1 files changed, 35 insertions, 4 deletions

diff --git a/arch/sparc/kernel/tsb.S b/arch/sparc/kernel/tsb.S
index d4bdc7a62375..a313e4a9399b 100644
--- a/arch/sparc/kernel/tsb.S
+++ b/arch/sparc/kernel/tsb.S
@@ -136,12 +136,43 @@ tsb_miss_page_table_walk_sun4v_fastpath:
          nop
 
         /* It is a huge page, use huge page TSB entry address we
-         * calculated above.
+         * calculated above.  If the huge page TSB has not been
+         * allocated, setup a trap stack and call hugetlb_setup()
+         * to do so, then return from the trap to replay the TLB
+         * miss.
+         *
+         * This is necessary to handle the case of transparent huge
+         * pages where we don't really have a non-atomic context
+         * in which to allocate the hugepage TSB hash table.  When
+         * the 'mm' faults in the hugepage for the first time, we
+         * thus handle it here.  This also makes sure that we can
+         * allocate the TSB hash table on the correct NUMA node.
          */
         TRAP_LOAD_TRAP_BLOCK(%g7, %g2)
-        ldx             [%g7 + TRAP_PER_CPU_TSB_HUGE_TEMP], %g2
-        cmp             %g2, -1
-        movne           %xcc, %g2, %g1
+        ldx             [%g7 + TRAP_PER_CPU_TSB_HUGE_TEMP], %g1
+        cmp             %g1, -1
+        bne,pt          %xcc, 60f
+         nop
+
+661:    rdpr            %pstate, %g5
+        wrpr            %g5, PSTATE_AG | PSTATE_MG, %pstate
+        .section        .sun4v_2insn_patch, "ax"
+        .word           661b
+        SET_GL(1)
+        nop
+        .previous
+
+        rdpr    %tl, %g3
+        cmp     %g3, 1
+        bne,pn  %xcc, winfix_trampoline
+         nop
+        ba,pt   %xcc, etrap
+         rd     %pc, %g7
+        call    hugetlb_setup
+         add    %sp, PTREGS_OFF, %o0
+        ba,pt   %xcc, rtrap
+         nop
+
 60:
 #endif