1 /*
2 * drivers/pci/pcie/aer/aerdrv.c
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * This file implements the AER root port service driver. The driver will
9 * register an irq handler. When root port triggers an AER interrupt, the irq
10 * handler will collect root port status and schedule a work.
11 *
12 * Copyright (C) 2006 Intel Corp.
13 * Tom Long Nguyen (tom.l.nguyen@intel.com)
14 * Zhang Yanmin (yanmin.zhang@intel.com)
15 *
16 */
17
18 #include <linux/module.h>
19 #include <linux/pci.h>
20 #include <linux/pci-acpi.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/pm.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/delay.h>
28 #include <linux/pcieport_if.h>
29 #include <linux/slab.h>
30
31 #include "aerdrv.h"
32 #include "../../pci.h"
33
34 /*
35 * Version Information
36 */
37 #define DRIVER_VERSION "v1.0"
38 #define DRIVER_AUTHOR "tom.l.nguyen@intel.com"
39 #define DRIVER_DESC "Root Port Advanced Error Reporting Driver"
40 MODULE_AUTHOR(DRIVER_AUTHOR);
41 MODULE_DESCRIPTION(DRIVER_DESC);
42 MODULE_LICENSE("GPL");
43
44 static int aer_probe(struct pcie_device *dev);
45 static void aer_remove(struct pcie_device *dev);
46 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
47 enum pci_channel_state error);
48 static void aer_error_resume(struct pci_dev *dev);
49 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
50
51 static const struct pci_error_handlers aer_error_handlers = {
52 .error_detected = aer_error_detected,
53 .resume = aer_error_resume,
54 };
55
56 static struct pcie_port_service_driver aerdriver = {
57 .name = "aer",
58 .port_type = PCI_EXP_TYPE_ROOT_PORT,
59 .service = PCIE_PORT_SERVICE_AER,
60
61 .probe = aer_probe,
62 .remove = aer_remove,
63
64 .err_handler = &aer_error_handlers,
65
66 .reset_link = aer_root_reset,
67 };
68
69 static int pcie_aer_disable;
70
pci_no_aer(void)71 void pci_no_aer(void)
72 {
73 pcie_aer_disable = 1; /* has priority over 'forceload' */
74 }
75
pci_aer_available(void)76 bool pci_aer_available(void)
77 {
78 return !pcie_aer_disable && pci_msi_enabled();
79 }
80
set_device_error_reporting(struct pci_dev * dev,void * data)81 static int set_device_error_reporting(struct pci_dev *dev, void *data)
82 {
83 bool enable = *((bool *)data);
84 int type = pci_pcie_type(dev);
85
86 if ((type == PCI_EXP_TYPE_ROOT_PORT) ||
87 (type == PCI_EXP_TYPE_UPSTREAM) ||
88 (type == PCI_EXP_TYPE_DOWNSTREAM)) {
89 if (enable)
90 pci_enable_pcie_error_reporting(dev);
91 else
92 pci_disable_pcie_error_reporting(dev);
93 }
94
95 if (enable)
96 pcie_set_ecrc_checking(dev);
97
98 return 0;
99 }
100
101 /**
102 * set_downstream_devices_error_reporting - enable/disable the error reporting bits on the root port and its downstream ports.
103 * @dev: pointer to root port's pci_dev data structure
104 * @enable: true = enable error reporting, false = disable error reporting.
105 */
set_downstream_devices_error_reporting(struct pci_dev * dev,bool enable)106 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
107 bool enable)
108 {
109 set_device_error_reporting(dev, &enable);
110
111 if (!dev->subordinate)
112 return;
113 pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
114 }
115
116 /**
117 * aer_enable_rootport - enable Root Port's interrupts when receiving messages
118 * @rpc: pointer to a Root Port data structure
119 *
120 * Invoked when PCIe bus loads AER service driver.
121 */
aer_enable_rootport(struct aer_rpc * rpc)122 static void aer_enable_rootport(struct aer_rpc *rpc)
123 {
124 struct pci_dev *pdev = rpc->rpd->port;
125 int aer_pos;
126 u16 reg16;
127 u32 reg32;
128
129 /* Clear PCIe Capability's Device Status */
130 pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, ®16);
131 pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
132
133 /* Disable system error generation in response to error messages */
134 pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
135 SYSTEM_ERROR_INTR_ON_MESG_MASK);
136
137 aer_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
138 /* Clear error status */
139 pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, ®32);
140 pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
141 pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, ®32);
142 pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
143 pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, ®32);
144 pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);
145
146 /*
147 * Enable error reporting for the root port device and downstream port
148 * devices.
