1 // SPDX-License-Identifier: GPL-2.0
3  * PCIe Native PME support
5  * Copyright (C) 2007 - 2009 Intel Corp
6  * Copyright (C) 2007 - 2009 Shaohua Li <[email protected]>
26  * If this switch is set, MSI will not be used for PCIe PME signaling.  This
27  * causes the PCIe port driver to use INTx interrupts only, but it turns out
28  * that using MSI for PCIe PME signaling doesn't play well with PCIe PME-based
29  * wake-up from system sleep states.
38 	return 1;  in pcie_pme_setup()
50  * pcie_pme_interrupt_enable - Enable/disable PCIe PME interrupt generation.
51  * @dev: PCIe root port or event collector.
65  * pcie_pme_walk_bus - Scan a PCI bus for devices asserting PME#.
75 	list_for_each_entry(dev, &bus->devices, bus_list) {  in pcie_pme_walk_bus()
76 		/* Skip PCIe devices in case we started from a root port. */  in pcie_pme_walk_bus()
78 			if (dev->pme_poll)  in pcie_pme_walk_bus()
79 				dev->pme_poll = false;  in pcie_pme_walk_bus()
82 			pm_request_resume(&dev->dev);  in pcie_pme_walk_bus()
86 		if (dev->subordinate && pcie_pme_walk_bus(dev->subordinate))  in pcie_pme_walk_bus()
94  * pcie_pme_from_pci_bridge - Check if PCIe-PCI bridge generated a PME.
98  * PME from PCI devices under a PCIe-PCI bridge may be converted to an in-band
99  * PCIe PME message.  In such that case the bridge should use the Requester ID
110 	dev = pci_dev_get(bus->self);  in pcie_pme_from_pci_bridge()
126  * pcie_pme_handle_request - Find device that generated PME and handle it.
127  * @port: Root port or event collector that generated the PME interrupt.
128  * @req_id: PCIe Requester ID of the device that generated the PME.
130 static void pcie_pme_handle_request(struct pci_dev *port, u16 req_id)  in pcie_pme_handle_request()  argument
137 	/* First, check if the PME is from the root port itself. */  in pcie_pme_handle_request()
138 	if (port->devfn == devfn && port->bus->number == busnr) {  in pcie_pme_handle_request()
139 		if (port->pme_poll)  in pcie_pme_handle_request()
140 			port->pme_poll = false;  in pcie_pme_handle_request()
142 		if (pci_check_pme_status(port)) {  in pcie_pme_handle_request()
143 			pm_request_resume(&port->dev);  in pcie_pme_handle_request()
147 			 * Apparently, the root port generated the PME on behalf  in pcie_pme_handle_request()
148 			 * of a non-PCIe device downstream.  If this is done by  in pcie_pme_handle_request()
149 			 * a root port, the Requester ID field in its status  in pcie_pme_handle_request()
150 			 * register may contain either the root port's, or the  in pcie_pme_handle_request()
155 			found = pcie_pme_walk_bus(port->subordinate);  in pcie_pme_handle_request()
162 	bus = pci_find_bus(pci_domain_nr(port->bus), busnr);  in pcie_pme_handle_request()
166 	/* Next, check if the PME is from a PCIe-PCI bridge. */  in pcie_pme_handle_request()
173 	list_for_each_entry(dev, &bus->devices, bus_list) {  in pcie_pme_handle_request()
175 		if (dev->devfn == devfn) {  in pcie_pme_handle_request()
187 			if (dev->pme_poll)  in pcie_pme_handle_request()
188 				dev->pme_poll = false;  in pcie_pme_handle_request()
191 			pm_request_resume(&dev->dev);  in pcie_pme_handle_request()
197 		 * assuming that the PME was reported by a PCIe-PCI bridge that  in pcie_pme_handle_request()
200 		pci_info(port, "interrupt generated for non-existent device %02x:%02x.%d\n",  in pcie_pme_handle_request()
207 		pci_info(port, "Spurious native interrupt!\n");  in pcie_pme_handle_request()
211  * pcie_pme_work_fn - Work handler for PCIe PME interrupt.
218 	struct pci_dev *port = data->srv->port;  in pcie_pme_work_fn()  local
221 	spin_lock_irq(&data->lock);  in pcie_pme_work_fn()
224 		if (data->noirq)  in pcie_pme_work_fn()
227 		pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);  in pcie_pme_work_fn()
233 			 * Clear PME status of the port.  If there are other  in pcie_pme_work_fn()
236 			pcie_clear_root_pme_status(port);  in pcie_pme_work_fn()
238 			spin_unlock_irq(&data->lock);  in pcie_pme_work_fn()
239 			pcie_pme_handle_request(port,  in pcie_pme_work_fn()
241 			spin_lock_irq(&data->lock);  in pcie_pme_work_fn()
250 		spin_unlock_irq(&data->lock);  in pcie_pme_work_fn()
252 		spin_lock_irq(&data->lock);  in pcie_pme_work_fn()
255 	if (!data->noirq)  in pcie_pme_work_fn()
256 		pcie_pme_interrupt_enable(port, true);  in pcie_pme_work_fn()
258 	spin_unlock_irq(&data->lock);  in pcie_pme_work_fn()
262  * pcie_pme_irq - Interrupt handler for PCIe root port PME interrupt.
