xref: /DragonOS/kernel/src/driver/clocksource/acpi_pm.rs (revision 7c28051e8c601312d3d0fd7bcb71bc71450d10c0)
1 use crate::{
2     alloc::string::ToString,
3     arch::{io::PortIOArch, CurrentPortIOArch},
4     driver::acpi::{
5         acpi_manager,
6         pmtmr::{ACPI_PM_MASK, PMTMR_TICKS_PER_SEC},
7     },
8     libs::spinlock::SpinLock,
9     time::{
10         clocksource::{Clocksource, ClocksourceData, ClocksourceFlags, ClocksourceMask, CycleNum},
11         PIT_TICK_RATE,
12     },
13 };
14 use acpi::fadt::Fadt;
15 use alloc::sync::{Arc, Weak};
16 use core::intrinsics::unlikely;
17 use core::sync::atomic::{AtomicU32, Ordering};
18 use log::info;
19 use system_error::SystemError;
20 
21 // 参考:https://code.dragonos.org.cn/xref/linux-6.6.21/drivers/clocksource/acpi_pm.c
22 
23 /// acpi_pmtmr所在的I/O端口
24 pub static PMTMR_IO_PORT: AtomicU32 = AtomicU32::new(0);
25 
26 /// # 读取acpi_pmtmr当前值,并对齐进行掩码操作
27 #[inline(always)]
28 fn read_pmtmr() -> u32 {
29     return unsafe { CurrentPortIOArch::in32(PMTMR_IO_PORT.load(Ordering::SeqCst) as u16) }
30         & ACPI_PM_MASK as u32;
31 }
32 
33 //参考: https://code.dragonos.org.cn/xref/linux-6.6.21/drivers/clocksource/acpi_pm.c#41
34 /// # 读取acpi_pmtmr的值,并进行多次读取以保证获取正确的值
35 ///
36 /// ## 返回值
37 /// - u32: 读取到的acpi_pmtmr值
38 #[allow(dead_code)]
39 pub fn acpi_pm_read_verified() -> u32 {
40     let mut v2: u32;
41 
42     // 因为某些损坏芯片组(如ICH4、PIIX4和PIIX4E)可能导致APCI PM时钟源未锁存
43     // 因此需要多次读取以保证获取正确的值
44     loop {
45         let v1 = read_pmtmr();
46         v2 = read_pmtmr();
47         let v3 = read_pmtmr();
48 
49         if !(unlikely((v2 > v3 || v1 < v3) && v1 > v2 || v1 < v3 && v2 > v3)) {
50             break;
51         }
52     }
53 
54     return v2;
55 }
56 
57 /// # 作为时钟源的读取函数
58 ///
59 /// ## 返回值
60 /// - u64: acpi_pmtmr的当前值
61 fn acpi_pm_read() -> u64 {
62     return read_pmtmr() as u64;
63 }
64 
65 pub static mut CLOCKSOURCE_ACPI_PM: Option<Arc<Acpipm>> = None;
66 
67 pub fn clocksource_acpi_pm() -> Arc<Acpipm> {
68     return unsafe { CLOCKSOURCE_ACPI_PM.as_ref().unwrap().clone() };
69 }
70 
71 #[derive(Debug)]
72 pub struct Acpipm(SpinLock<InnerAcpipm>);
73 
74 #[derive(Debug)]
75 struct InnerAcpipm {
76     data: ClocksourceData,
77     self_reaf: Weak<Acpipm>,
78 }
79 
80 impl Acpipm {
81     pub fn new() -> Arc<Self> {
82         let data = ClocksourceData {
83             name: "acpi_pm".to_string(),
84             rating: 200,
85             mask: ClocksourceMask::new(ACPI_PM_MASK),
86             mult: 0,
87             shift: 0,
88             max_idle_ns: Default::default(),
89             flags: ClocksourceFlags::CLOCK_SOURCE_IS_CONTINUOUS,
90             watchdog_last: CycleNum::new(0),
91             cs_last: CycleNum::new(0),
92             uncertainty_margin: 0,
93             maxadj: 0,
94             cycle_last: CycleNum::new(0),
95         };
96         let acpi_pm = Arc::new(Acpipm(SpinLock::new(InnerAcpipm {
97             data,
98             self_reaf: Default::default(),
99         })));
100         acpi_pm.0.lock().self_reaf = Arc::downgrade(&acpi_pm);
101 
102         return acpi_pm;
103     }
104 }
105 
106 impl Clocksource for Acpipm {
107     fn read(&self) -> CycleNum {
108         return CycleNum::new(acpi_pm_read());
109     }
110 
