fusd/include/kfusd.h

   1 /*
   2  *
   3  * Copyright (c) 2003 The Regents of the University of California.  All
   4  * rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * - Redistributions of source code must retain the above copyright
  11  *   notice, this list of conditions and the following disclaimer.
  12  *
  13  * - Neither the name of the University nor the names of its
  14  *   contributors may be used to endorse or promote products derived
  15  *   from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
  18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  19  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  20  * PARTICULAR  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
  21  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  24  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  25  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  */
  30
  31
  32 /*
  33  * FUSD: the Framework for User-Space Devices
  34  *
  35  * Jeremy Elson <jelson@circlemud.org>
  36  * Copyright (c) Sensoria Corporation 2001
  37  *
  38  * Private header file used by the Linux Kernel Module
  39  *
  40  * $Id$
  41  */
  42
  43 #ifndef __KFUSD_H__
  44 #define __KFUSD_H__
  45
  46 #include "fusd_msg.h"
  47
  48 /* magic numbers for structure checking; unique w.r.t
  49  * /usr/src/linux/Documentation/magic-number.txt */
  50 #define FUSD_DEV_MAGIC      0x8b43a123
  51 #define FUSD_FILE_MAGIC     0x613aa8fe
  52
  53 /* number of devices that can be created with fusd */
  54 #define MAX_FUSD_DEVICES    128
  55
  56 /* number of times each device can be opened simultaneously */
  57 #define MIN_FILEARRAY_SIZE  8  /* initialize allocation */
  58 #define MAX_FILEARRAY_SIZE  1024 /* maximum it can grow to */
  59
  60 /* maximum read/write size we're willing to service */
  61 #define MAX_RW_SIZE         (1024*128)
  62
  63
  64 /********************** Structure Definitions *******************************/
  65
  66 /* Container for a fusd msg */
  67 typedef struct fusd_msgC_s_t fusd_msgC_t;
  68
  69 struct fusd_msgC_s_t {
  70   fusd_msg_t fusd_msg;          /* the message itself */
  71   fusd_msgC_t *next;            /* pointer to next one in the list */
  72
  73   /* 1-bit flags */
  74   unsigned int peeked:1;        /* has the first half of this been read? */
  75 };
  76
  77 struct fusd_transaction
  78 {
  79         struct list_head list;
  80         long transid;
  81         int subcmd;
  82         int pid;
  83         int size;
  84         fusd_msg_t* msg_in;
  85 };
  86
  87 /* magical forward declarations to break the circular dependency */
  88 struct fusd_dev_t_s;
  89 typedef struct fusd_dev_t_s fusd_dev_t;
  90 struct CLASS;
  91 struct class_device;
  92
  93 /* state kept per opened file (i.e., an instance of a device) */
  94 typedef struct {
  95   /* general state management */
  96   int magic;                    /* magic number for sanity checking */
  97   fusd_dev_t *fusd_dev;         /* fusd device associated with this file */
  98   long fusd_dev_version;        /* version number of fusd device */
  99   void *private_data;           /* the user's private data (we ignore it) */
 100   struct file *file;            /* kernel's file pointer for this file */
 101   int index;                    /* our index in our device's file array */
 102   struct semaphore file_sem;    /* Semaphore for file structure */
 103   int cached_poll_state;        /* Latest result from a poll diff req */
 104   int last_poll_sent;           /* Last polldiff request we sent */
 105
 106   /* structures used for messaging */
 107   wait_queue_head_t file_wait;  /* Wait on this for a user->kernel msg */
