[POWERPC] PPC 4xx: Enable XMON on PPC 4xx boards

The following patch allows XMON to run on the 4xx platform.  Tested on
Walnut, Ebony, and Nova (440GX based) eval boards.  440EP, 440SP, and
440SPE boards should work as well.  Patch is against 2.6.18-rc6.

Signed-off-by: Josh Boyer <jdub@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 20 insertions, 6 deletions

diff --git a/arch/ppc/xmon/xmon.c b/arch/ppc/xmon/xmon.c
index 37d234f9339..25d032b2aec 100644
--- a/arch/ppc/xmon/xmon.c
+++ b/arch/ppc/xmon/xmon.c
@@ -153,6 +153,12 @@ static int xmon_trace[NR_CPUS];
 #define SSTEP   1               /* stepping because of 's' command */
 #define BRSTEP  2               /* stepping over breakpoint */
 
+#ifdef CONFIG_4xx
+#define MSR_SSTEP_ENABLE 0x200
+#else
+#define MSR_SSTEP_ENABLE 0x400
+#endif
+
 static struct pt_regs *xmon_regs[NR_CPUS];
 
 extern inline void sync(void)
@@ -211,6 +217,14 @@ static void get_tb(unsigned *p)
         p[1] = lo;
 }
 
+static inline void xmon_enable_sstep(struct pt_regs *regs)
+{
+        regs->msr |= MSR_SSTEP_ENABLE;
+#ifdef CONFIG_4xx
+        mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
+#endif
+}
+
 int xmon(struct pt_regs *excp)
 {
         struct pt_regs regs;
@@ -254,10 +268,10 @@ int xmon(struct pt_regs *excp)
         cmd = cmds(excp);
         if (cmd == 's') {
                 xmon_trace[smp_processor_id()] = SSTEP;
-                excp->msr |= 0x400;
+                xmon_enable_sstep(excp);
         } else if (at_breakpoint(excp->nip)) {
                 xmon_trace[smp_processor_id()] = BRSTEP;
-                excp->msr |= 0x400;
+                xmon_enable_sstep(excp);
         } else {
                 xmon_trace[smp_processor_id()] = 0;
                 insert_bpts();
@@ -298,7 +312,7 @@ xmon_bpt(struct pt_regs *regs)
                 remove_bpts();
                 excprint(regs);
                 xmon_trace[smp_processor_id()] = BRSTEP;
-                regs->msr |= 0x400;
+                xmon_enable_sstep(regs);
         } else {
                 xmon(regs);
         }
@@ -385,7 +399,7 @@ insert_bpts(void)
                 }
                 store_inst((void *) bp->address);
         }
-#if !defined(CONFIG_8xx)
+#if ! (defined(CONFIG_8xx) || defined(CONFIG_4xx))
         if (dabr.enabled)
                 set_dabr(dabr.address);
         if (iabr.enabled)
@@ -400,7 +414,7 @@ remove_bpts(void)
         struct bpt *bp;
         unsigned instr;
 
-#if !defined(CONFIG_8xx)
+#if ! (defined(CONFIG_8xx) || defined(CONFIG_4xx))
         set_dabr(0);
         set_iabr(0);
 #endif
@@ -677,7 +691,7 @@ bpt_cmds(void)
 
         cmd = inchar();
         switch (cmd) {
-#if !defined(CONFIG_8xx)
+#if ! (defined(CONFIG_8xx) || defined(CONFIG_4xx))
         case 'd':
                 mode = 7;
                 cmd = inchar();