[src/trunk]: src/sys/arch/mips add a "special3 offset" type of decode to ddb ...

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

details:   https://anonhg.NetBSD.org/src/rev/8a1226791b03
branches:  trunk
changeset: 1012964:8a1226791b03
user:      mrg <mrg%NetBSD.org@localhost>
date:      Mon Aug 17 03:14:08 2020 +0000

description:
add a "special3 offset" type of decode to ddb disasm so we see the
offsets properly decoded.  add mips r6 "cache" insn.

avoid signed/unsigned compare and ufetch_32() for upcoming crash(8).

diffstat:

 sys/arch/mips/include/mips_opcode.h |  23 +++++++++++++++++-
 sys/arch/mips/mips/db_disasm.c      |  47 +++++++++++++++++++++++++++++++-----
 2 files changed, 62 insertions(+), 8 deletions(-)

diffs (144 lines):

diff -r 71fdccbe91ee -r 8a1226791b03 sys/arch/mips/include/mips_opcode.h
--- a/sys/arch/mips/include/mips_opcode.h       Mon Aug 17 01:52:59 2020 +0000
+++ b/sys/arch/mips/include/mips_opcode.h       Mon Aug 17 03:14:08 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mips_opcode.h,v 1.23 2020/08/15 04:27:28 simonb Exp $  */
+/*     $NetBSD: mips_opcode.h,v 1.24 2020/08/17 03:14:08 mrg Exp $     */
 
 /*-
  * Copyright (c) 1992, 1993
@@ -79,6 +79,16 @@
                unsigned : 1;           /* always '1' */
                unsigned op: 6;         /* always '0x11' */
        } FRType;
+
+       struct {
+               unsigned func: 6;
+               unsigned zero: 1;       /* always '0' */
+               unsigned offset: 9;
+               unsigned rt: 5;
+               unsigned rs: 5;
+               unsigned op: 6;
+       } S3OType; /* has "special3 offset" type */
+
 #endif
 #if BYTE_ORDER == BIG_ENDIAN
        struct {
@@ -111,6 +121,16 @@
                unsigned fd: 5;
                unsigned func: 6;
        } FRType;
+
+       struct {
+               unsigned op: 6;
+               unsigned rs: 5;
+               unsigned rt: 5;
+               unsigned offset: 9;
+               unsigned zero: 1;       /* always '0' */
+               unsigned func: 6;
+       } S3OType; /* has "special3 offset" type */
+
 #endif
 } InstFmt;
 
@@ -323,6 +343,7 @@
 #define        OP_SWRE         042             /* EVA */
 #define        OP_PREFE        043             /* EVA */
 #define        OP_DBSHFL       044             /* MIPS32/64 r2 */
+#define        OP_CACHE_R6     045             /* MIPS32/64 r6 */
 #define        OP_LBUE         050             /* EVA */
 #define        OP_LHUE         051             /* EVA */
 #define        OP_LBE          054             /* EVA */
diff -r 71fdccbe91ee -r 8a1226791b03 sys/arch/mips/mips/db_disasm.c
--- a/sys/arch/mips/mips/db_disasm.c    Mon Aug 17 01:52:59 2020 +0000
+++ b/sys/arch/mips/mips/db_disasm.c    Mon Aug 17 03:14:08 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: db_disasm.c,v 1.32 2019/04/06 03:06:26 thorpej Exp $   */
+/*     $NetBSD: db_disasm.c,v 1.33 2020/08/17 03:14:08 mrg Exp $       */
 
 /*-
  * Copyright (c) 1991, 1993
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: db_disasm.c,v 1.32 2019/04/06 03:06:26 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_disasm.c,v 1.33 2020/08/17 03:14:08 mrg Exp $");
 
 #include <sys/param.h>
 #include <sys/cpu.h>
@@ -47,6 +47,7 @@
 
 #include <machine/db_machdep.h>
 
+#include <ddb/db_user.h>
 #include <ddb/db_interface.h>
 #include <ddb/db_output.h>
 #include <ddb/db_extern.h>
@@ -131,6 +132,7 @@
        [OP_SWRE] = "swre",
        [OP_PREFE] = "prefe",
        [OP_DBSHFL] = "dbshfl",
+       [OP_CACHE_R6] = "cache",
        [OP_LBUE] = "lbue",
        [OP_LHUE] = "lhue",
        [OP_LBE] = "lbe",
@@ -225,11 +227,15 @@
         * Take some care with addresses to not UTLB here as it
         * loses the current debugging context.  KSEG2 not checked.
         */
-       if (loc < MIPS_KSEG0_START) {
+       if (loc < (db_addr_t)MIPS_KSEG0_START) {
+#ifdef _KERNEL
                if (ufetch_32((void *)loc, &instr) != 0) {
                        db_printf("invalid address.\n");
                        return loc;
                }
+#else
+               return loc;
+#endif
        } else {
                instr =  *(uint32_t *)loc;
        }
@@ -507,10 +513,37 @@
                        }
                        break;
                }
-               db_printf("%s\t%s,%s",
-                       spec3_name[i.RType.func],
-                       reg_name[i.RType.rs],
-                       reg_name[i.RType.rt]);
+               switch (i.RType.func) {
+               case OP_LWLE:
+               case OP_LWRE:
+               case OP_CACHEE:
+               case OP_SBE:
+               case OP_SHE:
+               case OP_SCE:
+               case OP_SWE:
+               case OP_SWLE:
+               case OP_SWRE:
+               case OP_PREFE:
+               case OP_CACHE_R6:
+               case OP_LBUE:
+               case OP_LHUE:
+               case OP_LBE:
+               case OP_LHE:
+               case OP_LLE:
+               case OP_LWE:
+                       db_printf("%s\t%s,%d(%s)",
+                               spec3_name[i.RType.func],
+                               reg_name[i.RType.rs],
+                               i.S3OType.offset > 255 ?
+                                 -i.S3OType.offset : i.S3OType.offset,
+                               reg_name[i.RType.rt]);
+                       break;
+               default:
+                       db_printf("%s\t%s,%s",
+                               spec3_name[i.RType.func],
+                               reg_name[i.RType.rs],
+                               reg_name[i.RType.rt]);
+               }
                break;
 
        case OP_REGIMM: