From d18b56657f8a22c1c174dfb6a603cd28b605fa6f Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@codesourcery.com>
Date: Fri, 8 Jun 2012 02:04:40 +0100
Subject: [PATCH] MIPS/user: Fix reset CPU state initialization

 This change updates the CPU reset sequence to use a common piece of code
that figures out CPU state flags, fixing the problem with MIPS_HFLAG_COP1X
not being set where applicable that causes floating-point MADD family
instructions (and other instructions from the MIPS IV FP subset) to trap.

 As compute_hflags is now shared between op_helper.c and translate.c, the
function is now moved to a common header.  There are no changes to this
function.

 The problem was seen with the 24Kf MIPS32r2 processor in user emulation.
The new approach prevents system and user emulation from diverging -- all
the hflags state is initialized in one place now.

Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
(cherry picked from commit 03e6e5017757645f00b2f3b4f3a257973985e455)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 target-mips/cpu.h       | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 target-mips/op_helper.c | 49 -------------------------------------------------
 target-mips/translate.c | 16 +++-------------
 3 files changed, 52 insertions(+), 62 deletions(-)

diff --git a/target-mips/cpu.h b/target-mips/cpu.h
index be4f805..b7a5112 100644
--- a/target-mips/cpu.h
+++ b/target-mips/cpu.h
@@ -742,4 +742,53 @@ static inline void cpu_pc_from_tb(CPUMIPSState *env, TranslationBlock *tb)
     env->hflags |= tb->flags & MIPS_HFLAG_BMASK;
 }
 
+static inline void compute_hflags(CPUMIPSState *env)
+{
+    env->hflags &= ~(MIPS_HFLAG_COP1X | MIPS_HFLAG_64 | MIPS_HFLAG_CP0 |
+                     MIPS_HFLAG_F64 | MIPS_HFLAG_FPU | MIPS_HFLAG_KSU |
+                     MIPS_HFLAG_UX);
+    if (!(env->CP0_Status & (1 << CP0St_EXL)) &&
+        !(env->CP0_Status & (1 << CP0St_ERL)) &&
+        !(env->hflags & MIPS_HFLAG_DM)) {
+        env->hflags |= (env->CP0_Status >> CP0St_KSU) & MIPS_HFLAG_KSU;
+    }
+#if defined(TARGET_MIPS64)
+    if (((env->hflags & MIPS_HFLAG_KSU) != MIPS_HFLAG_UM) ||
+        (env->CP0_Status & (1 << CP0St_PX)) ||
+        (env->CP0_Status & (1 << CP0St_UX))) {
+        env->hflags |= MIPS_HFLAG_64;
+    }
+    if (env->CP0_Status & (1 << CP0St_UX)) {
+        env->hflags |= MIPS_HFLAG_UX;
+    }
+#endif
+    if ((env->CP0_Status & (1 << CP0St_CU0)) ||
+        !(env->hflags & MIPS_HFLAG_KSU)) {
+        env->hflags |= MIPS_HFLAG_CP0;
+    }
+    if (env->CP0_Status & (1 << CP0St_CU1)) {
+        env->hflags |= MIPS_HFLAG_FPU;
+    }
+    if (env->CP0_Status & (1 << CP0St_FR)) {
+        env->hflags |= MIPS_HFLAG_F64;
+    }
+    if (env->insn_flags & ISA_MIPS32R2) {
+        if (env->active_fpu.fcr0 & (1 << FCR0_F64)) {
+            env->hflags |= MIPS_HFLAG_COP1X;
+        }
+    } else if (env->insn_flags & ISA_MIPS32) {
+        if (env->hflags & MIPS_HFLAG_64) {
+            env->hflags |= MIPS_HFLAG_COP1X;
+        }
+    } else if (env->insn_flags & ISA_MIPS4) {
+        /* All supported MIPS IV CPUs use the XX (CU3) to enable
+           and disable the MIPS IV extensions to the MIPS III ISA.
+           Some other MIPS IV CPUs ignore the bit, so the check here
+           would be too restrictive for them.  */
+        if (env->CP0_Status & (1 << CP0St_CU3)) {
+            env->hflags |= MIPS_HFLAG_COP1X;
+        }
+    }
+}
+
 #endif /* !defined (__MIPS_CPU_H__) */
diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
index d2a8a55..ce5ddaf 100644
--- a/target-mips/op_helper.c
+++ b/target-mips/op_helper.c
@@ -30,55 +30,6 @@
 static inline void cpu_mips_tlb_flush (CPUMIPSState *env, int flush_global);
 #endif
 
