On 01/30/2018 07:02 AM, Peter Maydell wrote: > Currently armv7m_nvic_acknowledge_irq() does three things: > * make the current highest priority pending interrupt active > * return a bool indicating whether that interrupt is targeting > Secure or NonSecure state > * implicitly tell the caller which is the highest priority > pending interrupt by setting env->v7m.exception > > We need to split these jobs, because v7m_exception_taken() > needs to know whether the pending interrupt targets Secure so > it can choose to stack callee-saves registers or not, but it > must not make the interrupt active until after it has done > that stacking, in case the stacking causes a derived exception. > Similarly, it needs to know the number of the pending interrupt > so it can read the correct vector table entry before the > interrupt is made active, because vector table reads might > also cause a derived exception. > > Create a new armv7m_nvic_get_pending_irq_info() function which simply > returns information about the highest priority pending interrupt, and > use it to rearrange the v7m_exception_taken() code so we don't > acknowledge the exception until we've done all the things which could > possibly cause a derived exception. > > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > --- > target/arm/cpu.h | 19 ++++++++++++++++--- > hw/intc/armv7m_nvic.c | 30 +++++++++++++++++++++++------- > target/arm/helper.c | 16 ++++++++++++---- > hw/intc/trace-events | 3 ++- > 4 files changed, 53 insertions(+), 15 deletions(-)
Reviewed-by: Richard Henderson <richard.hender...@linaro.org> r~
