From: Brian Cain <bc...@quicinc.com> The hardware-assisted scheduler helps manage tasks on the run queue and interrupt steering.
This instruction is defined in the Qualcomm Hexagon V71 Programmer's Reference Manual - https://docs.qualcomm.com/bundle/publicresource/80-N2040-51_REV_AB_Hexagon_V71_ProgrammerS_Reference_Manual.pdf See ยง11.9.2 SYSTEM MONITOR. Signed-off-by: Brian Cain <brian.c...@oss.qualcomm.com> --- target/hexagon/op_helper.c | 65 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/target/hexagon/op_helper.c b/target/hexagon/op_helper.c index 0dce133d3a..d0dc4afac7 100644 --- a/target/hexagon/op_helper.c +++ b/target/hexagon/op_helper.c @@ -1465,6 +1465,57 @@ void HELPER(stop)(CPUHexagonState *env) hexagon_stop_thread(env); } +static inline QEMU_ALWAYS_INLINE void resched(CPUHexagonState *env) +{ + uint32_t schedcfg; + uint32_t schedcfg_en; + int int_number; + CPUState *cs; + uint32_t lowest_th_prio = 0; /* 0 is highest prio */ + uint32_t bestwait_reg; + uint32_t best_prio; + + BQL_LOCK_GUARD(); + qemu_log_mask(CPU_LOG_INT, "%s: check resched\n", __func__); + schedcfg = arch_get_system_reg(env, HEX_SREG_SCHEDCFG); + schedcfg_en = GET_FIELD(SCHEDCFG_EN, schedcfg); + int_number = GET_FIELD(SCHEDCFG_INTNO, schedcfg); + + if (!schedcfg_en) { + return; + } + + CPU_FOREACH(cs) { + HexagonCPU *thread = HEXAGON_CPU(cs); + CPUHexagonState *thread_env = &(thread->env); + uint32_t th_prio = GET_FIELD( + STID_PRIO, arch_get_system_reg(thread_env, HEX_SREG_STID)); + if (!hexagon_thread_is_enabled(thread_env)) { + continue; + } + + lowest_th_prio = (lowest_th_prio > th_prio) + ? lowest_th_prio + : th_prio; + } + + bestwait_reg = arch_get_system_reg(env, HEX_SREG_BESTWAIT); + best_prio = GET_FIELD(BESTWAIT_PRIO, bestwait_reg); + + /* + * If the lowest priority thread is lower priority than the + * value in the BESTWAIT register, we must raise the reschedule + * interrupt on the lowest priority thread. + */ + if (lowest_th_prio > best_prio) { + qemu_log_mask(CPU_LOG_INT, + "%s: raising resched int %d, cur PC 0x" TARGET_FMT_lx "\n", + __func__, int_number, arch_get_thread_reg(env, HEX_REG_PC)); + SET_SYSTEM_FIELD(env, HEX_SREG_BESTWAIT, BESTWAIT_PRIO, 0x1ff); + hex_raise_interrupts(env, 1 << int_number, CPU_INTERRUPT_SWI); + } +} + void HELPER(wait)(CPUHexagonState *env, target_ulong PC) { BQL_LOCK_GUARD(); @@ -1715,6 +1766,20 @@ uint64_t HELPER(greg_read_pair)(CPUHexagonState *env, uint32_t reg) void HELPER(setprio)(CPUHexagonState *env, uint32_t thread, uint32_t prio) { + CPUState *cs; + + BQL_LOCK_GUARD(); + CPU_FOREACH(cs) { + HexagonCPU *found_cpu = HEXAGON_CPU(cs); + CPUHexagonState *found_env = &found_cpu->env; + if (thread == found_env->threadId) { + SET_SYSTEM_FIELD(found_env, HEX_SREG_STID, STID_PRIO, prio); + qemu_log_mask(CPU_LOG_INT, "%s: tid %d prio = 0x%x\n", + __func__, found_env->threadId, prio); + resched(env); + return; + } + } g_assert_not_reached(); } -- 2.34.1
