summaryrefslogtreecommitdiffstats
path: root/drivers/pci/pcie/portdrv_core.c
blob: 7c37d815229e9ee20e7732695dda58344fc77a20 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
// SPDX-License-Identifier: GPL-2.0
/*
 * Purpose:	PCI Express Port Bus Driver's Core Functions
 *
 * Copyright (C) 2004 Intel
 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/aer.h>

#include "../pci.h"
#include "portdrv.h"

struct portdrv_service_data {
	struct pcie_port_service_driver *drv;
	struct device *dev;
	u32 service;
};

/**
 * release_pcie_device - free PCI Express port service device structure
 * @dev: Port service device to release
 *
 * Invoked automatically when device is being removed in response to
 * device_unregister(dev).  Release all resources being claimed.
 */
static void release_pcie_device(struct device *dev)
{
	kfree(to_pcie_device(dev));
}

/*
 * Fill in *pme, *aer, *dpc with the relevant Interrupt Message Numbers if
 * services are enabled in "mask".  Return the number of MSI/MSI-X vectors
 * required to accommodate the largest Message Number.
 */
static int pcie_message_numbers(struct pci_dev *dev, int mask,
				u32 *pme, u32 *aer, u32 *dpc)
{
	u32 nvec = 0, pos;
	u16 reg16;

	/*
	 * The Interrupt Message Number indicates which vector is used, i.e.,
	 * the MSI-X table entry or the MSI offset between the base Message
	 * Data and the generated interrupt message.  See PCIe r3.1, sec
	 * 7.8.2, 7.10.10, 7.31.2.
	 */

	if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
		pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
		*pme = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
		nvec = *pme + 1;
	}

#ifdef CONFIG_PCIEAER
	if (mask & PCIE_PORT_SERVICE_AER) {
		u32 reg32;

		pos = dev->aer_cap;
		if (pos) {
			pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS,
					      &reg32);
			*aer = (reg32 & PCI_ERR_ROOT_AER_IRQ) >> 27;
			nvec = max(nvec, *aer + 1);
		}
	}
#endif

	if (mask & PCIE_PORT_SERVICE_DPC) {
		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
		if (pos) {
			pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP,
					     &reg16);
			*dpc = reg16 & PCI_EXP_DPC_IRQ;
			nvec = max(nvec, *dpc + 1);
		}
	}

	return nvec;
}

/**
 * pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode
 * for given port
 * @dev: PCI Express port to handle
 * @irqs: Array of interrupt vectors to populate
 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
 *
 * Return value: 0 on success, error code on failure
 */
static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
{
	int nr_entries, nvec;
	u32 pme = 0, aer = 0, dpc = 0;

	/* Allocate the maximum possible number of MSI/MSI-X vectors */
	nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
			PCI_IRQ_MSIX | PCI_IRQ_MSI);
	if (nr_entries < 0)
		return nr_entries;

	/* See how many and which Interrupt Message Numbers we actually use */
	nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc);
	if (nvec > nr_entries) {
		pci_free_irq_vectors(dev);
		return -EIO;
	}

	/*
	 * If we allocated more than we need, free them and reallocate fewer.
	 *
	 * Reallocating may change the specific vectors we get, so
	 * pci_irq_vector() must be done *after* the reallocation.
	 *
	 * If we're using MSI, hardware is *allowed* to change the Interrupt
	 * Message Numbers when we free and reallocate the vectors, but we
	 * assume it won't because we allocate enough vectors for the
	 * biggest Message Number we found.
	 */
	if (nvec != nr_entries) {
		pci_free_irq_vectors(dev);

		nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
				PCI_IRQ_MSIX | PCI_IRQ_MSI);
		if (nr_entries < 0)
			return nr_entries;
	}

