On 01/16/2013 11:21:24 AM, Stuart Yoder wrote:
From: Stuart Yoder <stuart.yoder@xxxxxxxxxxxxx>
loop was derived from book3e_idle()
Signed-off-by: Stuart Yoder <stuart.yoder@xxxxxxxxxxxxx>
---
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
+
We should probably do this as an assembler macro, so we can have one
instance of it that gets instantiated for both "wait" and "ev_idle".
-Scott
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