Re: [Qemu-arm] [PATCH 02/11] target-arm: Add write_type argument to cpsr_write()

[Sergey Fedorov <serge.fdrv@gmail.com>]

On 15.02.2016 20:22, Peter Maydell wrote:
> 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>

> ---
>  linux-user/arm/nwfpe/fpa11.h |  2 +-
>  linux-user/main.c            |  6 +++---
>  linux-user/signal.c          |  4 ++--
>  target-arm/cpu.h             | 13 +++++++++++--
>  target-arm/gdbstub.c         |  2 +-
>  target-arm/helper.c          |  3 ++-
>  target-arm/kvm32.c           |  2 +-
>  target-arm/kvm64.c           |  2 +-
>  target-arm/machine.c         |  2 +-
>  target-arm/op_helper.c       |  6 +++---
>  10 files changed, 26 insertions(+), 16 deletions(-)
>
> diff --git a/linux-user/arm/nwfpe/fpa11.h b/linux-user/arm/nwfpe/fpa11.h
> index bb9ac65..faa6b00 100644
> --- a/linux-user/arm/nwfpe/fpa11.h
> +++ b/linux-user/arm/nwfpe/fpa11.h
> @@ -108,7 +108,7 @@ 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
> diff --git a/linux-user/main.c b/linux-user/main.c
> index e719a2d..1269470 100644
> --- a/linux-user/main.c
> +++ b/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];
>          }
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index 327c032..82f81c7 100644
> --- a/linux-user/signal.c
> +++ b/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);
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index 1623821..e72e33b 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -719,8 +719,17 @@ 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)
> diff --git a/target-arm/gdbstub.c b/target-arm/gdbstub.c
> index 08b91a4..3ba9aad 100644
> --- a/target-arm/gdbstub.c
> +++ b/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.  */
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index a420a2a..828822b 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -5199,7 +5199,8 @@ 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;
>  
> diff --git a/target-arm/kvm32.c b/target-arm/kvm32.c
> index ea01932..d44a7f9 100644
> --- a/target-arm/kvm32.c
> +++ b/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;
> diff --git a/target-arm/kvm64.c b/target-arm/kvm64.c
> index 0f1b4d6..08c2c81 100644
> --- a/target-arm/kvm64.c
> +++ b/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
> diff --git a/target-arm/machine.c b/target-arm/machine.c
> index ed1925a..0fc7df0 100644
> --- a/target-arm/machine.c
> +++ b/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;
>  }
>  
> diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
> index e3ddd5a..543d33a 100644
> --- a/target-arm/op_helper.c
> +++ b/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;
>          }