kernel/drivers/staging/unisys/uislib/uisutils.c

   1 /* uisutils.c
   2  *
   3  * Copyright (C) 2010 - 2013 UNISYS CORPORATION
   4  * All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  14  * NON INFRINGEMENT.  See the GNU General Public License for more
  15  * details.
  16  */
  17
  18 #include <linux/string.h>
  19 #include <linux/slab.h>
  20 #include <linux/types.h>
  21 #include <linux/uuid.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/list.h>
  24 #include "uisutils.h"
  25 #include "version.h"
  26 #include "vbushelper.h"
  27 #include <linux/skbuff.h>
  28 #ifdef CONFIG_HIGHMEM
  29 #include <linux/highmem.h>
  30 #endif
  31
  32 /* this is shorter than using __FILE__ (full path name) in
  33  * debug/info/error messages
  34  */
  35 #define CURRENT_FILE_PC UISLIB_PC_uisutils_c
  36 #define __MYFILE__ "uisutils.c"
  37
  38 /* exports */
  39 atomic_t uisutils_registered_services = ATOMIC_INIT(0);
  40                                         /* num registrations via
  41                                          * uisctrl_register_req_handler() or
  42                                          * uisctrl_register_req_handler_ex() */
  43
  44 /*****************************************************/
  45 /* Utility functions                                 */
  46 /*****************************************************/
  47
  48 int
  49 uisutil_add_proc_line_ex(int *total, char **buffer, int *buffer_remaining,
  50                          char *format, ...)
  51 {
  52         va_list args;
  53         int len;
  54
  55         va_start(args, format);
  56         len = vsnprintf(*buffer, *buffer_remaining, format, args);
  57         va_end(args);
  58         if (len >= *buffer_remaining) {
  59                 *buffer += *buffer_remaining;
  60                 *total += *buffer_remaining;
  61                 *buffer_remaining = 0;
  62                 return -1;
  63         }
  64         *buffer_remaining -= len;
  65         *buffer += len;
  66         *total += len;
  67         return len;
  68 }
  69 EXPORT_SYMBOL_GPL(uisutil_add_proc_line_ex);
  70
  71 int
  72 uisctrl_register_req_handler(int type, void *fptr,
  73                              struct ultra_vbus_deviceinfo *chipset_driver_info)
  74 {
  75         switch (type) {
  76         case 2:
  77                 if (fptr) {
  78                         if (!virt_control_chan_func)
  79                                 atomic_inc(&uisutils_registered_services);
  80                         virt_control_chan_func = fptr;
  81                 } else {
  82                         if (virt_control_chan_func)
  83                                 atomic_dec(&uisutils_registered_services);
  84                         virt_control_chan_func = NULL;
  85                 }
  86                 break;
  87
  88         default:
  89                 return 0;
  90         }
  91         if (chipset_driver_info)
  92                 bus_device_info_init(chipset_driver_info, "chipset", "uislib",
  93                                      VERSION, NULL);
  94
  95         return 1;
  96 }
  97 EXPORT_SYMBOL_GPL(uisctrl_register_req_handler);
  98
  99 /*
 100  * unsigned int uisutil_copy_fragsinfo_from_skb(unsigned char *calling_ctx,
 101  *                                           void *skb_in,
 102  *                                           unsigned int firstfraglen,
 103  *                                           unsigned int frags_max,
 104  *                                           struct phys_info frags[])
 105  *
 106  *      calling_ctx - input -   a string that is displayed to show
 107  *                              who called * this func
 108  *      void *skb_in -  skb whose frag info we're copying type is hidden so we
 109  *                      don't need to include skbbuff in uisutils.h which is
 110  *                      included in non-networking code.
 111  *      unsigned int firstfraglen - input - length of first fragment in skb
 112  *      unsigned int frags_max - input - max len of frags array
 113  *      struct phys_info frags[] - output - frags array filled in on output
 114  *                                          return value indicates number of
 115  *                                          entries filled in frags
 116  */
 117
 118 static LIST_HEAD(req_handler_info_list); /* list of struct req_handler_info */
 119 static DEFINE_SPINLOCK(req_handler_info_list_lock);
 120
 121 struct req_handler_info *
 122 req_handler_find(uuid_le switch_uuid)
 123 {
 124         struct list_head *lelt, *tmp;
 125         struct req_handler_info *entry = NULL;
 126
 127         spin_lock(&req_handler_info_list_lock);
 128         list_for_each_safe(lelt, tmp, &req_handler_info_list) {
 129                 entry = list_entry(lelt, struct req_handler_info, list_link);
 130                 if (uuid_le_cmp(entry->switch_uuid, switch_uuid) == 0) {
 131                         spin_unlock(&req_handler_info_list_lock);
 132                         return entry;
 133                 }
 134         }
 135         spin_unlock(&req_handler_info_list_lock);
 136         return NULL;
 137 }