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.h>
15 #include <linux/platform_device.h>
16 #include <linux/fault-inject.h>
17
18 /* TMR Inject Register offsets */
19 #define XTMR_INJECT_CR_OFFSET 0x0
20 #define XTMR_INJECT_AIR_OFFSET 0x4
21 #define XTMR_INJECT_IIR_OFFSET 0xC
22 #define XTMR_INJECT_EAIR_OFFSET 0x10
23 #define XTMR_INJECT_ERR_OFFSET 0x204
24
25 /* Register Bitmasks/shifts */
26 #define XTMR_INJECT_CR_CPUID_SHIFT 8
27 #define XTMR_INJECT_CR_IE_SHIFT 10
28 #define XTMR_INJECT_IIR_ADDR_MASK GENMASK(31, 16)
29
30 #define XTMR_INJECT_MAGIC_MAX_VAL 255
31
32 /**
33 * struct xtmr_inject_dev - Driver data for TMR Inject
34 * @regs: device physical base address
35 * @magic: Magic hardware configuration value
36 */
37 struct xtmr_inject_dev {
38 void __iomem *regs;
39 u32 magic;
40 };
41
42 static DECLARE_FAULT_ATTR(inject_fault);
43 static char *inject_request;
44 module_param(inject_request, charp, 0);
45 MODULE_PARM_DESC(inject_request, "default fault injection attributes");
46 static struct dentry *dbgfs_root;
47
48 /* IO accessors */
xtmr_inject_write(struct xtmr_inject_dev * xtmr_inject,u32 addr,u32 value)49 static inline void xtmr_inject_write(struct xtmr_inject_dev *xtmr_inject,
50 u32 addr, u32 value)
51 {
52 iowrite32(value, xtmr_inject->regs + addr);
53 }
54
xtmr_inject_read(struct xtmr_inject_dev * xtmr_inject,u32 addr)55 static inline u32 xtmr_inject_read(struct xtmr_inject_dev *xtmr_inject,
56 u32 addr)
57 {
58 return ioread32(xtmr_inject->regs + addr);
59 }
60
xtmr_inject_set(void * data,u64 val)61 static int xtmr_inject_set(void *data, u64 val)
62 {
63 if (val != 1)
64 return -EINVAL;
65
66 xmb_inject_err();
67 return 0;
68 }
69 DEFINE_DEBUGFS_ATTRIBUTE(xtmr_inject_fops, NULL, xtmr_inject_set, "%llu\n");
70
xtmr_init_debugfs(struct xtmr_inject_dev * xtmr_inject)71 static void xtmr_init_debugfs(struct xtmr_inject_dev *xtmr_inject)
72 {
73 struct dentry *dir;
74
75 dbgfs_root = debugfs_create_dir("xtmr_inject", NULL);
76 dir = fault_create_debugfs_attr("inject_fault", dbgfs_root,
77 &inject_fault);
78 debugfs_create_file("inject_fault", 0200, dir, NULL,
79 &xtmr_inject_fops);
80 }
81
xtmr_inject_init(struct xtmr_inject_dev * xtmr_inject)82 static void xtmr_inject_init(struct xtmr_inject_dev *xtmr_inject)
83 {
84 u32 cr_val;
85
86 if (inject_request)
87 setup_fault_attr(&inject_fault, inject_request);
88 /* Allow fault injection */
89 cr_val = xtmr_inject->magic |
90 (1 << XTMR_INJECT_CR_IE_SHIFT) |
91 (1 << XTMR_INJECT_CR_CPUID_SHIFT);
92 xtmr_inject_write(xtmr_inject, XTMR_INJECT_CR_OFFSET,
93 cr_val);
94 /* Initialize the address inject and instruction inject registers */
95 xtmr_inject_write(xtmr_inject, XTMR_INJECT_AIR_OFFSET,
96 XMB_INJECT_ERR_OFFSET);
97 xtmr_inject_write(xtmr_inject, XTMR_INJECT_IIR_OFFSET,
98 XMB_INJECT_ERR_OFFSET & XTMR_INJECT_IIR_ADDR_MASK);
99 }
100
101 /**
102 * xtmr_inject_probe - Driver probe function
103 * @pdev: Pointer to the platform_device structure
104 *
105 * This is the driver probe routine. It does all the memory
106 * allocation for the device.
107 *
108 * Return: 0 on success and failure value on error
109 */
xtmr_inject_probe(struct platform_device * pdev)110 static int xtmr_inject_probe(struct platform_device *pdev)
111 {
112 struct xtmr_inject_dev *xtmr_inject;
113 int err;
114
115 xtmr_inject = devm_kzalloc(&pdev->dev, sizeof(*xtmr_inject),
116 GFP_KERNEL);
117 if (!xtmr_inject)
118 return -ENOMEM;
119
120 xtmr_inject->regs = devm_platform_ioremap_resource(pdev, 0);
121 if (IS_ERR(xtmr_inject->regs))
122 return PTR_ERR(xtmr_inject->regs);
123
124 err = of_property_read_u32(pdev->dev.of_node, "xlnx,magic",
125 &xtmr_inject->magic);
126 if (err < 0) {
127 dev_err(&pdev->dev, "unable to read xlnx,magic property");
128 return err;
129 }
130
131 if (xtmr_inject->magic > XTMR_INJECT_MAGIC_MAX_VAL) {
132 dev_err(&pdev->dev, "invalid xlnx,magic property value");
133 return -EINVAL;
134 }
135
136 /* Initialize TMR Inject */
137 xtmr_inject_init(xtmr_inject);
138
139 xtmr_init_debugfs(xtmr_inject);
140
141 platform_set_drvdata(pdev, xtmr_inject);
142
143 return 0;
144 }
145
xtmr_inject_remove(struct platform_device * pdev)146 static int xtmr_inject_remove(struct platform_device *pdev)
147 {
148 debugfs_remove_recursive(dbgfs_root);
149 dbgfs_root = NULL;
150 return 0;
151 }
152
153 static const struct of_device_id xtmr_inject_of_match[] = {
154 {
155 .compatible = "xlnx,tmr-inject-1.0",
156 },
157 { /* end of table */ }
158 };
159 MODULE_DEVICE_TABLE(of, xtmr_inject_of_match);
160
161 static struct platform_driver xtmr_inject_driver = {
162 .driver = {
163 .name = "xilinx-tmr_inject",
164 .of_match_table = xtmr_inject_of_match,
165 },
166 .probe = xtmr_inject_probe,
167 .remove = xtmr_inject_remove,
168 };
169 module_platform_driver(xtmr_inject_driver);
170 MODULE_AUTHOR("Advanced Micro Devices, Inc");
171 MODULE_DESCRIPTION("Xilinx TMR Inject Driver");
172 MODULE_LICENSE("GPL");
173