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51fac8388a
The second argument of ACPI driver .remove() operation is only used by the ACPI processor driver and the value passed to that driver through it is always available from the given struct acpi_device object's removal_type field. For this reason, the second ACPI driver .remove() argument is in fact useless, so drop it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Toshi Kani <toshi.kani@hp.com> Acked-by: Yinghai Lu <yinghai@kernel.org>
532 lines
13 KiB
C
532 lines
13 KiB
C
/*
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* acpi_pad.c ACPI Processor Aggregator Driver
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*
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* Copyright (c) 2009, Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/cpumask.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/kthread.h>
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#include <linux/freezer.h>
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#include <linux/cpu.h>
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#include <linux/clockchips.h>
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#include <linux/slab.h>
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#include <acpi/acpi_bus.h>
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#include <acpi/acpi_drivers.h>
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#include <asm/mwait.h>
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#define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad"
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#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"
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#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
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static DEFINE_MUTEX(isolated_cpus_lock);
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static DEFINE_MUTEX(round_robin_lock);
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static unsigned long power_saving_mwait_eax;
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static unsigned char tsc_detected_unstable;
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static unsigned char tsc_marked_unstable;
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static unsigned char lapic_detected_unstable;
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static unsigned char lapic_marked_unstable;
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static void power_saving_mwait_init(void)
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{
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unsigned int eax, ebx, ecx, edx;
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unsigned int highest_cstate = 0;
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unsigned int highest_subcstate = 0;
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int i;
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if (!boot_cpu_has(X86_FEATURE_MWAIT))
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return;
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if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
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return;
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cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx);
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if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
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!(ecx & CPUID5_ECX_INTERRUPT_BREAK))
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return;
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edx >>= MWAIT_SUBSTATE_SIZE;
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for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
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if (edx & MWAIT_SUBSTATE_MASK) {
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highest_cstate = i;
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highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
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}
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}
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power_saving_mwait_eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
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(highest_subcstate - 1);
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#if defined(CONFIG_X86)
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switch (boot_cpu_data.x86_vendor) {
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case X86_VENDOR_AMD:
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case X86_VENDOR_INTEL:
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/*
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* AMD Fam10h TSC will tick in all
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* C/P/S0/S1 states when this bit is set.
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*/
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if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
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tsc_detected_unstable = 1;
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if (!boot_cpu_has(X86_FEATURE_ARAT))
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lapic_detected_unstable = 1;
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break;
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default:
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/* TSC & LAPIC could halt in idle */
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tsc_detected_unstable = 1;
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lapic_detected_unstable = 1;
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}
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#endif
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}
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static unsigned long cpu_weight[NR_CPUS];
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static int tsk_in_cpu[NR_CPUS] = {[0 ... NR_CPUS-1] = -1};
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static DECLARE_BITMAP(pad_busy_cpus_bits, NR_CPUS);
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static void round_robin_cpu(unsigned int tsk_index)
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{
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struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);
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cpumask_var_t tmp;
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int cpu;
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unsigned long min_weight = -1;
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unsigned long uninitialized_var(preferred_cpu);
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if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
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return;
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mutex_lock(&round_robin_lock);
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cpumask_clear(tmp);
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for_each_cpu(cpu, pad_busy_cpus)
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cpumask_or(tmp, tmp, topology_thread_cpumask(cpu));
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cpumask_andnot(tmp, cpu_online_mask, tmp);
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/* avoid HT sibilings if possible */
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if (cpumask_empty(tmp))
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cpumask_andnot(tmp, cpu_online_mask, pad_busy_cpus);
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if (cpumask_empty(tmp)) {
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mutex_unlock(&round_robin_lock);
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return;
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}
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for_each_cpu(cpu, tmp) {
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if (cpu_weight[cpu] < min_weight) {
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min_weight = cpu_weight[cpu];
