1 // Copyright 2024, Linaro Limited 2 // Author(s): Manos Pitsidianakis <manos.pitsidianakis@linaro.org> 3 // SPDX-License-Identifier: GPL-2.0-or-later 4 5 use core::ptr::{addr_of_mut, NonNull}; 6 use std::{ 7 ffi::CStr, 8 os::raw::{c_int, c_uchar, c_uint, c_void}, 9 }; 10 11 use qemu_api::{ 12 bindings::{self, *}, 13 c_str, 14 definitions::ObjectImpl, 15 device_class::{DeviceImpl, TYPE_SYS_BUS_DEVICE}, 16 impl_device_class, 17 irq::InterruptSource, 18 }; 19 20 use crate::{ 21 device_class, 22 memory_ops::PL011_OPS, 23 registers::{self, Interrupt}, 24 RegisterOffset, 25 }; 26 27 /// Integer Baud Rate Divider, `UARTIBRD` 28 const IBRD_MASK: u32 = 0xffff; 29 30 /// Fractional Baud Rate Divider, `UARTFBRD` 31 const FBRD_MASK: u32 = 0x3f; 32 33 const DATA_BREAK: u32 = 1 << 10; 34 35 /// QEMU sourced constant. 36 pub const PL011_FIFO_DEPTH: usize = 16_usize; 37 38 #[derive(Clone, Copy, Debug)] 39 enum DeviceId { 40 #[allow(dead_code)] 41 Arm = 0, 42 Luminary, 43 } 44 45 impl std::ops::Index<hwaddr> for DeviceId { 46 type Output = c_uchar; 47 48 fn index(&self, idx: hwaddr) -> &Self::Output { 49 match self { 50 Self::Arm => &Self::PL011_ID_ARM[idx as usize], 51 Self::Luminary => &Self::PL011_ID_LUMINARY[idx as usize], 52 } 53 } 54 } 55 56 impl DeviceId { 57 const PL011_ID_ARM: [c_uchar; 8] = [0x11, 0x10, 0x14, 0x00, 0x0d, 0xf0, 0x05, 0xb1]; 58 const PL011_ID_LUMINARY: [c_uchar; 8] = [0x11, 0x00, 0x18, 0x01, 0x0d, 0xf0, 0x05, 0xb1]; 59 } 60 61 #[repr(C)] 62 #[derive(Debug, qemu_api_macros::Object, qemu_api_macros::offsets)] 63 /// PL011 Device Model in QEMU 64 pub struct PL011State { 65 pub parent_obj: SysBusDevice, 66 pub iomem: MemoryRegion, 67 #[doc(alias = "fr")] 68 pub flags: registers::Flags, 69 #[doc(alias = "lcr")] 70 pub line_control: registers::LineControl, 71 #[doc(alias = "rsr")] 72 pub receive_status_error_clear: registers::ReceiveStatusErrorClear, 73 #[doc(alias = "cr")] 74 pub control: registers::Control, 75 pub dmacr: u32, 76 pub int_enabled: u32, 77 pub int_level: u32, 78 pub read_fifo: [u32; PL011_FIFO_DEPTH], 79 pub ilpr: u32, 80 pub ibrd: u32, 81 pub fbrd: u32, 82 pub ifl: u32, 83 pub read_pos: usize, 84 pub read_count: usize, 85 pub read_trigger: usize, 86 #[doc(alias = "chr")] 87 pub char_backend: CharBackend, 88 /// QEMU interrupts 89 /// 90 /// ```text 91 /// * sysbus MMIO region 0: device registers 92 /// * sysbus IRQ 0: `UARTINTR` (combined interrupt line) 93 /// * sysbus IRQ 1: `UARTRXINTR` (receive FIFO interrupt line) 94 /// * sysbus IRQ 2: `UARTTXINTR` (transmit FIFO interrupt line) 95 /// * sysbus IRQ 3: `UARTRTINTR` (receive timeout interrupt line) 96 /// * sysbus IRQ 4: `UARTMSINTR` (momem status interrupt line) 97 /// * sysbus IRQ 5: `UARTEINTR` (error interrupt line) 98 /// ``` 99 #[doc(alias = "irq")] 100 pub interrupts: [InterruptSource; IRQMASK.len()], 101 #[doc(alias = "clk")] 102 pub clock: NonNull<Clock>, 103 #[doc(alias = "migrate_clk")] 104 pub migrate_clock: bool, 105 /// The byte string that identifies the device. 