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 __devinit 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 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
85 if ((dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT) ||
86 (dev->pcie_type == PCI_EXP_TYPE_UPSTREAM) ||
87 (dev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)) {
88 if (enable)
89 pci_enable_pcie_error_reporting(dev);
90 else
91 pci_disable_pcie_error_reporting(dev);
92 }
93
94 if (enable)
95 pcie_set_ecrc_checking(dev);
96
97 return 0;
98 }
99
100 /**
101 * set_downstream_devices_error_reporting - enable/disable the error reporting bits on the root port and its downstream ports.
102 * @dev: pointer to root port's pci_dev data structure
103 * @enable: true = enable error reporting, false = disable error reporting.
104 */
set_downstream_devices_error_reporting(struct pci_dev * dev,bool enable)105 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
106 bool enable)
107 {
108 set_device_error_reporting(dev, &enable);
109
110 if (!dev->subordinate)
111 return;
112 pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
113 }
114
115 /**
116 * aer_enable_rootport - enable Root Port's interrupts when receiving messages
117 * @rpc: pointer to a Root Port data structure
118 *
119 * Invoked when PCIe bus loads AER service driver.
120 */
aer_enable_rootport(struct aer_rpc * rpc)121 static void aer_enable_rootport(struct aer_rpc *rpc)
122 {
123 struct pci_dev *pdev = rpc->rpd->port;
124 int pos, aer_pos;
125 u16 reg16;
126 u32 reg32;
127
128 pos = pci_pcie_cap(pdev);
129 /* Clear PCIe Capability's Device Status */
130 pci_read_config_word(pdev, pos+PCI_EXP_DEVSTA, ®16);
131 pci_write_config_word(pdev, pos+PCI_EXP_DEVSTA, reg16);
132
133 /* Disable system error generation in response to error messages */
134 pci_read_config_word(pdev, pos + PCI_EXP_RTCTL, ®16);
135 reg16 &= ~(SYSTEM_ERROR_INTR_ON_MESG_MASK);
136 pci_write_config_word(pdev, pos + PCI_EXP_RTCTL, reg16);
137
138 aer_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
139 /* Clear error status */
140 pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, ®32);
141 pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
142 pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, ®32);
143 pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
144 pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, ®32);
145 pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);
146
147 /*
148 * Enable error reporting for the root port device and downstream port
149 * devices.
150 */
151 set_downstream_devices_error_reporting(pdev, true);
152
153 /* Enable Root Port's interrupt in response to error messages */
154 pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, ®32);
155 reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
156 pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32);
157 }
158
159 /**
160 * aer_disable_rootport - disable Root Port's interrupts when receiving messages
161 * @rpc: pointer to a Root Port data structure
162 *
163 * Invoked when PCIe bus unloads AER service driver.
164 */
aer_disable_rootport(struct aer_rpc * rpc)165 static void aer_disable_rootport(struct aer_rpc *rpc)
166 {
167 struct pci_dev *pdev = rpc->rpd->port;
168 u32 reg32;
169 int pos;
170
171 /*
172 * Disable error reporting for the root port device and downstream port
173 * devices.
174 */
175 set_downstream_devices_error_reporting(pdev, false);
176
177 pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
178 /* Disable Root's interrupt in response to error messages */
179 pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, ®32);
180 reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
181 pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32);
182
183 /* Clear Root's error status reg */
184 pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, ®32);
185 pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
186 }
187
188 /**
189 * aer_irq - Root Port's ISR
190 * @irq: IRQ assigned to Root Port
191 * @context: pointer to Root Port data structure
192 *
193 * Invoked when Root Port detects AER messages.
194 */
aer_irq(int irq,void * context)195 irqreturn_t aer_irq(int irq, void *context)
196 {
197 unsigned int status, id;
198 struct pcie_device *pdev = (struct pcie_device *)context;
199 struct aer_rpc *rpc = get_service_data(pdev);
200 int next_prod_idx;
201 unsigned long flags;
202 int pos;
203
204 pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
205 /*
206 * Must lock access to Root Error Status Reg, Root Error ID Reg,
207 * and Root error producer/consumer index
208 */
209 spin_lock_irqsave(&rpc->e_lock, flags);
210
211 /* Read error status */
212 pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
213 if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) {
214 spin_unlock_irqrestore(&rpc->e_lock, flags);
215 return IRQ_NONE;
216 }
217
218 /* Read error source and clear error status */
219 pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
220 pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
221
222 /* Store error source for later DPC handler */
223 next_prod_idx = rpc->prod_idx + 1;
224 if (next_prod_idx == AER_ERROR_SOURCES_MAX)
225 next_prod_idx = 0;
226 if (next_prod_idx == rpc->cons_idx) {
227 /*
228 * Error Storm Condition - possibly the same error occurred.
229 * Drop the error.
230 */
231 spin_unlock_irqrestore(&rpc->e_lock, flags);
232 return IRQ_HANDLED;
233 }
234 rpc->e_sources[rpc->prod_idx].status = status;
235 rpc->e_sources[rpc->prod_idx].id = id;
236 rpc->prod_idx = next_prod_idx;
237 spin_unlock_irqrestore(&rpc->e_lock, flags);
238
239 /* Invoke DPC handler */
240 schedule_work(&rpc->dpc_handler);
241
242 return IRQ_HANDLED;
243 }
244 EXPORT_SYMBOL_GPL(aer_irq);
245
246 /**
247 * aer_alloc_rpc - allocate Root Port data structure
248 * @dev: pointer to the pcie_dev data structure
249 *
250 * Invoked when Root Port's AER service is loaded.
