1 | /****************************************************************************** |
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2 | * balloon/sysfs.c |
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3 | * |
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4 | * Xen balloon driver - sysfs interfaces. |
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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 version 2 |
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8 | * as published by the Free Software Foundation; or, when distributed |
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9 | * separately from the Linux kernel or incorporated into other |
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10 | * software packages, subject to the following license: |
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11 | * |
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12 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
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13 | * of this source file (the "Software"), to deal in the Software without |
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14 | * restriction, including without limitation the rights to use, copy, modify, |
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15 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
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16 | * and to permit persons to whom the Software is furnished to do so, subject to |
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17 | * the following conditions: |
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18 | * |
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19 | * The above copyright notice and this permission notice shall be included in |
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20 | * all copies or substantial portions of the Software. |
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21 | * |
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22 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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23 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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24 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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25 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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26 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
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27 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
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28 | * IN THE SOFTWARE. |
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29 | */ |
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30 | |
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31 | #include <linux/capability.h> |
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32 | #include <linux/errno.h> |
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33 | #include <linux/stat.h> |
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34 | #include <linux/string.h> |
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35 | #include <linux/sysdev.h> |
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36 | #include "common.h" |
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37 | |
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38 | #ifdef HAVE_XEN_PLATFORM_COMPAT_H |
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39 | #include <xen/platform-compat.h> |
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40 | #endif |
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41 | |
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42 | #define BALLOON_CLASS_NAME "memory" |
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43 | |
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44 | #define BALLOON_SHOW(name, format, args...) \ |
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45 | static ssize_t show_##name(struct sys_device *dev, \ |
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46 | char *buf) \ |
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47 | { \ |
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48 | return sprintf(buf, format, ##args); \ |
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49 | } \ |
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50 | static SYSDEV_ATTR(name, S_IRUGO, show_##name, NULL) |
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51 | |
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52 | BALLOON_SHOW(current_kb, "%lu\n", PAGES2KB(bs.current_pages)); |
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53 | BALLOON_SHOW(low_kb, "%lu\n", PAGES2KB(bs.balloon_low)); |
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54 | BALLOON_SHOW(high_kb, "%lu\n", PAGES2KB(bs.balloon_high)); |
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55 | BALLOON_SHOW(hard_limit_kb, |
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56 | (bs.hard_limit!=~0UL) ? "%lu\n" : "???\n", |
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57 | (bs.hard_limit!=~0UL) ? PAGES2KB(bs.hard_limit) : 0); |
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58 | BALLOON_SHOW(driver_kb, "%lu\n", PAGES2KB(bs.driver_pages)); |
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59 | |
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60 | static ssize_t show_target_kb(struct sys_device *dev, char *buf) |
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61 | { |
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62 | return sprintf(buf, "%lu\n", PAGES2KB(bs.target_pages)); |
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63 | } |
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64 | |
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65 | static ssize_t store_target_kb(struct sys_device *dev, |
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66 | const char *buf, |
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67 | size_t count) |
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68 | { |
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69 | char memstring[64], *endchar; |
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70 | unsigned long long target_bytes; |
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71 | |
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72 | if (!capable(CAP_SYS_ADMIN)) |
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73 | return -EPERM; |
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74 | |
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75 | if (count <= 1) |
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76 | return -EBADMSG; /* runt */ |
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77 | if (count > sizeof(memstring)) |
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78 | return -EFBIG; /* too long */ |
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79 | strcpy(memstring, buf); |
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80 | |
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81 | target_bytes = memparse(memstring, &endchar); |
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82 | balloon_set_new_target(target_bytes >> PAGE_SHIFT); |
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83 | |
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84 | return count; |
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85 | } |
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86 | |
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87 | static SYSDEV_ATTR(target_kb, S_IRUGO | S_IWUSR, |
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88 | show_target_kb, store_target_kb); |
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89 | |
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90 | static struct sysdev_attribute *balloon_attrs[] = { |
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91 | &attr_target_kb, |
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92 | }; |
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93 | |
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94 | static struct attribute *balloon_info_attrs[] = { |
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95 | &attr_current_kb.attr, |
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96 | &attr_low_kb.attr, |
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97 | &attr_high_kb.attr, |
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98 | &attr_hard_limit_kb.attr, |
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99 | &attr_driver_kb.attr, |
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100 | NULL |
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101 | }; |
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102 | |
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103 | static struct attribute_group balloon_info_group = { |
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104 | .name = "info", |
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105 | .attrs = balloon_info_attrs, |
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106 | }; |
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107 | |
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108 | static struct sysdev_class balloon_sysdev_class = { |
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109 | set_kset_name(BALLOON_CLASS_NAME), |
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110 | }; |
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111 | |
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112 | static struct sys_device balloon_sysdev; |
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113 | |
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114 | static int register_balloon(struct sys_device *sysdev) |
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115 | { |
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116 | int i, error; |
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117 | |
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118 | error = sysdev_class_register(&balloon_sysdev_class); |
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119 | if (error) |
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120 | return error; |
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121 | |
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122 | sysdev->id = 0; |
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123 | sysdev->cls = &balloon_sysdev_class; |
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124 | |
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125 | error = sysdev_register(sysdev); |
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126 | if (error) { |
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127 | sysdev_class_unregister(&balloon_sysdev_class); |
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128 | return error; |
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129 | } |
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130 | |
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131 | for (i = 0; i < ARRAY_SIZE(balloon_attrs); i++) { |
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132 | error = sysdev_create_file(sysdev, balloon_attrs[i]); |
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133 | if (error) |
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134 | goto fail; |
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135 | } |
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136 | |
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137 | error = sysfs_create_group(&sysdev->kobj, &balloon_info_group); |
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138 | if (error) |
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139 | goto fail; |
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140 | |
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141 | return 0; |
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142 | |
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143 | fail: |
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144 | while (--i >= 0) |
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145 | sysdev_remove_file(sysdev, balloon_attrs[i]); |
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146 | sysdev_unregister(sysdev); |
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147 | sysdev_class_unregister(&balloon_sysdev_class); |
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148 | return error; |
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149 | } |
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150 | |
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151 | static void unregister_balloon(struct sys_device *sysdev) |
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152 | { |
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153 | int i; |
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154 | |
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155 | sysfs_remove_group(&sysdev->kobj, &balloon_info_group); |
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156 | for (i = 0; i < ARRAY_SIZE(balloon_attrs); i++) |
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157 | sysdev_remove_file(sysdev, balloon_attrs[i]); |
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158 | sysdev_unregister(sysdev); |
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159 | sysdev_class_unregister(&balloon_sysdev_class); |
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160 | } |
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161 | |
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162 | int balloon_sysfs_init(void) |
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163 | { |
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164 | return register_balloon(&balloon_sysdev); |
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165 | } |
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166 | |
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167 | void balloon_sysfs_exit(void) |
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168 | { |
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169 | unregister_balloon(&balloon_sysdev); |
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170 | } |
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