[src/trunk]: src/sys/arch/alpha/alpha Use alpha_pal_swpipl() directly instead...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/4b1988cfc4b0
branches:  trunk
changeset: 938877:4b1988cfc4b0
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri Sep 18 00:02:43 2020 +0000

description:
Use alpha_pal_swpipl() directly instead of splhigh()/splx(), do avoid
soft int processing while dealing with entering / leaving the debugger.
Soft ints will be correctly handled during exception_return().

diffstat:

 sys/arch/alpha/alpha/db_interface.c |  15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diffs (50 lines):

diff -r a02504870f03 -r 4b1988cfc4b0 sys/arch/alpha/alpha/db_interface.c
--- a/sys/arch/alpha/alpha/db_interface.c       Thu Sep 17 20:29:03 2020 +0000
+++ b/sys/arch/alpha/alpha/db_interface.c       Fri Sep 18 00:02:43 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: db_interface.c,v 1.34 2012/02/06 02:14:10 matt Exp $ */
+/* $NetBSD: db_interface.c,v 1.35 2020/09/18 00:02:43 thorpej Exp $ */
 
 /*
  * Mach Operating System
@@ -52,7 +52,7 @@
 
 #include <sys/cdefs.h>                 /* RCS ID & Copyright macro defns */
 
-__KERNEL_RCSID(0, "$NetBSD: db_interface.c,v 1.34 2012/02/06 02:14:10 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_interface.c,v 1.35 2020/09/18 00:02:43 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/proc.h>
@@ -176,7 +176,7 @@
 ddb_trap(unsigned long a0, unsigned long a1, unsigned long a2, unsigned long entry, db_regs_t *regs)
 {
        struct cpu_info *ci = curcpu();
-       int s;
+       unsigned long psl;
 
        if (entry != ALPHA_KENTRY_IF ||
            (a0 != ALPHA_IF_CODE_BPT && a0 != ALPHA_IF_CODE_BUGCHK)) {
@@ -200,7 +200,12 @@
        /* Our register state is simply the trapframe. */
        ddb_regp = ci->ci_db_regs = regs;
 
-       s = splhigh();
+       /*
+        * Use SWPIPL directly; we want to avoid processing
+        * software interrrupts when we go back.  Soft ints
+        * will be caught later, so not to worry.
+        */
+       psl = alpha_pal_swpipl(ALPHA_PSL_IPL_HIGH);
 
        db_active++;
        cnpollc(true);          /* Set polling mode, unblank video */
@@ -210,7 +215,7 @@
        cnpollc(false);         /* Resume interrupt mode */
        db_active--;
 
-       splx(s);
+       alpha_pal_swpipl(psl);
 
        ddb_regp = ci->ci_db_regs = NULL;