mem.c

linux字符驱动源码

 <a name=L73 href="source/kernel/chr_drv/mem.c?v=0.97#L73">73</a>         addr = <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos;
 <a name=L74 href="source/kernel/chr_drv/mem.c?v=0.97#L74">74</a>         tmp = <a href="ident?v=0.97;i=buf">buf</a>;
 <a name=L75 href="source/kernel/chr_drv/mem.c?v=0.97#L75">75</a>         while (<a href="ident?v=0.97;i=count">count</a> &gt; 0) {
 <a name=L76 href="source/kernel/chr_drv/mem.c?v=0.97#L76">76</a>                 if (<a href="ident?v=0.97;i=current">current</a>-&gt;signal &amp; ~current-&gt;blocked)
 <a name=L77 href="source/kernel/chr_drv/mem.c?v=0.97#L77">77</a>                         break;
 <a name=L78 href="source/kernel/chr_drv/mem.c?v=0.97#L78">78</a>                 pde = (unsigned long) <a href="ident?v=0.97;i=pg_dir">pg_dir</a> + (addr &gt;&gt; 20 &amp; 0xffc);
 <a name=L79 href="source/kernel/chr_drv/mem.c?v=0.97#L79">79</a>                 pte = *(unsigned long *) pde;
 <a name=L80 href="source/kernel/chr_drv/mem.c?v=0.97#L80">80</a>                 if (!(pte &amp; <a href="ident?v=0.97;i=PAGE_PRESENT">PAGE_PRESENT</a>))
 <a name=L81 href="source/kernel/chr_drv/mem.c?v=0.97#L81">81</a>                         break;
 <a name=L82 href="source/kernel/chr_drv/mem.c?v=0.97#L82">82</a>                 pte &amp;= 0xfffff000;
 <a name=L83 href="source/kernel/chr_drv/mem.c?v=0.97#L83">83</a>                 pte += (addr &gt;&gt; 10) &amp; 0xffc;
 <a name=L84 href="source/kernel/chr_drv/mem.c?v=0.97#L84">84</a>                 page = *(unsigned long *) pte;
 <a name=L85 href="source/kernel/chr_drv/mem.c?v=0.97#L85">85</a>                 if (!(page &amp; <a href="ident?v=0.97;i=PAGE_PRESENT">PAGE_PRESENT</a>))
 <a name=L86 href="source/kernel/chr_drv/mem.c?v=0.97#L86">86</a>                         break;
 <a name=L87 href="source/kernel/chr_drv/mem.c?v=0.97#L87">87</a>                 if (!(page &amp; 2)) {
 <a name=L88 href="source/kernel/chr_drv/mem.c?v=0.97#L88">88</a>                         <a href="ident?v=0.97;i=do_wp_page">do_wp_page</a>(0,addr,<a href="ident?v=0.97;i=current">current</a>,0);
 <a name=L89 href="source/kernel/chr_drv/mem.c?v=0.97#L89">89</a>                         continue;
 <a name=L90 href="source/kernel/chr_drv/mem.c?v=0.97#L90">90</a>                 }
 <a name=L91 href="source/kernel/chr_drv/mem.c?v=0.97#L91">91</a>                 page &amp;= 0xfffff000;
 <a name=L92 href="source/kernel/chr_drv/mem.c?v=0.97#L92">92</a>                 page += addr &amp; 0xfff;
 <a name=L93 href="source/kernel/chr_drv/mem.c?v=0.97#L93">93</a>                 i = 4096-(addr &amp; 0xfff);
 <a name=L94 href="source/kernel/chr_drv/mem.c?v=0.97#L94">94</a>                 if (i &gt; <a href="ident?v=0.97;i=count">count</a>)
 <a name=L95 href="source/kernel/chr_drv/mem.c?v=0.97#L95">95</a>                         i = <a href="ident?v=0.97;i=count">count</a>;
 <a name=L96 href="source/kernel/chr_drv/mem.c?v=0.97#L96">96</a>                 <a href="ident?v=0.97;i=memcpy_fromfs">memcpy_fromfs</a>((void *) page,tmp,i);
 <a name=L97 href="source/kernel/chr_drv/mem.c?v=0.97#L97">97</a>                 addr += i;
 <a name=L98 href="source/kernel/chr_drv/mem.c?v=0.97#L98">98</a>                 tmp += i;
