summaryrefslogtreecommitdiffstats
path: root/drivers/pci/pcie/aer/aerdrv.c
blob: 6f5fabbd14e58f77453c112e9c77850af1d38b52 (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
/*
 * drivers/pci/pcie/aer/aerdrv.c
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * This file implements the AER root port service driver. The driver will
 * register an irq handler. When root port triggers an AER interrupt, the irq
 * handler will collect root port status and schedule a work.
 *
 * Copyright (C) 2006 Intel Corp.
 *	Tom Long Nguyen (tom.l.nguyen@intel.com)
 *	Zhang Yanmin (yanmin.zhang@intel.com)
 *
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/pcieport_if.h>

#include "aerdrv.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.0"
#define DRIVER_AUTHOR "tom.l.nguyen@intel.com"
#define DRIVER_DESC "Root Port Advanced Error Reporting Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

static int __devinit aer_probe (struct pcie_device *dev,
	const struct pcie_port_service_id *id );
static void aer_remove(struct pcie_device *dev);
static int aer_suspend(struct pcie_device *dev, pm_message_t state)
{return 0;}
static int aer_resume(struct pcie_device *dev) {return 0;}
static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
	enum pci_channel_state error);
static void aer_error_resume(struct pci_dev *dev);
static pci_ers_result_t aer_root_reset(struct pci_dev *dev);

/*
 * PCI Express bus's AER Root service driver data structure
 */
static struct pcie_port_service_id aer_id[] = {
	{
	.vendor 	= PCI_ANY_ID,
	.device 	= PCI_ANY_ID,
	.port_type 	= PCIE_RC_PORT,
	.service_type 	= PCIE_PORT_SERVICE_AER,
	},
	{ /* end: all zeroes */ }
};

static struct pci_error_handlers aer_error_handlers = {
	.error_detected = aer_error_detected,
	.resume = aer_error_resume,
};

static struct pcie_port_service_driver aerdrv = {
	.name		= "aer",
	.id_table	= &aer_id[0],

	.probe		= aer_probe,
	.remove		= aer_remove,

	.suspend	= aer_suspend,
	.resume		= aer_resume,

	.err_handler	= &aer_error_handlers,

	.reset_link	= aer_root_reset,
};

/**
 * aer_irq - Root Port's ISR
 * @irq: IRQ assigned to Root Port
 * @context: pointer to Root Port data structure
 *
 * Invoked when Root Port detects AER messages.
 **/
static irqreturn_t aer_irq(int irq, void *context)
{
	unsigned int status, id;
	struct pcie_device *pdev = (struct pcie_device *)context;
	struct aer_rpc *rpc = get_service_data(pdev);
	int next_prod_idx;
	unsigned long flags;
	int pos;

	pos = pci_find_aer_capability(pdev->port);
	/*
	 * Must lock access to Root Error Status Reg, Root Error ID Reg,
	 * and Root error producer/consumer index
	 */
	spin_lock_irqsave(&rpc->e_lock, flags);

	/* Read error status */
	pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
	if (!(status & ROOT_ERR_STATUS_MASKS)) {
		spin_unlock_irqrestore(&rpc->e_lock, flags);
		return IRQ_NONE;
	}

	/* Read error source and clear error status */
	pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_COR_SRC, &id);
	pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);

	/* Store error source for later DPC handler */
	next_prod_idx = rpc->prod_idx + 1;
	if (next_prod_idx == AER_ERROR_SOURCES_MAX)
		next_prod_idx = 0;
	if (next_prod_idx == rpc->cons_idx) {
		/*
		 * Error Storm Condition - possibly the same error occurred.
		 * Drop the error.
		 */
		spin_unlock_irqrestore(&rpc->e_lock, flags);
		return IRQ_HANDLED;
	}
	rpc->e_sources[rpc->prod_idx].status =  status;
	rpc->e_sources[rpc->prod_idx].id = id;
	rpc->prod_idx = next_prod_idx;
	spin_unlock_irqrestore(&rpc->e_lock, flags);

	/*  Invoke DPC handler */
	schedule_work(&rpc->dpc_handler);

	return IRQ_HANDLED;
}

/**
 * aer_alloc_rpc - allocate Root Port data structure
 * @dev: pointer to the pcie_dev data structure
 *
 * Invoked when Root Port's AER service is loaded.
 **/
static struct aer_rpc* aer_alloc_rpc(struct pcie_device *dev)
{
	struct aer_rpc *rpc;

	if (!(rpc = kmalloc(sizeof(struct aer_rpc),
		GFP_KERNEL)))
		return NULL;

	memset(rpc, 0, sizeof(struct aer_rpc));
	/*
	 * Initialize Root lock access, e_lock, to Root Error Status Reg,
	 * Root Error ID Reg, and Root error producer/consumer index.
	 */
	rpc->e_lock = SPIN_LOCK_UNLOCKED;

	rpc->rpd = dev;
	INIT_WORK(&rpc->dpc_handler, aer_isr);
	rpc->prod_idx = rpc->cons_idx = 0;
	mutex_init(&rpc->rpc_mutex);
	init_waitqueue_head(&rpc->wait_release);