106 device_id: DeviceId, 107 } 108 109 impl ObjectImpl for PL011State { 110 type Class = PL011Class; 111 const TYPE_NAME: &'static CStr = crate::TYPE_PL011; 112 const PARENT_TYPE_NAME: Option<&'static CStr> = Some(TYPE_SYS_BUS_DEVICE); 113 const INSTANCE_INIT: Option<unsafe fn(&mut Self)> = Some(Self::init); 114 } 115 116 #[repr(C)] 117 pub struct PL011Class { 118 _inner: [u8; 0], 119 } 120 121 impl DeviceImpl for PL011State { 122 fn properties() -> &'static [Property] { 123 &device_class::PL011_PROPERTIES 124 } 125 fn vmsd() -> Option<&'static VMStateDescription> { 126 Some(&device_class::VMSTATE_PL011) 127 } 128 const REALIZE: Option<fn(&mut Self)> = Some(Self::realize); 129 const RESET: Option<fn(&mut Self)> = Some(Self::reset); 130 } 131 132 impl_device_class!(PL011State); 133 134 impl PL011State { 135 /// Initializes a pre-allocated, unitialized instance of `PL011State`. 136 /// 137 /// # Safety 138 /// 139 /// `self` must point to a correctly sized and aligned location for the 140 /// `PL011State` type. It must not be called more than once on the same 141 /// location/instance. All its fields are expected to hold unitialized 142 /// values with the sole exception of `parent_obj`. 143 unsafe fn init(&mut self) { 144 const CLK_NAME: &CStr = c_str!("clk"); 145 146 let sbd = unsafe { &mut *(addr_of_mut!(*self).cast::<SysBusDevice>()) }; 147 148 // SAFETY: 149 // 150 // self and self.iomem are guaranteed to be valid at this point since callers 151 // must make sure the `self` reference is valid. 152 unsafe { 153 memory_region_init_io( 154 addr_of_mut!(self.iomem), 155 addr_of_mut!(*self).cast::<Object>(), 156 &PL011_OPS, 157 addr_of_mut!(*self).cast::<c_void>(), 158 Self::TYPE_NAME.as_ptr(), 159 0x1000, 160 ); 161 sysbus_init_mmio(sbd, addr_of_mut!(self.iomem)); 162 } 163 164 for irq in self.interrupts.iter() { 165 sbd.init_irq(irq); 166 } 167 168 let dev = addr_of_mut!(*self).cast::<DeviceState>(); 169 170 // SAFETY: 171 // 172 // self.clock is not initialized at this point; but since `NonNull<_>` is Copy, 173 // we can overwrite the undefined value without side effects. This is 174 // safe since all PL011State instances are created by QOM code which 175 // calls this function to initialize the fields; therefore no code is 176 // able to access an invalid self.clock value. 177 unsafe { 178 self.clock = NonNull::new(qdev_init_clock_in( 179 dev, 180 CLK_NAME.as_ptr(), 181 None, /* pl011_clock_update */ 182 addr_of_mut!(*self).cast::<c_void>(), 183 ClockEvent::ClockUpdate.0, 184 )) 185 .unwrap(); 186 } 187 } 188 189 pub fn read(&mut self, offset: hwaddr, _size: c_uint) -> std::ops::ControlFlow<u64, u64> { 190 use RegisterOffset::*; 191 192 std::ops::ControlFlow::Break(match RegisterOffset::try_from(offset) { 193 Err(v) if (0x3f8..0x400).contains(&(v >> 2)) => { 194 u64::from(self.device_id[(offset - 0xfe0) >> 2]) 195 } 196 Err(_) => { 197 // qemu_log_mask(LOG_GUEST_ERROR, "pl011_read: Bad offset 0x%x\n", (int)offset); 198 0 199 } 200 Ok(DR) => { 201 self.flags.set_receive_fifo_full(false); 202 let c = self.read_fifo[self.read_pos]; 203 if self.read_count > 0 { 204 self.read_count -= 1; 205 self.read_pos = (self.read_pos + 1) & (self.fifo_depth() - 1); 206 } 207 if self.read_count == 0 { 208 self.flags.set_receive_fifo_empty(true); 209 } 210 if self.read_count + 1 == self.read_trigger { 211 self.int_level &= !registers::INT_RX; 