pci-txe.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2013-2020, Intel Corporation. All rights reserved.
  4 * Intel Management Engine Interface (Intel MEI) Linux driver
  5 */
  6
  7#include <linux/module.h>
  8#include <linux/kernel.h>
  9#include <linux/device.h>
 10#include <linux/errno.h>
 11#include <linux/types.h>
 12#include <linux/pci.h>
 13#include <linux/init.h>
 14#include <linux/sched.h>
 15#include <linux/interrupt.h>
 16#include <linux/workqueue.h>
 17#include <linux/pm_domain.h>
 18#include <linux/pm_runtime.h>
 19
 20#include <linux/mei.h>
 21
 22
 23#include "mei_dev.h"
 24#include "hw-txe.h"
 25
 26static const struct pci_device_id mei_txe_pci_tbl[] = {
 27	{PCI_VDEVICE(INTEL, 0x0F18)}, /* Baytrail */
 28	{PCI_VDEVICE(INTEL, 0x2298)}, /* Cherrytrail */
 29
 30	{0, }
 31};
 32MODULE_DEVICE_TABLE(pci, mei_txe_pci_tbl);
 33
 34#ifdef CONFIG_PM
 35static inline void mei_txe_set_pm_domain(struct mei_device *dev);
 36static inline void mei_txe_unset_pm_domain(struct mei_device *dev);
 37#else
 38static inline void mei_txe_set_pm_domain(struct mei_device *dev) {}
 39static inline void mei_txe_unset_pm_domain(struct mei_device *dev) {}
 40#endif /* CONFIG_PM */
 41
 42/**
 43 * mei_txe_probe - Device Initialization Routine
 44 *
 45 * @pdev: PCI device structure
 46 * @ent: entry in mei_txe_pci_tbl
 47 *
 48 * Return: 0 on success, <0 on failure.
 49 */
 50static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 51{
 52	struct mei_device *dev;
 53	struct mei_txe_hw *hw;
 54	const int mask = BIT(SEC_BAR) | BIT(BRIDGE_BAR);
 55	int err;
 56
 57	/* enable pci dev */
 58	err = pcim_enable_device(pdev);
 59	if (err) {
 60		dev_err(&pdev->dev, "failed to enable pci device.\n");
 61		goto end;
 62	}
 63	/* set PCI host mastering  */
 64	pci_set_master(pdev);
 65	/* pci request regions and mapping IO device memory for mei driver */
 66	err = pcim_iomap_regions(pdev, mask, KBUILD_MODNAME);
 67	if (err) {
 68		dev_err(&pdev->dev, "failed to get pci regions.\n");
 69		goto end;
 70	}
 71
 72	err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(36));
 73	if (err) {
 74		err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
 75		if (err) {
 76			dev_err(&pdev->dev, "No suitable DMA available.\n");
 77			goto end;
 78		}
 79	}
 80
 81	/* allocates and initializes the mei dev structure */
 82	dev = mei_txe_dev_init(pdev);
 83	if (!dev) {
 84		err = -ENOMEM;
 85		goto end;
 86	}
 87	hw = to_txe_hw(dev);
 88	hw->mem_addr = pcim_iomap_table(pdev);
 89
 90	err = mei_register(dev, &pdev->dev);
 91	if (err)
 92		goto end;
 93
 94	pci_enable_msi(pdev);
 95
 96	/* clear spurious interrupts */
 97	mei_clear_interrupts(dev);
 98
 99	/* request and enable interrupt  */
100	if (pci_dev_msi_enabled(pdev))
101		err = request_threaded_irq(pdev->irq,
102			NULL,
103			mei_txe_irq_thread_handler,
104			IRQF_ONESHOT, KBUILD_MODNAME, dev);
105	else
106		err = request_threaded_irq(pdev->irq,
107			mei_txe_irq_quick_handler,
108			mei_txe_irq_thread_handler,
109			IRQF_SHARED, KBUILD_MODNAME, dev);
110	if (err) {
111		dev_err(&pdev->dev, "mei: request_threaded_irq failure. irq = %d\n",
112			pdev->irq);
113		goto deregister;
114	}
115
116	if (mei_start(dev)) {
117		dev_err(&pdev->dev, "init hw failure.\n");
118		err = -ENODEV;
119		goto deregister;
120	}
121
122	pm_runtime_set_autosuspend_delay(&pdev->dev, MEI_TXI_RPM_TIMEOUT);
123	pm_runtime_use_autosuspend(&pdev->dev);
124
125	pci_set_drvdata(pdev, dev);
126
127	/*
128	 * MEI requires to resume from runtime suspend mode
129	 * in order to perform link reset flow upon system suspend.
