1 // SPDX-License-Identifier: (BSD-3-Clause OR GPL-2.0-only)
2 /* Copyright(c) 2014 - 2020 Intel Corporation */
3 #include <linux/kernel.h>
4 #include <linux/pci.h>
5 #include <linux/completion.h>
6 #include <linux/workqueue.h>
7 #include <linux/delay.h>
8 #include "adf_accel_devices.h"
9 #include "adf_common_drv.h"
10 
11 static struct workqueue_struct *device_reset_wq;
12 
13 static pci_ers_result_t adf_error_detected(struct pci_dev *pdev,
14 					   pci_channel_state_t state)
15 {
16 	struct adf_accel_dev *accel_dev = adf_devmgr_pci_to_accel_dev(pdev);
17 
18 	dev_info(&pdev->dev, "Acceleration driver hardware error detected.\n");
19 	if (!accel_dev) {
20 		dev_err(&pdev->dev, "Can't find acceleration device\n");
21 		return PCI_ERS_RESULT_DISCONNECT;
22 	}
23 
24 	if (state == pci_channel_io_perm_failure) {
25 		dev_err(&pdev->dev, "Can't recover from device error\n");
26 		return PCI_ERS_RESULT_DISCONNECT;
27 	}
28 
29 	return PCI_ERS_RESULT_NEED_RESET;
30 }
31 
32 /* reset dev data */
33 struct adf_reset_dev_data {
34 	int mode;
35 	struct adf_accel_dev *accel_dev;
36 	struct completion compl;
37 	struct work_struct reset_work;
38 };
39 
40 void adf_reset_sbr(struct adf_accel_dev *accel_dev)
41 {
42 	struct pci_dev *pdev = accel_to_pci_dev(accel_dev);
43 	struct pci_dev *parent = pdev->bus->self;
44 	u16 bridge_ctl = 0;
45 
46 	if (!parent)
47 		parent = pdev;
48 
49 	if (!pci_wait_for_pending_transaction(pdev))
50 		dev_info(&GET_DEV(accel_dev),
51 			 "Transaction still in progress. Proceeding\n");
52 
53 	dev_info(&GET_DEV(accel_dev), "Secondary bus reset\n");
54 
55 	pci_read_config_word(parent, PCI_BRIDGE_CONTROL, &bridge_ctl);
56 	bridge_ctl |= PCI_BRIDGE_CTL_BUS_RESET;
57 	pci_write_config_word(parent, PCI_BRIDGE_CONTROL, bridge_ctl);
58 	msleep(100);
59 	bridge_ctl &= ~PCI_BRIDGE_CTL_BUS_RESET;
60 	pci_write_config_word(parent, PCI_BRIDGE_CONTROL, bridge_ctl);
61 	msleep(100);
62 }
63 EXPORT_SYMBOL_GPL(adf_reset_sbr);
64 
65 void adf_reset_flr(struct adf_accel_dev *accel_dev)
66 {
67 	pcie_flr(accel_to_pci_dev(accel_dev));
68 }
69 EXPORT_SYMBOL_GPL(adf_reset_flr);
70 
71 void adf_dev_restore(struct adf_accel_dev *accel_dev)
72 {
73 	struct adf_hw_device_data *hw_device = accel_dev->hw_device;
74 	struct pci_dev *pdev = accel_to_pci_dev(accel_dev);
75 
76 	if (hw_device->reset_device) {
77 		dev_info(&GET_DEV(accel_dev), "Resetting device qat_dev%d\n",
78 			 accel_dev->accel_id);
79 		hw_device->reset_device(accel_dev);
80 		pci_restore_state(pdev);
81 		pci_save_state(pdev);
82 	}
83 }
84 
85 static void adf_device_reset_worker(struct work_struct *work)
86 {
87 	struct adf_reset_dev_data *reset_data =
88 		  container_of(work, struct adf_reset_dev_data, reset_work);
89 	struct adf_accel_dev *accel_dev = reset_data->accel_dev;
90 
91 	adf_dev_restarting_notify(accel_dev);
92 	if (adf_dev_restart(accel_dev)) {
93 		/* The device hanged and we can't restart it so stop here */
94 		dev_err(&GET_DEV(accel_dev), "Restart device failed\n");
95 		if (reset_data->mode == ADF_DEV_RESET_ASYNC ||
96 		    completion_done(&reset_data->compl))
97 			kfree(reset_data);
98 		WARN(1, "QAT: device restart failed. Device is unusable\n");
99 		return;
100 	}
101 	adf_dev_restarted_notify(accel_dev);
102 	clear_bit(ADF_STATUS_RESTARTING, &accel_dev->status);
103 
104 	/*
105 	 * The dev is back alive. Notify the caller if in sync mode
106 	 *
107 	 * If device restart will take a more time than expected,
108 	 * the schedule_reset() function can timeout and exit. This can be
109 	 * detected by calling the completion_done() function. In this case
110 	 * the reset_data structure needs to be freed here.
111 	 */
112 	if (reset_data->mode == ADF_DEV_RESET_ASYNC ||
113 	    completion_done(&reset_data->compl))
114 		kfree(reset_data);
115 	else
116 		complete(&reset_data->compl);
117 }
118 
119 static int adf_dev_aer_schedule_reset(struct adf_accel_dev *accel_dev,
120 				      enum adf_dev_reset_mode mode)
121 {
122 	struct adf_reset_dev_data *reset_data;
123 
124 	if (!adf_dev_started(accel_dev) ||
125 	    test_bit(ADF_STATUS_RESTARTING, &accel_dev->status))
126 		return 0;
127 
128 	set_bit(ADF_STATUS_RESTARTING, &accel_dev->status);
129 	reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
130 	if (!reset_data)
131 		return -ENOMEM;
132 	reset_data->accel_dev = accel_dev;
133 	init_completion(&reset_data->compl);
134 	reset_data->mode = mode;
135 	INIT_WORK(&reset_data->reset_work, adf_device_reset_worker);
136 	queue_work(device_reset_wq, &reset_data->reset_work);
137 
138 	/* If in sync mode wait for the result */
139 	if (mode == ADF_DEV_RESET_SYNC) {
140 		int ret = 0;
141 		/* Maximum device reset time is 10 seconds */
142 		unsigned long wait_jiffies = msecs_to_jiffies(10000);
143 		unsigned long timeout = wait_for_completion_timeout(
144 				   &reset_data->compl, wait_jiffies);
145 		if (!timeout) {
146 			dev_err(&GET_DEV(accel_dev),
147 				"Reset device timeout expired\n");
148 			ret = -EFAULT;
149 		} else {
150 			kfree(reset_data);
151 		}
152 		return ret;
153 	}
154 	return 0;
155 }
156 
157 static pci_ers_result_t adf_slot_reset(struct pci_dev *pdev)
158 {
159 	struct adf_accel_dev *accel_dev = adf_devmgr_pci_to_accel_dev(pdev);
160 
161 	if (!accel_dev) {
162 		pr_err("QAT: Can't find acceleration device\n");
163 		return PCI_ERS_RESULT_DISCONNECT;
164 	}
165 	if (adf_dev_aer_schedule_reset(accel_dev, ADF_DEV_RESET_SYNC))
166 		return PCI_ERS_RESULT_DISCONNECT;
167 
168 	return PCI_ERS_RESULT_RECOVERED;
169 }
170 
171 static void adf_resume(struct pci_dev *pdev)
172 {
173 	dev_info(&pdev->dev, "Acceleration driver reset completed\n");
174 	dev_info(&pdev->dev, "Device is up and running\n");
175 }
176 
177 const struct pci_error_handlers adf_err_handler = {
178 	.error_detected = adf_error_detected,
179 	.slot_reset = adf_slot_reset,
180 	.resume = adf_resume,
181 };
182 EXPORT_SYMBOL_GPL(adf_err_handler);
183 
184 int adf_init_aer(void)
185 {
186 	device_reset_wq = alloc_workqueue("qat_device_reset_wq",
187 					  WQ_MEM_RECLAIM, 0);
188 	return !device_reset_wq ? -EFAULT : 0;
189 }
190 
191 void adf_exit_aer(void)
192 {
193 	if (device_reset_wq)
194 		destroy_workqueue(device_reset_wq);
195 	device_reset_wq = NULL;
196 }
197