212 } 213 // Update error bits. 214 self.receive_status_error_clear = c.to_be_bytes()[3].into(); 215 self.update(); 216 // Must call qemu_chr_fe_accept_input, so return Continue: 217 return std::ops::ControlFlow::Continue(c.into()); 218 } 219 Ok(RSR) => u8::from(self.receive_status_error_clear).into(), 220 Ok(FR) => u16::from(self.flags).into(), 221 Ok(FBRD) => self.fbrd.into(), 222 Ok(ILPR) => self.ilpr.into(), 223 Ok(IBRD) => self.ibrd.into(), 224 Ok(LCR_H) => u16::from(self.line_control).into(), 225 Ok(CR) => { 226 // We exercise our self-control. 227 u16::from(self.control).into() 228 } 229 Ok(FLS) => self.ifl.into(), 230 Ok(IMSC) => self.int_enabled.into(), 231 Ok(RIS) => self.int_level.into(), 232 Ok(MIS) => u64::from(self.int_level & self.int_enabled), 233 Ok(ICR) => { 234 // "The UARTICR Register is the interrupt clear register and is write-only" 235 // Source: ARM DDI 0183G 3.3.13 Interrupt Clear Register, UARTICR 236 0 237 } 238 Ok(DMACR) => self.dmacr.into(), 239 }) 240 } 241 242 pub fn write(&mut self, offset: hwaddr, value: u64) { 243 // eprintln!("write offset {offset} value {value}"); 244 use RegisterOffset::*; 245 let value: u32 = value as u32; 246 match RegisterOffset::try_from(offset) { 247 Err(_bad_offset) => { 248 eprintln!("write bad offset {offset} value {value}"); 249 } 250 Ok(DR) => { 251 // ??? Check if transmitter is enabled. 252 let ch: u8 = value as u8; 253 // XXX this blocks entire thread. Rewrite to use 254 // qemu_chr_fe_write and background I/O callbacks 255 256 // SAFETY: self.char_backend is a valid CharBackend instance after it's been 257 // initialized in realize(). 258 unsafe { 259 qemu_chr_fe_write_all(addr_of_mut!(self.char_backend), &ch, 1); 260 } 261 self.loopback_tx(value); 262 self.int_level |= registers::INT_TX; 263 self.update(); 264 } 265 Ok(RSR) => { 266 self.receive_status_error_clear = 0.into(); 267 } 268 Ok(FR) => { 269 // flag writes are ignored 270 } 271 Ok(ILPR) => { 272 self.ilpr = value; 273 } 274 Ok(IBRD) => { 275 self.ibrd = value; 276 } 277 Ok(FBRD) => { 278 self.fbrd = value; 279 } 280 Ok(LCR_H) => { 281 let value = value as u16; 282 let new_val: registers::LineControl = value.into(); 283 // Reset the FIFO state on FIFO enable or disable 284 if bool::from(self.line_control.fifos_enabled()) 285 ^ bool::from(new_val.fifos_enabled()) 286 { 287 self.reset_fifo(); 288 } 289 if self.line_control.send_break() ^ new_val.send_break() { 290 let mut break_enable: c_int = new_val.send_break().into(); 291 // SAFETY: self.char_backend is a valid CharBackend instance after it's been 292 // initialized in realize(). 293 unsafe { 294 qemu_chr_fe_ioctl( 295 addr_of_mut!(self.char_backend), 296 CHR_IOCTL_SERIAL_SET_BREAK as i32, 297 addr_of_mut!(break_enable).cast::<c_void>(), 298 ); 299 } 300 self.loopback_break(break_enable > 0); 301 } 302 self.line_control = new_val; 303 self.set_read_trigger(); 304 } 305 Ok(CR) => { 306 // ??? Need to implement the enable bit. 307 let value = value as u16; 308 self.control = value.into(); 309 self.loopback_mdmctrl(); 310 } 311 Ok(FLS) => { 312 self.ifl = value; 313 self.set_read_trigger(); 314 } 315 Ok(IMSC) => { 316 self.int_enabled = value; 317 self.update(); 318 } 319 Ok(RIS) => {} 320 Ok(MIS) => {} 321 Ok(ICR) => { 322 self.int_level &= !value; 323 self.update(); 324 } 325 Ok(DMACR) => { 326 self.dmacr = value; 327 if value & 3 > 0 { 328 // qemu_log_mask(LOG_UNIMP, "pl011: DMA not implemented\n"); 329 eprintln!