	/* PME and hotplug share an MSI/MSI-X vector */
	if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
		irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, pme);
		irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, pme);
	}

	if (mask & PCIE_PORT_SERVICE_AER)
		irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, aer);

	if (mask & PCIE_PORT_SERVICE_DPC)
		irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc);

	return 0;
}

/**
 * pcie_init_service_irqs - initialize irqs for PCI Express port services
 * @dev: PCI Express port to handle
 * @irqs: Array of irqs to populate
 * @mask: Bitmask of port capabilities returned by get_port_device_capability()
 *
 * Return value: Interrupt mode associated with the port
 */
static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
{
	int ret, i;

	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
		irqs[i] = -1;

	/*
	 * If we support PME but can't use MSI/MSI-X for it, we have to
	 * fall back to INTx or other interrupts, e.g., a system shared
	 * interrupt.
	 */
	if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
		goto legacy_irq;

	/* Try to use MSI-X or MSI if supported */
	if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
		return 0;

legacy_irq:
	/* fall back to legacy IRQ */
	ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
	if (ret < 0)
		return -ENODEV;

	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
		irqs[i] = pci_irq_vector(dev, 0);

	return 0;
}

/**
 * get_port_device_capability - discover capabilities of a PCI Express port
 * @dev: PCI Express port to examine
 *
 * The capabilities are read from the port's PCI Express configuration registers
 * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
 * 7.9 - 7.11.
 *
 * Return value: Bitmask of discovered port capabilities
 */
static int get_port_device_capability(struct pci_dev *dev)
{
	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
	int services = 0;

	if (dev->is_hotplug_bridge &&
	    (pcie_ports_native || host->native_pcie_hotplug)) {
		services |= PCIE_PORT_SERVICE_HP;

		/*
		 * Disable hot-plug interrupts in case they have been enabled
		 * by the BIOS and the hot-plug service driver is not loaded.
		 */
		pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
			  PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
	}

#ifdef CONFIG_PCIEAER
	if (dev->aer_cap && pci_aer_available() &&
	    (pcie_ports_native || host->native_aer)) {
		services |= PCIE_PORT_SERVICE_AER;

		/*
		 * Disable AER on this port in case it's been enabled by the
		 * BIOS (the AER service driver will enable it when necessary).
		 */
		pci_disable_pcie_error_reporting(dev);
	}
#endif

	/*
	 * Root ports are capable of generating PME too.  Root Complex
	 * Event Collectors can also generate PMEs, but we don't handle
	 * those yet.
	 */
	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
	    (pcie_ports_native || host->native_pme)) {
		services |= PCIE_PORT_SERVICE_PME;

		/*
		 * Disable PME interrupt on this port in case it's been enabled
		 * by the BIOS (the PME service driver will enable it when
		 * necessary).
		 */
		pcie_pme_interrupt_enable(dev, false);
	}

	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
	    pci_aer_available() && services & PCIE_PORT_SERVICE_AER)
		services |= PCIE_PORT_SERVICE_DPC;

	return services;
}

/**
 * pcie_device_init - allocate and initialize PCI Express port service device
 * @pdev: PCI Express port to associate the service device with
 * @service: Type of service to associate with the service device
 * @irq: Interrupt vector to associate with the service device
 */
static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
{
	int retval;
	struct pcie_device *pcie;
	struct device *device;

	pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
	if (!pcie)
		return -ENOMEM;
	pcie->port = pdev;
	pcie->irq = irq;
	pcie->service = service;

	/* Initialize generic device interface */
	device = &pcie->device;
	device->bus = &pcie_port_bus_type;
	device->release = release_pcie_device;	/* callback to free pcie dev */
	dev_set_name(device, "%s:pcie%03x",
		     pci_name(pdev),
		     get_descriptor_id(pci_pcie_type(pdev), service));
	device->parent = &pdev->dev;
	device_enable_async_suspend(device);

	retval = device_register(device);
	if (retval) {
		put_device(device);
		return retval;
	}

	pm_runtime_no_callbacks(device);

	return 0;
}

/**
 * pcie_port_device_register - register PCI Express port
 * @dev: PCI Express port to register
 *
 * Allocate the port extension structure and register services associated with
 * the port.
 */
int pcie_port_device_register(struct pci_dev *dev)
{
	int status, capabilities, i, nr_service;
	int irqs[PCIE_PORT_DEVICE_MAXSERVICES];