130	 */
131	dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE);
132
133	/*
134	 * TXE maps runtime suspend/resume to own power gating states,
135	 * hence we need to go around native PCI runtime service which
136	 * eventually brings the device into D3cold/hot state.
137	 * But the TXE device cannot wake up from D3 unlike from own
138	 * power gating. To get around PCI device native runtime pm,
139	 * TXE uses runtime pm domain handlers which take precedence.
140	 */
141	mei_txe_set_pm_domain(dev);
142
143	pm_runtime_put_noidle(&pdev->dev);
144
145	return 0;
146
147deregister:
148	mei_cancel_work(dev);
149	mei_disable_interrupts(dev);
150	free_irq(pdev->irq, dev);
151	mei_deregister(dev);
152end:
153	dev_err(&pdev->dev, "initialization failed.\n");
154	return err;
155}
156
157/**
158 * mei_txe_shutdown- Device Shutdown Routine
159 *
160 * @pdev: PCI device structure
161 *
162 *  mei_txe_shutdown is called from the reboot notifier
163 *  it's a simplified version of remove so we go down
164 *  faster.
165 */
166static void mei_txe_shutdown(struct pci_dev *pdev)
167{
168	struct mei_device *dev = pci_get_drvdata(pdev);
169
170	dev_dbg(&pdev->dev, "shutdown\n");
171	mei_stop(dev);
172
173	mei_txe_unset_pm_domain(dev);
174
175	mei_disable_interrupts(dev);
176	free_irq(pdev->irq, dev);
177}
178
179/**
180 * mei_txe_remove - Device Removal Routine
181 *
182 * @pdev: PCI device structure
183 *
184 * mei_remove is called by the PCI subsystem to alert the driver
185 * that it should release a PCI device.
186 */
187static void mei_txe_remove(struct pci_dev *pdev)
188{
189	struct mei_device *dev = pci_get_drvdata(pdev);
190
191	pm_runtime_get_noresume(&pdev->dev);
192
193	mei_stop(dev);
194
195	mei_txe_unset_pm_domain(dev);
196
197	mei_disable_interrupts(dev);
198	free_irq(pdev->irq, dev);
199
200	mei_deregister(dev);
201}
202
203
204#ifdef CONFIG_PM_SLEEP
205static int mei_txe_pci_suspend(struct device *device)
206{
207	struct pci_dev *pdev = to_pci_dev(device);
208	struct mei_device *dev = pci_get_drvdata(pdev);
209
210	dev_dbg(&pdev->dev, "suspend\n");
211
212	mei_stop(dev);
213
214	mei_disable_interrupts(dev);
215
216	free_irq(pdev->irq, dev);
217	pci_disable_msi(pdev);
218
219	return 0;
220}
221
222static int mei_txe_pci_resume(struct device *device)
223{
224	struct pci_dev *pdev = to_pci_dev(device);
225	struct mei_device *dev = pci_get_drvdata(pdev);
226	int err;
227
228	pci_enable_msi(pdev);
229
230	mei_clear_interrupts(dev);
231
232	/* request and enable interrupt */
233	if (pci_dev_msi_enabled(pdev))
234		err = request_threaded_irq(pdev->irq,
235			NULL,
236			mei_txe_irq_thread_handler,
237			IRQF_ONESHOT, KBUILD_MODNAME, dev);
238	else
239		err = request_threaded_irq(pdev->irq,
240			mei_txe_irq_quick_handler,
241			mei_txe_irq_thread_handler,
242			IRQF_SHARED, KBUILD_MODNAME, dev);
243	if (err) {
244		dev_err(&pdev->dev, "request_threaded_irq failed: irq = %d.\n",
245				pdev->irq);
246		return err;
247	}
248
249	err = mei_restart(dev);
250
251	return err;
252}
253#endif /* CONFIG_PM_SLEEP */
254
255#ifdef CONFIG_PM