111     fn clocksource_data(&self) -> ClocksourceData {
112         let inner = self.0.lock_irqsave();
113         return inner.data.clone();
114     }
115 
116     fn clocksource(&self) -> Arc<dyn Clocksource> {
117         return self.0.lock_irqsave().self_reaf.upgrade().unwrap();
118     }
119 
120     fn update_clocksource_data(&self, data: ClocksourceData) -> Result<(), SystemError> {
121         let d = &mut self.0.lock_irqsave().data;
122         d.set_name(data.name);
123         d.set_rating(data.rating);
124         d.set_mask(data.mask);
125         d.set_mult(data.mult);
126         d.set_shift(data.shift);
127         d.set_max_idle_ns(data.max_idle_ns);
128         d.set_flags(data.flags);
129         d.watchdog_last = data.watchdog_last;
130         d.cs_last = data.cs_last;
131         d.set_uncertainty_margin(data.uncertainty_margin);
132         d.set_maxadj(data.maxadj);
133         d.cycle_last = data.cycle_last;
134         return Ok(());
135     }
136 }
137 
138 // 参考:https://code.dragonos.org.cn/xref/linux-6.6.21/arch/x86/include/asm/mach_timer.h?fi=mach_prepare_counter
139 #[allow(dead_code)]
140 pub const CALIBRATE_TIME_MSEC: u64 = 30;
141 pub const CALIBRATE_LATCH: u64 = (PIT_TICK_RATE * CALIBRATE_TIME_MSEC + 1000 / 2) / 1000;
142 
143 #[inline(always)]
144 #[allow(dead_code)]
145 pub fn mach_prepare_counter() {
146     unsafe {
147         // 将Gate位设置为高电平,从而禁用扬声器
148         CurrentPortIOArch::out8(0x61, (CurrentPortIOArch::in8(0x61) & !0x02) | 0x01);
149 
150         // 针对计数器/定时器控制器的通道2进行配置,设置为模式0,二进制计数
151         CurrentPortIOArch::out8(0x43, 0xb0);
152         CurrentPortIOArch::out8(0x42, (CALIBRATE_LATCH & 0xff) as u8);
153         CurrentPortIOArch::out8(0x42, (CALIBRATE_LATCH >> 8) as u8);
154     }
155 }
156 
157 #[allow(dead_code)]
158 pub fn mach_countup(count: &mut u32) {
159     let mut tmp: u32 = 0;
160     loop {
161         tmp += 1;
162         if (unsafe { CurrentPortIOArch::in8(0x61) } & 0x20) != 0 {
163             break;
164         }
165     }
166     *count = tmp;
167 }
168 
169 #[allow(dead_code)]
170 const PMTMR_EXPECTED_RATE: u64 =
171     (CALIBRATE_LATCH * (PMTMR_TICKS_PER_SEC >> 10)) / (PIT_TICK_RATE >> 10);
172 
173 /// # 验证ACPI PM Timer的运行速率是否在预期范围内(在x86_64架构以外的情况下验证)
174 ///
175 /// ## 返回值
176 /// - i32:如果为0则表示在预期范围内,否则不在
177 #[cfg(not(target_arch = "x86_64"))]
178 #[allow(dead_code)]
179 fn verify_pmtmr_rate() -> bool {
180     use log::info;
181 
182     let mut count: u32 = 0;
183 
184     mach_prepare_counter();
185     let value1 = clocksource_acpi_pm().read().data();
186     mach_countup(&mut count);
187     let value2 = clocksource_acpi_pm().read().data();
188     let delta = (value2 - value1) & ACPI_PM_MASK;
189 
190     if (delta < (PMTMR_EXPECTED_RATE * 19) / 20) || (delta > (PMTMR_EXPECTED_RATE * 21) / 20) {
191         info!(
192             "PM Timer running at invalid rate: {}",
193             100 * delta / PMTMR_EXPECTED_RATE
194         );
195         return false;
196     }
197 
198     return true;
199 }
200 #[cfg(target_arch = "x86_64")]
201 fn verify_pmtmr_rate() -> bool {
202     return true;
203 }
204 
205 const ACPI_PM_MONOTONIC_CHECKS: u32 = 10;
206 const ACPI_PM_READ_CHECKS: u32 = 10000;
207 
208 /// # 解析fadt
209 fn find_acpi_pm_clock() -> Result<(), SystemError> {
