1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright IBM Corp. 2012
6 * Jan Glauber <jang@linux.vnet.ibm.com>
9 #define KMSG_COMPONENT "zpci"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 #include <linux/kernel.h>
13 #include <linux/pci.h>
14 #include <asm/pci_debug.h>
15 #include <asm/pci_dma.h>
20 /* Content Code Description for PCI Function Error */
21 struct zpci_ccdf_err {
23 u32 fh; /* function handle */
24 u32 fid; /* function id */
25 u32 ett : 4; /* expected table type */
26 u32 mvn : 12; /* MSI vector number */
27 u32 dmaas : 8; /* DMA address space */
29 u32 q : 1; /* event qualifier */
30 u32 rw : 1; /* read/write */
31 u64 faddr; /* failing address */
34 u16 pec; /* PCI event code */
37 /* Content Code Description for PCI Function Availability */
38 struct zpci_ccdf_avail {
40 u32 fh; /* function handle */
41 u32 fid; /* function id */
47 u16 pec; /* PCI event code */
50 static inline bool ers_result_indicates_abort(pci_ers_result_t ers_res)
53 case PCI_ERS_RESULT_CAN_RECOVER:
54 case PCI_ERS_RESULT_RECOVERED:
55 case PCI_ERS_RESULT_NEED_RESET:
62 static bool is_passed_through(struct zpci_dev *zdev)
64 return zdev->s390_domain;
67 static bool is_driver_supported(struct pci_driver *driver)
69 if (!driver || !driver->err_handler)
71 if (!driver->err_handler->error_detected)
73 if (!driver->err_handler->slot_reset)
75 if (!driver->err_handler->resume)
80 static pci_ers_result_t zpci_event_notify_error_detected(struct pci_dev *pdev,
81 struct pci_driver *driver)
83 pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
85 ers_res = driver->err_handler->error_detected(pdev, pdev->error_state);
86 if (ers_result_indicates_abort(ers_res))
87 pr_info("%s: Automatic recovery failed after initial reporting\n", pci_name(pdev));
88 else if (ers_res == PCI_ERS_RESULT_NEED_RESET)
89 pr_debug("%s: Driver needs reset to recover\n", pci_name(pdev));
94 static pci_ers_result_t zpci_event_do_error_state_clear(struct pci_dev *pdev,
95 struct pci_driver *driver)
97 pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
98 struct zpci_dev *zdev = to_zpci(pdev);
101 pr_info("%s: Unblocking device access for examination\n", pci_name(pdev));
102 rc = zpci_reset_load_store_blocked(zdev);
104 pr_err("%s: Unblocking device access failed\n", pci_name(pdev));
105 /* Let's try a full reset instead */
106 return PCI_ERS_RESULT_NEED_RESET;
109 if (driver->err_handler->mmio_enabled) {
110 ers_res = driver->err_handler->mmio_enabled(pdev);
111 if (ers_result_indicates_abort(ers_res)) {
112 pr_info("%s: Automatic recovery failed after MMIO re-enable\n",
115 } else if (ers_res == PCI_ERS_RESULT_NEED_RESET) {
116 pr_debug("%s: Driver needs reset to recover\n", pci_name(pdev));
121 pr_debug("%s: Unblocking DMA\n", pci_name(pdev));
122 rc = zpci_clear_error_state(zdev);
124 pdev->error_state = pci_channel_io_normal;
126 pr_err("%s: Unblocking DMA failed\n", pci_name(pdev));
127 /* Let's try a full reset instead */
128 return PCI_ERS_RESULT_NEED_RESET;
134 static pci_ers_result_t zpci_event_do_reset(struct pci_dev *pdev,
135 struct pci_driver *driver)
137 pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
139 pr_info("%s: Initiating reset\n", pci_name(pdev));
140 if (zpci_hot_reset_device(to_zpci(pdev))) {
141 pr_err("%s: The reset request failed\n", pci_name(pdev));
144 pdev->error_state = pci_channel_io_normal;
145 ers_res = driver->err_handler->slot_reset(pdev);
146 if (ers_result_indicates_abort(ers_res)) {
147 pr_info("%s: Automatic recovery failed after slot reset\n", pci_name(pdev));
154 /* zpci_event_attempt_error_recovery - Try to recover the given PCI function
155 * @pdev: PCI function to recover currently in the error state
157 * We follow the scheme outlined in Documentation/PCI/pci-error-recovery.rst.
158 * With the simplification that recovery always happens per function
159 * and the platform determines which functions are affected for
160 * multi-function devices.
162 static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *pdev)
164 pci_ers_result_t ers_res = PCI_ERS_RESULT_DISCONNECT;
165 struct pci_driver *driver;
168 * Ensure that the PCI function is not removed concurrently, no driver
169 * is unbound or probed and that userspace can't access its
170 * configuration space while we perform recovery.