256static int mei_txe_pm_runtime_idle(struct device *device)
257{
258	struct mei_device *dev = dev_get_drvdata(device);
259
260	dev_dbg(device, "rpm: txe: runtime_idle\n");
261
262	if (mei_write_is_idle(dev))
263		pm_runtime_autosuspend(device);
264
265	return -EBUSY;
266}
267static int mei_txe_pm_runtime_suspend(struct device *device)
268{
269	struct mei_device *dev = dev_get_drvdata(device);
270	int ret;
271
272	dev_dbg(device, "rpm: txe: runtime suspend\n");
273
274	mutex_lock(&dev->device_lock);
275
276	if (mei_write_is_idle(dev))
277		ret = mei_txe_aliveness_set_sync(dev, 0);
278	else
279		ret = -EAGAIN;
280
281	/* keep irq on we are staying in D0 */
282
283	dev_dbg(device, "rpm: txe: runtime suspend ret=%d\n", ret);
284
285	mutex_unlock(&dev->device_lock);
286
287	if (ret && ret != -EAGAIN)
288		schedule_work(&dev->reset_work);
289
290	return ret;
291}
292
293static int mei_txe_pm_runtime_resume(struct device *device)
294{
295	struct mei_device *dev = dev_get_drvdata(device);
296	int ret;
297
298	dev_dbg(device, "rpm: txe: runtime resume\n");
299
300	mutex_lock(&dev->device_lock);
301
302	mei_enable_interrupts(dev);
303
304	ret = mei_txe_aliveness_set_sync(dev, 1);
305
306	mutex_unlock(&dev->device_lock);
307
308	dev_dbg(device, "rpm: txe: runtime resume ret = %d\n", ret);
309
310	if (ret)
311		schedule_work(&dev->reset_work);
312
313	return ret;
314}
315
316/**
317 * mei_txe_set_pm_domain - fill and set pm domain structure for device
318 *
319 * @dev: mei_device
320 */
321static inline void mei_txe_set_pm_domain(struct mei_device *dev)
322{
323	struct pci_dev *pdev  = to_pci_dev(dev->parent);
324
325	if (pdev->dev.bus && pdev->dev.bus->pm) {
326		dev->pg_domain.ops = *pdev->dev.bus->pm;
327
328		dev->pg_domain.ops.runtime_suspend = mei_txe_pm_runtime_suspend;
329		dev->pg_domain.ops.runtime_resume = mei_txe_pm_runtime_resume;
330		dev->pg_domain.ops.runtime_idle = mei_txe_pm_runtime_idle;
331
332		dev_pm_domain_set(&pdev->dev, &dev->pg_domain);
333	}
334}
335
336/**
337 * mei_txe_unset_pm_domain - clean pm domain structure for device
338 *
339 * @dev: mei_device
340 */
341static inline void mei_txe_unset_pm_domain(struct mei_device *dev)
342{
343	/* stop using pm callbacks if any */
344	dev_pm_domain_set(dev->parent, NULL);
345}
346
347static const struct dev_pm_ops mei_txe_pm_ops = {
348	SET_SYSTEM_SLEEP_PM_OPS(mei_txe_pci_suspend,
349				mei_txe_pci_resume)
350	SET_RUNTIME_PM_OPS(
351		mei_txe_pm_runtime_suspend,
352		mei_txe_pm_runtime_resume,
353		mei_txe_pm_runtime_idle)
354};
355
356#define MEI_TXE_PM_OPS	(&mei_txe_pm_ops)
357#else
358#define MEI_TXE_PM_OPS	NULL
359#endif /* CONFIG_PM */
360
361/*
362 *  PCI driver structure
363 */
364static struct pci_driver mei_txe_driver = {
365	.name = KBUILD_MODNAME,
366	.id_table = mei_txe_pci_tbl,
367	.probe = mei_txe_probe,
368	.remove = mei_txe_remove,
369	.shutdown = mei_txe_shutdown,
370	.driver.pm = MEI_TXE_PM_OPS,
371};
372
373module_pci_driver(mei_txe_driver);
374
375MODULE_AUTHOR("Intel Corporation");
376MODULE_DESCRIPTION("Intel(R) Trusted Execution Environment Interface");
377MODULE_LICENSE("GPL v2");