/* * Xen stolen ticks accounting. */ #include #include #include #include #include #include #include #include #include #include #include #include /* runstate info updated by Xen */ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); /* return an consistent snapshot of 64-bit time/counter value */ static u64 get64(const u64 *p) { u64 ret; if (BITS_PER_LONG < 64) { u32 *p32 = (u32 *)p; u32 h, l, h2; /* * Read high then low, and then make sure high is * still the same; this will only loop if low wraps * and carries into high. * XXX some clean way to make this endian-proof? */ do { h = READ_ONCE(p32[1]); l = READ_ONCE(p32[0]); h2 = READ_ONCE(p32[1]); } while(h2 != h); ret = (((u64)h) << 32) | l; } else ret = READ_ONCE(*p); return ret; } static void xen_get_runstate_snapshot_cpu(struct vcpu_runstate_info *res, unsigned int cpu) { u64 state_time; struct vcpu_runstate_info *state; BUG_ON(preemptible()); state = per_cpu_ptr(&xen_runstate, cpu); do { state_time = get64(&state->state_entry_time); rmb(); /* Hypervisor might update data. */ *res = READ_ONCE(*state); rmb(); /* Hypervisor might update data. */ } while (get64(&state->state_entry_time) != state_time || (state_time & XEN_RUNSTATE_UPDATE)); } /* * Runstate accounting */ void xen_get_runstate_snapshot(struct vcpu_runstate_info *res) { xen_get_runstate_snapshot_cpu(res, smp_processor_id()); } /* return true when a vcpu could run but has no real cpu to run on */ bool xen_vcpu_stolen(int vcpu) { return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; } u64 xen_steal_clock(int cpu) { struct vcpu_runstate_info state; xen_get_runstate_snapshot_cpu(&state, cpu); return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline]; } void xen_setup_runstate_info(int cpu) { struct vcpu_register_runstate_memory_area area; area.addr.v = &per_cpu(xen_runstate, cpu); if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, xen_vcpu_nr(cpu), &area)) BUG(); } void __init xen_time_setup_guest(void) { bool xen_runstate_remote; xen_runstate_remote = !HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_runstate_update_flag); pv_time_ops.steal_clock = xen_steal_clock; static_key_slow_inc(¶virt_steal_enabled); if (xen_runstate_remote) static_key_slow_inc(¶virt_steal_rq_enabled); } g msg

path: root/tools/build/feature/test-all.c

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