Re: [PATCH v7 19/20] target/arm: Rebuild hflags for M-profile.

[Richard Henderson <richard.henderson@linaro.org>]

On 10/18/19 5:25 AM, Peter Maydell wrote:
> On Thu, 17 Oct 2019 at 19:51, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> Continue setting, but not relying upon, env->hflags.
>>
>> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>> v7: Add rebuilds for v7m_msr and nvic_writel to v7m.ccr.
>> ---
>>  hw/intc/armv7m_nvic.c  | 1 +
>>  target/arm/m_helper.c  | 6 ++++++
>>  target/arm/translate.c | 5 ++++-
>>  3 files changed, 11 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
>> index 8e93e51e81..a3993e7b72 100644
>> --- a/hw/intc/armv7m_nvic.c
>> +++ b/hw/intc/armv7m_nvic.c
>> @@ -1604,6 +1604,7 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value,
>>          }
>>
>>          cpu->env.v7m.ccr[attrs.secure] = value;
>> +        arm_rebuild_hflags(&cpu->env);
>>          break;
>>      case 0xd24: /* System Handler Control and State (SHCSR) */
>>          if (!arm_feature(&cpu->env, ARM_FEATURE_V7)) {
> 
> This seems fragile -- we have to remember to add in
> a call to arm_rebuild_hflags() for every individual
> case of a memory-mapped system register that we choose
> to cache in tb flags. It doesn't seem consistent with
> the choice for A-profile to rebuild hflags for pretty
> much any sysreg write. Maybe it would be better to just
> always rebuild hflags at the end of nvic_sysreg_write() ?

I thought about that, but there were too many returns out of the middle.  I
suppose a wrapper function would take care of that.


r~