>
 #include <machine/elf.h>
 #include <machine/fpu.h>
+#include <machine/hid.h>
 #include <machine/kdb.h>
 #include <machine/md_var.h>
 #include <machine/metadata.h>
@@ -737,15 +738,22 @@ cpu_halt(void)
 void
 cpu_idle(void)
 {
-	/* TODO: Insert code to halt (until next interrupt) */
+	uint32_t msr;
+
+	msr = mfmsr();
 
 #ifdef INVARIANTS
-	if ((mfmsr() & PSL_EE) != PSL_EE) {
+	if ((msr & PSL_EE) != PSL_EE) {
 		struct thread *td = curthread;
 		printf("td msr %x\n", td->td_md.md_saved_msr);
 		panic("ints disabled in idleproc!");
 	}
 #endif
+	if (powerpc_pow_enabled) {
+		__asm __volatile("sync");
+		mtmsr(msr | PSL_POW);
+		isync();
+	}
 }
 
 /*
diff --git a/sys/powerpc/include/md_var.h b/sys/powerpc/include/md_var.h
index d0b350f..f0f254a 100644
--- a/sys/powerpc/include/md_var.h
+++ b/sys/powerpc/include/md_var.h
@@ -44,6 +44,8 @@ extern	vm_offset_t	kstack0_phys;
 
 extern	u_long	ns_per_tick;
 
+extern	int powerpc_pow_enabled;
+
 #if defined(_KERNEL) || defined(_STANDALONE)
 #define	CACHELINESIZE	32
 #endif
diff --git a/sys/powerpc/powerpc/cpu.c b/sys/powerpc/powerpc/cpu.c
index 5d0b279..93cb655 100644
--- a/sys/powerpc/powerpc/cpu.c
+++ b/sys/powerpc/powerpc/cpu.c
@@ -70,6 +70,8 @@
 #include <machine/md_var.h>
 #include <machine/spr.h>
 
+int powerpc_pow_enabled;
+
 struct cputab {
 	const char	*name;
 	uint16_t	version;
@@ -183,9 +185,7 @@ cpu_setup(u_int cpuid)
 			/* Select DOZE mode. */
 			hid0 &= ~(HID0_DOZE | HID0_NAP | HID0_SLEEP);
 			hid0 |= HID0_DOZE | HID0_DPM;
-#ifdef notyet
-			powersave = 1;
-#endif
+			powerpc_pow_enabled = 1;
 			break;
 
 		case MPC7448:
@@ -203,9 +203,7 @@ cpu_setup(u_int cpuid)
 			/* Select NAP mode. */
 			hid0 &= ~(HID0_DOZE | HID0_NAP | HID0_SLEEP);
 			hid0 |= HID0_NAP | HID0_DPM;
-#ifdef notyet
-			powersave = 0;		/* but don't use it */
-#endif
+			powerpc_pow_enabled = 1;
 			break;
 
 		default: