From 2f979de8a716bdbdc9f4db532652fbca08ed710c Mon Sep 17 00:00:00 2001
From: Liu Yu-B13201 <Yu.Liu@freescale.com>
Date: Tue, 3 Jul 2012 05:48:53 +0000
Subject: KVM: PPC: ev_idle hcall support for e500 guests

Signed-off-by: Liu Yu <yu.liu@freescale.com>
[varun: 64-bit changes]
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/powerpc/kernel/epapr_hcalls.S | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'arch/powerpc/kernel/epapr_hcalls.S')

diff --git a/arch/powerpc/kernel/epapr_hcalls.S b/arch/powerpc/kernel/epapr_hcalls.S
index 697b390ebfd8..62c0dc237826 100644
--- a/arch/powerpc/kernel/epapr_hcalls.S
+++ b/arch/powerpc/kernel/epapr_hcalls.S
@@ -8,13 +8,41 @@
  */
 
 #include <linux/threads.h>
+#include <asm/epapr_hcalls.h>
 #include <asm/reg.h>
 #include <asm/page.h>
 #include <asm/cputable.h>
 #include <asm/thread_info.h>
 #include <asm/ppc_asm.h>
+#include <asm/asm-compat.h>
 #include <asm/asm-offsets.h>
 
+/* epapr_ev_idle() was derived from e500_idle() */
+_GLOBAL(epapr_ev_idle)
+	CURRENT_THREAD_INFO(r3, r1)
+	PPC_LL	r4, TI_LOCAL_FLAGS(r3)	/* set napping bit */
+	ori	r4, r4,_TLF_NAPPING	/* so when we take an exception */
+	PPC_STL	r4, TI_LOCAL_FLAGS(r3)	/* it will return to our caller */
+
+	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
+
+	/*
+	 * Guard against spurious wakeups from a hypervisor --
+	 * only interrupt will cause us to return to LR due to
+	 * _TLF_NAPPING.
+	 */
+	b	idle_loop
+
 /* Hypercall entry point. Will be patched with device tree instructions. */
 .global epapr_hypercall_start
 epapr_hypercall_start:
-- 
cgit