summaryrefslogtreecommitdiff
path: root/drivers/pci/pcie/portdrv_core.c
blob: d8feef6e77bbb1d3463b34177676f3017efe7096 (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
/*
 * File:	portdrv_core.c
 * 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/pcieport_if.h>
#include <linux/aer.h>

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

bool pciehp_msi_disabled;

static int __init pciehp_setup(char *str)
{
	if (!strncmp(str, "nomsi", 5))
		pciehp_msi_disabled = true;

	return 1;
}
__setup("pcie_hp=", pciehp_setup);

/**
 * 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));
}

/**
 * pcie_port_enable_msix - try to set up MSI-X 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_msix(struct pci_dev *dev, int *irqs, int mask)
{
	int nr_entries, entry, nvec = 0;

	/*
	 * Allocate as many entries as the port wants, so that we can check
	 * which of them will be useful.  Moreover, if nr_entries is correctly
	 * equal to the number of entries this port actually uses, we'll happily
	 * go through without any tricks.
	 */
	nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSIX_ENTRIES,
			PCI_IRQ_MSIX);
	if (nr_entries < 0)
		return nr_entries;

	if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
		u16 reg16;

		/*
		 * The code below follows the PCI Express Base Specification 2.0
		 * stating in Section 6.1.6 that "PME and Hot-Plug Event
		 * interrupts (when both are implemented) always share the same
		 * MSI or MSI-X vector, as indicated by the Interrupt Message
		 * Number field in the PCI Express Capabilities register", where
		 * according to Section 7.8.2 of the specification "For MSI-X,
		 * the value in this field indicates which MSI-X Table entry is
		 * used to generate the interrupt message."
		 */
		pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
		entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
		if (entry >= nr_entries)
			goto out_free_irqs;

		irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);
		irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);

		nvec = max(nvec, entry + 1);
	}

	if (mask & PCIE_PORT_SERVICE_AER) {
		u32 reg32, pos;

		/*
		 * The code below follows Section 7.10.10 of the PCI Express
		 * Base Specification 2.0 stating that bits 31-27 of the Root
		 * Error Status Register contain a value indicating which of the
		 * MSI/MSI-X vectors assigned to the port is going to be used
		 * for AER, where "For MSI-X, the value in this register
		 * indicates which MSI-X Table entry is used to generate the
		 * interrupt message."
		 */
		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
		pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
		entry = reg32 >> 27;
		if (entry >= nr_entries)
			goto out_free_irqs;

		irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);

		nvec = max(nvec, entry + 1);
	}

	/*
	 * If nvec is equal to the allocated number of entries, we can just use
	 * what we have.  Otherwise, the port has some extra entries not for the
	 * services we know and we need to work around that.
	 */
	if (nvec != nr_entries) {
		/* Drop the temporary MSI-X setup */
		pci_free_irq_vectors(dev);

		/* Now allocate the MSI-X vectors for real */
		nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
				PCI_IRQ_MSIX);
		if (nr_entries < 0)
			return nr_entries;
	}

	return 0;

out_free_irqs:
	pci_free_irq_vectors(dev);
	return -EIO;
}

/**
 * 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)
{
	unsigned flags = PCI_IRQ_LEGACY | PCI_IRQ_MSI;
	int ret, i;

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

	/*
	 * If MSI cannot be used for PCIe PME or hotplug, we have to use
	 * INTx or other interrupts, e.g. system shared interrupt.
	 */
	if (((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi()) ||
	    ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())) {
		flags &= ~PCI_IRQ_MSI;
	} else {
		/* Try to use MSI-X if supported */
		if (!pcie_port_enable_msix(dev, irqs, mask))
			return 0;
	}

	ret = pci_alloc_irq_vectors(dev, 1, 1, flags);
	if (ret < 0)
		return -ENODEV;

	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
		if (i != PCIE_PORT_SERVICE_VC_SHIFT)
			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)
{
	int services = 0;
	int cap_mask = 0;

	if (pcie_ports_disabled)
		return 0;

	cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
			| PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_DPC;
	if (pci_aer_available())
		cap_mask |= PCIE_PORT_SERVICE_AER;

	if (pcie_ports_auto)
		pcie_port_platform_notify(dev, &cap_mask);

	/* Hot-Plug Capable */
	if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) {
		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);
	}
	/* AER capable */
	if ((cap_mask & PCIE_PORT_SERVICE_AER)
	    && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
		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);
	}
	/* VC support */
	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
		services |= PCIE_PORT_SERVICE_VC;
	/* Root ports are capable of generating PME too */
	if ((cap_mask & PCIE_PORT_SERVICE_PME)
	    && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
		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))
		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);
dev_info(&dev->dev, "PCIe capabilities: 0x%x\n", capabilities);
	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);
dev_info(&dev->dev, "init_service_irqs: %d\n", status);
	if (status) {
		capabilities &= PCIE_PORT_SERVICE_VC | 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
static int suspend_iter(struct device *dev, void *data)
{
	struct pcie_port_service_driver *service_driver;

	if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
		service_driver = to_service_driver(dev->driver);
		if (service_driver->suspend)
			service_driver->suspend(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)
{
	return device_for_each_child(dev, NULL, suspend_iter);
}

static int resume_iter(struct device *dev, void *data)
{
	struct pcie_port_service_driver *service_driver;

	if ((dev->bus == &pcie_port_bus_type) &&
	    (dev->driver)) {
		service_driver = to_service_driver(dev->driver);
		if (service_driver->resume)
			service_driver->resume(to_pcie_device(dev));
	}
	return 0;
}

/**
 * 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)
{
	return device_for_each_child(dev, NULL, resume_iter);
}
#endif /* PM */

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

/**
 * 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);