[U-Boot] [PATCH 05/11] MIPS: add sleep handler for slave CPUs in multi-processor systems

[Daniel Schwierzeck]

This handler can be activated on multi-processor systems to boot only
the master CPU. All slave CPUs are halted by executing the WAIT
instruction. This is also useful to reduce the power consumption at
boot time.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at googlemail.com>
---
 arch/mips/cpu/mips32/start.S |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/arch/mips/cpu/mips32/start.S b/arch/mips/cpu/mips32/start.S
index 9c1b2f7..b6cb4be 100644
--- a/arch/mips/cpu/mips32/start.S
+++ b/arch/mips/cpu/mips32/start.S
@@ -224,6 +224,14 @@ reset:
 
 	setup_c0_status_reset
 
+	/* Set all slave CPUs in sleep mode */
+#ifdef CONFIG_SYS_MPS_SLAVE_CPU_SLEEP
+	mfc0	k0, CP0_EBASE
+	and	k0, EBASEF_CPUNUM
+	bne	k0, zero, slave_cpu_sleep
+	 nop
+#endif
+
 	/* Init Timer */
 	mtc0	zero, CP0_COUNT
 	mtc0	zero, CP0_COMPARE
@@ -383,3 +391,11 @@ romReserved:
 
 romExcHandle:
 	b	romExcHandle
+
+	/* Additional handlers */
+#ifdef CONFIG_SYS_MPS_SLAVE_CPU_SLEEP
+slave_cpu_sleep:
+	wait
+	b	slave_cpu_sleep
+	 nop
+#endif
-- 
1.7.7.2