powerpc: Add paravirt idle loop for 64-bit Book-E

Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

2 files changed, 32 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/epapr_hcalls.S b/arch/powerpc/kernel/epapr_hcalls.S
index 62c0dc237826..9f1ebf7338f1 100644
--- a/arch/powerpc/kernel/epapr_hcalls.S
+++ b/arch/powerpc/kernel/epapr_hcalls.S
@@ -17,6 +17,7 @@
 #include <asm/asm-compat.h>
 #include <asm/asm-offsets.h>
 
+#ifndef CONFIG_PPC64
 /* epapr_ev_idle() was derived from e500_idle() */
 _GLOBAL(epapr_ev_idle)
         CURRENT_THREAD_INFO(r3, r1)
@@ -42,6 +43,7 @@ epapr_ev_idle_start:
          * _TLF_NAPPING.
          */
         b       idle_loop
+#endif
 
 /* Hypercall entry point. Will be patched with device tree instructions. */
 .global epapr_hypercall_start
diff --git a/arch/powerpc/kernel/idle_book3e.S b/arch/powerpc/kernel/idle_book3e.S
index 4c7cb4008585..bfb73cc209ce 100644
--- a/arch/powerpc/kernel/idle_book3e.S
+++ b/arch/powerpc/kernel/idle_book3e.S
@@ -16,11 +16,13 @@
 #include <asm/ppc-opcode.h>
 #include <asm/processor.h>
 #include <asm/thread_info.h>
+#include <asm/epapr_hcalls.h>
 
 /* 64-bit version only for now */
 #ifdef CONFIG_PPC64
 
-_GLOBAL(book3e_idle)
+.macro BOOK3E_IDLE name loop
+_GLOBAL(\name)
         /* Save LR for later */
         mflr    r0
         std     r0,16(r1)
@@ -67,7 +69,33 @@ _GLOBAL(book3e_idle)
 
         /* We can now re-enable hard interrupts and go to sleep */
         wrteei  1
-1:      PPC_WAIT(0)
+        \loop
+
+.endm
+
+.macro BOOK3E_IDLE_LOOP
+1:
+        PPC_WAIT(0)
         b       1b
+.endm
+
+/* epapr_ev_idle_start below is patched with the proper hcall
+   opcodes during kernel initialization */
+.macro EPAPR_EV_IDLE_LOOP
+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
+.endm
+
+BOOK3E_IDLE epapr_ev_idle EPAPR_EV_IDLE_LOOP
+
+BOOK3E_IDLE book3e_idle BOOK3E_IDLE_LOOP
 
 #endif /* CONFIG_PPC64 */