1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Intel Speed Select Interface: MMIO Interface
4 * Copyright (c) 2019, Intel Corporation.
5 * All rights reserved.
6 *
7 * Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/pci.h>
12 #include <linux/sched/signal.h>
13 #include <linux/uaccess.h>
14 #include <uapi/linux/isst_if.h>
15
16 #include "isst_if_common.h"
17
18 struct isst_mmio_range {
19 int beg;
20 int end;
21 };
22
23 struct isst_mmio_range mmio_range[] = {
24 {0x04, 0x14},
25 {0x20, 0xD0},
26 };
27
28 struct isst_if_device {
29 void __iomem *punit_mmio;
30 u32 range_0[5];
31 u32 range_1[45];
32 struct mutex mutex;
33 };
34
isst_if_mmio_rd_wr(u8 * cmd_ptr,int * write_only,int resume)35 static long isst_if_mmio_rd_wr(u8 *cmd_ptr, int *write_only, int resume)
36 {
37 struct isst_if_device *punit_dev;
38 struct isst_if_io_reg *io_reg;
39 struct pci_dev *pdev;
40
41 io_reg = (struct isst_if_io_reg *)cmd_ptr;
42 if (io_reg->reg < 0x04 || io_reg->reg > 0xD0)
43 return -EINVAL;
44
45 if (io_reg->read_write && !capable(CAP_SYS_ADMIN))
46 return -EPERM;
47
48 pdev = isst_if_get_pci_dev(io_reg->logical_cpu, 0, 0, 1);
49 if (!pdev)
50 return -EINVAL;
51
52 punit_dev = pci_get_drvdata(pdev);
53 if (!punit_dev)
54 return -EINVAL;
55
56 /*
57 * Ensure that operation is complete on a PCI device to avoid read
58 * write race by using per PCI device mutex.
59 */
60 mutex_lock(&punit_dev->mutex);
61 if (io_reg->read_write) {
62 writel(io_reg->value, punit_dev->punit_mmio+io_reg->reg);
63 *write_only = 1;
64 } else {
65 io_reg->value = readl(punit_dev->punit_mmio+io_reg->reg);
66 *write_only = 0;
67 }
68 mutex_unlock(&punit_dev->mutex);
69
70 return 0;
71 }
72
73 static const struct pci_device_id isst_if_ids[] = {
74 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, INTEL_RAPL_PRIO_DEVID_0)},
75 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, INTEL_RAPL_PRIO_DEVID_1)},
76 { 0 },
77 };
78 MODULE_DEVICE_TABLE(pci, isst_if_ids);
79
isst_if_probe(struct pci_dev * pdev,const struct pci_device_id * ent)80 static int isst_if_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
81 {
82 struct isst_if_device *punit_dev;
83 struct isst_if_cmd_cb cb;
84 u32 mmio_base, pcu_base;
85 u64 base_addr;
86 int ret;
87
88 punit_dev = devm_kzalloc(&pdev->dev, sizeof(*punit_dev), GFP_KERNEL);
89 if (!punit_dev)
90 return -ENOMEM;
91
92 ret = pcim_enable_device(pdev);
93 if (ret)
94 return ret;
95
96 ret = pci_read_config_dword(pdev, 0xD0, &mmio_base);
97 if (ret)
98 return ret;
99
100 ret = pci_read_config_dword(pdev, 0xFC, &pcu_base);
101 if (ret)
102 return ret;
103
104 pcu_base &= GENMASK(10, 0);
105 base_addr = (u64)mmio_base << 23 | (u64) pcu_base << 12;
106 punit_dev->punit_mmio = devm_ioremap(&pdev->dev, base_addr, 256);
107 if (!punit_dev->punit_mmio)
108 return -ENOMEM;
109
110 mutex_init(&punit_dev->mutex);
111 pci_set_drvdata(pdev, punit_dev);
112
113 memset(&cb, 0, sizeof(cb));
114 cb.cmd_size = sizeof(struct isst_if_io_reg);
115 cb.offset = offsetof(struct isst_if_io_regs, io_reg);
116 cb.cmd_callback = isst_if_mmio_rd_wr;
117 cb.owner = THIS_MODULE;
118 ret = isst_if_cdev_register(ISST_IF_DEV_MMIO, &cb);
119 if (ret)
120 mutex_destroy(&punit_dev->mutex);
121
122 return ret;
123 }
124
isst_if_remove(struct pci_dev * pdev)125 static void isst_if_remove(struct pci_dev *pdev)
126 {
127 struct isst_if_device *punit_dev;
128
129 punit_dev = pci_get_drvdata(pdev);
130 isst_if_cdev_unregister(ISST_IF_DEV_MMIO);
131 mutex_destroy(&punit_dev->mutex);
132 }
133
isst_if_suspend(struct device * device)134 static int __maybe_unused isst_if_suspend(struct device *device)
135 {
136 struct isst_if_device *punit_dev = dev_get_drvdata(device);
137 int i;
138
139 for (i = 0; i < ARRAY_SIZE(punit_dev->range_0); ++i)
140 punit_dev->range_0[i] = readl(punit_dev->punit_mmio +
141 mmio_range[0].beg + 4 * i);
142 for (i = 0; i < ARRAY_SIZE(punit_dev->range_1); ++i)
143 punit_dev->range_1[i] = readl(punit_dev->punit_mmio +
144 mmio_range[1].beg + 4 * i);
145
146 return 0;
147 }
148
isst_if_resume(struct device * device)149 static int __maybe_unused isst_if_resume(struct device *device)
150 {
151 struct isst_if_device *punit_dev = dev_get_drvdata(device);
152 int i;
153
154 for (i = 0; i < ARRAY_SIZE(punit_dev->range_0); ++i)
155 writel(punit_dev->range_0[i], punit_dev->punit_mmio +
156 mmio_range[0].beg + 4 * i);
157 for (i = 0; i < ARRAY_SIZE(punit_dev->range_1); ++i)
158 writel(punit_dev->range_1[i], punit_dev->punit_mmio +
159 mmio_range[1].beg + 4 * i);
160
161 return 0;
162 }
163
164 static SIMPLE_DEV_PM_OPS(isst_if_pm_ops, isst_if_suspend, isst_if_resume);
165
166 static struct pci_driver isst_if_pci_driver = {
167 .name = "isst_if_pci",
168 .id_table = isst_if_ids,
169 .probe = isst_if_probe,
170 .remove = isst_if_remove,
171 .driver.pm = &isst_if_pm_ops,
172 };
173
174 module_pci_driver(isst_if_pci_driver);
175
176 MODULE_LICENSE("GPL v2");
177 MODULE_DESCRIPTION("Intel speed select interface mmio driver");
178