[SPARC64]: Sanitize %pstate writes for sun4v.

If we're just switching between different alternate global
sets, nop it out on sun4v.  Also, get rid of all of the
alternate global save/restore in the OBP CIF trampoline code.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 2 deletions

diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S
index 9b415ab6db6b..c1335432124e 100644
--- a/arch/sparc64/kernel/ktlb.S
+++ b/arch/sparc64/kernel/ktlb.S
@@ -60,8 +60,15 @@ kvmap_itlb_load:
         retry
 
 kvmap_itlb_longpath:
-        rdpr    %pstate, %g5
+
+661:    rdpr    %pstate, %g5
         wrpr    %g5, PSTATE_AG | PSTATE_MG, %pstate
+        .section .gl_2insn_patch, "ax"
+        .word   661b
+        nop
+        nop
+        .previous
+
         rdpr    %tpc, %g5
         ba,pt   %xcc, sparc64_realfault_common
          mov    FAULT_CODE_ITLB, %g4
@@ -161,8 +168,15 @@ kvmap_check_obp:
          nop
 
 kvmap_dtlb_longpath:
-        rdpr    %pstate, %g5
+
+661:    rdpr    %pstate, %g5
         wrpr    %g5, PSTATE_AG | PSTATE_MG, %pstate
+        .section .gl_2insn_patch, "ax"
+        .word   661b
+        nop
+        nop
+        .previous
+
         rdpr    %tl, %g4
         cmp     %g4, 1
         mov     TLB_TAG_ACCESS, %g4