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preferred_cpu = cpu;
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}
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}
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if (tsk_in_cpu[tsk_index] != -1)
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cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);
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tsk_in_cpu[tsk_index] = preferred_cpu;
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cpumask_set_cpu(preferred_cpu, pad_busy_cpus);
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cpu_weight[preferred_cpu]++;
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mutex_unlock(&round_robin_lock);
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set_cpus_allowed_ptr(current, cpumask_of(preferred_cpu));
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}
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static void exit_round_robin(unsigned int tsk_index)
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{
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struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits);
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cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus);
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tsk_in_cpu[tsk_index] = -1;
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}
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static unsigned int idle_pct = 5; /* percentage */
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static unsigned int round_robin_time = 1; /* second */
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static int power_saving_thread(void *data)
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{
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struct sched_param param = {.sched_priority = 1};
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int do_sleep;
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unsigned int tsk_index = (unsigned long)data;
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u64 last_jiffies = 0;
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sched_setscheduler(current, SCHED_RR, ¶m);
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while (!kthread_should_stop()) {
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int cpu;
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u64 expire_time;
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try_to_freeze();
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/* round robin to cpus */
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if (last_jiffies + round_robin_time * HZ < jiffies) {
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last_jiffies = jiffies;
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round_robin_cpu(tsk_index);
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}
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do_sleep = 0;
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expire_time = jiffies + HZ * (100 - idle_pct) / 100;
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while (!need_resched()) {
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if (tsc_detected_unstable && !tsc_marked_unstable) {
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/* TSC could halt in idle, so notify users */
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mark_tsc_unstable("TSC halts in idle");
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tsc_marked_unstable = 1;
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}
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if (lapic_detected_unstable && !lapic_marked_unstable) {
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int i;
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/* LAPIC could halt in idle, so notify users */
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for_each_online_cpu(i)
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clockevents_notify(
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CLOCK_EVT_NOTIFY_BROADCAST_ON,
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&i);
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lapic_marked_unstable = 1;
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}
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local_irq_disable();
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cpu = smp_processor_id();
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if (lapic_marked_unstable)
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clockevents_notify(
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CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
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stop_critical_timings();
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__monitor((void *)¤t_thread_info()->flags, 0, 0);
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smp_mb();
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if (!need_resched())
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__mwait(power_saving_mwait_eax, 1);
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start_critical_timings();
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if (lapic_marked_unstable)
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clockevents_notify(
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CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
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local_irq_enable();
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if (jiffies > expire_time) {
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do_sleep = 1;
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break;
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}
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}
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/*
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* current sched_rt has threshold for rt task running time.
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* When a rt task uses 95% CPU time, the rt thread will be
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* scheduled out for 5% CPU time to not starve other tasks. But
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* the mechanism only works when all CPUs have RT task running,
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* as if one CPU hasn't RT task, RT task from other CPUs will
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* borrow CPU time from this CPU and cause RT task use > 95%
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* CPU time. To make 'avoid starvation' work, takes a nap here.
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*/
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if (do_sleep)
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schedule_timeout_killable(HZ * idle_pct / 100);
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}
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exit_round_robin(tsk_index);
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return 0;
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}
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static struct task_struct *ps_tsks[NR_CPUS];
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static unsigned int ps_tsk_num;
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static int create_power_saving_task(void)
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{
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int rc = -ENOMEM;
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ps_tsks[ps_tsk_num] = kthread_run(power_saving_thread,
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(void *)(unsigned long)ps_tsk_num,
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"acpi_pad/%d", ps_tsk_num);
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rc = IS_ERR(ps_tsks[ps_tsk_num]) ? PTR_ERR(ps_tsks[ps_tsk_num]) : 0;
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if (!rc)
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ps_tsk_num++;
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else
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ps_tsks[ps_tsk_num] = NULL;
