1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for Xilinx TMR Inject IP.
4 *
5 * Copyright (C) 2022 Advanced Micro Devices, Inc.
6 *
7 * Description:
8 * This driver is developed for TMR Inject IP,The Triple Modular Redundancy(TMR)
9 * Inject provides fault injection.
10 */
11
12 #include <asm/xilinx_mb_manager.h>
13 #include <linux/module.h>
14 #include <linux/of_device.h>
15 #include <linux/fault-inject.h>
16
17 /* TMR Inject Register offsets */
18 #define XTMR_INJECT_CR_OFFSET 0x0
19 #define XTMR_INJECT_AIR_OFFSET 0x4
20 #define XTMR_INJECT_IIR_OFFSET 0xC
21 #define XTMR_INJECT_EAIR_OFFSET 0x10
22 #define XTMR_INJECT_ERR_OFFSET 0x204
23
24 /* Register Bitmasks/shifts */
25 #define XTMR_INJECT_CR_CPUID_SHIFT 8
26 #define XTMR_INJECT_CR_IE_SHIFT 10
27 #define XTMR_INJECT_IIR_ADDR_MASK GENMASK(31, 16)
28
29 #define XTMR_INJECT_MAGIC_MAX_VAL 255
30
31 /**
32 * struct xtmr_inject_dev - Driver data for TMR Inject
33 * @regs: device physical base address
34 * @magic: Magic hardware configuration value
35 */
36 struct xtmr_inject_dev {
37 void __iomem *regs;
38 u32 magic;
39 };
40
41 static DECLARE_FAULT_ATTR(inject_fault);
42 static char *inject_request;
43 module_param(inject_request, charp, 0);
44 MODULE_PARM_DESC(inject_request, "default fault injection attributes");
45 static struct dentry *dbgfs_root;
46
47 /* IO accessors */
xtmr_inject_write(struct xtmr_inject_dev * xtmr_inject,u32 addr,u32 value)48 static inline void xtmr_inject_write(struct xtmr_inject_dev *xtmr_inject,
49 u32 addr, u32 value)
50 {
51 iowrite32(value, xtmr_inject->regs + addr);
52 }
53
xtmr_inject_read(struct xtmr_inject_dev * xtmr_inject,u32 addr)54 static inline u32 xtmr_inject_read(struct xtmr_inject_dev *xtmr_inject,
55 u32 addr)
56 {
57 return ioread32(xtmr_inject->regs + addr);
58 }
59
xtmr_inject_set(void * data,u64 val)60 static int xtmr_inject_set(void *data, u64 val)
61 {
62 if (val != 1)
63 return -EINVAL;
64
65 xmb_inject_err();
66 return 0;
67 }
68 DEFINE_DEBUGFS_ATTRIBUTE(xtmr_inject_fops, NULL, xtmr_inject_set, "%llu\n");
69
xtmr_init_debugfs(struct xtmr_inject_dev * xtmr_inject)70 static void xtmr_init_debugfs(struct xtmr_inject_dev *xtmr_inject)
71 {
72 struct dentry *dir;
73
74 dbgfs_root = debugfs_create_dir("xtmr_inject", NULL);
75 dir = fault_create_debugfs_attr("inject_fault", dbgfs_root,
76 &inject_fault);
77 debugfs_create_file("inject_fault", 0200, dir, NULL,
78 &xtmr_inject_fops);
79 }
80
xtmr_inject_init(struct xtmr_inject_dev * xtmr_inject)81 static void xtmr_inject_init(struct xtmr_inject_dev *xtmr_inject)
82 {
83 u32 cr_val;
84
85 if (inject_request)
86 setup_fault_attr(&inject_fault, inject_request);
87 /* Allow fault injection */
88 cr_val = xtmr_inject->magic |
89 (1 << XTMR_INJECT_CR_IE_SHIFT) |
90 (1 << XTMR_INJECT_CR_CPUID_SHIFT);
91 xtmr_inject_write(xtmr_inject, XTMR_INJECT_CR_OFFSET,
92 cr_val);
93 /* Initialize the address inject and instruction inject registers */
94 xtmr_inject_write(xtmr_inject, XTMR_INJECT_AIR_OFFSET,
95 XMB_INJECT_ERR_OFFSET);
96 xtmr_inject_write(xtmr_inject, XTMR_INJECT_IIR_OFFSET,
97 XMB_INJECT_ERR_OFFSET & XTMR_INJECT_IIR_ADDR_MASK);
98 }
99
100 /**
101 * xtmr_inject_probe - Driver probe function
102 * @pdev: Pointer to the platform_device structure
103 *
104 * This is the driver probe routine. It does all the memory
105 * allocation for the device.
106 *
107 * Return: 0 on success and failure value on error
108 */
xtmr_inject_probe(struct platform_device * pdev)109 static int xtmr_inject_probe(struct platform_device *pdev)
110 {
111 struct xtmr_inject_dev *xtmr_inject;
112 int err;
113
114 xtmr_inject = devm_kzalloc(&pdev->dev, sizeof(*xtmr_inject),
115 GFP_KERNEL);
116 if (!xtmr_inject)
117 return -ENOMEM;
118
119 xtmr_inject->regs = devm_platform_ioremap_resource(pdev, 0);
120 if (IS_ERR(xtmr_inject->regs))
121 return PTR_ERR(xtmr_inject->regs);
122
123 err = of_property_read_u32(pdev->dev.of_node, "xlnx,magic",
124 &xtmr_inject->magic);
125 if (err < 0) {
126 dev_err(&pdev->dev, "unable to read xlnx,magic property");
127 return err;
128 }
129
130 if (xtmr_inject->magic > XTMR_INJECT_MAGIC_MAX_VAL) {
131 dev_err(&pdev->dev, "invalid xlnx,magic property value");
132 return -EINVAL;
133 }
134
135 /* Initialize TMR Inject */
136 xtmr_inject_init(xtmr_inject);
137
138 xtmr_init_debugfs(xtmr_inject);
139
140 platform_set_drvdata(pdev, xtmr_inject);
141
142 return 0;
143 }
144
xtmr_inject_remove(struct platform_device * pdev)145 static int xtmr_inject_remove(struct platform_device *pdev)
146 {
147 debugfs_remove_recursive(dbgfs_root);
148 dbgfs_root = NULL;
149 return 0;
150 }
151
152 static const struct of_device_id xtmr_inject_of_match[] = {
153 {
154 .compatible = "xlnx,tmr-inject-1.0",
155 },
156 { /* end of table */ }
157 };
158 MODULE_DEVICE_TABLE(of, xtmr_inject_of_match);
159
160 static struct platform_driver xtmr_inject_driver = {
161 .driver = {
162 .name = "xilinx-tmr_inject",
163 .of_match_table = xtmr_inject_of_match,
164 },
165 .probe = xtmr_inject_probe,
166 .remove = xtmr_inject_remove,
167 };
168 module_platform_driver(xtmr_inject_driver);
169 MODULE_AUTHOR("Advanced Micro Devices, Inc");
170 MODULE_DESCRIPTION("Xilinx TMR Inject Driver");
171 MODULE_LICENSE("GPL");
172