("pl011: DMA not implemented"); 330 } 331 } 332 } 333 } 334 335 #[inline] 336 fn loopback_tx(&mut self, value: u32) { 337 if !self.loopback_enabled() { 338 return; 339 } 340 341 // Caveat: 342 // 343 // In real hardware, TX loopback happens at the serial-bit level 344 // and then reassembled by the RX logics back into bytes and placed 345 // into the RX fifo. That is, loopback happens after TX fifo. 346 // 347 // Because the real hardware TX fifo is time-drained at the frame 348 // rate governed by the configured serial format, some loopback 349 // bytes in TX fifo may still be able to get into the RX fifo 350 // that could be full at times while being drained at software 351 // pace. 352 // 353 // In such scenario, the RX draining pace is the major factor 354 // deciding which loopback bytes get into the RX fifo, unless 355 // hardware flow-control is enabled. 356 // 357 // For simplicity, the above described is not emulated. 358 self.put_fifo(value); 359 } 360 361 fn loopback_mdmctrl(&mut self) { 362 if !self.loopback_enabled() { 363 return; 364 } 365 366 /* 367 * Loopback software-driven modem control outputs to modem status inputs: 368 * FR.RI <= CR.Out2 369 * FR.DCD <= CR.Out1 370 * FR.CTS <= CR.RTS 371 * FR.DSR <= CR.DTR 372 * 373 * The loopback happens immediately even if this call is triggered 374 * by setting only CR.LBE. 375 * 376 * CTS/RTS updates due to enabled hardware flow controls are not 377 * dealt with here. 378 */ 379 380 self.flags.set_ring_indicator(self.control.out_2()); 381 self.flags.set_data_carrier_detect(self.control.out_1()); 382 self.flags.set_clear_to_send(self.control.request_to_send()); 383 self.flags 384 .set_data_set_ready(self.control.data_transmit_ready()); 385 386 // Change interrupts based on updated FR 387 let mut il = self.int_level; 388 389 il &= !Interrupt::MS; 390 391 if self.flags.data_set_ready() { 392 il |= Interrupt::DSR as u32; 393 } 394 if self.flags.data_carrier_detect() { 395 il |= Interrupt::DCD as u32; 396 } 397 if self.flags.clear_to_send() { 398 il |= Interrupt::CTS as u32; 399 } 400 if self.flags.ring_indicator() { 401 il |= Interrupt::RI as u32; 402 } 403 self.int_level = il; 404 self.update(); 405 } 406 407 fn loopback_break(&mut self, enable: bool) { 408 if enable { 409 self.loopback_tx(DATA_BREAK); 410 } 411 } 412 413 fn set_read_trigger(&mut self) { 414 self.read_trigger = 1; 415 } 416 417 pub fn realize(&mut self) { 418 // SAFETY: self.char_backend has the correct size and alignment for a 419 // CharBackend object, and its callbacks are of the correct types. 420 unsafe { 421 qemu_chr_fe_set_handlers( 422 addr_of_mut!(self.char_backend), 423 Some(pl011_can_receive), 424 Some(pl011_receive), 425 Some(pl011_event), 426 None, 427 addr_of_mut!