.. | .. |
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| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
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1 | 2 | /* |
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2 | | - * PowerNV LPC bus handling. |
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| 3 | + * PowerNV SCOM bus debugfs interface |
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3 | 4 | * |
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| 5 | + * Copyright 2010 Benjamin Herrenschmidt, IBM Corp |
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| 6 | + * <benh@kernel.crashing.org> |
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| 7 | + * and David Gibson, IBM Corporation. |
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4 | 8 | * Copyright 2013 IBM Corp. |
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5 | | - * |
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6 | | - * This program is free software; you can redistribute it and/or |
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7 | | - * modify it under the terms of the GNU General Public License |
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8 | | - * as published by the Free Software Foundation; either version |
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9 | | - * 2 of the License, or (at your option) any later version. |
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10 | 9 | */ |
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11 | 10 | |
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12 | 11 | #include <linux/kernel.h> |
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.. | .. |
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14 | 13 | #include <linux/bug.h> |
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15 | 14 | #include <linux/gfp.h> |
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16 | 15 | #include <linux/slab.h> |
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| 16 | +#include <linux/uaccess.h> |
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17 | 17 | |
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18 | 18 | #include <asm/machdep.h> |
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19 | 19 | #include <asm/firmware.h> |
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20 | 20 | #include <asm/opal.h> |
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21 | | -#include <asm/scom.h> |
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22 | | - |
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23 | | -/* |
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24 | | - * We could probably fit that inside the scom_map_t |
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25 | | - * which is a void* after all but it's really too ugly |
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26 | | - * so let's kmalloc it for now |
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27 | | - */ |
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28 | | -struct opal_scom_map { |
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29 | | - uint32_t chip; |
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30 | | - uint64_t addr; |
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31 | | -}; |
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32 | | - |
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33 | | -static scom_map_t opal_scom_map(struct device_node *dev, u64 reg, u64 count) |
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34 | | -{ |
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35 | | - struct opal_scom_map *m; |
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36 | | - const __be32 *gcid; |
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37 | | - |
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38 | | - if (!of_get_property(dev, "scom-controller", NULL)) { |
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39 | | - pr_err("%s: device %pOF is not a SCOM controller\n", |
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40 | | - __func__, dev); |
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41 | | - return SCOM_MAP_INVALID; |
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42 | | - } |
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43 | | - gcid = of_get_property(dev, "ibm,chip-id", NULL); |
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44 | | - if (!gcid) { |
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45 | | - pr_err("%s: device %pOF has no ibm,chip-id\n", |
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46 | | - __func__, dev); |
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47 | | - return SCOM_MAP_INVALID; |
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48 | | - } |
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49 | | - m = kmalloc(sizeof(*m), GFP_KERNEL); |
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50 | | - if (!m) |
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51 | | - return NULL; |
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52 | | - m->chip = be32_to_cpup(gcid); |
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53 | | - m->addr = reg; |
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54 | | - |
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55 | | - return (scom_map_t)m; |
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56 | | -} |
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57 | | - |
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58 | | -static void opal_scom_unmap(scom_map_t map) |
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59 | | -{ |
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60 | | - kfree(map); |
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61 | | -} |
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62 | | - |
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63 | | -static int opal_xscom_err_xlate(int64_t rc) |
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64 | | -{ |
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65 | | - switch(rc) { |
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66 | | - case 0: |
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67 | | - return 0; |
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68 | | - /* Add more translations if necessary */ |
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69 | | - default: |
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70 | | - return -EIO; |
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71 | | - } |
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72 | | -} |
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| 21 | +#include <asm/debugfs.h> |
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| 22 | +#include <asm/prom.h> |
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73 | 23 | |
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74 | 24 | static u64 opal_scom_unmangle(u64 addr) |
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75 | 25 | { |
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.. | .. |
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102 | 52 | return addr; |
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103 | 53 | } |
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104 | 54 | |
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105 | | -static int opal_scom_read(scom_map_t map, u64 reg, u64 *value) |
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| 55 | +static int opal_scom_read(uint32_t chip, uint64_t addr, u64 reg, u64 *value) |