	/* Enable PCI Express port device */
	status = pci_enable_device(dev);
	if (status)
		return status;

	/* Get and check PCI Express port services */
	capabilities = get_port_device_capability(dev);
	if (!capabilities)
		return 0;

	pci_set_master(dev);
	/*
	 * Initialize service irqs. Don't use service devices that
	 * require interrupts if there is no way to generate them.
	 * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
	 * that can be used in the absence of irqs.  Allow them to determine
	 * if that is to be used.
	 */
	status = pcie_init_service_irqs(dev, irqs, capabilities);
	if (status) {
		capabilities &= PCIE_PORT_SERVICE_HP;
		if (!capabilities)
			goto error_disable;
	}

	/* Allocate child services if any */
	status = -ENODEV;
	nr_service = 0;
	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
		int service = 1 << i;
		if (!(capabilities & service))
			continue;
		if (!pcie_device_init(dev, service, irqs[i]))
			nr_service++;
	}
	if (!nr_service)
		goto error_cleanup_irqs;

	return 0;

error_cleanup_irqs:
	pci_free_irq_vectors(dev);
error_disable:
	pci_disable_device(dev);
	return status;
}

#ifdef CONFIG_PM
typedef int (*pcie_pm_callback_t)(struct pcie_device *);

static int pm_iter(struct device *dev, void *data)
{
	struct pcie_port_service_driver *service_driver;
	size_t offset = *(size_t *)data;
	pcie_pm_callback_t cb;

	if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
		service_driver = to_service_driver(dev->driver);
		cb = *(pcie_pm_callback_t *)((void *)service_driver + offset);
		if (cb)
			return cb(to_pcie_device(dev));
	}
	return 0;
}

/**
 * pcie_port_device_suspend - suspend port services associated with a PCIe port
 * @dev: PCI Express port to handle
 */
int pcie_port_device_suspend(struct device *dev)
{
	size_t off = offsetof(struct pcie_port_service_driver, suspend);
	return device_for_each_child(dev, &off, pm_iter);
}

int pcie_port_device_resume_noirq(struct device *dev)
{
	size_t off = offsetof(struct pcie_port_service_driver, resume_noirq);
	return device_for_each_child(dev, &off, pm_iter);
}

/**
 * pcie_port_device_resume - resume port services associated with a PCIe port
 * @dev: PCI Express port to handle
 */
int pcie_port_device_resume(struct device *dev)
{
	size_t off = offsetof(struct pcie_port_service_driver, resume);
	return device_for_each_child(dev, &off, pm_iter);
}
#endif /* PM */

static int remove_iter(struct device *dev, void *data)
{
	if (dev->bus == &pcie_port_bus_type)
		device_unregister(dev);
	return 0;
}

static int find_service_iter(struct device *device, void *data)
{
	struct pcie_port_service_driver *service_driver;
	struct portdrv_service_data *pdrvs;
	u32 service;

	pdrvs = (struct portdrv_service_data *) data;
	service = pdrvs->service;

	if (device->bus == &pcie_port_bus_type && device->driver) {
		service_driver = to_service_driver(device->driver);
		if (service_driver->service == service) {
			pdrvs->drv = service_driver;
			pdrvs->dev = device;
			return 1;
		}
	}

	return 0;
}

/**
 * pcie_port_find_service - find the service driver
 * @dev: PCI Express port the service is associated with
 * @service: Service to find
 *
 * Find PCI Express port service driver associated with given service
 */
struct pcie_port_service_driver *pcie_port_find_service(struct pci_dev *dev,
							u32 service)
{
	struct pcie_port_service_driver *drv;
	struct portdrv_service_data pdrvs;