	/* Use PCIE bus function to store rpc into PCIE device */
	set_service_data(dev, rpc);

	return rpc;
}

/**
 * aer_remove - clean up resources
 * @dev: pointer to the pcie_dev data structure
 *
 * Invoked when PCI Express bus unloads or AER probe fails.
 **/
static void aer_remove(struct pcie_device *dev)
{
	struct aer_rpc *rpc = get_service_data(dev);

	if (rpc) {
		/* If register interrupt service, it must be free. */
		if (rpc->isr)
			free_irq(dev->irq, dev);

		wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);

		aer_delete_rootport(rpc);
		set_service_data(dev, NULL);
	}
}

/**
 * aer_probe - initialize resources
 * @dev: pointer to the pcie_dev data structure
 * @id: pointer to the service id data structure
 *
 * Invoked when PCI Express bus loads AER service driver.
 **/
static int __devinit aer_probe (struct pcie_device *dev,
				const struct pcie_port_service_id *id )
{
	int status;
	struct aer_rpc *rpc;
	struct device *device = &dev->device;

	/* Init */
	if ((status = aer_init(dev)))
		return status;

	/* Alloc rpc data structure */
	if (!(rpc = aer_alloc_rpc(dev))) {
		printk(KERN_DEBUG "%s: Alloc rpc fails on PCIE device[%s]\n",
			__FUNCTION__, device->bus_id);
		aer_remove(dev);
		return -ENOMEM;
	}

	/* Request IRQ ISR */
	if ((status = request_irq(dev->irq, aer_irq, SA_SHIRQ, "aerdrv",
				dev))) {
		printk(KERN_DEBUG "%s: Request ISR fails on PCIE device[%s]\n",
			__FUNCTION__, device->bus_id);
		aer_remove(dev);
		return status;
	}

	rpc->isr = 1;

	aer_enable_rootport(rpc);

	return status;
}

/**
 * aer_root_reset - reset link on Root Port
 * @dev: pointer to Root Port's pci_dev data structure
 *
 * Invoked by Port Bus driver when performing link reset at Root Port.
 **/
static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
{
	u16 p2p_ctrl;
	u32 status;
	int pos;

	pos = pci_find_aer_capability(dev);

	/* Disable Root's interrupt in response to error messages */
	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, 0);

	/* Assert Secondary Bus Reset */
	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
	p2p_ctrl |= PCI_CB_BRIDGE_CTL_CB_RESET;
	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);

	/* De-assert Secondary Bus Reset */
	p2p_ctrl &= ~PCI_CB_BRIDGE_CTL_CB_RESET;
	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);

	/*
	 * System software must wait for at least 100ms from the end
	 * of a reset of one or more device before it is permitted
	 * to issue Configuration Requests to those devices.
	 */
	msleep(200);
	printk(KERN_DEBUG "Complete link reset at Root[%s]\n", dev->dev.bus_id);

	/* Enable Root Port's interrupt in response to error messages */
	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
	pci_write_config_dword(dev,
		pos + PCI_ERR_ROOT_COMMAND,
		ROOT_PORT_INTR_ON_MESG_MASK);

	return PCI_ERS_RESULT_RECOVERED;
}

/**
 * aer_error_detected - update severity status
 * @dev: pointer to Root Port's pci_dev data structure
 * @error: error severity being notified by port bus
 *
 * Invoked by Port Bus driver during error recovery.
 **/
static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
			enum pci_channel_state error)
{
	/* Root Port has no impact. Always recovers. */
	return PCI_ERS_RESULT_CAN_RECOVER;
}

/**
 * aer_error_resume - clean up corresponding error status bits
 * @dev: pointer to Root Port's pci_dev data structure
 *
 * Invoked by Port Bus driver during nonfatal recovery.
 **/
static void aer_error_resume(struct pci_dev *dev)
{
	int pos;
	u32 status, mask;
	u16 reg16;

	/* Clean up Root device status */
	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
	pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
	pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);

	/* Clean AER Root Error Status */
	pos = pci_find_aer_capability(dev);
	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
	if (dev->error_state == pci_channel_io_normal)
		status &= ~mask; /* Clear corresponding nonfatal bits */
	else
		status &= mask; /* Clear corresponding fatal bits */
	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
}

/**
 * aer_service_init - register AER root service driver
 *
 * Invoked when AER root service driver is loaded.
 **/
static int __init aer_service_init(void)
{
	return pcie_port_service_register(&aerdrv);
}

/**
 * aer_service_exit - unregister AER root service driver
 *
 * Invoked when AER root service driver is unloaded.
 **/
static void __exit aer_service_exit(void)
{
	pcie_port_service_unregister(&aerdrv);
}

module_init(aer_service_init);
module_exit(aer_service_exit);