If the guest hypervisor node contains "has-idle" property.
Signed-off-by: Liu Yu <yu....@freescale.com>
---
v5: no change
arch/powerpc/kernel/epapr_hcalls.S | 29 +++++++++++++++++++++++++++++
arch/powerpc/kernel/epapr_paravirt.c | 11 ++++++++++-
2 files changed, 39 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/kernel/epapr_hcalls.S
b/arch/powerpc/kernel/epapr_hcalls.S
index 697b390..72fa234 100644
--- a/arch/powerpc/kernel/epapr_hcalls.S
+++ b/arch/powerpc/kernel/epapr_hcalls.S
@@ -15,6 +15,35 @@
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
+#define HC_VENDOR_EPAPR (1 << 16)
+#define HC_EV_IDLE 16
+
+_GLOBAL(epapr_ev_idle)
+epapr_ev_idle:
+ rlwinm r3,r1,0,0,31-THREAD_SHIFT /* current thread_info */
+ lwz r4,TI_LOCAL_FLAGS(r3) /* set napping bit */
+ ori r4,r4,_TLF_NAPPING /* so when we take an exception */
+ stw r4,TI_LOCAL_FLAGS(r3) /* it will return to our caller */
+
+ wrteei 1
+
+idle_loop:
+ LOAD_REG_IMMEDIATE(r11, HC_VENDOR_EPAPR | HC_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:
diff --git a/arch/powerpc/kernel/epapr_paravirt.c
b/arch/powerpc/kernel/epapr_paravirt.c
index e601da7..43d875e 100644
--- a/arch/powerpc/kernel/epapr_paravirt.c
+++ b/arch/powerpc/kernel/epapr_paravirt.c
@@ -21,6 +21,10 @@
#include <asm/epapr_hcalls.h>
#include <asm/cacheflush.h>
#include <asm/code-patching.h>
+#include <asm/machdep.h>
+
+extern void epapr_ev_idle(void);
+extern u32 epapr_ev_idle_start[];
bool epapr_para_enabled = false;
@@ -39,8 +43,13 @@ static int __init epapr_para_init(void)
insts = of_get_property(hyper_node, "hcall-instructions", &len);
if (insts && !(len % 4) && len <= (4 * 4)) {
- for (i = 0; i < (len / 4); i++)
+ for (i = 0; i < (len / 4); i++) {
patch_instruction(epapr_hypercall_start + i, insts[i]);
+ patch_instruction(epapr_ev_idle_start + i, insts[i]);
+ }
+
+ if (of_get_property(hyper_node, "has-idle", NULL))
+ ppc_md.power_save = epapr_ev_idle;
epapr_para_enabled = true;
} else {
--
1.7.0.4
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