	pdrvs.drv = NULL;
	pdrvs.service = service;
	device_for_each_child(&dev->dev, &pdrvs, find_service_iter);

	drv = pdrvs.drv;
	return drv;
}

/**
 * pcie_port_find_device - find the struct device
 * @dev: PCI Express port the service is associated with
 * @service: For the service to find
 *
 * Find the struct device associated with given service on a pci_dev
 */
struct device *pcie_port_find_device(struct pci_dev *dev,
				      u32 service)
{
	struct device *device;
	struct portdrv_service_data pdrvs;

	pdrvs.dev = NULL;
	pdrvs.service = service;
	device_for_each_child(&dev->dev, &pdrvs, find_service_iter);

	device = pdrvs.dev;
	return device;
}

/**
 * pcie_port_device_remove - unregister PCI Express port service devices
 * @dev: PCI Express port the service devices to unregister are associated with
 *
 * Remove PCI Express port service devices associated with given port and
 * disable MSI-X or MSI for the port.
 */
void pcie_port_device_remove(struct pci_dev *dev)
{
	device_for_each_child(&dev->dev, NULL, remove_iter);
	pci_free_irq_vectors(dev);
	pci_disable_device(dev);
}

/**
 * pcie_port_probe_service - probe driver for given PCI Express port service
 * @dev: PCI Express port service device to probe against
 *
 * If PCI Express port service driver is registered with
 * pcie_port_service_register(), this function will be called by the driver core
 * whenever match is found between the driver and a port service device.
 */
static int pcie_port_probe_service(struct device *dev)
{
	struct pcie_device *pciedev;
	struct pcie_port_service_driver *driver;
	int status;

	if (!dev || !dev->driver)
		return -ENODEV;

	driver = to_service_driver(dev->driver);
	if (!driver || !driver->probe)
		return -ENODEV;

	pciedev = to_pcie_device(dev);
	status = driver->probe(pciedev);
	if (status)
		return status;

	get_device(dev);
	return 0;
}

/**
 * pcie_port_remove_service - detach driver from given PCI Express port service
 * @dev: PCI Express port service device to handle
 *
 * If PCI Express port service driver is registered with
 * pcie_port_service_register(), this function will be called by the driver core
 * when device_unregister() is called for the port service device associated
 * with the driver.
 */
static int pcie_port_remove_service(struct device *dev)
{
	struct pcie_device *pciedev;
	struct pcie_port_service_driver *driver;

	if (!dev || !dev->driver)
		return 0;

	pciedev = to_pcie_device(dev);
	driver = to_service_driver(dev->driver);
	if (driver && driver->remove) {
		driver->remove(pciedev);
		put_device(dev);
	}
	return 0;
}

/**
 * pcie_port_shutdown_service - shut down given PCI Express port service
 * @dev: PCI Express port service device to handle
 *
 * If PCI Express port service driver is registered with
 * pcie_port_service_register(), this function will be called by the driver core
 * when device_shutdown() is called for the port service device associated
 * with the driver.
 */
static void pcie_port_shutdown_service(struct device *dev) {}

/**
 * pcie_port_service_register - register PCI Express port service driver
 * @new: PCI Express port service driver to register
 */
int pcie_port_service_register(struct pcie_port_service_driver *new)
{
	if (pcie_ports_disabled)
		return -ENODEV;

	new->driver.name = new->name;
	new->driver.bus = &pcie_port_bus_type;
	new->driver.probe = pcie_port_probe_service;
	new->driver.remove = pcie_port_remove_service;
	new->driver.shutdown = pcie_port_shutdown_service;

	return driver_register(&new->driver);
}
EXPORT_SYMBOL(pcie_port_service_register);

/**
 * pcie_port_service_unregister - unregister PCI Express port service driver
 * @drv: PCI Express port service driver to unregister
 */
void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
{
	driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(pcie_port_service_unregister);