From 49c80c380d665bcc7d5b68ea1ec3617e51a90d73 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 12 Sep 2017 19:14:02 +0100 Subject: [PATCH] nvic: Handle v8M changes in nvic_exec_prio() Update nvic_exec_prio() to support the v8M changes: * BASEPRI, FAULTMASK and PRIMASK are all banked * AIRCR.PRIS can affect NS priorities * AIRCR.BFHFNMINS affects FAULTMASK behaviour These changes mean that it's no longer possible to definitely say that if FAULTMASK is set it overrides PRIMASK, and if PRIMASK is set it overrides BASEPRI (since if PRIMASK_NS is set and AIRCR.PRIS is set then whether that 0x80 priority should take effect or the priority in BASEPRI_S depends on the value of BASEPRI_S, for instance). So we switch to the same approach used by the pseudocode of working through BASEPRI, PRIMASK and FAULTMASK and overriding the previous values if needed. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 1505240046-11454-16-git-send-email-peter.maydell@linaro.org --- hw/intc/armv7m_nvic.c | 53 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 43 insertions(+), 10 deletions(-) diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c index 35225c812d..1f9e1aab2f 100644 --- a/hw/intc/armv7m_nvic.c +++ b/hw/intc/armv7m_nvic.c @@ -319,18 +319,51 @@ static void nvic_recompute_state(NVICState *s) static inline int nvic_exec_prio(NVICState *s) { CPUARMState *env = &s->cpu->env; - int running; + int running = NVIC_NOEXC_PRIO; - if (env->v7m.faultmask[env->v7m.secure]) { - running = -1; - } else if (env->v7m.primask[env->v7m.secure]) { - running = 0; - } else if (env->v7m.basepri[env->v7m.secure] > 0) { - running = env->v7m.basepri[env->v7m.secure] & - nvic_gprio_mask(s, env->v7m.secure); - } else { - running = NVIC_NOEXC_PRIO; /* lower than any possible priority */ + if (env->v7m.basepri[M_REG_NS] > 0) { + running = exc_group_prio(s, env->v7m.basepri[M_REG_NS], M_REG_NS); } + + if (env->v7m.basepri[M_REG_S] > 0) { + int basepri = exc_group_prio(s, env->v7m.basepri[M_REG_S], M_REG_S); + if (running > basepri) { + running = basepri; + } + } + + if (env->v7m.primask[M_REG_NS]) { + if (env->v7m.aircr & R_V7M_AIRCR_PRIS_MASK) { + if (running > NVIC_NS_PRIO_LIMIT) { + running = NVIC_NS_PRIO_LIMIT; + } + } else { + running = 0; + } + } + + if (env->v7m.primask[M_REG_S]) { + running = 0; + } + + if (env->v7m.faultmask[M_REG_NS]) { + if (env->v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK) { + running = -1; + } else { + if (env->v7m.aircr & R_V7M_AIRCR_PRIS_MASK) { + if (running > NVIC_NS_PRIO_LIMIT) { + running = NVIC_NS_PRIO_LIMIT; + } + } else { + running = 0; + } + } + } + + if (env->v7m.faultmask[M_REG_S]) { + running = (env->v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK) ? -3 : -1; + } + /* consider priority of active handler */ return MIN(running, s->exception_prio); }