powerpc/pseries: Add extended_cede_processor() helper function.

This patch provides an extended_cede_processor() helper function
which takes the cede latency hint as an argument. This hint is to be passed
on to the hypervisor to cede to the corresponding state on platforms
which support it.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h
index f78f65c38f05..14b592dfb4e8 100644
--- a/arch/powerpc/include/asm/lppaca.h
+++ b/arch/powerpc/include/asm/lppaca.h
@@ -100,7 +100,14 @@ struct lppaca {
         // Used to pass parms from the OS to PLIC for SetAsrAndRfid
         u64     saved_gpr3;             // Saved GPR3                   x20-x27
         u64     saved_gpr4;             // Saved GPR4                   x28-x2F
-        u64     saved_gpr5;             // Saved GPR5                   x30-x37
+        union {
+                u64     saved_gpr5;     /* Saved GPR5               x30-x37 */
+                struct {
+                        u8      cede_latency_hint;  /*                  x30 */
+                        u8      reserved[7];        /*              x31-x36 */
+                } fields;
+        } gpr5_dword;
+
 
         u8      dtl_enable_mask;        // Dispatch Trace Log mask      x38-x38
         u8      donate_dedicated_cpu;   // Donate dedicated CPU cycles  x39-x39