sparc: Add kgdb support.
Current limitations:
1) On SMP single stepping has some fundamental issues,
shared with other sw single-step architectures such
as mips and arm.
2) On 32-bit sparc we don't support SMP kgdb yet. That
requires some reworking of the IPI mechanisms and
infrastructure on that platform.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/mm/ultra.S b/arch/sparc64/mm/ultra.S
index e686a67..796e005 100644
--- a/arch/sparc64/mm/ultra.S
+++ b/arch/sparc64/mm/ultra.S
@@ -676,6 +676,33 @@
wr %g0, (1 << PIL_SMP_CTX_NEW_VERSION), %set_softint
retry
+#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, 15, %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
+#endif
+
#endif /* CONFIG_SMP */