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 */ 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 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 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 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 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 */ 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 } 145 146 static void xtmr_inject_remove(struct platform_device *pdev) 147 { 148 debugfs_remove_recursive(dbgfs_root); 149 dbgfs_root = NULL; 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_new = 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