(*self).cast::<c_void>(), 428 core::ptr::null_mut(), 429 true, 430 ); 431 } 432 } 433 434 pub fn reset(&mut self) { 435 self.line_control.reset(); 436 self.receive_status_error_clear.reset(); 437 self.dmacr = 0; 438 self.int_enabled = 0; 439 self.int_level = 0; 440 self.ilpr = 0; 441 self.ibrd = 0; 442 self.fbrd = 0; 443 self.read_trigger = 1; 444 self.ifl = 0x12; 445 self.control.reset(); 446 self.flags = 0.into(); 447 self.reset_fifo(); 448 } 449 450 pub fn reset_fifo(&mut self) { 451 self.read_count = 0; 452 self.read_pos = 0; 453 454 /* Reset FIFO flags */ 455 self.flags.reset(); 456 } 457 458 pub fn can_receive(&self) -> bool { 459 // trace_pl011_can_receive(s->lcr, s->read_count, r); 460 self.read_count < self.fifo_depth() 461 } 462 463 pub fn event(&mut self, event: QEMUChrEvent) { 464 if event == bindings::QEMUChrEvent::CHR_EVENT_BREAK && !self.fifo_enabled() { 465 self.put_fifo(DATA_BREAK); 466 self.receive_status_error_clear.set_break_error(true); 467 } 468 } 469 470 #[inline] 471 pub fn fifo_enabled(&self) -> bool { 472 matches!(self.line_control.fifos_enabled(), registers::Mode::FIFO) 473 } 474 475 #[inline] 476 pub fn loopback_enabled(&self) -> bool { 477 self.control.enable_loopback() 478 } 479 480 #[inline] 481 pub fn fifo_depth(&self) -> usize { 482 // Note: FIFO depth is expected to be power-of-2 483 if self.fifo_enabled() { 484 return PL011_FIFO_DEPTH; 485 } 486 1 487 } 488 489 pub fn put_fifo(&mut self, value: c_uint) { 490 let depth = self.fifo_depth(); 491 assert!(depth > 0); 492 let slot = (self.read_pos + self.read_count) & (depth - 1); 493 self.read_fifo[slot] = value; 494 self.read_count += 1; 495 self.flags.set_receive_fifo_empty(false); 496 if self.read_count == depth { 497 self.flags.set_receive_fifo_full(true); 498 } 499 500 if self.read_count == self.read_trigger { 501 self.int_level |= registers::INT_RX; 502 self.update(); 503 } 504 } 505 506 pub fn update(&self) { 507 let flags = self.int_level & self.int_enabled; 508 for (irq, i) in self.interrupts.iter().zip(IRQMASK) { 509 irq.set(flags & i != 0); 510 } 511 } 512 513 pub fn post_load(&mut self, _version_id: u32) -> Result<(), ()> { 514 /* Sanity-check input state */ 515 if self.read_pos >= self.read_fifo.len() || self.read_count > self.read_fifo.len() { 516 return Err(()); 517 } 518 519 if !self.fifo_enabled() && self.read_count > 0 && self.read_pos > 0 { 520 // Older versions of PL011 didn't ensure that the single 521 // character in the FIFO in FIFO-disabled mode is in 522 // element 0 of the array; convert to follow the current 523 // code's assumptions. 524 self.read_fifo[0] = self.read_fifo[self.read_pos]; 525 self.read_pos = 0; 526 } 527 528 self.ibrd &= IBRD_MASK; 529 self.fbrd &= FBRD_MASK; 530 531 Ok(()) 532 } 533 } 534 535 /// Which bits in the interrupt status matter for each outbound IRQ line ? 536 pub const IRQMASK: [u32; 6] = [ 537 /* combined IRQ */ 538 Interrupt::E 539 | Interrupt::MS 540 | Interrupt::RT as u32 541 | Interrupt::TX as u32 542 | Interrupt::RX as u32, 543 Interrupt::RX as u32, 544 Interrupt::TX as u32, 545 Interrupt::RT as u32, 546 Interrupt::MS, 547 Interrupt::E, 548 ]; 549 550 /// # Safety 551 /// 552 /// We expect the FFI user of this function to pass a valid pointer, that has 553 /// the same size as [`PL011State`]. We also expect the device is 554 /// readable/writeable from one thread at any time. 555 pub unsafe extern "C" fn pl011_can_receive(opaque: *mut c_void) -> c_int { 556 unsafe { 557 debug_assert!