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return rc;
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}
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static void destroy_power_saving_task(void)
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{
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if (ps_tsk_num > 0) {
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ps_tsk_num--;
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kthread_stop(ps_tsks[ps_tsk_num]);
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ps_tsks[ps_tsk_num] = NULL;
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}
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}
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static void set_power_saving_task_num(unsigned int num)
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{
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if (num > ps_tsk_num) {
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while (ps_tsk_num < num) {
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if (create_power_saving_task())
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return;
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}
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} else if (num < ps_tsk_num) {
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while (ps_tsk_num > num)
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destroy_power_saving_task();
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}
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}
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static void acpi_pad_idle_cpus(unsigned int num_cpus)
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{
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get_online_cpus();
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num_cpus = min_t(unsigned int, num_cpus, num_online_cpus());
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set_power_saving_task_num(num_cpus);
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put_online_cpus();
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}
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static uint32_t acpi_pad_idle_cpus_num(void)
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{
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return ps_tsk_num;
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}
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static ssize_t acpi_pad_rrtime_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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unsigned long num;
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if (kstrtoul(buf, 0, &num))
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return -EINVAL;
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if (num < 1 || num >= 100)
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return -EINVAL;
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mutex_lock(&isolated_cpus_lock);
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round_robin_time = num;
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mutex_unlock(&isolated_cpus_lock);
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return count;
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}
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static ssize_t acpi_pad_rrtime_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return scnprintf(buf, PAGE_SIZE, "%d\n", round_robin_time);
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}
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static DEVICE_ATTR(rrtime, S_IRUGO|S_IWUSR,
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acpi_pad_rrtime_show,
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acpi_pad_rrtime_store);
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static ssize_t acpi_pad_idlepct_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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unsigned long num;
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if (kstrtoul(buf, 0, &num))
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return -EINVAL;
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if (num < 1 || num >= 100)
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return -EINVAL;
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mutex_lock(&isolated_cpus_lock);
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idle_pct = num;
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mutex_unlock(&isolated_cpus_lock);
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return count;
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}
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static ssize_t acpi_pad_idlepct_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return scnprintf(buf, PAGE_SIZE, "%d\n", idle_pct);
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}
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static DEVICE_ATTR(idlepct, S_IRUGO|S_IWUSR,
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acpi_pad_idlepct_show,
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acpi_pad_idlepct_store);
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static ssize_t acpi_pad_idlecpus_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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unsigned long num;
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if (kstrtoul(buf, 0, &num))
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return -EINVAL;
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mutex_lock(&isolated_cpus_lock);
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acpi_pad_idle_cpus(num);
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mutex_unlock(&isolated_cpus_lock);
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return count;
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}
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static ssize_t acpi_pad_idlecpus_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int n = 0;
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n = cpumask_scnprintf(buf, PAGE_SIZE-2, to_cpumask(pad_busy_cpus_bits));
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buf[n++] = '\n';
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buf[n] = '\0';
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return n;
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}
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static DEVICE_ATTR(idlecpus, S_IRUGO|S_IWUSR,
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acpi_pad_idlecpus_show,
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acpi_pad_idlecpus_store);
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static int acpi_pad_add_sysfs(struct acpi_device *device)
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{
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int result;
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result = device_create_file(&device->dev, &dev_attr_idlecpus);
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if (result)
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return -ENODEV;
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result = device_create_file(&device->dev, &dev_attr_idlepct);
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if (result) {
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device_remove_file(&device->dev, &dev_attr_idlecpus);
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return -ENODEV;
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}
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result = device_create_file(&device->dev, &dev_attr_rrtime);
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if (result) {
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device_remove_file(&device->dev, &dev_attr_idlecpus);
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device_remove_file(&device->dev, &dev_attr_idlepct);
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return -ENODEV;
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}
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return 0;
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}
