drivers/gpu/drm/i915/i915_debugfs_params.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright © 2019 Intel Corporation
   4  */
   5
   6 #include <linux/kernel.h>
   7
   8 #include "i915_debugfs_params.h"
   9 #include "i915_drv.h"
  10 #include "i915_params.h"
  11
  12 /* int param */
  13 static int i915_param_int_show(struct seq_file *m, void *data)
  14 {
  15         int *value = m->private;
  16
  17         seq_printf(m, "%d\n", *value);
  18
  19         return 0;
  20 }
  21
  22 static int i915_param_int_open(struct inode *inode, struct file *file)
  23 {
  24         return single_open(file, i915_param_int_show, inode->i_private);
  25 }
  26
  27 static ssize_t i915_param_int_write(struct file *file,
  28                                     const char __user *ubuf, size_t len,
  29                                     loff_t *offp)
  30 {
  31         struct seq_file *m = file->private_data;
  32         int *value = m->private;
  33         int ret;
  34
  35         ret = kstrtoint_from_user(ubuf, len, 0, value);
  36         if (ret) {
  37                 /* support boolean values too */
  38                 bool b;
  39
  40                 ret = kstrtobool_from_user(ubuf, len, &b);
  41                 if (!ret)
  42                         *value = b;
  43         }
  44
  45         return ret ?: len;
  46 }
  47
  48 static const struct file_operations i915_param_int_fops = {
  49         .owner = THIS_MODULE,
  50         .open = i915_param_int_open,
  51         .read = seq_read,
  52         .write = i915_param_int_write,
  53         .llseek = default_llseek,
  54         .release = single_release,
  55 };
  56
  57 static const struct file_operations i915_param_int_fops_ro = {
  58         .owner = THIS_MODULE,
  59         .open = i915_param_int_open,
  60         .read = seq_read,
  61         .llseek = default_llseek,
  62         .release = single_release,
  63 };
  64
  65 /* unsigned int param */
  66 static int i915_param_uint_show(struct seq_file *m, void *data)
  67 {
  68         unsigned int *value = m->private;
  69
  70         seq_printf(m, "%u\n", *value);
  71
  72         return 0;
  73 }
  74
  75 static int i915_param_uint_open(struct inode *inode, struct file *file)
  76 {
  77         return single_open(file, i915_param_uint_show, inode->i_private);
  78 }
  79
  80 static ssize_t i915_param_uint_write(struct file *file,
  81                                      const char __user *ubuf, size_t len,
  82                                      loff_t *offp)
  83 {
  84         struct seq_file *m = file->private_data;
  85         unsigned int *value = m->private;
  86         int ret;
  87
  88         ret = kstrtouint_from_user(ubuf, len, 0, value);
  89         if (ret) {
  90                 /* support boolean values too */
  91                 bool b;
  92
  93                 ret = kstrtobool_from_user(ubuf, len, &b);
  94                 if (!ret)
  95                         *value = b;
  96         }
  97
  98         return ret ?: len;
  99 }
 100
 101 static const struct file_operations i915_param_uint_fops = {
 102         .owner = THIS_MODULE,
 103         .open = i915_param_uint_open,
 104         .read = seq_read,
 105         .write = i915_param_uint_write,
 106         .llseek = default_llseek,
 107         .release = single_release,
 108 };
 109
 110 static const struct file_operations i915_param_uint_fops_ro = {
 111         .owner = THIS_MODULE,
 112         .open = i915_param_uint_open,
 113         .read = seq_read,
 114         .llseek = default_llseek,
 115         .release = single_release,
 116 };
 117
 118 /* char * param */
 119 static int i915_param_charp_show(struct seq_file *m, void *data)
 120 {
 121         const char **s = m->private;
 122
 123         seq_printf(m, "%s\n", *s);
 124
 125         return 0;
 126 }
 127
 128 static int i915_param_charp_open(struct inode *inode, struct file *file)
 129 {
 130         return single_open(file, i915_param_charp_show, inode->i_private);
 131 }
 132
 133 static ssize_t i915_param_charp_write(struct file *file,
 134                                       const char __user *ubuf, size_t len,
 135                                       loff_t *offp)