173 if (pdev->error_state == pci_channel_io_perm_failure) {
174 ers_res = PCI_ERS_RESULT_DISCONNECT;
177 pdev->error_state = pci_channel_io_frozen;
179 if (is_passed_through(to_zpci(pdev))) {
180 pr_info("%s: Cannot be recovered in the host because it is a pass-through device\n",
185 driver = to_pci_driver(pdev->dev.driver);
186 if (!is_driver_supported(driver)) {
188 pr_info("%s: Cannot be recovered because no driver is bound to the device\n",
191 pr_info("%s: The %s driver bound to the device does not support error recovery\n",
197 ers_res = zpci_event_notify_error_detected(pdev, driver);
198 if (ers_result_indicates_abort(ers_res))
201 if (ers_res == PCI_ERS_RESULT_CAN_RECOVER) {
202 ers_res = zpci_event_do_error_state_clear(pdev, driver);
203 if (ers_result_indicates_abort(ers_res))
207 if (ers_res == PCI_ERS_RESULT_NEED_RESET)
208 ers_res = zpci_event_do_reset(pdev, driver);
210 if (ers_res != PCI_ERS_RESULT_RECOVERED) {
211 pr_err("%s: Automatic recovery failed; operator intervention is required\n",
216 pr_info("%s: The device is ready to resume operations\n", pci_name(pdev));
217 if (driver->err_handler->resume)
218 driver->err_handler->resume(pdev);
220 pci_dev_unlock(pdev);
225 /* zpci_event_io_failure - Report PCI channel failure state to driver
226 * @pdev: PCI function for which to report
227 * @es: PCI channel failure state to report
229 static void zpci_event_io_failure(struct pci_dev *pdev, pci_channel_state_t es)
231 struct pci_driver *driver;
234 pdev->error_state = es;
236 * While vfio-pci's error_detected callback notifies user-space QEMU
237 * reacts to this by freezing the guest. In an s390 environment PCI
238 * errors are rarely fatal so this is overkill. Instead in the future
239 * we will inject the error event and let the guest recover the device
242 if (is_passed_through(to_zpci(pdev)))
244 driver = to_pci_driver(pdev->dev.driver);
245 if (driver && driver->err_handler && driver->err_handler->error_detected)
246 driver->err_handler->error_detected(pdev, pdev->error_state);
248 pci_dev_unlock(pdev);
251 static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
253 struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
254 struct pci_dev *pdev = NULL;
255 pci_ers_result_t ers_res;
257 zpci_dbg(3, "err fid:%x, fh:%x, pec:%x\n",
258 ccdf->fid, ccdf->fh, ccdf->pec);
259 zpci_err("error CCDF:\n");
260 zpci_err_hex(ccdf, sizeof(*ccdf));
263 zpci_update_fh(zdev, ccdf->fh);
265 pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
268 pr_err("%s: Event 0x%x reports an error for PCI function 0x%x\n",
269 pdev ? pci_name(pdev) : "n/a", ccdf->pec, ccdf->fid);
275 case 0x003a: /* Service Action or Error Recovery Successful */
276 ers_res = zpci_event_attempt_error_recovery(pdev);
277 if (ers_res != PCI_ERS_RESULT_RECOVERED)
278 zpci_event_io_failure(pdev, pci_channel_io_perm_failure);
282 * Mark as frozen not permanently failed because the device
283 * could be subsequently recovered by the platform.
285 zpci_event_io_failure(pdev, pci_channel_io_frozen);
293 void zpci_event_error(void *data)
295 if (zpci_is_enabled())
296 __zpci_event_error(data);
299 static void zpci_event_hard_deconfigured(struct zpci_dev *zdev, u32 fh)
301 zpci_update_fh(zdev, fh);
302 /* Give the driver a hint that the function is
305 zpci_bus_remove_device(zdev, true);
306 /* Even though the device is already gone we still
307 * need to free zPCI resources as part of the disable.
310 zpci_dma_exit_device(zdev);
311 if (zdev_enabled(zdev))
312 zpci_disable_device(zdev);
313 zdev->state = ZPCI_FN_STATE_STANDBY;
316 static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
318 struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
319 bool existing_zdev = !!zdev;
320 enum zpci_state state;
322 zpci_dbg(3, "avl fid:%x, fh:%x, pec:%x\n",
323 ccdf->fid, ccdf->fh, ccdf->pec);
325 case 0x0301: /* Reserved|Standby -> Configured */
327 zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_CONFIGURED);
331 /* the configuration request may be stale */
332 if (zdev->state != ZPCI_FN_STATE_STANDBY)
334 zdev->state = ZPCI_FN_STATE_CONFIGURED;
336 zpci_scan_configured_device(zdev, ccdf->fh);
338 case 0x0302: /* Reserved -> Standby */
340 zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY);
342 zpci_update_fh(zdev, ccdf->fh);
344 case 0x0303: /* Deconfiguration requested */
346 /* The event may have been queued before we confirgured
349 if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
351 zpci_update_fh(zdev, ccdf->fh);
352 zpci_deconfigure_device(zdev);
355 case 0x0304: /* Configured -> Standby|Reserved */
357 /* The event may have been queued before we confirgured
360 if (zdev->state == ZPCI_FN_STATE_CONFIGURED)
361 zpci_event_hard_deconfigured(zdev, ccdf->fh);
362 /* The 0x0304 event may immediately reserve the device */
363 if (!clp_get_state(zdev->fid, &state) &&
364 state == ZPCI_FN_STATE_RESERVED) {
365 zpci_device_reserved(zdev);
369 case 0x0306: /* 0x308 or 0x302 for multiple devices */
370 zpci_remove_reserved_devices();
371 clp_scan_pci_devices();
373 case 0x0308: /* Standby -> Reserved */
376 zpci_device_reserved(zdev);
385 void zpci_event_availability(void *data)
387 if (zpci_is_enabled())
388 __zpci_event_availability(data);