sparc32 do_unassigned_access overhaul v2

[qemu.git] / target-sparc / op_helper.c

diff --git a/target-sparc/op_helper.c b/target-sparc/op_helper.c
index 381e6c49d78fea2fe71d2938cf8060e5876831e3..ce8c6f1aca2790d2c848c332cfae384a94d59023 100644 (file)
--- a/target-sparc/op_helper.c
+++ b/target-sparc/op_helper.c
@@ -3714,6 +3714,7 @@ void do_unassigned_access(target_phys_addr_t addr, int is_write, int is_exec,
                           int is_asi, int size)
 {
     CPUState *saved_env;
+    int fault_type;
 
     /* XXX: hack to restore env in all cases, even if not called from
        generated code */
@@ -3731,18 +3732,29 @@ void do_unassigned_access(target_phys_addr_t addr, int is_write, int is_exec,
                is_exec ? "exec" : is_write ? "write" : "read", size,
                size == 1 ? "" : "s", addr, env->pc);
 #endif
-    if (env->mmuregs[3]) /* Fault status register */
-        env->mmuregs[3] = 1; /* overflow (not read before another fault) */
-    if (is_asi)
-        env->mmuregs[3] |= 1 << 16;
-    if (env->psrs)
-        env->mmuregs[3] |= 1 << 5;
-    if (is_exec)
-        env->mmuregs[3] |= 1 << 6;
-    if (is_write)
-        env->mmuregs[3] |= 1 << 7;
-    env->mmuregs[3] |= (5 << 2) | 2;
-    env->mmuregs[4] = addr; /* Fault address register */
+    /* Don't overwrite translation and access faults */
+    fault_type = (env->mmuregs[3] & 0x1c) >> 2;
+    if ((fault_type > 4) || (fault_type == 0)) {
+        env->mmuregs[3] = 0; /* Fault status register */
+        if (is_asi)
+            env->mmuregs[3] |= 1 << 16;
+        if (env->psrs)
+            env->mmuregs[3] |= 1 << 5;
+        if (is_exec)
+            env->mmuregs[3] |= 1 << 6;
+        if (is_write)
+            env->mmuregs[3] |= 1 << 7;
+        env->mmuregs[3] |= (5 << 2) | 2;
+        /* SuperSPARC will never place instruction fault addresses in the FAR */
+        if (!is_exec) {
+            env->mmuregs[4] = addr; /* Fault address register */
+        }
+    }
+    /* overflow (same type fault was not read before another fault) */
+    if (fault_type == ((env->mmuregs[3] & 0x1c)) >> 2) {
+        env->mmuregs[3] |= 1;
+    }
+
     if ((env->mmuregs[0] & MMU_E) && !(env->mmuregs[0] & MMU_NF)) {
         if (is_exec)
             raise_exception(TT_CODE_ACCESS);
@@ -3750,6 +3762,12 @@ void do_unassigned_access(target_phys_addr_t addr, int is_write, int is_exec,
             raise_exception(TT_DATA_ACCESS);
     }
     env = saved_env;
+
+    /* flush neverland mappings created during no-fault mode,
+       so the sequential MMU faults report proper fault types */
+    if (env->mmuregs[0] & MMU_NF) {
+        tlb_flush(env, 1);
+    }
 }
 #else
 void do_unassigned_access(target_phys_addr_t addr, int is_write, int is_exec,