- else if (errata.piix4.bmisx) {
- if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
- || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
- pr->power.bm_activity |= 0x1;
- }
-
- pr->power.bm_check_timestamp = jiffies;
-
- /*
- * If bus mastering is or was active this jiffy, demote
- * to avoid a faulty transition. Note that the processor
- * won't enter a low-power state during this call (to this
- * function) but should upon the next.
- *
- * TBD: A better policy might be to fallback to the demotion
- * state (use it for this quantum only) istead of
- * demoting -- and rely on duration as our sole demotion
- * qualification. This may, however, introduce DMA
- * issues (e.g. floppy DMA transfer overrun/underrun).
- */
- if ((pr->power.bm_activity & 0x1) &&
- cx->demotion.threshold.bm) {
- local_irq_enable();
- next_state = cx->demotion.state;
- goto end;
- }
- }
-
-#ifdef CONFIG_HOTPLUG_CPU
- /*
- * Check for P_LVL2_UP flag before entering C2 and above on
- * an SMP system. We do it here instead of doing it at _CST/P_LVL
- * detection phase, to work cleanly with logical CPU hotplug.
- */
- if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
- !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
- cx = &pr->power.states[ACPI_STATE_C1];
-#endif
-
- /*
- * Sleep:
- * ------
- * Invoke the current Cx state to put the processor to sleep.
- */
- if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we
- * test NEED_RESCHED:
- */
- smp_mb();
- if (need_resched()) {
- current_thread_info()->status |= TS_POLLING;
- local_irq_enable();
- return;
- }
- }
-
- switch (cx->type) {
-
- case ACPI_STATE_C1:
- /*
- * Invoke C1.
- * Use the appropriate idle routine, the one that would
- * be used without acpi C-states.
- */
- if (pm_idle_save)
- pm_idle_save();
- else
- acpi_safe_halt();
-
- /*
- * TBD: Can't get time duration while in C1, as resumes
- * go to an ISR rather than here. Need to instrument
- * base interrupt handler.
- *
- * Note: the TSC better not stop in C1, sched_clock() will
- * skew otherwise.
- */
- sleep_ticks = 0xFFFFFFFF;
- break;
-
- case ACPI_STATE_C2:
- /* Get start time (ticks) */
- t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
- /* Tell the scheduler that we are going deep-idle: */
- sched_clock_idle_sleep_event();
- /* Invoke C2 */
- acpi_state_timer_broadcast(pr, cx, 1);
- acpi_cstate_enter(cx);
- /* Get end time (ticks) */
- t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
-
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
- /* TSC halts in C2, so notify users */
- mark_tsc_unstable("possible TSC halt in C2");
-#endif
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks = ticks_elapsed(t1, t2);
-
- /* Tell the scheduler how much we idled: */
- sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
-
- /* Re-enable interrupts */
- local_irq_enable();
- /* Do not account our idle-switching overhead: */
- sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
-
- current_thread_info()->status |= TS_POLLING;
- acpi_state_timer_broadcast(pr, cx, 0);
- break;
-
- case ACPI_STATE_C3:
- /*
- * disable bus master
- * bm_check implies we need ARB_DIS
- * !bm_check implies we need cache flush
- * bm_control implies whether we can do ARB_DIS
- *
- * That leaves a case where bm_check is set and bm_control is
- * not set. In that case we cannot do much, we enter C3
- * without doing anything.
- */
- if (pr->flags.bm_check && pr->flags.bm_control) {
- if (atomic_inc_return(&c3_cpu_count) ==
- num_online_cpus()) {
- /*
- * All CPUs are trying to go to C3
- * Disable bus master arbitration
- */
- acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
- }
- } else if (!pr->flags.bm_check) {
- /* SMP with no shared cache... Invalidate cache */
- ACPI_FLUSH_CPU_CACHE();
- }
-
- /* Get start time (ticks) */
- t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
- /* Invoke C3 */
- acpi_state_timer_broadcast(pr, cx, 1);
- /* Tell the scheduler that we are going deep-idle: */
- sched_clock_idle_sleep_event();
- acpi_cstate_enter(cx);
- /* Get end time (ticks) */
- t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
- if (pr->flags.bm_check && pr->flags.bm_control) {
- /* Enable bus master arbitration */
- atomic_dec(&c3_cpu_count);
- acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
- }
-
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
- /* TSC halts in C3, so notify users */
- mark_tsc_unstable("TSC halts in C3");
-#endif
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks = ticks_elapsed(t1, t2);
- /* Tell the scheduler how much we idled: */
- sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
-
- /* Re-enable interrupts */
- local_irq_enable();
- /* Do not account our idle-switching overhead: */
- sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
-
- current_thread_info()->status |= TS_POLLING;
- acpi_state_timer_broadcast(pr, cx, 0);
- break;