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-rw-r--r--arch/sparc64/kernel/entry.S30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/entry.S b/arch/sparc64/kernel/entry.S
index 6be4d2d2904e..49eca4b1cf25 100644
--- a/arch/sparc64/kernel/entry.S
+++ b/arch/sparc64/kernel/entry.S
@@ -1705,6 +1705,36 @@ __flushw_user:
2: retl
nop
+ /* Flush %fp and %i7 to the stack for all register
+ * windows active inside of the cpu. This allows
+ * show_stack_trace() to avoid using an expensive
+ * 'flushw'.
+ */
+ .globl stack_trace_flush
+ .type stack_trace_flush,#function
+stack_trace_flush:
+ rdpr %pstate, %o0
+ wrpr %o0, PSTATE_IE, %pstate
+
+ rdpr %cwp, %g1
+ rdpr %canrestore, %g2
+ sub %g1, 1, %g3
+
+1: brz,pn %g2, 2f
+ sub %g2, 1, %g2
+ wrpr %g3, %cwp
+ stx %fp, [%sp + STACK_BIAS + RW_V9_I6]
+ stx %i7, [%sp + STACK_BIAS + RW_V9_I7]
+ ba,pt %xcc, 1b
+ sub %g3, 1, %g3
+
+2: wrpr %g1, %cwp
+ wrpr %o0, %pstate
+
+ retl
+ nop
+ .size stack_trace_flush,.-stack_trace_flush
+
#ifdef CONFIG_SMP
.globl hard_smp_processor_id
hard_smp_processor_id: