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10#include <linux/cpufeature.h>
11#include <linux/module.h>
12#include <linux/pci.h>
13#include <linux/sched/signal.h>
14#include <linux/uaccess.h>
15#include <uapi/linux/isst_if.h>
16
17#include "isst_if_common.h"
18
19#define PUNIT_MAILBOX_DATA 0xA0
20#define PUNIT_MAILBOX_INTERFACE 0xA4
21#define PUNIT_MAILBOX_BUSY_BIT 31
22
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26
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28
29
30
31
32#define OS_MAILBOX_TIMEOUT_AVG_US 40
33#define OS_MAILBOX_TIMEOUT_MAX_US 1000
34
35struct isst_if_device {
36 struct mutex mutex;
37};
38
39static int isst_if_mbox_cmd(struct pci_dev *pdev,
40 struct isst_if_mbox_cmd *mbox_cmd)
41{
42 s64 tm_delta = 0;
43 ktime_t tm;
44 u32 data;
45 int ret;
46
47
48 tm = ktime_get();
49 do {
50 ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_INTERFACE,
51 &data);
52 if (ret)
53 return ret;
54
55 if (data & BIT_ULL(PUNIT_MAILBOX_BUSY_BIT)) {
56 ret = -EBUSY;
57 tm_delta = ktime_us_delta(ktime_get(), tm);
58 if (tm_delta > OS_MAILBOX_TIMEOUT_AVG_US)
59 cond_resched();
60 continue;
61 }
62 ret = 0;
63 break;
64 } while (tm_delta < OS_MAILBOX_TIMEOUT_MAX_US);
65
66 if (ret)
67 return ret;
68
69
70 ret = pci_write_config_dword(pdev, PUNIT_MAILBOX_DATA,
71 mbox_cmd->req_data);
72 if (ret)
73 return ret;
74
75
76 data = BIT_ULL(PUNIT_MAILBOX_BUSY_BIT) |
77 (mbox_cmd->parameter & GENMASK_ULL(13, 0)) << 16 |
78 (mbox_cmd->sub_command << 8) |
79 mbox_cmd->command;
80
81 ret = pci_write_config_dword(pdev, PUNIT_MAILBOX_INTERFACE, data);
82 if (ret)
83 return ret;
84
85
86 tm_delta = 0;
87 tm = ktime_get();
88 do {
89 ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_INTERFACE,
90 &data);
91 if (ret)
92 return ret;
93
94 if (data & BIT_ULL(PUNIT_MAILBOX_BUSY_BIT)) {
95 ret = -EBUSY;
96 tm_delta = ktime_us_delta(ktime_get(), tm);
97 if (tm_delta > OS_MAILBOX_TIMEOUT_AVG_US)
98 cond_resched();
99 continue;
100 }
101
102 if (data & 0xff)
103 return -ENXIO;
104
105 ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_DATA, &data);
106 if (ret)
107 return ret;
108
109 mbox_cmd->resp_data = data;
110 ret = 0;
111 break;
112 } while (tm_delta < OS_MAILBOX_TIMEOUT_MAX_US);
113
114 return ret;
115}
116
117static long isst_if_mbox_proc_cmd(u8 *cmd_ptr, int *write_only, int resume)
118{
119 struct isst_if_mbox_cmd *mbox_cmd;
120 struct isst_if_device *punit_dev;
121 struct pci_dev *pdev;
122 int ret;
123
124 mbox_cmd = (struct isst_if_mbox_cmd *)cmd_ptr;
125
126 if (isst_if_mbox_cmd_invalid(mbox_cmd))
127 return -EINVAL;
128
129 if (isst_if_mbox_cmd_set_req(mbox_cmd) && !capable(CAP_SYS_ADMIN))
130 return -EPERM;
131
132 pdev = isst_if_get_pci_dev(mbox_cmd->logical_cpu, 1, 30, 1);
133 if (!pdev)
134 return -EINVAL;
135
136 punit_dev = pci_get_drvdata(pdev);
137 if (!punit_dev)
138 return -EINVAL;
139
140
141
142
143
144 mutex_lock(&punit_dev->mutex);
145 ret = isst_if_mbox_cmd(pdev, mbox_cmd);
146 if (!ret && !resume && isst_if_mbox_cmd_set_req(mbox_cmd))
147 ret = isst_store_cmd(mbox_cmd->command,
148 mbox_cmd->sub_command,
149 mbox_cmd->logical_cpu, 1,
150 mbox_cmd->parameter,
151 mbox_cmd->req_data);
152 mutex_unlock(&punit_dev->mutex);
153 if (ret)
154 return ret;
155
156 *write_only = 0;
157
158 return 0;
159}
160
161static const struct pci_device_id isst_if_mbox_ids[] = {
162 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CFG_MBOX_DEVID_0)},
163 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CFG_MBOX_DEVID_1)},
164 { 0 },
165};
166MODULE_DEVICE_TABLE(pci, isst_if_mbox_ids);
167
168static int isst_if_mbox_probe(struct pci_dev *pdev,
169 const struct pci_device_id *ent)
170{
171 struct isst_if_device *punit_dev;
172 struct isst_if_cmd_cb cb;
173 int ret;
174
175 punit_dev = devm_kzalloc(&pdev->dev, sizeof(*punit_dev), GFP_KERNEL);
176 if (!punit_dev)
177 return -ENOMEM;
178
179 ret = pcim_enable_device(pdev);
180 if (ret)
181 return ret;
182
183 mutex_init(&punit_dev->mutex);
184 pci_set_drvdata(pdev, punit_dev);
185
186 memset(&cb, 0, sizeof(cb));
187 cb.cmd_size = sizeof(struct isst_if_mbox_cmd);
188 cb.offset = offsetof(struct isst_if_mbox_cmds, mbox_cmd);
189 cb.cmd_callback = isst_if_mbox_proc_cmd;
190 cb.owner = THIS_MODULE;
191 ret = isst_if_cdev_register(ISST_IF_DEV_MBOX, &cb);
192
193 if (ret)
194 mutex_destroy(&punit_dev->mutex);
195
196 return ret;
197}
198
199static void isst_if_mbox_remove(struct pci_dev *pdev)
200{
201 struct isst_if_device *punit_dev;
202
203 punit_dev = pci_get_drvdata(pdev);
204 isst_if_cdev_unregister(ISST_IF_DEV_MBOX);
205 mutex_destroy(&punit_dev->mutex);
206}
207
208static int __maybe_unused isst_if_resume(struct device *device)
209{
210 isst_resume_common();
211 return 0;
212}
213
214static SIMPLE_DEV_PM_OPS(isst_if_pm_ops, NULL, isst_if_resume);
215
216static struct pci_driver isst_if_pci_driver = {
217 .name = "isst_if_mbox_pci",
218 .id_table = isst_if_mbox_ids,
219 .probe = isst_if_mbox_probe,
220 .remove = isst_if_mbox_remove,
221 .driver.pm = &isst_if_pm_ops,
222};
223
224module_pci_driver(isst_if_pci_driver);
225
226MODULE_LICENSE("GPL v2");
227MODULE_DESCRIPTION("Intel speed select interface pci mailbox driver");
228
