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