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106 | 56 | { |
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107 | | - struct opal_scom_map *m = map; |
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108 | 57 | int64_t rc; |
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109 | 58 | __be64 v; |
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110 | 59 | |
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111 | | - reg = opal_scom_unmangle(m->addr + reg); |
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112 | | - rc = opal_xscom_read(m->chip, reg, (__be64 *)__pa(&v)); |
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| 60 | + reg = opal_scom_unmangle(addr + reg); |
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| 61 | + rc = opal_xscom_read(chip, reg, (__be64 *)__pa(&v)); |
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| 62 | + if (rc) { |
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| 63 | + *value = 0xfffffffffffffffful; |
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| 64 | + return -EIO; |
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| 65 | + } |
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113 | 66 | *value = be64_to_cpu(v); |
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114 | | - return opal_xscom_err_xlate(rc); |
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115 | | -} |
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116 | | - |
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117 | | -static int opal_scom_write(scom_map_t map, u64 reg, u64 value) |
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118 | | -{ |
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119 | | - struct opal_scom_map *m = map; |
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120 | | - int64_t rc; |
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121 | | - |
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122 | | - reg = opal_scom_unmangle(m->addr + reg); |
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123 | | - rc = opal_xscom_write(m->chip, reg, value); |
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124 | | - return opal_xscom_err_xlate(rc); |
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125 | | -} |
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126 | | - |
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127 | | -static const struct scom_controller opal_scom_controller = { |
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128 | | - .map = opal_scom_map, |
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129 | | - .unmap = opal_scom_unmap, |
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130 | | - .read = opal_scom_read, |
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131 | | - .write = opal_scom_write |
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132 | | -}; |
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133 | | - |
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134 | | -static int opal_xscom_init(void) |
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135 | | -{ |
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136 | | - if (firmware_has_feature(FW_FEATURE_OPAL)) |
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137 | | - scom_init(&opal_scom_controller); |
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138 | 67 | return 0; |
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139 | 68 | } |
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140 | | -machine_arch_initcall(powernv, opal_xscom_init); |
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| 69 | + |
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| 70 | +static int opal_scom_write(uint32_t chip, uint64_t addr, u64 reg, u64 value) |
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| 71 | +{ |
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| 72 | + int64_t rc; |
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| 73 | + |
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| 74 | + reg = opal_scom_unmangle(addr + reg); |
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| 75 | + rc = opal_xscom_write(chip, reg, value); |
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| 76 | + if (rc) |
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| 77 | + return -EIO; |
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| 78 | + return 0; |
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| 79 | +} |
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| 80 | + |
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| 81 | +struct scom_debug_entry { |
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| 82 | + u32 chip; |
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| 83 | + struct debugfs_blob_wrapper path; |
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| 84 | + char name[16]; |
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| 85 | +}; |
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| 86 | + |
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| 87 | +static ssize_t scom_debug_read(struct file *filp, char __user *ubuf, |
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| 88 | + size_t count, loff_t *ppos) |
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| 89 | +{ |
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| 90 | + struct scom_debug_entry *ent = filp->private_data; |
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| 91 | + u64 __user *ubuf64 = (u64 __user *)ubuf; |
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| 92 | + loff_t off = *ppos; |
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| 93 | + ssize_t done = 0; |
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| 94 | + u64 reg, reg_base, reg_cnt, val; |
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| 95 | + int rc; |
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| 96 | + |
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| 97 | + if (off < 0 || (off & 7) || (count & 7)) |
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| 98 | + return -EINVAL; |
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| 99 | + reg_base = off >> 3; |
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| 100 | + reg_cnt = count >> 3; |
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| 101 | + |
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| 102 | + for (reg = 0; reg < reg_cnt; reg++) { |
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| 103 | + rc = opal_scom_read(ent->chip, reg_base, reg, &val); |
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| 104 | + if (!rc) |
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| 105 | + rc = put_user(val, ubuf64); |
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| 106 | + if (rc) { |
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| 107 | + if (!done) |
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| 108 | + done = rc; |
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| 109 | + break; |
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| 110 | + } |
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| 111 | + ubuf64++; |
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| 112 | + *ppos += 8; |
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| 113 | + done += 8; |
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| 114 | + } |
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| 115 | + return done; |
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| 116 | +} |