 108   wait_queue_head_t poll_wait;  /* Given to kernel for poll() queue */
 109         struct list_head transactions;
 110         struct semaphore transactions_sem;
 111
 112 } fusd_file_t;
 113
 114
 115 /* state kept per device registered under fusd */
 116 struct fusd_dev_t_s {
 117   int magic;                    /* Magic number for sanity checking */
 118   long version;                 /* Instance number of this device */
 119   int zombie;                   /* Is the device dead? */
 120   pid_t pid;                    /* PID of device driver */
 121   struct task_struct* task;
 122
 123   char *name;                   /* Name of the device under devfs (/dev) */
 124   char *class_name;
 125   char *dev_name;
 126   struct CLASS *clazz;
 127   int owns_class;
 128   struct class_device *class_device;
 129
 130   void *private_data;           /* User's private data */
 131   struct cdev* handle;
 132   dev_t dev_id;
 133
 134   fusd_file_t **files;          /* Array of this device's open files */
 135   int array_size;               /* Size of the array pointed to by 'files' */
 136   int num_files;                /* Number of array entries that are valid */
 137   int open_in_progress;         /* File is referencing this struct,
 138                                    but not yet part of the file array */
 139   /* messaging */
 140   fusd_msgC_t *msg_head;        /* linked list head for message queue */
 141   fusd_msgC_t *msg_tail;        /* linked list tail for message queue */
 142
 143   /* synchronization */
 144   wait_queue_head_t dev_wait;   /* Wait queue for kernel->user msgs */
 145   struct semaphore dev_sem;     /* Sempahore for device structure */
 146
 147   /* pointer to allow a dev to be placed on a dev_list */
 148   struct list_head devlist;
 149 };
 150
 151
 152 /**** Function Prototypes ****/
 153
 154 STATIC int maybe_free_fusd_dev(fusd_dev_t *fusd_dev);
 155
 156 STATIC int find_fusd_file(fusd_dev_t *fusd_dev, fusd_file_t *fusd_file);
 157 STATIC int free_fusd_file(fusd_dev_t *fusd_dev, fusd_file_t *fusd_file);
 158
 159 STATIC int fusd_fops_call_send(fusd_file_t *fusd_file_arg,
 160                                fusd_msg_t *fusd_msg, struct fusd_transaction** transaction);
 161 STATIC int fusd_fops_call_wait(fusd_file_t *fusd_file_arg,
 162                                fusd_msg_t **fusd_msg_reply, struct fusd_transaction* transaction);
 163 STATIC void fusd_fops_call_done(fusd_file_t *fusd_file);
 164
 165 STATIC void fusd_forge_close(fusd_msg_t *msg, fusd_dev_t *fusd_dev);
 166
 167 STATIC int fusd_add_transaction(fusd_file_t *fusd_file, int transid, int subcmd, int size, struct fusd_transaction** out_transaction);
 168 STATIC void fusd_cleanup_transaction(fusd_file_t *fusd_file, struct fusd_transaction* transaction);
 169 STATIC void fusd_remove_transaction(fusd_file_t *fusd_file, struct fusd_transaction* transaction);
 170 STATIC struct fusd_transaction* fusd_find_transaction(fusd_file_t *fusd_file, int transid);
 171 STATIC struct fusd_transaction* fusd_find_transaction_by_pid(fusd_file_t *fusd_file, int pid);
 172
 173
 174
 175 /**** Utility functions & macros ****/
 176
 177 #ifdef CONFIG_FUSD_USE_WAKEUPSYNC
 178 #define WAKE_UP_INTERRUPTIBLE_SYNC(x) wake_up_interruptible_sync(x)
 179 #else
 180 #define WAKE_UP_INTERRUPTIBLE_SYNC(x) wake_up_interruptible(x)
 181 #endif /* CONFIG_FUSD_USE_WAKEUPSYNC */
 182
 183 #ifdef CONFIG_FUSD_DEBUG
 184 static void rdebug_real(char *fmt, ...)
 185   __attribute__ ((format (printf, 1, 2)));
 186
 187 #define RDEBUG(message_level, args...) do { \
 188    if (fusd_debug_level >= message_level) rdebug_real(args); \
 189 } while(0)
 190 #else
 191 #define RDEBUG(message_level, args...)
