xref: /openbmc/linux/drivers/misc/mei/pci-txe.c (revision 5febf6d6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2013-2017, 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/fs.h>
11 #include <linux/errno.h>
12 #include <linux/types.h>
13 #include <linux/pci.h>
14 #include <linux/init.h>
15 #include <linux/sched.h>
16 #include <linux/uuid.h>
17 #include <linux/jiffies.h>
18 #include <linux/interrupt.h>
19 #include <linux/workqueue.h>
20 #include <linux/pm_domain.h>
21 #include <linux/pm_runtime.h>
22 
23 #include <linux/mei.h>
24 
25 
26 #include "mei_dev.h"
27 #include "hw-txe.h"
28 
29 static const struct pci_device_id mei_txe_pci_tbl[] = {
30 	{PCI_VDEVICE(INTEL, 0x0F18)}, /* Baytrail */
31 	{PCI_VDEVICE(INTEL, 0x2298)}, /* Cherrytrail */
32 
33 	{0, }
34 };
35 MODULE_DEVICE_TABLE(pci, mei_txe_pci_tbl);
36 
37 #ifdef CONFIG_PM
38 static inline void mei_txe_set_pm_domain(struct mei_device *dev);
39 static inline void mei_txe_unset_pm_domain(struct mei_device *dev);
40 #else
41 static inline void mei_txe_set_pm_domain(struct mei_device *dev) {}
42 static inline void mei_txe_unset_pm_domain(struct mei_device *dev) {}
43 #endif /* CONFIG_PM */
44 
45 /**
46  * mei_txe_probe - Device Initialization Routine
47  *
48  * @pdev: PCI device structure
49  * @ent: entry in mei_txe_pci_tbl
50  *
51  * Return: 0 on success, <0 on failure.
52  */
53 static int mei_txe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
54 {
55 	struct mei_device *dev;
56 	struct mei_txe_hw *hw;
57 	const int mask = BIT(SEC_BAR) | BIT(BRIDGE_BAR);
58 	int err;
59 
60 	/* enable pci dev */
61 	err = pcim_enable_device(pdev);
62 	if (err) {
63 		dev_err(&pdev->dev, "failed to enable pci device.\n");
64 		goto end;
65 	}
66 	/* set PCI host mastering  */
67 	pci_set_master(pdev);
68 	/* pci request regions and mapping IO device memory for mei driver */
69 	err = pcim_iomap_regions(pdev, mask, KBUILD_MODNAME);
70 	if (err) {
71 		dev_err(&pdev->dev, "failed to get pci regions.\n");
72 		goto end;
73 	}
74 
75 	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(36));
76 	if (err) {
77 		err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
78 		if (err) {
79 			dev_err(&pdev->dev, "No suitable DMA available.\n");
80 			goto end;
81 		}
82 	}
83 
84 	/* allocates and initializes the mei dev structure */
85 	dev = mei_txe_dev_init(pdev);
86 	if (!dev) {
87 		err = -ENOMEM;
88 		goto end;
89 	}
90 	hw = to_txe_hw(dev);
91 	hw->mem_addr = pcim_iomap_table(pdev);
92 
93 	pci_enable_msi(pdev);
94 
95 	/* clear spurious interrupts */
96 	mei_clear_interrupts(dev);
97 
98 	/* request and enable interrupt  */
99 	if (pci_dev_msi_enabled(pdev))
100 		err = request_threaded_irq(pdev->irq,
101 			NULL,
102 			mei_txe_irq_thread_handler,
103 			IRQF_ONESHOT, KBUILD_MODNAME, dev);
104 	else
105 		err = request_threaded_irq(pdev->irq,
106 			mei_txe_irq_quick_handler,
107 			mei_txe_irq_thread_handler,
108 			IRQF_SHARED, KBUILD_MODNAME, dev);
109 	if (err) {
110 		dev_err(&pdev->dev, "mei: request_threaded_irq failure. irq = %d\n",
111 			pdev->irq);
112 		goto end;
113 	}
114 
115 	if (mei_start(dev)) {
116 		dev_err(&pdev->dev, "init hw failure.\n");
117 		err = -ENODEV;
118 		goto release_irq;
119 	}
120 
121 	pm_runtime_set_autosuspend_delay(&pdev->dev, MEI_TXI_RPM_TIMEOUT);
122 	pm_runtime_use_autosuspend(&pdev->dev);
123 
124 	err = mei_register(dev, &pdev->dev);
125 	if (err)
126 		goto stop;
127 
128 	pci_set_drvdata(pdev, dev);
129 
130 	/*
131 	 * MEI requires to resume from runtime suspend mode
132 	 * in order to perform link reset flow upon system suspend.