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| 117 | + |
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| 118 | +static ssize_t scom_debug_write(struct file *filp, const char __user *ubuf, |
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| 119 | + size_t count, loff_t *ppos) |
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| 120 | +{ |
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| 121 | + struct scom_debug_entry *ent = filp->private_data; |
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| 122 | + u64 __user *ubuf64 = (u64 __user *)ubuf; |
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| 123 | + loff_t off = *ppos; |
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| 124 | + ssize_t done = 0; |
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| 125 | + u64 reg, reg_base, reg_cnt, val; |
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| 126 | + int rc; |
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| 127 | + |
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| 128 | + if (off < 0 || (off & 7) || (count & 7)) |
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| 129 | + return -EINVAL; |
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| 130 | + reg_base = off >> 3; |
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| 131 | + reg_cnt = count >> 3; |
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| 132 | + |
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| 133 | + for (reg = 0; reg < reg_cnt; reg++) { |
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| 134 | + rc = get_user(val, ubuf64); |
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| 135 | + if (!rc) |
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| 136 | + rc = opal_scom_write(ent->chip, reg_base, reg, val); |
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| 137 | + if (rc) { |
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| 138 | + if (!done) |
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| 139 | + done = rc; |
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| 140 | + break; |
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| 141 | + } |
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| 142 | + ubuf64++; |
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| 143 | + done += 8; |
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| 144 | + } |
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| 145 | + return done; |
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| 146 | +} |
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| 147 | + |
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| 148 | +static const struct file_operations scom_debug_fops = { |
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| 149 | + .read = scom_debug_read, |
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| 150 | + .write = scom_debug_write, |
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| 151 | + .open = simple_open, |
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| 152 | + .llseek = default_llseek, |
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| 153 | +}; |
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| 154 | + |
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| 155 | +static int scom_debug_init_one(struct dentry *root, struct device_node *dn, |
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| 156 | + int chip) |
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| 157 | +{ |
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| 158 | + struct scom_debug_entry *ent; |
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| 159 | + struct dentry *dir; |
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| 160 | + |
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| 161 | + ent = kzalloc(sizeof(*ent), GFP_KERNEL); |
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| 162 | + if (!ent) |
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| 163 | + return -ENOMEM; |
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| 164 | + |
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| 165 | + ent->chip = chip; |
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| 166 | + snprintf(ent->name, 16, "%08x", chip); |
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| 167 | + ent->path.data = (void *)kasprintf(GFP_KERNEL, "%pOF", dn); |
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| 168 | + ent->path.size = strlen((char *)ent->path.data); |
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| 169 | + |
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| 170 | + dir = debugfs_create_dir(ent->name, root); |
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| 171 | + if (!dir) { |
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| 172 | + kfree(ent->path.data); |
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| 173 | + kfree(ent); |
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| 174 | + return -1; |
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| 175 | + } |
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| 176 | + |
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| 177 | + debugfs_create_blob("devspec", 0400, dir, &ent->path); |
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| 178 | + debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops); |
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| 179 | + |
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| 180 | + return 0; |
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| 181 | +} |
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| 182 | + |
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| 183 | +static int scom_debug_init(void) |
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| 184 | +{ |
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| 185 | + struct device_node *dn; |
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| 186 | + struct dentry *root; |
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| 187 | + int chip, rc; |
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| 188 | + |
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| 189 | + if (!firmware_has_feature(FW_FEATURE_OPAL)) |
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| 190 | + return 0; |
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| 191 | + |
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| 192 | + root = debugfs_create_dir("scom", powerpc_debugfs_root); |
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| 193 | + if (!root) |
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| 194 | + return -1; |
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| 195 | + |
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| 196 | + rc = 0; |
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| 197 | + for_each_node_with_property(dn, "scom-controller") { |
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| 198 | + chip = of_get_ibm_chip_id(dn); |
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| 199 | + WARN_ON(chip == -1); |
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| 200 | + rc |= scom_debug_init_one(root, dn, chip); |
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| 201 | + } |
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| 202 | + |
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| 203 | + return rc; |
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| 204 | +} |
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| 205 | +device_initcall(scom_debug_init); |
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