Add support for 2nd DAWR in xmon. With this, we can have two
simultaneous breakpoints from xmon.

Signed-off-by: Ravi Bangoria <redacted>
---
  arch/powerpc/xmon/xmon.c | 101 ++++++++++++++++++++++++++-------------
  1 file changed, 69 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index ac18fe3e4295..20adc83404c8 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c

@@ -110,7 +110,7 @@ struct bpt {
  
  #define NBPTS	256
  static struct bpt bpts[NBPTS];
-static struct bpt dabr;
+static struct bpt dabr[HBP_NUM_MAX];
  static struct bpt *iabr;
  static unsigned bpinstr = 0x7fe00008;	/* trap */
  

@@ -786,10 +786,17 @@ static int xmon_sstep(struct pt_regs *regs)
  
  static int xmon_break_match(struct pt_regs *regs)
  {
+	int i;
+
  	if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) != (MSR_IR|MSR_64BIT))
  		return 0;
-	if (dabr.enabled == 0)
-		return 0;
+	for (i = 0; i < nr_wp_slots(); i++) {
+		if (dabr[i].enabled)
+			goto found;
+	}
+	return 0;
+
+found:
  	xmon_core(regs, 0);
  	return 1;
  }

@@ -928,13 +935,16 @@ static void insert_bpts(void)
  
  static void insert_cpu_bpts(void)
  {
+	int i;
  	struct arch_hw_breakpoint brk;
  
-	if (dabr.enabled) {
-		brk.address = dabr.address;
-		brk.type = (dabr.enabled & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
-		brk.len = DABR_MAX_LEN;
-		__set_breakpoint(&brk, 0);
+	for (i = 0; i < nr_wp_slots(); i++) {
+		if (dabr[i].enabled) {
+			brk.address = dabr[i].address;
+			brk.type = (dabr[i].enabled & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL;
+			brk.len = 8;
+			__set_breakpoint(&brk, i);
+		}
  	}
  
  	if (iabr)

@@ -1348,6 +1358,35 @@ static long check_bp_loc(unsigned long addr)
  	return 1;
  }
  
+static int free_data_bpt(void)

+{
+	int i;
+
+	for (i = 0; i < nr_wp_slots(); i++) {
+		if (!dabr[i].enabled)
+			return i;
+	}
+	printf("Couldn't find free breakpoint register\n");
+	return -1;
+}
+
+static void print_data_bpts(void)
+{
+	int i;
+
+	for (i = 0; i < nr_wp_slots(); i++) {
+		if (!dabr[i].enabled)
+			continue;
+
+		printf("   data   "REG"  [", dabr[i].address);
+		if (dabr[i].enabled & 1)
+			printf("r");
+		if (dabr[i].enabled & 2)
+			printf("w");
+		printf("]\n");
+	}
+}
+
  static char *breakpoint_help_string =
      "Breakpoint command usage:\n"
      "b                show breakpoints\n"

@@ -1381,10 +1420,9 @@ bpt_cmds(void)
  			printf("Hardware data breakpoint not supported on this cpu\n");
  			break;
  		}
-		if (dabr.enabled) {
-			printf("Couldn't find free breakpoint register\n");
+		i = free_data_bpt();
+		if (i < 0)
  			break;
-		}
  		mode = 7;
  		cmd = inchar();
  		if (cmd == 'r')

@@ -1393,15 +1431,15 @@ bpt_cmds(void)
  			mode = 6;
  		else
  			termch = cmd;
-		dabr.address = 0;
-		dabr.enabled = 0;
-		if (scanhex(&dabr.address)) {
-			if (!is_kernel_addr(dabr.address)) {
+		dabr[i].address = 0;
+		dabr[i].enabled = 0;
+		if (scanhex(&dabr[i].address)) {
+			if (!is_kernel_addr(dabr[i].address)) {
  				printf(badaddr);
  				break;
  			}
-			dabr.address &= ~HW_BRK_TYPE_DABR;
-			dabr.enabled = mode | BP_DABR;
+			dabr[i].address &= ~HW_BRK_TYPE_DABR;
+			dabr[i].enabled = mode | BP_DABR;
  		}
  
  		force_enable_xmon();

@@ -1440,7 +1478,9 @@ bpt_cmds(void)
  			for (i = 0; i < NBPTS; ++i)
  				bpts[i].enabled = 0;
  			iabr = NULL;
-			dabr.enabled = 0;
+			for (i = 0; i < nr_wp_slots(); i++)
+				dabr[i].enabled = 0;
+
  			printf("All breakpoints cleared\n");
  			break;
  		}

@@ -1474,14 +1514,7 @@ bpt_cmds(void)
  		if (xmon_is_ro || !scanhex(&a)) {
  			/* print all breakpoints */
  			printf("   type            address\n");
-			if (dabr.enabled) {
-				printf("   data   "REG"  [", dabr.address);
-				if (dabr.enabled & 1)
-					printf("r");
-				if (dabr.enabled & 2)
-					printf("w");
-				printf("]\n");
-			}
+			print_data_bpts();
  			for (bp = bpts; bp < &bpts[NBPTS]; ++bp) {
  				if (!bp->enabled)
  					continue;

@@ -1941,8 +1974,13 @@ static void dump_207_sprs(void)
  
  	printf("hfscr  = %.16lx  dhdes = %.16lx rpr    = %.16lx\n",
  		mfspr(SPRN_HFSCR), mfspr(SPRN_DHDES), mfspr(SPRN_RPR));
-	printf("dawr   = %.16lx  dawrx = %.16lx ciabr  = %.16lx\n",
-		mfspr(SPRN_DAWR0), mfspr(SPRN_DAWRX0), mfspr(SPRN_CIABR));
+	printf("dawr0  = %.16lx dawrx0 = %.16lx\n",
+		mfspr(SPRN_DAWR0), mfspr(SPRN_DAWRX0));
+	if (nr_wp_slots() > 1) {
+		printf("dawr1  = %.16lx dawrx1 = %.16lx\n",
+			mfspr(SPRN_DAWR1), mfspr(SPRN_DAWRX1));
+	}
+	printf("ciabr  = %.16lx\n", mfspr(SPRN_CIABR));
  #endif
  }
  

@@ -3862,10 +3900,9 @@ static void clear_all_bpt(void)
  		bpts[i].enabled = 0;
  
  	/* Clear any data or iabr breakpoints */
-	if (iabr || dabr.enabled) {
-		iabr = NULL;
-		dabr.enabled = 0;
-	}
+	iabr = NULL;
+	for (i = 0; i < nr_wp_slots(); i++)
+		dabr[i].enabled = 0;
  }
  
  #ifdef CONFIG_DEBUG_FS