 192 #endif /* CONFIG_FUSD_DEBUG */
 193
 194
 195 #define ZOMBIE(fusd_dev)  ((fusd_dev)->zombie)
 196
 197
 198 #define GET_FUSD_DEV(candidate, fusd_dev) do { \
 199   fusd_dev = candidate; \
 200   if (fusd_dev == NULL || fusd_dev->magic != FUSD_DEV_MAGIC) \
 201         goto invalid_dev; \
 202 } while (0)
 203
 204 #define GET_FUSD_FILE_AND_DEV(candidate, fusd_file, fusd_dev) do { \
 205   fusd_file = candidate; \
 206   if (fusd_file == NULL || fusd_file->magic != FUSD_FILE_MAGIC) \
 207      goto invalid_file; \
 208   GET_FUSD_DEV(fusd_file->fusd_dev, fusd_dev); \
 209   if (fusd_dev->version != fusd_file->fusd_dev_version) \
 210     goto invalid_file; \
 211 } while (0)
 212
 213
 214 #define LOCK_FUSD_DEV(fusd_dev) \
 215   do { down(&fusd_dev->dev_sem); \
 216   if (ZOMBIE(fusd_dev)) { up(&fusd_dev->dev_sem); goto zombie_dev; } \
 217  } while (0)
 218
 219 /* rawlock does not do a zombie check */
 220 #define RAWLOCK_FUSD_DEV(fusd_dev) \
 221   do { down(&fusd_dev->dev_sem); } while (0)
 222
 223 #define UNLOCK_FUSD_DEV(fusd_dev) \
 224   do { up(&fusd_dev->dev_sem); } while (0)
 225
 226
 227 #define LOCK_FUSD_FILE(fusd_file) \
 228   do { down(&fusd_file->file_sem); \
 229  } while (0)
 230
 231 #define UNLOCK_FUSD_FILE(fusd_file) \
 232   do { up(&fusd_file->file_sem); } while (0)
 233
 234 #define FREE_FUSD_MSGC(fusd_msgc) do { \
 235    if ((fusd_msgc)->fusd_msg.data != NULL) VFREE(fusd_msgc->fusd_msg.data); \
 236    KFREE(fusd_msgc); \
 237 } while (0)
 238
 239 #define NAME(fusd_dev) ((fusd_dev)->name == NULL ? \
 240                         "<noname>" : (fusd_dev)->name)
 241
 242 #ifdef CONFIG_FUSD_MEMDEBUG
 243 static int  fusd_mem_init(void);
 244 static void fusd_mem_cleanup(void);
 245 static void fusd_mem_add(void *ptr, int line, int size);
 246 static void fusd_mem_del(void *ptr);
 247 static void *fusd_kmalloc(size_t size, int type, int line);
 248 static void fusd_kfree(void *ptr);
 249 static void *fusd_vmalloc(size_t size, int line);
 250 static void fusd_vfree(void *ptr);
 251 # define KMALLOC(size, type) fusd_kmalloc(size, type, __LINE__)
 252 # define KFREE(ptr) fusd_kfree(ptr)
 253 # define VMALLOC(size) fusd_vmalloc(size, __LINE__)
 254 # define VFREE(ptr) fusd_vfree(ptr)
 255 #else /* no memory debugging */
 256 # define KMALLOC(size, type) kmalloc(size, type)
 257 # define KFREE(ptr) kfree(ptr)
 258 /*# define VMALLOC(size) vmalloc(size)*/
 259 # define VMALLOC(size) kmalloc(size, GFP_KERNEL)
 260 # define VFREE(ptr) kfree(ptr)
 261 #endif /* CONFIG_FUSD_MEMDEBUG */
 262
 263
 264
 265 /* Functions like this should be in the kernel, but they are not.  Sigh. */
 266 #ifdef CONFIG_SMP
 267
 268 DECLARE_MUTEX(atomic_ops);
 269
 270 static __inline__ int atomic_inc_and_ret(int *i)
 271 {
 272   int val;
 273
 274   down(&atomic_ops);
 275   val = (++(*i));
 276   up(&atomic_ops);
 277   return val;
 278 }
 279 #else
 280 static __inline__ int atomic_inc_and_ret(int *i)
 281 {
 282   return (++(*i));
 283 }
 284 #endif
 285
 286
 287 #endif /* __KFUSD_H__ */