133 	 */
134 	dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP);
135 
136 	/*
137 	 * TXE maps runtime suspend/resume to own power gating states,
138 	 * hence we need to go around native PCI runtime service which
139 	 * eventually brings the device into D3cold/hot state.
140 	 * But the TXE device cannot wake up from D3 unlike from own
141 	 * power gating. To get around PCI device native runtime pm,
142 	 * TXE uses runtime pm domain handlers which take precedence.
143 	 */
144 	mei_txe_set_pm_domain(dev);
145 
146 	pm_runtime_put_noidle(&pdev->dev);
147 
148 	return 0;
149 
150 stop:
151 	mei_stop(dev);
152 release_irq:
153 	mei_cancel_work(dev);
154 	mei_disable_interrupts(dev);
155 	free_irq(pdev->irq, dev);
156 end:
157 	dev_err(&pdev->dev, "initialization failed.\n");
158 	return err;
159 }
160 
161 /**
162  * mei_txe_remove - Device Shutdown Routine
163  *
164  * @pdev: PCI device structure
165  *
166  *  mei_txe_shutdown is called from the reboot notifier
167  *  it's a simplified version of remove so we go down
168  *  faster.
169  */
170 static void mei_txe_shutdown(struct pci_dev *pdev)
171 {
172 	struct mei_device *dev;
173 
174 	dev = pci_get_drvdata(pdev);
175 	if (!dev)
176 		return;
177 
178 	dev_dbg(&pdev->dev, "shutdown\n");
179 	mei_stop(dev);
180 
181 	mei_txe_unset_pm_domain(dev);
182 
183 	mei_disable_interrupts(dev);
184 	free_irq(pdev->irq, dev);
185 }
186 
187 /**
188  * mei_txe_remove - Device Removal Routine
189  *
190  * @pdev: PCI device structure
191  *
192  * mei_remove is called by the PCI subsystem to alert the driver
193  * that it should release a PCI device.
194  */
195 static void mei_txe_remove(struct pci_dev *pdev)
196 {
197 	struct mei_device *dev;
198 
199 	dev = pci_get_drvdata(pdev);
200 	if (!dev) {
201 		dev_err(&pdev->dev, "mei: dev == NULL\n");
202 		return;
203 	}
204 
205 	pm_runtime_get_noresume(&pdev->dev);
206 
207 	mei_stop(dev);
208 
209 	mei_txe_unset_pm_domain(dev);
210 
211 	mei_disable_interrupts(dev);
212 	free_irq(pdev->irq, dev);
213 
214 	mei_deregister(dev);
215 }
216 
217 
218 #ifdef CONFIG_PM_SLEEP
219 static int mei_txe_pci_suspend(struct device *device)
220 {
221 	struct pci_dev *pdev = to_pci_dev(device);
222 	struct mei_device *dev = pci_get_drvdata(pdev);
223 
224 	if (!dev)
225 		return -ENODEV;
226 
227 	dev_dbg(&pdev->dev, "suspend\n");
228 
229 	mei_stop(dev);
230 
231 	mei_disable_interrupts(dev);
232 
233 	free_irq(pdev->irq, dev);
234 	pci_disable_msi(pdev);
235 
236 	return 0;
237 }
238 
239 static int mei_txe_pci_resume(struct device *device)
240 {
241 	struct pci_dev *pdev = to_pci_dev(device);
242 	struct mei_device *dev;
243 	int err;
244 
245 	dev = pci_get_drvdata(pdev);
246 	if (!dev)
247 		return -ENODEV;
248 
249 	pci_enable_msi(pdev);
250 
251 	mei_clear_interrupts(dev);
252 
253 	/* request and enable interrupt */
254 	if (pci_dev_msi_enabled(pdev))
255 		err = request_threaded_irq(pdev->irq,
256 			NULL,
257 			mei_txe_irq_thread_handler,
258 			IRQF_ONESHOT, KBUILD_MODNAME, dev);
259 	else
260 		err = request_threaded_irq(pdev->irq,
261 			mei_txe_irq_quick_handler,
262 			mei_txe_irq_thread_handler,
263 			IRQF_SHARED, KBUILD_MODNAME, dev);
264 	if (err) {
265 		dev_err(&pdev->dev, "request_threaded_irq failed: irq = %d.\n",
266 				pdev->irq);
267 		return err;
268 	}
269 
270 	err = mei_restart(dev);
271 
272 	return err;
273 }
274 #endif /* CONFIG_PM_SLEEP */