149 */
150 set_downstream_devices_error_reporting(pdev, true);
151
152 /* Enable Root Port's interrupt in response to error messages */
153 pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, ®32);
154 reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
155 pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32);
156 }
157
158 /**
159 * aer_disable_rootport - disable Root Port's interrupts when receiving messages
160 * @rpc: pointer to a Root Port data structure
161 *
162 * Invoked when PCIe bus unloads AER service driver.
163 */
aer_disable_rootport(struct aer_rpc * rpc)164 static void aer_disable_rootport(struct aer_rpc *rpc)
165 {
166 struct pci_dev *pdev = rpc->rpd->port;
167 u32 reg32;
168 int pos;
169
170 /*
171 * Disable error reporting for the root port device and downstream port
172 * devices.
173 */
174 set_downstream_devices_error_reporting(pdev, false);
175
176 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
177 /* Disable Root's interrupt in response to error messages */
178 pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, ®32);
179 reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
180 pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32);
181
182 /* Clear Root's error status reg */
183 pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, ®32);
184 pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
185 }
186
187 /**
188 * aer_irq - Root Port's ISR
189 * @irq: IRQ assigned to Root Port
190 * @context: pointer to Root Port data structure
191 *
192 * Invoked when Root Port detects AER messages.
193 */
aer_irq(int irq,void * context)194 irqreturn_t aer_irq(int irq, void *context)
195 {
196 unsigned int status, id;
197 struct pcie_device *pdev = (struct pcie_device *)context;
198 struct aer_rpc *rpc = get_service_data(pdev);
199 int next_prod_idx;
200 unsigned long flags;
201 int pos;
202
203 pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
204 /*
205 * Must lock access to Root Error Status Reg, Root Error ID Reg,
206 * and Root error producer/consumer index
207 */
208 spin_lock_irqsave(&rpc->e_lock, flags);
209
210 /* Read error status */
211 pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
212 if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) {
213 spin_unlock_irqrestore(&rpc->e_lock, flags);
214 return IRQ_NONE;
215 }
216
217 /* Read error source and clear error status */
218 pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
219 pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
220
221 /* Store error source for later DPC handler */
222 next_prod_idx = rpc->prod_idx + 1;
223 if (next_prod_idx == AER_ERROR_SOURCES_MAX)
224 next_prod_idx = 0;
225 if (next_prod_idx == rpc->cons_idx) {
226 /*
227 * Error Storm Condition - possibly the same error occurred.
228 * Drop the error.
229 */
230 spin_unlock_irqrestore(&rpc->e_lock, flags);
231 return IRQ_HANDLED;
232 }
233 rpc->e_sources[rpc->prod_idx].status = status;
234 rpc->e_sources[rpc->prod_idx].id = id;
235 rpc->prod_idx = next_prod_idx;
236 spin_unlock_irqrestore(&rpc->e_lock, flags);
237
238 /* Invoke DPC handler */
239 schedule_work(&rpc->dpc_handler);
240
241 return IRQ_HANDLED;
242 }
243 EXPORT_SYMBOL_GPL(aer_irq);
244
245 /**
246 * aer_alloc_rpc - allocate Root Port data structure
247 * @dev: pointer to the pcie_dev data structure
248 *
249 * Invoked when Root Port's AER service is loaded.
250 */
aer_alloc_rpc(struct pcie_device * dev)251 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
252 {
253 struct aer_rpc *rpc;
254
255 rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
256 if (!rpc)
257 return NULL;
258
259 /* Initialize Root lock access, e_lock, to Root Error Status Reg */
260 spin_lock_init(&rpc->e_lock);
261
262 rpc->rpd = dev;
263 INIT_WORK(&rpc->dpc_handler, aer_isr);
264 mutex_init(&rpc->rpc_mutex);
265
266 /* Use PCIe bus function to store rpc into PCIe device */
267 set_service_data(dev, rpc);
268
269 return rpc;
270 }
271
272 /**
273 * aer_remove - clean up resources
274 * @dev: pointer to the pcie_dev data structure
275 *
276 * Invoked when PCI Express bus unloads or AER probe fails.