251 */
aer_alloc_rpc(struct pcie_device * dev)252 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
253 {
254 struct aer_rpc *rpc;
255
256 rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
257 if (!rpc)
258 return NULL;
259
260 /* Initialize Root lock access, e_lock, to Root Error Status Reg */
261 spin_lock_init(&rpc->e_lock);
262
263 rpc->rpd = dev;
264 INIT_WORK(&rpc->dpc_handler, aer_isr);
265 mutex_init(&rpc->rpc_mutex);
266 init_waitqueue_head(&rpc->wait_release);
267
268 /* Use PCIe bus function to store rpc into PCIe device */
269 set_service_data(dev, rpc);
270
271 return rpc;
272 }
273
274 /**
275 * aer_remove - clean up resources
276 * @dev: pointer to the pcie_dev data structure
277 *
278 * Invoked when PCI Express bus unloads or AER probe fails.
279 */
aer_remove(struct pcie_device * dev)280 static void aer_remove(struct pcie_device *dev)
281 {
282 struct aer_rpc *rpc = get_service_data(dev);
283
284 if (rpc) {
285 /* If register interrupt service, it must be free. */
286 if (rpc->isr)
287 free_irq(dev->irq, dev);
288
289 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
290
291 aer_disable_rootport(rpc);
292 kfree(rpc);
293 set_service_data(dev, NULL);
294 }
295 }
296
297 /**
298 * aer_probe - initialize resources
299 * @dev: pointer to the pcie_dev data structure
300 * @id: pointer to the service id data structure
301 *
302 * Invoked when PCI Express bus loads AER service driver.
303 */
aer_probe(struct pcie_device * dev)304 static int __devinit aer_probe(struct pcie_device *dev)
305 {
306 int status;
307 struct aer_rpc *rpc;
308 struct device *device = &dev->device;
309
310 /* Init */
311 status = aer_init(dev);
312 if (status)
313 return status;
314
315 /* Alloc rpc data structure */
316 rpc = aer_alloc_rpc(dev);
317 if (!rpc) {
318 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
319 aer_remove(dev);
320 return -ENOMEM;
321 }
322
323 /* Request IRQ ISR */
324 status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
325 if (status) {
326 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
327 aer_remove(dev);
328 return status;
329 }
330
331 rpc->isr = 1;
332
333 aer_enable_rootport(rpc);
334
335 return status;
336 }
337
338 /**
339 * aer_root_reset - reset link on Root Port
340 * @dev: pointer to Root Port's pci_dev data structure
341 *
342 * Invoked by Port Bus driver when performing link reset at Root Port.
343 */
aer_root_reset(struct pci_dev * dev)344 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
345 {
346 u32 reg32;
347 int pos;
348
349 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
350
351 /* Disable Root's interrupt in response to error messages */
352 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, ®32);
353 reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
354 pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
355
356 aer_do_secondary_bus_reset(dev);
357 dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
358
359 /* Clear Root Error Status */
360 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32);
361 pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32);
362
363 /* Enable Root Port's interrupt in response to error messages */
364 pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, ®32);
365 reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
366 pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
367
368 return PCI_ERS_RESULT_RECOVERED;
369 }
370
371 /**
372 * aer_error_detected - update severity status
373 * @dev: pointer to Root Port's pci_dev data structure
374 * @error: error severity being notified by port bus
375 *
376 * Invoked by Port Bus driver during error recovery.
377 */
aer_error_detected(struct pci_dev * dev,enum pci_channel_state error)378 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
379 enum pci_channel_state error)
380 {
381 /* Root Port has no impact. Always recovers. */
382 return PCI_ERS_RESULT_CAN_RECOVER;
383 }
384
385 /**
386 * aer_error_resume - clean up corresponding error status bits
387 * @dev: pointer to Root Port's pci_dev data structure
388 *
389 * Invoked by Port Bus driver during nonfatal recovery.
390 */
aer_error_resume(struct pci_dev * dev)391 static void aer_error_resume(struct pci_dev *dev)
392 {
393 int pos;
394 u32 status, mask;
395 u16 reg16;
396
397 /* Clean up Root device status */
398 pos = pci_pcie_cap(dev);
399 pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, ®16);
400 pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
401
402 /* Clean AER Root Error Status */
403 pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
404 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
405 pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
406 if (dev->error_state == pci_channel_io_normal)
407 status &= ~mask; /* Clear corresponding nonfatal bits */
408 else
409 status &= mask; /* Clear corresponding fatal bits */
410 pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
411 }
412
413 /**
414 * aer_service_init - register AER root service driver
415 *
416 * Invoked when AER root service driver is loaded.
417 */
aer_service_init(void)418 static int __init aer_service_init(void)
419 {
420 if (!pci_aer_available() || aer_acpi_firmware_first())
421 return -ENXIO;
422 return pcie_port_service_register(&aerdriver);
423 }
424
425 /**
426 * aer_service_exit - unregister AER root service driver
427 *
428 * Invoked when AER root service driver is unloaded.
429 */
aer_service_exit(void)430 static void __exit aer_service_exit(void)
431 {
432 pcie_port_service_unregister(&aerdriver);
433 }
434
435 module_init(aer_service_init);
436 module_exit(aer_service_exit);
437