(!opaque.is_null()); 558 let state = NonNull::new_unchecked(opaque.cast::<PL011State>()); 559 state.as_ref().can_receive().into() 560 } 561 } 562 563 /// # Safety 564 /// 565 /// We expect the FFI user of this function to pass a valid pointer, that has 566 /// the same size as [`PL011State`]. We also expect the device is 567 /// readable/writeable from one thread at any time. 568 /// 569 /// The buffer and size arguments must also be valid. 570 pub unsafe extern "C" fn pl011_receive(opaque: *mut c_void, buf: *const u8, size: c_int) { 571 unsafe { 572 debug_assert!(!opaque.is_null()); 573 let mut state = NonNull::new_unchecked(opaque.cast::<PL011State>()); 574 if state.as_ref().loopback_enabled() { 575 return; 576 } 577 if size > 0 { 578 debug_assert!(!buf.is_null()); 579 state.as_mut().put_fifo(c_uint::from(buf.read_volatile())) 580 } 581 } 582 } 583 584 /// # Safety 585 /// 586 /// We expect the FFI user of this function to pass a valid pointer, that has 587 /// the same size as [`PL011State`]. We also expect the device is 588 /// readable/writeable from one thread at any time. 589 pub unsafe extern "C" fn pl011_event(opaque: *mut c_void, event: QEMUChrEvent) { 590 unsafe { 591 debug_assert!(!opaque.is_null()); 592 let mut state = NonNull::new_unchecked(opaque.cast::<PL011State>()); 593 state.as_mut().event(event) 594 } 595 } 596 597 /// # Safety 598 /// 599 /// We expect the FFI user of this function to pass a valid pointer for `chr`. 600 #[no_mangle] 601 pub unsafe extern "C" fn pl011_create( 602 addr: u64, 603 irq: qemu_irq, 604 chr: *mut Chardev, 605 ) -> *mut DeviceState { 606 unsafe { 607 let dev: *mut DeviceState = qdev_new(PL011State::TYPE_NAME.as_ptr()); 608 let sysbus: *mut SysBusDevice = dev.cast::<SysBusDevice>(); 609 610 qdev_prop_set_chr(dev, c_str!("chardev").as_ptr(), chr); 611 sysbus_realize_and_unref(sysbus, addr_of_mut!(error_fatal)); 612 sysbus_mmio_map(sysbus, 0, addr); 613 sysbus_connect_irq(sysbus, 0, irq); 614 dev 615 } 616 } 617 618 #[repr(C)] 619 #[derive(Debug, qemu_api_macros::Object)] 620 /// PL011 Luminary device model. 621 pub struct PL011Luminary { 622 parent_obj: PL011State, 623 } 624 625 #[repr(C)] 626 pub struct PL011LuminaryClass { 627 _inner: [u8; 0], 628 } 629 630 impl PL011Luminary { 631 /// Initializes a pre-allocated, unitialized instance of `PL011Luminary`. 632 /// 633 /// # Safety 634 /// 635 /// We expect the FFI user of this function to pass a valid pointer, that 636 /// has the same size as [`PL011Luminary`]. We also expect the device is 637 /// readable/writeable from one thread at any time. 638 unsafe fn init(&mut self) { 639 self.parent_obj.device_id = DeviceId::Luminary; 640 } 641 } 642 643 impl ObjectImpl for PL011Luminary { 644 type Class = PL011LuminaryClass; 645 const TYPE_NAME: &'static CStr = crate::TYPE_PL011_LUMINARY; 646 const PARENT_TYPE_NAME: Option<&'static CStr> = Some(crate::TYPE_PL011); 647 const INSTANCE_INIT: Option<unsafe fn(&mut Self)> = Some(Self::init); 648 } 649 650 impl DeviceImpl for PL011Luminary {} 651 652 impl_device_class!(PL011Luminary); 653