[Blackfin] arch: fix gdb testing regression
When transferring to IRQ5 from an exception, save SYSCFG in memory across the
transfer and clear the trace bit.
When we get a single step exception, check whether we can safely clear the
trace bit in SYSCFG. We can (and should) clear it after the first instruction
of the interrupt handler; the first insn saves SYSCFG to the stack in all
handlers.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
diff --git a/include/asm-blackfin/entry.h b/include/asm-blackfin/entry.h
index 562c6d3..c4f721e 100644
--- a/include/asm-blackfin/entry.h
+++ b/include/asm-blackfin/entry.h
@@ -17,6 +17,11 @@
#define PF_DTRACE_OFF 1
#define PF_DTRACE_BIT 5
+/*
+ * NOTE! The single-stepping code assumes that all interrupt handlers
+ * start by saving SYSCFG on the stack with their first instruction.
+ */
+
/* This one is used for exceptions, emulation, and NMI. It doesn't push
RETI and doesn't do cli. */
#define SAVE_ALL_SYS save_context_no_interrupts