210     let fadt = acpi_manager()
211         .tables()
212         .unwrap()
213         .find_table::<Fadt>()
214         .expect("failed to find FADT table");
215     let pm_timer_block = fadt.pm_timer_block().map_err(|_| SystemError::ENODEV)?;
216     let pm_timer_block = pm_timer_block.ok_or(SystemError::ENODEV)?;
217     let pmtmr_addr = pm_timer_block.address;
218 
219     PMTMR_IO_PORT.store(pmtmr_addr as u32, Ordering::SeqCst);
220 
221     info!(
222         "apic_pmtmr I/O port: {}",
223         PMTMR_IO_PORT.load(Ordering::SeqCst)
224     );
225 
226     return Ok(());
227 }
228 
229 /// # 初始化ACPI PM Timer作为系统时钟源
230 // #[unified_init(INITCALL_FS)]
231 #[inline(never)]
232 #[allow(dead_code)]
233 pub fn init_acpi_pm_clocksource() -> Result<(), SystemError> {
234     let acpi_pm = Acpipm::new();
235 
236     // 解析fadt
237     find_acpi_pm_clock()?;
238 
239     // 检查pmtmr_io_port是否被设置
240     if PMTMR_IO_PORT.load(Ordering::SeqCst) == 0 {
241         return Err(SystemError::ENODEV);
242     }
243 
244     unsafe {
245         CLOCKSOURCE_ACPI_PM = Some(acpi_pm);
246     }
247 
248     // 验证ACPI PM Timer作为时钟源的稳定性和一致性
249     for j in 0..ACPI_PM_MONOTONIC_CHECKS {
250         let mut cnt = 100 * j;
251         while cnt > 0 {
252             cnt -= 1;
253         }
254 
255         let value1 = clocksource_acpi_pm().read().data();
256         let mut i = 0;
257         for _ in 0..ACPI_PM_READ_CHECKS {
258             let value2 = clocksource_acpi_pm().read().data();
259             if value2 == value1 {
260                 i += 1;
261                 continue;
262             }
263             if value2 > value1 {
264                 break;
265             }
266             if (value2 < value1) && (value2 < 0xfff) {
267                 break;
268             }
269             info!("PM Timer had inconsistens results: {} {}", value1, value2);
270 
271             PMTMR_IO_PORT.store(0, Ordering::SeqCst);
272 
273             return Err(SystemError::EINVAL);
274         }
275         if i == ACPI_PM_READ_CHECKS {
276             info!("PM Timer failed consistency check: {}", value1);
277 
278             PMTMR_IO_PORT.store(0, Ordering::SeqCst);
279 
280             return Err(SystemError::EINVAL);
281         }
282     }
283 
284     // 检查ACPI PM Timer的频率是否正确
285     if !verify_pmtmr_rate() {
286         PMTMR_IO_PORT.store(0, Ordering::SeqCst);
287     }
288 
289     // 检查TSC时钟源的监视器是否被禁用,如果被禁用则将时钟源的标志设置为CLOCK_SOURCE_MUST_VERIFY
290     // 是因为jiffies精度小于acpi pm,所以不需要被jiffies监视
291     let tsc_clocksource_watchdog_disabled = false;
292     if tsc_clocksource_watchdog_disabled {
293         clocksource_acpi_pm().0.lock_irqsave().data.flags |=
294             ClocksourceFlags::CLOCK_SOURCE_MUST_VERIFY;
295     }
296 
297     // 注册ACPI PM Timer
298     let acpi_pmtmr = clocksource_acpi_pm() as Arc<dyn Clocksource>;
299     match acpi_pmtmr.register(1, PMTMR_TICKS_PER_SEC as u32) {
300         Ok(_) => {
301             info!("ACPI PM Timer registered as clocksource sccessfully");
302             return Ok(());
303         }
304         Err(_) => {
305             info!("ACPI PM Timer init registered failed");
306             return Err(SystemError::ENOSYS);
307         }
308     };
309 }
310