275 
276 #ifdef CONFIG_PM
277 static int mei_txe_pm_runtime_idle(struct device *device)
278 {
279 	struct mei_device *dev;
280 
281 	dev_dbg(device, "rpm: txe: runtime_idle\n");
282 
283 	dev = dev_get_drvdata(device);
284 	if (!dev)
285 		return -ENODEV;
286 	if (mei_write_is_idle(dev))
287 		pm_runtime_autosuspend(device);
288 
289 	return -EBUSY;
290 }
291 static int mei_txe_pm_runtime_suspend(struct device *device)
292 {
293 	struct mei_device *dev;
294 	int ret;
295 
296 	dev_dbg(device, "rpm: txe: runtime suspend\n");
297 
298 	dev = dev_get_drvdata(device);
299 	if (!dev)
300 		return -ENODEV;
301 
302 	mutex_lock(&dev->device_lock);
303 
304 	if (mei_write_is_idle(dev))
305 		ret = mei_txe_aliveness_set_sync(dev, 0);
306 	else
307 		ret = -EAGAIN;
308 
309 	/* keep irq on we are staying in D0 */
310 
311 	dev_dbg(device, "rpm: txe: runtime suspend ret=%d\n", ret);
312 
313 	mutex_unlock(&dev->device_lock);
314 
315 	if (ret && ret != -EAGAIN)
316 		schedule_work(&dev->reset_work);
317 
318 	return ret;
319 }
320 
321 static int mei_txe_pm_runtime_resume(struct device *device)
322 {
323 	struct mei_device *dev;
324 	int ret;
325 
326 	dev_dbg(device, "rpm: txe: runtime resume\n");
327 
328 	dev = dev_get_drvdata(device);
329 	if (!dev)
330 		return -ENODEV;
331 
332 	mutex_lock(&dev->device_lock);
333 
334 	mei_enable_interrupts(dev);
335 
336 	ret = mei_txe_aliveness_set_sync(dev, 1);
337 
338 	mutex_unlock(&dev->device_lock);
339 
340 	dev_dbg(device, "rpm: txe: runtime resume ret = %d\n", ret);
341 
342 	if (ret)
343 		schedule_work(&dev->reset_work);
344 
345 	return ret;
346 }
347 
348 /**
349  * mei_txe_set_pm_domain - fill and set pm domain structure for device
350  *
351  * @dev: mei_device
352  */
353 static inline void mei_txe_set_pm_domain(struct mei_device *dev)
354 {
355 	struct pci_dev *pdev  = to_pci_dev(dev->dev);
356 
357 	if (pdev->dev.bus && pdev->dev.bus->pm) {
358 		dev->pg_domain.ops = *pdev->dev.bus->pm;
359 
360 		dev->pg_domain.ops.runtime_suspend = mei_txe_pm_runtime_suspend;
361 		dev->pg_domain.ops.runtime_resume = mei_txe_pm_runtime_resume;
362 		dev->pg_domain.ops.runtime_idle = mei_txe_pm_runtime_idle;
363 
364 		dev_pm_domain_set(&pdev->dev, &dev->pg_domain);
365 	}
366 }
367 
368 /**
369  * mei_txe_unset_pm_domain - clean pm domain structure for device
370  *
371  * @dev: mei_device
372  */
373 static inline void mei_txe_unset_pm_domain(struct mei_device *dev)
374 {
375 	/* stop using pm callbacks if any */
376 	dev_pm_domain_set(dev->dev, NULL);
377 }
378 
379 static const struct dev_pm_ops mei_txe_pm_ops = {
380 	SET_SYSTEM_SLEEP_PM_OPS(mei_txe_pci_suspend,
381 				mei_txe_pci_resume)
382 	SET_RUNTIME_PM_OPS(
383 		mei_txe_pm_runtime_suspend,
384 		mei_txe_pm_runtime_resume,
385 		mei_txe_pm_runtime_idle)
386 };
387 
388 #define MEI_TXE_PM_OPS	(&mei_txe_pm_ops)
389 #else
390 #define MEI_TXE_PM_OPS	NULL
391 #endif /* CONFIG_PM */
392 
393 /*
394  *  PCI driver structure
395  */
396 static struct pci_driver mei_txe_driver = {
397 	.name = KBUILD_MODNAME,
398 	.id_table = mei_txe_pci_tbl,
399 	.probe = mei_txe_probe,
400 	.remove = mei_txe_remove,
401 	.shutdown = mei_txe_shutdown,
402 	.driver.pm = MEI_TXE_PM_OPS,
403 };
404 
405 module_pci_driver(mei_txe_driver);
406 
407 MODULE_AUTHOR("Intel Corporation");
408 MODULE_DESCRIPTION("Intel(R) Trusted Execution Environment Interface");
409 MODULE_LICENSE("GPL v2");
410