268 	struct pci_dev *port;  in pcie_pme_irq()  local
273 	port = ((struct pcie_device *)context)->port;  in pcie_pme_irq()
276 	spin_lock_irqsave(&data->lock, flags);  in pcie_pme_irq()
277 	pcie_capability_read_dword(port, PCI_EXP_RTSTA, &rtsta);  in pcie_pme_irq()
280 		spin_unlock_irqrestore(&data->lock, flags);  in pcie_pme_irq()
284 	pcie_pme_interrupt_enable(port, false);  in pcie_pme_irq()
285 	spin_unlock_irqrestore(&data->lock, flags);  in pcie_pme_irq()
288 	schedule_work(&data->work);  in pcie_pme_irq()
294  * pcie_pme_can_wakeup - Set the wakeup capability flag.
300 	device_set_wakeup_capable(&dev->dev, true);  in pcie_pme_can_wakeup()
305  * pcie_pme_mark_devices - Set the wakeup flag for devices below a port.
306  * @port: PCIe root port or event collector to handle.
308  * For each device below given root port, including the port itself (or for each
309  * root complex integrated endpoint if @port is a root complex event collector)
310  * set the flag indicating that it can signal run-time wake-up events.
312 static void pcie_pme_mark_devices(struct pci_dev *port)  in pcie_pme_mark_devices()  argument
314 	pcie_pme_can_wakeup(port, NULL);  in pcie_pme_mark_devices()
316 	if (pci_pcie_type(port) == PCI_EXP_TYPE_RC_EC)  in pcie_pme_mark_devices()
317 		pcie_walk_rcec(port, pcie_pme_can_wakeup, NULL);  in pcie_pme_mark_devices()
318 	else if (port->subordinate)  in pcie_pme_mark_devices()
319 		pci_walk_bus(port->subordinate, pcie_pme_can_wakeup, NULL);  in pcie_pme_mark_devices()
323  * pcie_pme_probe - Initialize PCIe PME service for given root port.
324  * @srv: PCIe service to initialize.
328 	struct pci_dev *port = srv->port;  in pcie_pme_probe()  local
330 	int type = pci_pcie_type(port);  in pcie_pme_probe()
333 	/* Limit to Root Ports or Root Complex Event Collectors */  in pcie_pme_probe()
336 		return -ENODEV;  in pcie_pme_probe()
340 		return -ENOMEM;  in pcie_pme_probe()
342 	spin_lock_init(&data->lock);  in pcie_pme_probe()
343 	INIT_WORK(&data->work, pcie_pme_work_fn);  in pcie_pme_probe()
344 	data->srv = srv;  in pcie_pme_probe()
347 	pcie_pme_interrupt_enable(port, false);  in pcie_pme_probe()
348 	pcie_clear_root_pme_status(port);  in pcie_pme_probe()
350 	ret = request_irq(srv->irq, pcie_pme_irq, IRQF_SHARED, "PCIe PME", srv);  in pcie_pme_probe()
356 	pci_info(port, "Signaling with IRQ %d\n", srv->irq);  in pcie_pme_probe()
358 	pcie_pme_mark_devices(port);  in pcie_pme_probe()
359 	pcie_pme_interrupt_enable(port, true);  in pcie_pme_probe()
370 	list_for_each_entry(dev, &bus->devices, bus_list)  in pcie_pme_check_wakeup()
371 		if (device_may_wakeup(&dev->dev)  in pcie_pme_check_wakeup()
372 		    || pcie_pme_check_wakeup(dev->subordinate))  in pcie_pme_check_wakeup()
378 static void pcie_pme_disable_interrupt(struct pci_dev *port,  in pcie_pme_disable_interrupt()  argument
381 	spin_lock_irq(&data->lock);  in pcie_pme_disable_interrupt()
382 	pcie_pme_interrupt_enable(port, false);  in pcie_pme_disable_interrupt()
383 	pcie_clear_root_pme_status(port);  in pcie_pme_disable_interrupt()
384 	data->noirq = true;  in pcie_pme_disable_interrupt()
385 	spin_unlock_irq(&data->lock);  in pcie_pme_disable_interrupt()
389  * pcie_pme_suspend - Suspend PCIe PME service device.
390  * @srv: PCIe service device to suspend.
395 	struct pci_dev *port = srv->port;  in pcie_pme_suspend()  local
399 	if (device_may_wakeup(&port->dev)) {  in pcie_pme_suspend()
403 		wakeup = pcie_pme_check_wakeup(port->subordinate);  in pcie_pme_suspend()
407 		ret = enable_irq_wake(srv->irq);  in pcie_pme_suspend()
412 	pcie_pme_disable_interrupt(port, data);  in pcie_pme_suspend()
414 	synchronize_irq(srv->irq);  in pcie_pme_suspend()
420  * pcie_pme_resume - Resume PCIe PME service device.
421  * @srv: PCIe service device to resume.
427 	spin_lock_irq(&data->lock);  in pcie_pme_resume()
428 	if (data->noirq) {  in pcie_pme_resume()
429 		struct pci_dev *port = srv->port;  in pcie_pme_resume()  local
431 		pcie_clear_root_pme_status(port);  in pcie_pme_resume()
432 		pcie_pme_interrupt_enable(port, true);  in pcie_pme_resume()
433 		data->noirq = false;  in pcie_pme_resume()
435 		disable_irq_wake(srv->irq);  in pcie_pme_resume()
437 	spin_unlock_irq(&data->lock);  in pcie_pme_resume()
443  * pcie_pme_remove - Prepare PCIe PME service device for removal.
444  * @srv: PCIe service device to remove.
450 	pcie_pme_disable_interrupt(srv->port, data);  in pcie_pme_remove()
451 	free_irq(srv->irq, srv);  in pcie_pme_remove()
452 	cancel_work_sync(&data->work);  in pcie_pme_remove()
468  * pcie_pme_init - Register the PCIe PME service driver.