Improve ARM debug_monitor for SMP machines

- Reset debug architecture and enable monitor for secondary
  CPUs in init_secondary() rather than when configuring watchpoint, etc.
- Disable HW debugging capabilities when one of the CPU cores fails
  to set up.
- Use dbg_capable() in a more atomic manner to avoid any mismatch
  between CPUs.

Differential Revision: https://reviews.freebsd.org/D6009

1 files changed, 5 insertions, 1 deletions

diff --git a/sys/arm/include/debug_monitor.h b/sys/arm/include/debug_monitor.h
index 776d344..3656e9a 100644
--- a/sys/arm/include/debug_monitor.h
+++ b/sys/arm/include/debug_monitor.h
@@ -45,6 +45,7 @@ enum dbg_access_t {
 
 #if __ARM_ARCH >= 6
 void dbg_monitor_init(void);
+void dbg_monitor_init_secondary(void);
 void dbg_show_watchpoint(void);
 int dbg_setup_watchpoint(db_expr_t, db_expr_t, enum dbg_access_t);
 int dbg_remove_watchpoint(db_expr_t, db_expr_t);
@@ -69,7 +70,10 @@ static __inline void
 dbg_monitor_init(void)
 {
 }
-
+static __inline void
+dbg_monitor_init_secondary(void)
+{
+}
 static __inline void
 dbg_resume_dbreg(void)
 {