target-arm: Add write_type argument to cpsr_write()

Add an argument to cpsr_write() to indicate what kind of CPSR
write is being requested, since the exact behaviour should
differ for the different cases.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Sergey Fedorov <serge.fdrv@gmail.com>
Message-id: 1455556977-3644-3-git-send-email-peter.maydell@linaro.org

linux-user/arm/nwfpe/fpa11.h

@@ -105,7 +105,7 @@ static inline void writeRegister(unsigned int x, unsigned int y)
 
 static inline void writeConditionCodes(unsigned int x)
 {
-        cpsr_write(user_registers,x,CPSR_NZCV);
+    cpsr_write(user_registers, x, CPSR_NZCV, CPSRWriteByInstr);
 }
 
 #define ARM_REG_PC 15

linux-user/main.c

@@ -513,7 +513,7 @@ static void arm_kernel_cmpxchg64_helper(CPUARMState *env)
         env->regs[0] = -1;
         cpsr &= ~CPSR_C;
     }
-    cpsr_write(env, cpsr, CPSR_C);
+    cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr);
     end_exclusive();
     return;
 
@@ -562,7 +562,7 @@ do_kernel_trap(CPUARMState *env)
             env->regs[0] = -1;
             cpsr &= ~CPSR_C;
         }
-        cpsr_write(env, cpsr, CPSR_C);
+        cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr);
         end_exclusive();
         break;
     case 0xffff0fe0: /* __kernel_get_tls */
@@ -4446,7 +4446,7 @@ int main(int argc, char **argv, char **envp)
 #elif defined(TARGET_ARM)
     {
         int i;
-        cpsr_write(env, regs->uregs[16], 0xffffffff);
+        cpsr_write(env, regs->uregs[16], 0xffffffff, CPSRWriteByInstr);
         for(i = 0; i < 16; i++) {
             env->regs[i] = regs->uregs[i];
         }

linux-user/signal.c

@@ -1611,7 +1611,7 @@ setup_return(CPUARMState *env, struct target_sigaction *ka,
 	env->regs[13] = frame_addr;
 	env->regs[14] = retcode;
 	env->regs[15] = handler & (thumb ? ~1 : ~3);
-	cpsr_write(env, cpsr, 0xffffffff);
+        cpsr_write(env, cpsr, 0xffffffff, CPSRWriteByInstr);
 }
 
 static abi_ulong *setup_sigframe_v2_vfp(abi_ulong *regspace, CPUARMState *env)
@@ -1843,7 +1843,7 @@ restore_sigcontext(CPUARMState *env, struct target_sigcontext *sc)
     __get_user(env->regs[15], &sc->arm_pc);
 #ifdef TARGET_CONFIG_CPU_32
     __get_user(cpsr, &sc->arm_cpsr);
-        cpsr_write(env, cpsr, CPSR_USER | CPSR_EXEC);
+    cpsr_write(env, cpsr, CPSR_USER | CPSR_EXEC, CPSRWriteByInstr);
 #endif
 
 	err |= !valid_user_regs(env);

target-arm/cpu.h

@@ -718,8 +718,17 @@ static inline void pstate_write(CPUARMState *env, uint32_t val)
 
 /* Return the current CPSR value.  */
 uint32_t cpsr_read(CPUARMState *env);
-/* Set the CPSR.  Note that some bits of mask must be all-set or all-clear.  */
-void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask);
+
+typedef enum CPSRWriteType {
+    CPSRWriteByInstr = 0,         /* from guest MSR or CPS */
+    CPSRWriteExceptionReturn = 1, /* from guest exception return insn */
+    CPSRWriteRaw = 2,             /* trust values, do not switch reg banks */
+    CPSRWriteByGDBStub = 3,       /* from the GDB stub */
+} CPSRWriteType;
+
+/* Set the CPSR.  Note that some bits of mask must be all-set or all-clear.*/
+void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask,
+                CPSRWriteType write_type);
 
 /* Return the current xPSR value.  */
 static inline uint32_t xpsr_read(CPUARMState *env)

target-arm/gdbstub.c

@@ -94,7 +94,7 @@ int arm_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
         return 4;
     case 25:
         /* CPSR */
-        cpsr_write(env, tmp, 0xffffffff);
+        cpsr_write(env, tmp, 0xffffffff, CPSRWriteByGDBStub);
         return 4;
     }
     /* Unknown register.  */

target-arm/helper.c

@@ -5233,7 +5233,8 @@ uint32_t cpsr_read(CPUARMState *env)
         | (env->GE << 16) | (env->daif & CPSR_AIF);
 }
 
-void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
+void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask,
+                CPSRWriteType write_type)
 {
     uint32_t changed_daif;
 

target-arm/kvm32.c

@@ -428,7 +428,7 @@ int kvm_arch_get_registers(CPUState *cs)
     if (ret) {
         return ret;
     }
-    cpsr_write(env, cpsr, 0xffffffff);
+    cpsr_write(env, cpsr, 0xffffffff, CPSRWriteRaw);
 
     /* Make sure the current mode regs are properly set */
     mode = env->uncached_cpsr & CPSR_M;

target-arm/kvm64.c

@@ -723,7 +723,7 @@ int kvm_arch_get_registers(CPUState *cs)
         pstate_write(env, val);
     } else {
         env->uncached_cpsr = val & CPSR_M;
-        cpsr_write(env, val, 0xffffffff);
+        cpsr_write(env, val, 0xffffffff, CPSRWriteRaw);
     }
 
     /* KVM puts SP_EL0 in regs.sp and SP_EL1 in regs.sp_el1. On the

target-arm/machine.c

@@ -175,7 +175,7 @@ static int get_cpsr(QEMUFile *f, void *opaque, size_t size)
 
     /* Avoid mode switch when restoring CPSR */
     env->uncached_cpsr = val & CPSR_M;
-    cpsr_write(env, val, 0xffffffff);
+    cpsr_write(env, val, 0xffffffff, CPSRWriteRaw);
     return 0;
 }
 

target-arm/op_helper.c

@@ -422,13 +422,13 @@ uint32_t HELPER(cpsr_read)(CPUARMState *env)
 
 void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask)
 {
-    cpsr_write(env, val, mask);
+    cpsr_write(env, val, mask, CPSRWriteByInstr);
 }
 
 /* Write the CPSR for a 32-bit exception return */
 void HELPER(cpsr_write_eret)(CPUARMState *env, uint32_t val)
 {
-    cpsr_write(env, val, CPSR_ERET_MASK);
+    cpsr_write(env, val, CPSR_ERET_MASK, CPSRWriteExceptionReturn);
 }
 
 /* Access to user mode registers from privileged modes.  */
@@ -780,7 +780,7 @@ void HELPER(exception_return)(CPUARMState *env)
     if (!return_to_aa64) {
         env->aarch64 = 0;
         env->uncached_cpsr = spsr & CPSR_M;
-        cpsr_write(env, spsr, ~0);
+        cpsr_write(env, spsr, ~0, CPSRWriteRaw);
         if (!arm_singlestep_active(env)) {
             env->uncached_cpsr &= ~PSTATE_SS;
         }