 136 {
 137         struct seq_file *m = file->private_data;
 138         char **s = m->private;
 139         char *new, *old;
 140
 141         old = *s;
 142         new = strndup_user(ubuf, PAGE_SIZE);
 143         if (IS_ERR(new)) {
 144                 len = PTR_ERR(new);
 145                 goto out;
 146         }
 147
 148         *s = new;
 149
 150         kfree(old);
 151 out:
 152         return len;
 153 }
 154
 155 static const struct file_operations i915_param_charp_fops = {
 156         .owner = THIS_MODULE,
 157         .open = i915_param_charp_open,
 158         .read = seq_read,
 159         .write = i915_param_charp_write,
 160         .llseek = default_llseek,
 161         .release = single_release,
 162 };
 163
 164 static const struct file_operations i915_param_charp_fops_ro = {
 165         .owner = THIS_MODULE,
 166         .open = i915_param_charp_open,
 167         .read = seq_read,
 168         .llseek = default_llseek,
 169         .release = single_release,
 170 };
 171
 172 #define RO(mode) (((mode) & 0222) == 0)
 173
 174 static struct dentry *
 175 i915_debugfs_create_int(const char *name, umode_t mode,
 176                         struct dentry *parent, int *value)
 177 {
 178         return debugfs_create_file_unsafe(name, mode, parent, value,
 179                                           RO(mode) ? &i915_param_int_fops_ro :
 180                                           &i915_param_int_fops);
 181 }
 182
 183 static struct dentry *
 184 i915_debugfs_create_uint(const char *name, umode_t mode,
 185                          struct dentry *parent, unsigned int *value)
 186 {
 187         return debugfs_create_file_unsafe(name, mode, parent, value,
 188                                           RO(mode) ? &i915_param_uint_fops_ro :
 189                                           &i915_param_uint_fops);
 190 }
 191
 192 static struct dentry *
 193 i915_debugfs_create_charp(const char *name, umode_t mode,
 194                           struct dentry *parent, char **value)
 195 {
 196         return debugfs_create_file(name, mode, parent, value,
 197                                    RO(mode) ? &i915_param_charp_fops_ro :
 198                                    &i915_param_charp_fops);
 199 }
 200
 201 static __always_inline void
 202 _i915_param_create_file(struct dentry *parent, const char *name,
 203                         const char *type, int mode, void *value)
 204 {
 205         if (!mode)
 206                 return;
 207
 208         if (!__builtin_strcmp(type, "bool"))
 209                 debugfs_create_bool(name, mode, parent, value);
 210         else if (!__builtin_strcmp(type, "int"))
 211                 i915_debugfs_create_int(name, mode, parent, value);
 212         else if (!__builtin_strcmp(type, "unsigned int"))
 213                 i915_debugfs_create_uint(name, mode, parent, value);
 214         else if (!__builtin_strcmp(type, "unsigned long"))
 215                 debugfs_create_ulong(name, mode, parent, value);
 216         else if (!__builtin_strcmp(type, "char *"))
 217                 i915_debugfs_create_charp(name, mode, parent, value);
 218         else
 219                 WARN(1, "no debugfs fops defined for param type %s (i915.%s)\n",
 220                      type, name);
 221 }
 222
 223 /* add a subdirectory with files for each i915 param */
 224 struct dentry *i915_debugfs_params(struct drm_i915_private *i915)
 225 {
 226         struct drm_minor *minor = i915->drm.primary;
 227         struct i915_params *params = &i915->params;
 228         struct dentry *dir;
 229
 230         dir = debugfs_create_dir("i915_params", minor->debugfs_root);
 231         if (IS_ERR(dir))
 232                 return dir;
 233
 234         /*
 235          * Note: We could create files for params needing special handling
 236          * here. Set mode in params to 0 to skip the generic create file, or
 237          * just let the generic create file fail silently with -EEXIST.
 238          */
 239
 240 #define REGISTER(T, x, unused, mode, ...) _i915_param_create_file(dir, #x, #T, mode, &params->x);
 241         I915_PARAMS_FOR_EACH(REGISTER);
 242 #undef REGISTER
 243
 244         return dir;
 245 }