[Qemu-devel] [PATCH] target-i386:slightly refactor dr7 related function

[liguang]

1. define names of breakpoints in dr7
2. slightly refactor bits field of breakpoint
   related functions.

Signed-off-by: liguang <address@hidden>
---
 target-i386/cpu.h         |    6 ++++
 target-i386/helper.c      |   59 ++++++++++++++++++++++++++++----------------
 target-i386/machine.c     |    2 +-
 target-i386/misc_helper.c |    4 +-
 target-i386/seg_helper.c  |    4 +-
 5 files changed, 48 insertions(+), 27 deletions(-)

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 90ef1ff..2da6ea0 100644
--- a/target-i386/cpu.h
+++ b/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_L0_3        0x55
+#define DR7_MAX_BP      4
+#define DR7_BP_INST     0x0
+#define DR7_DATA_WR     0x1
+#define DR7_IO_RW       0x2
+#define DR7_DATA_RW     0x3
 
 #define PG_PRESENT_BIT 0
 #define PG_RW_BIT      1
diff --git a/target-i386/helper.c b/target-i386/helper.c
index bf206cf..54d6712 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -966,27 +966,26 @@ hwaddr cpu_get_phys_page_debug(CPUX86State *env, 
target_ulong addr)
 
 void hw_breakpoint_insert(CPUX86State *env, int index)
 {
-    int type, err = 0;
+    int type = 0, err = 0;
 
     switch (hw_breakpoint_type(env->dr[7], index)) {
-    case 0:
+    case DR7_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_DATA_WR:
         type = BP_CPU | BP_MEM_WRITE;
-        goto insert_wp;
-    case 2:
-         /* No support for I/O watchpoints yet */
-        break;
-    case 3:
-        type = BP_CPU | BP_MEM_ACCESS;
-    insert_wp:
+    case DR7_DATA_RW:
+        if (!type)
+            type = BP_CPU | BP_MEM_ACCESS;
         err = cpu_watchpoint_insert(env, env->dr[index],
                                     hw_breakpoint_len(env->dr[7], index),
                                     type, &env->cpu_watchpoint[index]);
         break;
+    case DR7_IO_RW:
+         /* No support for I/O watchpoints yet */
+        break;
     }
     if (err)
         env->cpu_breakpoint[index] = NULL;
@@ -997,15 +996,15 @@ 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_BP_INST:
         if (hw_breakpoint_enabled(env->dr[7], index))
             cpu_breakpoint_remove_by_ref(env, env->cpu_breakpoint[index]);
         break;
-    case 1:
-    case 3:
+    case DR7_DATA_WR:
+    case DR7_DATA_RW:
         cpu_watchpoint_remove_by_ref(env, env->cpu_watchpoint[index]);
         break;
-    case 2:
+    case DR7_IO_RW:
         /* No support for I/O watchpoints yet */
         break;
     }
@@ -1014,22 +1013,38 @@ void hw_breakpoint_remove(CPUX86State *env, int index)
 int check_hw_breakpoints(CPUX86State *env, int force_dr6_update)
 {
     target_ulong dr6;
-    int reg, type;
+    int index, type = 0;
     int hit_enabled = 0;
 
     dr6 = env->dr[6] & ~0xf;
-    for (reg = 0; reg < 4; reg++) {
-        type = hw_breakpoint_type(env->dr[7], reg);
-        if ((type == 0 && env->dr[reg] == env->eip) ||
-            ((type & 1) && env->cpu_watchpoint[reg] &&
-             (env->cpu_watchpoint[reg]->flags & BP_WATCHPOINT_HIT))) {
-            dr6 |= 1 << reg;
-            if (hw_breakpoint_enabled(env->dr[7], reg))
+    for (index = 0; index < DR7_MAX_BP; index++) {
+        switch (hw_breakpoint_type(env->dr[7], index)) {
+        case DR7_BP_INST:
+            if (env->dr[index] != env->eip)
+                break;
+            type = 1;
+            break;
+        case DR7_DATA_WR:
+        case DR7_DATA_RW:
+            if (!env->cpu_watchpoint[index])
+                break;
+            if (!(env->cpu_watchpoint[index]->flags & BP_WATCHPOINT_HIT))
+                break;
+            type = 1;
+            break;
+        case DR7_IO_RW:
+            break;
+        }
+        if (type) {
+            dr6 |= 1 << index;
+            if (hw_breakpoint_enabled(env->dr[7], index))
                 hit_enabled = 1;
+            type = 0;
         }
     }
     if (hit_enabled || force_dr6_update)
         env->dr[6] = dr6;
+
     return hit_enabled;
 }
 
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 4771508..a4b1a1e 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -265,7 +265,7 @@ 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);
diff --git a/target-i386/misc_helper.c b/target-i386/misc_helper.c
index a020379..5ee0863 100644
--- a/target-i386/misc_helper.c
+++ b/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 {
diff --git a/target-i386/seg_helper.c b/target-i386/seg_helper.c
index ff93374..317187b 100644
--- a/target-i386/seg_helper.c
+++ b/target-i386/seg_helper.c
@@ -465,8 +465,8 @@ static void switch_tss(CPUX86State *env, int tss_selector,
 
 #ifndef CONFIG_USER_ONLY
     /* reset local breakpoints */
-    if (env->dr[7] & 0x55) {
-        for (i = 0; i < 4; i++) {
+    if (env->dr[7] & DR7_L0_3) {
+        for (i = 0; i < DR7_MAX_BP; i++) {
             if (hw_breakpoint_enabled(env->dr[7], i) == 0x1) {
                 hw_breakpoint_remove(env, i);
             }
-- 
1.7.2.5