This adds hardware breakpoint support for i386.  This is not as well tested as
software breakpoints, but in some minimal testing appears to be functional.

Signed-off-by: Milind Dumbare <milind@linsyssoft.com>

 kgdb.c |   49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

Index: linux-2.6.16/arch/i386/kernel/kgdb.c
===================================================================
--- linux-2.6.16.orig/arch/i386/kernel/kgdb.c	2006-04-25 11:30:47.000000000 +0530
+++ linux-2.6.16/arch/i386/kernel/kgdb.c	2006-04-25 11:45:34.000000000 +0530
@@ -184,6 +184,54 @@
 		asm volatile ("movl %0, %%db7\n"::"r" (dr7));
 }
 
+int kgdb_remove_hw_break(unsigned long addr)
+{
+	int i, idx = -1;
+	for (i = 0; i < 4; i++) {
+		if (breakinfo[i].addr == addr && breakinfo[i].enabled) {
+			idx = i;
+			break;
+		}
+	}
+	if (idx == -1)
+		return -1;
+
+	breakinfo[idx].enabled = 0;
+	return 0;
+}
+
+void kgdb_remove_all_hw_break(void)
+{
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		if (breakinfo[i].enabled) {
+			/* Do what? */
+			;
+		}
+		memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint));
+	}
+}
+
+int kgdb_set_hw_break(unsigned long addr)
+{
+	int i, idx = -1;
+	for (i = 0; i < 4; i++) {
+		if (!breakinfo[i].enabled) {
+			idx = i;
+			break;
+		}
+	}
+	if (idx == -1)
+		return -1;
+
+	breakinfo[idx].enabled = 1;
+	breakinfo[idx].type = 1;
+	breakinfo[idx].len = 1;
+	breakinfo[idx].addr = addr;
+	return 0;
+}
+
 void kgdb_disable_hw_debug(struct pt_regs *regs)
 {
 	/* Disable hardware debugging while we are in kgdb */
@@ -311,4 +359,5 @@
 
 struct kgdb_arch arch_kgdb_ops = {
 	.gdb_bpt_instr = {0xcc},
+	.flags = KGDB_HW_BREAKPOINT,
 };