From: Stuart Yoder <stuart.yo...@freescale.com>

loop was derived from book3e_idle()

Signed-off-by: Stuart Yoder <stuart.yo...@freescale.com>
---
 arch/powerpc/kernel/epapr_hcalls.S |   63 ++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/arch/powerpc/kernel/epapr_hcalls.S 
b/arch/powerpc/kernel/epapr_hcalls.S
index 62c0dc2..6a46bfb 100644
--- a/arch/powerpc/kernel/epapr_hcalls.S
+++ b/arch/powerpc/kernel/epapr_hcalls.S
@@ -17,6 +17,68 @@
 #include <asm/asm-compat.h>
 #include <asm/asm-offsets.h>
 
+#ifdef CONFIG_PPC64
+/* epapr_ev_idle() was derived from book3e_idle() */
+_GLOBAL(epapr_ev_idle)
+       /* Save LR for later */
+       mflr    r0
+       std     r0,16(r1)
+
+       /* Hard disable interrupts */
+       wrteei  0
+
+       /* Now check if an interrupt came in while we were soft disabled
+        * since we may otherwise lose it (doorbells etc...).
+        */
+       lbz     r3,PACAIRQHAPPENED(r13)
+       cmpwi   cr0,r3,0
+       bnelr
+
+       /* Now we are going to mark ourselves as soft and hard enabled in
+        * order to be able to take interrupts while asleep. We inform lockdep
+        * of that. We don't actually turn interrupts on just yet tho.
+        */
+#ifdef CONFIG_TRACE_IRQFLAGS
+       stdu    r1,-128(r1)
+       bl      .trace_hardirqs_on
+       addi    r1,r1,128
+#endif
+       li      r0,1
+       stb     r0,PACASOFTIRQEN(r13)
+       
+       /* Interrupts will make use return to LR, so get something we want
+        * in there
+        */
+       bl      1f
+
+       /* And return (interrupts are on) */
+       ld      r0,16(r1)
+       mtlr    r0
+       blr
+
+1:     /* Let's set the _TLF_NAPPING flag so interrupts make us return
+        * to the right spot
+       */
+       CURRENT_THREAD_INFO(r11, r1)
+       ld      r10,TI_LOCAL_FLAGS(r11)
+       ori     r10,r10,_TLF_NAPPING
+       std     r10,TI_LOCAL_FLAGS(r11)
+
+       /* We can now re-enable hard interrupts and go to sleep */
+       wrteei  1
+idle_loop:
+       LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
+
+.global epapr_ev_idle_start
+epapr_ev_idle_start:
+       li      r3, -1
+       nop
+       nop
+       nop
+       b       idle_loop
+
+#else /* CONFIG_PPC64 */
+
 /* epapr_ev_idle() was derived from e500_idle() */
 _GLOBAL(epapr_ev_idle)
        CURRENT_THREAD_INFO(r3, r1)
@@ -42,6 +104,7 @@ epapr_ev_idle_start:
         * _TLF_NAPPING.
         */
        b       idle_loop
+#endif
 
 /* Hypercall entry point. Will be patched with device tree instructions. */
 .global epapr_hypercall_start
-- 
1.7.9.7


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