277 */
aer_remove(struct pcie_device * dev)278 static void aer_remove(struct pcie_device *dev)
279 {
280 struct aer_rpc *rpc = get_service_data(dev);
281
282 if (rpc) {
283 /* If register interrupt service, it must be free. */
284 if (rpc->isr)
285 free_irq(dev->irq, dev);
286
287 flush_work(&rpc->dpc_handler);
288 aer_disable_rootport(rpc);
289 kfree(rpc);
290 set_service_data(dev, NULL);
291 }
292 }
293
294 /**
295 * aer_probe - initialize resources
296 * @dev: pointer to the pcie_dev data structure
297 * @id: pointer to the service id data structure
298 *
299 * Invoked when PCI Express bus loads AER service driver.
300 */
aer_probe(struct pcie_device * dev)301 static int aer_probe(struct pcie_device *dev)
302 {
303 int status;
304 struct aer_rpc *rpc;
305 struct device *device = &dev->device;
306
307 /* Init */
308 status = aer_init(dev);
309 if (status)
310 return status;
311
312 /* Alloc rpc data structure */
313 rpc = aer_alloc_rpc(dev);
314 if (!rpc) {
315 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
316 aer_remove(dev);
317 return -ENOMEM;
318 }
319
320 /* Request IRQ ISR */
321 status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
322 if (status) {
323 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
324 aer_remove(dev);
325 return status;
326 }
327
328 rpc->isr = 1;
329
330 aer_enable_rootport(rpc);
331
332 return status;
333 }
334
335 /**
336 * aer_root_reset - reset link on Root Port
337 * @dev: pointer to Root Port's pci_dev data structure
338 *
339 * Invoked by Port Bus driver when performing link reset at Root Port.
340 */
aer_root_reset(struct pci_dev * dev)341 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
342 {
343 u32 reg32;
344 int pos;
345
346 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
347
348 /* Disable Root's interrupt in response to error messages */
349 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, ®32);
350 reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
351 pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
352
353 pci_reset_bridge_secondary_bus(dev);
354 dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
355
356 /* Clear Root Error Status */
357 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
358 pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32);
359
360 /* Enable Root Port's interrupt in response to error messages */
361 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, ®32);
362 reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
363 pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
364
365 return PCI_ERS_RESULT_RECOVERED;
366 }
367
368 /**
369 * aer_error_detected - update severity status
370 * @dev: pointer to Root Port's pci_dev data structure
371 * @error: error severity being notified by port bus
372 *
373 * Invoked by Port Bus driver during error recovery.
374 */
aer_error_detected(struct pci_dev * dev,enum pci_channel_state error)375 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
376 enum pci_channel_state error)
377 {
378 /* Root Port has no impact. Always recovers. */
379 return PCI_ERS_RESULT_CAN_RECOVER;
380 }
381
382 /**
383 * aer_error_resume - clean up corresponding error status bits
384 * @dev: pointer to Root Port's pci_dev data structure
385 *
386 * Invoked by Port Bus driver during nonfatal recovery.
387 */
aer_error_resume(struct pci_dev * dev)388 static void aer_error_resume(struct pci_dev *dev)
389 {
390 int pos;
391 u32 status, mask;
392 u16 reg16;
393
394 /* Clean up Root device status */
395 pcie_capability_read_word(dev, PCI_EXP_DEVSTA, ®16);
396 pcie_capability_write_word(dev, PCI_EXP_DEVSTA, reg16);
397
398 /* Clean AER Root Error Status */
399 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
400 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
401 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
402 if (dev->error_state == pci_channel_io_normal)
403 status &= ~mask; /* Clear corresponding nonfatal bits */
404 else
405 status &= mask; /* Clear corresponding fatal bits */
406 pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
407 }
408
409 /**
410 * aer_service_init - register AER root service driver
411 *
412 * Invoked when AER root service driver is loaded.
413 */
aer_service_init(void)414 static int __init aer_service_init(void)
415 {
416 if (!pci_aer_available() || aer_acpi_firmware_first())
417 return -ENXIO;
418 return pcie_port_service_register(&aerdriver);
419 }
420
421 /**
422 * aer_service_exit - unregister AER root service driver
423 *
424 * Invoked when AER root service driver is unloaded.
425 */
aer_service_exit(void)426 static void __exit aer_service_exit(void)
427 {
428 pcie_port_service_unregister(&aerdriver);
429 }
430
431 module_init(aer_service_init);
432 module_exit(aer_service_exit);
433