-static inline void compute_hflags(CPUMIPSState *env)
-{
-    env->hflags &= ~(MIPS_HFLAG_COP1X | MIPS_HFLAG_64 | MIPS_HFLAG_CP0 |
-                     MIPS_HFLAG_F64 | MIPS_HFLAG_FPU | MIPS_HFLAG_KSU |
-                     MIPS_HFLAG_UX);
-    if (!(env->CP0_Status & (1 << CP0St_EXL)) &&
-        !(env->CP0_Status & (1 << CP0St_ERL)) &&
-        !(env->hflags & MIPS_HFLAG_DM)) {
-        env->hflags |= (env->CP0_Status >> CP0St_KSU) & MIPS_HFLAG_KSU;
-    }
-#if defined(TARGET_MIPS64)
-    if (((env->hflags & MIPS_HFLAG_KSU) != MIPS_HFLAG_UM) ||
-        (env->CP0_Status & (1 << CP0St_PX)) ||
-        (env->CP0_Status & (1 << CP0St_UX))) {
-        env->hflags |= MIPS_HFLAG_64;
-    }
-    if (env->CP0_Status & (1 << CP0St_UX)) {
-        env->hflags |= MIPS_HFLAG_UX;
-    }
-#endif
-    if ((env->CP0_Status & (1 << CP0St_CU0)) ||
-        !(env->hflags & MIPS_HFLAG_KSU)) {
-        env->hflags |= MIPS_HFLAG_CP0;
-    }
-    if (env->CP0_Status & (1 << CP0St_CU1)) {
-        env->hflags |= MIPS_HFLAG_FPU;
-    }
-    if (env->CP0_Status & (1 << CP0St_FR)) {
-        env->hflags |= MIPS_HFLAG_F64;
-    }
-    if (env->insn_flags & ISA_MIPS32R2) {
-        if (env->active_fpu.fcr0 & (1 << FCR0_F64)) {
-            env->hflags |= MIPS_HFLAG_COP1X;
-        }
-    } else if (env->insn_flags & ISA_MIPS32) {
-        if (env->hflags & MIPS_HFLAG_64) {
-            env->hflags |= MIPS_HFLAG_COP1X;
-        }
-    } else if (env->insn_flags & ISA_MIPS4) {
-        /* All supported MIPS IV CPUs use the XX (CU3) to enable
-           and disable the MIPS IV extensions to the MIPS III ISA.
-           Some other MIPS IV CPUs ignore the bit, so the check here
-           would be too restrictive for them.  */
-        if (env->CP0_Status & (1 << CP0St_CU3)) {
-            env->hflags |= MIPS_HFLAG_COP1X;
-        }
-    }
-}
-
 /*****************************************************************************/
 /* Exceptions processing helpers */
 
diff --git a/target-mips/translate.c b/target-mips/translate.c
index aba7935..4e04e97 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -12816,18 +12816,13 @@ void cpu_state_reset(CPUMIPSState *env)
     env->insn_flags = env->cpu_model->insn_flags;
 
 #if defined(CONFIG_USER_ONLY)
-    env->hflags = MIPS_HFLAG_UM;
+    env->CP0_Status = (MIPS_HFLAG_UM << CP0St_KSU);
     /* Enable access to the CPUNum, SYNCI_Step, CC, and CCRes RDHWR
        hardware registers.  */
     env->CP0_HWREna |= 0x0000000F;
     if (env->CP0_Config1 & (1 << CP0C1_FP)) {
-        env->hflags |= MIPS_HFLAG_FPU;
+        env->CP0_Status |= (1 << CP0St_CU1);
     }
-#ifdef TARGET_MIPS64
-    if (env->active_fpu.fcr0 & (1 << FCR0_F64)) {
-        env->hflags |= MIPS_HFLAG_F64;
-    }
-#endif
 #else
     if (env->hflags & MIPS_HFLAG_BMASK) {
         /* If the exception was raised from a delay slot,
@@ -12857,7 +12852,6 @@ void cpu_state_reset(CPUMIPSState *env)
     }
     /* Count register increments in debug mode, EJTAG version 1 */
     env->CP0_Debug = (1 << CP0DB_CNT) | (0x1 << CP0DB_VER);
-    env->hflags = MIPS_HFLAG_CP0;
 
     if (env->CP0_Config3 & (1 << CP0C3_MT)) {
         int i;
@@ -12885,11 +12879,7 @@ void cpu_state_reset(CPUMIPSState *env)
         }
     }
 #endif
-#if defined(TARGET_MIPS64)
-    if (env->cpu_model->insn_flags & ISA_MIPS3) {
-        env->hflags |= MIPS_HFLAG_64;
-    }
-#endif
+    compute_hflags(env);
     env->exception_index = EXCP_NONE;
 }