arch/metag/tbx/tbistring.c

   1 /*
   2  * tbistring.c
   3  *
   4  * Copyright (C) 2001, 2002, 2003, 2005, 2007, 2012 Imagination Technologies.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it under
   7  * the terms of the GNU General Public License version 2 as published by the
   8  * Free Software Foundation.
   9  *
  10  * String table functions provided as part of the thread binary interface for
  11  * Meta processors
  12  */
  13
  14 #include <linux/export.h>
  15 #include <linux/string.h>
  16 #include <asm/tbx.h>
  17
  18 /*
  19  * There are not any functions to modify the string table currently, if these
  20  * are required at some later point I suggest having a seperate module and
  21  * ensuring that creating new entries does not interfere with reading old
  22  * entries in any way.
  23  */
  24
  25 const TBISTR *__TBIFindStr(const TBISTR *start,
  26                            const char *str, int match_len)
  27 {
  28         const TBISTR *search = start;
  29         bool exact = true;
  30         const TBISEG *seg;
  31
  32         if (match_len < 0) {
  33                 /* Make match_len always positive for the inner loop */
  34                 match_len = -match_len;
  35                 exact = false;
  36         } else {
  37                 /*
  38                  * Also support historic behaviour, which expected match_len to
  39                  * include null terminator
  40                  */
  41                 if (match_len && str[match_len-1] == '\0')
  42                         match_len--;
  43         }
  44
  45         if (!search) {
  46                 /* Find global string table segment */
  47                 seg = __TBIFindSeg(NULL, TBID_SEG(TBID_THREAD_GLOBAL,
  48                                                   TBID_SEGSCOPE_GLOBAL,
  49                                                   TBID_SEGTYPE_STRING));
  50
  51                 if (!seg || seg->Bytes < sizeof(TBISTR))
  52                         /* No string table! */
  53                         return NULL;
  54
  55                 /* Start of string table */
  56                 search = seg->pGAddr;
  57         }
  58
  59         for (;;) {
  60                 while (!search->Tag)
  61                         /* Allow simple gaps which are just zero initialised */
  62                         search = (const TBISTR *)((const char *)search + 8);
  63
  64                 if (search->Tag == METAG_TBI_STRE) {
  65                         /* Reached the end of the table */
  66                         search = NULL;
  67                         break;
  68                 }
  69
  70                 if ((search->Len >= match_len) &&
  71                     (!exact || (search->Len == match_len + 1)) &&
  72                     (search->Tag != METAG_TBI_STRG)) {
  73                         /* Worth searching */
  74                         if (!strncmp(str, (const char *)search->String,
  75                                      match_len))
  76                                 break;
  77                 }
  78
  79                 /* Next entry */
  80                 search = (const TBISTR *)((const char *)search + search->Bytes);
  81         }
  82
  83         return search;
  84 }
  85
  86 const void *__TBITransStr(const char *str, int len)
  87 {
  88         const TBISTR *search = NULL;
  89         const void *res = NULL;
  90
  91         for (;;) {
  92                 /* Search onwards */
  93                 search = __TBIFindStr(search, str, len);
  94
  95                 /* No translation returns NULL */
  96                 if (!search)
  97                         break;
  98
  99                 /* Skip matching entries with no translation data */
 100                 if (search->TransLen != METAG_TBI_STRX) {
 101                         /* Calculate base of translation string */
 102                         res = (const char *)search->String +
 103                                 ((search->Len + 7) & ~7);
 104                         break;
 105                 }
 106
 107                 /* Next entry */
 108                 search = (const TBISTR *)((const char *)search + search->Bytes);
 109         }
 110
 111         /* Return base address of translation data or NULL */
 112         return res;
 113 }
 114 EXPORT_SYMBOL(__TBITransStr);