On 2016/12/28 5:59, Matt Thomas wrote:
Why don't use you
ACCESS_PROLOG(CI_DDBSAVE)
bla ddbtrap
and just rid of ddbstk? since ddbstk/ipkdbstk don't support nested traps.
Ditto for ipkdbtrap.
Thank you very much for your reply. I revised the patch accordingly, and
it passed some stress tests on my OPENBLOCKS266.
However, sorry for bothering you, but I don't understand why this work.
The original DDB/IPKDB handlers use ddbstk/ipkdbstk, that clearly do not
support nested traps, as you pointed out. The patched version uses
CI_{DDB,IPKDB}SAVE, that are save areas in cpu_info. It seems to me that
they also do not support nested traps; a succeeding trap overwrites
save areas already used by a preceding trap, doesn't it? I'm a beginner
of assembler programming, and maybe I misunderstand something...
Thanks,
Rin
====
--- src/sys/arch/powerpc/ibm4xx/trap_subr.S.orig 2016-12-28
07:56:49.376180545 +0900
+++ src/sys/arch/powerpc/ibm4xx/trap_subr.S 2016-12-28 07:58:42.785516679
+0900
@@ -191,20 +191,9 @@
/*
* In case of DDB we want a separate trap catcher for it
*/
- .lcomm ddbstk,INTSTK,16 /* ddb stack */
-
.globl _C_LABEL(ddblow),_C_LABEL(ddbsize)
_C_LABEL(ddblow):
- mtsprg1 %r1 /* save SP */
- GET_CPUINFO(%r1)
- stmw %r28,CI_DDBSAVE(%r1) /* free r28-r31 */
- mflr %r28 /* save LR */
- mfcr %r29 /* save CR */
- mfsrr0 %r30
- mfsrr1 %r31
- stmw %r30,(CI_DDBSAVE+CPUSAVE_SRR0)(%r1) /* save srr0/srr1 */
- lis %r1,ddbstk+INTSTK-CALLFRAMELEN@ha /* get new SP */
- addi %r1,%r1,ddbstk+INTSTK-CALLFRAMELEN@l
+ ACCESS_PROLOG(CI_DDBSAVE)
bla ddbtrap
_C_LABEL(ddbsize) = .-_C_LABEL(ddblow)
#endif /* DDB || KGDB */
@@ -213,21 +202,9 @@
/*
* In case of IPKDB we want a separate trap catcher for it
*/
-
- .lcomm ipkdbstk,INTSTK,16 /* ipkdb stack */
-
.globl _C_LABEL(ipkdblow),_C_LABEL(ipkdbsize)
_C_LABEL(ipkdblow):
- mtsprg1 %r1 /* save SP */
- GET_CPUINFO(%r1)
- stmw %r28,CI_IPKDBSAVE(%r1) /* free r28-r31 */
- mflr %r28 /* save LR */
- mfcr %r29 /* save CR */
- mfsrr0 %r30
- mfsrr1 %r31
- stmw %r30,(CI_IPKDBSAVE+CPUSAVE_SRR0)(%r1) /* save srr0/srr1 */
- lis %r1,ipkdbstk+INTSTK-CALLFRAMELEN@ha /* get new SP */
- addi %r1,%r1,ipkdbstk+INTSTK-CALLFRAMELEN@l
+ ACCESS_PROLOG(CI_IPKDBSAVE)
bla ipkdbtrap
_C_LABEL(ipkdbsize) = .-_C_LABEL(ipkdblow)
#endif /* IPKDB */
