sparc64: Reschedule KGDB capture to a software interrupt.

Otherwise it might interrupt switch_to() midstream and use
half-cooked register window state.

Reported-by: Chris Torek <chris.torek@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 22 deletions

diff --git a/arch/sparc/mm/ultra.S b/arch/sparc/mm/ultra.S
index 80c788ec7c32..b57a5942ba64 100644
--- a/arch/sparc/mm/ultra.S
+++ b/arch/sparc/mm/ultra.S
@@ -679,28 +679,8 @@ xcall_new_mmu_context_version:
 #ifdef CONFIG_KGDB
         .globl          xcall_kgdb_capture
 xcall_kgdb_capture:
-661:    rdpr            %pstate, %g2
-        wrpr            %g2, PSTATE_IG | PSTATE_AG, %pstate
-        .section        .sun4v_2insn_patch, "ax"
-        .word           661b
-        nop
-        nop
-        .previous
-
-        rdpr            %pil, %g2
-        wrpr            %g0, PIL_NORMAL_MAX, %pil
-        sethi           %hi(109f), %g7
-        ba,pt           %xcc, etrap_irq
-109:     or             %g7, %lo(109b), %g7
-#ifdef CONFIG_TRACE_IRQFLAGS
-        call            trace_hardirqs_off
-         nop
-#endif
-        call            smp_kgdb_capture_client
-         add            %sp, PTREGS_OFF, %o0
-        /* Has to be a non-v9 branch due to the large distance. */
-        ba              rtrap_xcall
-         ldx            [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
+        wr              %g0, (1 << PIL_KGDB_CAPTURE), %set_softint
+        retry
 #endif
 
 #endif /* CONFIG_SMP */