target-i386: Define DR7 bit field constants

Implicit use of dr7 bit field is a little hard to understand,
so define constants for them and use them consistently.

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

target-i386/cpu.h

@@ -231,6 +231,12 @@
 #define DR7_TYPE_SHIFT  16
 #define DR7_LEN_SHIFT   18
 #define DR7_FIXED_1     0x00000400
+#define DR7_LOCAL_BP_MASK    0x55
+#define DR7_MAX_BP           4
+#define DR7_TYPE_BP_INST     0x0
+#define DR7_TYPE_DATA_WR     0x1
+#define DR7_TYPE_IO_RW       0x2
+#define DR7_TYPE_DATA_RW     0x3
 
 #define PG_PRESENT_BIT	0
 #define PG_RW_BIT	1

target-i386/helper.c

@@ -969,18 +969,18 @@ void hw_breakpoint_insert(CPUX86State *env, int index)
     int type, err = 0;
 
     switch (hw_breakpoint_type(env->dr[7], index)) {
-    case 0:
+    case DR7_TYPE_BP_INST:
         if (hw_breakpoint_enabled(env->dr[7], index))
             err = cpu_breakpoint_insert(env, env->dr[index], BP_CPU,
                                         &env->cpu_breakpoint[index]);
         break;
-    case 1:
+    case DR7_TYPE_DATA_WR:
         type = BP_CPU | BP_MEM_WRITE;
         goto insert_wp;
-    case 2:
+    case DR7_TYPE_IO_RW:
          /* No support for I/O watchpoints yet */
         break;
-    case 3:
+    case DR7_TYPE_DATA_RW:
         type = BP_CPU | BP_MEM_ACCESS;
     insert_wp:
         err = cpu_watchpoint_insert(env, env->dr[index],
@@ -997,15 +997,15 @@ void hw_breakpoint_remove(CPUX86State *env, int index)
     if (!env->cpu_breakpoint[index])
         return;
     switch (hw_breakpoint_type(env->dr[7], index)) {
-    case 0:
+    case DR7_TYPE_BP_INST:
         if (hw_breakpoint_enabled(env->dr[7], index))
             cpu_breakpoint_remove_by_ref(env, env->cpu_breakpoint[index]);
         break;
-    case 1:
+    case DR7_TYPE_DATA_WR:
-    case 3:
+    case DR7_TYPE_DATA_RW:
         cpu_watchpoint_remove_by_ref(env, env->cpu_watchpoint[index]);
         break;
-    case 2:
+    case DR7_TYPE_IO_RW:
         /* No support for I/O watchpoints yet */
         break;
     }
@@ -1018,7 +1018,7 @@ int check_hw_breakpoints(CPUX86State *env, int force_dr6_update)
     int hit_enabled = 0;
 
     dr6 = env->dr[6] & ~0xf;
-    for (reg = 0; reg < 4; reg++) {
+    for (reg = 0; reg < DR7_MAX_BP; reg++) {
         type = hw_breakpoint_type(env->dr[7], reg);
         if ((type == 0 && env->dr[reg] == env->eip) ||
             ((type & 1) && env->cpu_watchpoint[reg] &&

target-i386/machine.c

@@ -265,10 +265,11 @@ static int cpu_post_load(void *opaque, int version_id)
 
     cpu_breakpoint_remove_all(env, BP_CPU);
     cpu_watchpoint_remove_all(env, BP_CPU);
-    for (i = 0; i < 4; i++)
+    for (i = 0; i < DR7_MAX_BP; i++) {
         hw_breakpoint_insert(env, i);
-
+    }
     tlb_flush(env, 1);
+
     return 0;
 }
 

target-i386/misc_helper.c

@@ -197,11 +197,11 @@ void helper_movl_drN_T0(CPUX86State *env, int reg, target_ulong t0)
         env->dr[reg] = t0;
         hw_breakpoint_insert(env, reg);
     } else if (reg == 7) {
-        for (i = 0; i < 4; i++) {
+        for (i = 0; i < DR7_MAX_BP; i++) {
             hw_breakpoint_remove(env, i);
         }
         env->dr[7] = t0;
-        for (i = 0; i < 4; i++) {
+        for (i = 0; i < DR7_MAX_BP; i++) {
             hw_breakpoint_insert(env, i);
         }
     } else {

target-i386/seg_helper.c

@@ -465,13 +465,13 @@ static void switch_tss(CPUX86State *env, int tss_selector,
 
 #ifndef CONFIG_USER_ONLY
     /* reset local breakpoints */
-    if (env->dr[7] & 0x55) {
+    if (env->dr[7] & DR7_LOCAL_BP_MASK) {
-        for (i = 0; i < 4; i++) {
+        for (i = 0; i < DR7_MAX_BP; i++) {
             if (hw_breakpoint_enabled(env->dr[7], i) == 0x1) {
                 hw_breakpoint_remove(env, i);
             }
         }
-        env->dr[7] &= ~0x55;
+        env->dr[7] &= ~DR7_LOCAL_BP_MASK;
     }
 #endif
 }