drivers/misc/xilinx_tmr_inject.c

   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 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");