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static void acpi_pad_remove_sysfs(struct acpi_device *device)
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{
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device_remove_file(&device->dev, &dev_attr_idlecpus);
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device_remove_file(&device->dev, &dev_attr_idlepct);
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device_remove_file(&device->dev, &dev_attr_rrtime);
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}
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/*
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* Query firmware how many CPUs should be idle
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* return -1 on failure
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*/
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static int acpi_pad_pur(acpi_handle handle)
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{
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struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
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union acpi_object *package;
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int num = -1;
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if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
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return num;
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if (!buffer.length || !buffer.pointer)
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return num;
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package = buffer.pointer;
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if (package->type == ACPI_TYPE_PACKAGE &&
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package->package.count == 2 &&
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package->package.elements[0].integer.value == 1) /* rev 1 */
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num = package->package.elements[1].integer.value;
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kfree(buffer.pointer);
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return num;
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}
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/* Notify firmware how many CPUs are idle */
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static void acpi_pad_ost(acpi_handle handle, int stat,
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uint32_t idle_cpus)
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{
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union acpi_object params[3] = {
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{.type = ACPI_TYPE_INTEGER,},
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{.type = ACPI_TYPE_INTEGER,},
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{.type = ACPI_TYPE_BUFFER,},
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};
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struct acpi_object_list arg_list = {3, params};
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params[0].integer.value = ACPI_PROCESSOR_AGGREGATOR_NOTIFY;
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params[1].integer.value = stat;
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params[2].buffer.length = 4;
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params[2].buffer.pointer = (void *)&idle_cpus;
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acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
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}
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static void acpi_pad_handle_notify(acpi_handle handle)
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{
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int num_cpus;
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uint32_t idle_cpus;
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mutex_lock(&isolated_cpus_lock);
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num_cpus = acpi_pad_pur(handle);
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if (num_cpus < 0) {
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mutex_unlock(&isolated_cpus_lock);
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return;
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}
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acpi_pad_idle_cpus(num_cpus);
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idle_cpus = acpi_pad_idle_cpus_num();
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acpi_pad_ost(handle, 0, idle_cpus);
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mutex_unlock(&isolated_cpus_lock);
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}
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static void acpi_pad_notify(acpi_handle handle, u32 event,
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void *data)
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{
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struct acpi_device *device = data;
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switch (event) {
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case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
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acpi_pad_handle_notify(handle);
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acpi_bus_generate_proc_event(device, event, 0);
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acpi_bus_generate_netlink_event(device->pnp.device_class,
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dev_name(&device->dev), event, 0);
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break;
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default:
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pr_warn("Unsupported event [0x%x]\n", event);
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break;
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}
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}
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static int acpi_pad_add(struct acpi_device *device)
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{
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acpi_status status;
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strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);
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strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);
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if (acpi_pad_add_sysfs(device))
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return -ENODEV;
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status = acpi_install_notify_handler(device->handle,
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ACPI_DEVICE_NOTIFY, acpi_pad_notify, device);
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if (ACPI_FAILURE(status)) {
|
|
acpi_pad_remove_sysfs(device);
|
|
return -ENODEV;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int acpi_pad_remove(struct acpi_device *device)
|
|
{
|
|
mutex_lock(&isolated_cpus_lock);
|
|
acpi_pad_idle_cpus(0);
|
|
mutex_unlock(&isolated_cpus_lock);
|
|
|
|
acpi_remove_notify_handler(device->handle,
|
|
ACPI_DEVICE_NOTIFY, acpi_pad_notify);
|
|
acpi_pad_remove_sysfs(device);
|
|
return 0;
|
|
}
|
|
|
|
static const struct acpi_device_id pad_device_ids[] = {
|
|
{"ACPI000C", 0},
|
|
{"", 0},
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, pad_device_ids);
|
|
|
|
static struct acpi_driver acpi_pad_driver = {
|
|
.name = "processor_aggregator",
|
|
.class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
|
|
.ids = pad_device_ids,
|
|
.ops = {
|
|
.add = acpi_pad_add,
|
|
.remove = acpi_pad_remove,
|
|
},
|
|
};
|
|
|
|
static int __init acpi_pad_init(void)
|
|
{
|
|
power_saving_mwait_init();
|
|
if (power_saving_mwait_eax == 0)
|
|
return -EINVAL;
|
|
|
|
return acpi_bus_register_driver(&acpi_pad_driver);
|
|
}
|
|
|
|
static void __exit acpi_pad_exit(void)
|
|
{
|
|
acpi_bus_unregister_driver(&acpi_pad_driver);
|
|
}
|
|
|
|
module_init(acpi_pad_init);
|
|
module_exit(acpi_pad_exit);
|
|
MODULE_AUTHOR("Shaohua Li<shaohua.li@intel.com>");
|
|
MODULE_DESCRIPTION("ACPI Processor Aggregator Driver");
|
|
MODULE_LICENSE("GPL");
|