 <a name=L99 href="source/kernel/chr_drv/mem.c?v=0.97#L99">99</a>                 <a href="ident?v=0.97;i=count">count</a> -= i;
<a name=L100 href="source/kernel/chr_drv/mem.c?v=0.97#L100">100</a>         }
<a name=L101 href="source/kernel/chr_drv/mem.c?v=0.97#L101">101</a>         <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos = addr;
<a name=L102 href="source/kernel/chr_drv/mem.c?v=0.97#L102">102</a>         if (tmp != <a href="ident?v=0.97;i=buf">buf</a>)
<a name=L103 href="source/kernel/chr_drv/mem.c?v=0.97#L103">103</a>                 return tmp-<a href="ident?v=0.97;i=buf">buf</a>;
<a name=L104 href="source/kernel/chr_drv/mem.c?v=0.97#L104">104</a>         if (<a href="ident?v=0.97;i=current">current</a>-&gt;signal &amp; ~current-&gt;blocked)
<a name=L105 href="source/kernel/chr_drv/mem.c?v=0.97#L105">105</a>                 return -<a href="ident?v=0.97;i=ERESTARTSYS">ERESTARTSYS</a>;
<a name=L106 href="source/kernel/chr_drv/mem.c?v=0.97#L106">106</a>         return 0;
<a name=L107 href="source/kernel/chr_drv/mem.c?v=0.97#L107">107</a> }
<a name=L108 href="source/kernel/chr_drv/mem.c?v=0.97#L108">108</a> 
<a name=L109 href="source/kernel/chr_drv/mem.c?v=0.97#L109">109</a> static int <a href="ident?v=0.97;i=read_kmem">read_kmem</a>(struct <a href="ident?v=0.97;i=inode">inode</a> * <a href="ident?v=0.97;i=inode">inode</a>, struct <a href="ident?v=0.97;i=file">file</a> * <a href="ident?v=0.97;i=file">file</a>,char * <a href="ident?v=0.97;i=buf">buf</a>, int <a href="ident?v=0.97;i=count">count</a>)
<a name=L110 href="source/kernel/chr_drv/mem.c?v=0.97#L110">110</a> {
<a name=L111 href="source/kernel/chr_drv/mem.c?v=0.97#L111">111</a>         unsigned long p = <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos;
<a name=L112 href="source/kernel/chr_drv/mem.c?v=0.97#L112">112</a> 
<a name=L113 href="source/kernel/chr_drv/mem.c?v=0.97#L113">113</a>         if (<a href="ident?v=0.97;i=count">count</a> &lt; 0)
<a name=L114 href="source/kernel/chr_drv/mem.c?v=0.97#L114">114</a>                 return -<a href="ident?v=0.97;i=EINVAL">EINVAL</a>;
<a name=L115 href="source/kernel/chr_drv/mem.c?v=0.97#L115">115</a>         if (p &gt;= <a href="ident?v=0.97;i=high_memory">high_memory</a>)
<a name=L116 href="source/kernel/chr_drv/mem.c?v=0.97#L116">116</a>                 return 0;
<a name=L117 href="source/kernel/chr_drv/mem.c?v=0.97#L117">117</a>         if (<a href="ident?v=0.97;i=count">count</a> &gt; <a href="ident?v=0.97;i=high_memory">high_memory</a> - p)
<a name=L118 href="source/kernel/chr_drv/mem.c?v=0.97#L118">118</a>                 <a href="ident?v=0.97;i=count">count</a> = <a href="ident?v=0.97;i=high_memory">high_memory</a> - p;
<a name=L119 href="source/kernel/chr_drv/mem.c?v=0.97#L119">119</a>         <a href="ident?v=0.97;i=memcpy_tofs">memcpy_tofs</a>(<a href="ident?v=0.97;i=buf">buf</a>,(void *) p,<a href="ident?v=0.97;i=count">count</a>);
<a name=L120 href="source/kernel/chr_drv/mem.c?v=0.97#L120">120</a>         <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos += <a href="ident?v=0.97;i=count">count</a>;
<a name=L121 href="source/kernel/chr_drv/mem.c?v=0.97#L121">121</a>         return <a href="ident?v=0.97;i=count">count</a>;
<a name=L122 href="source/kernel/chr_drv/mem.c?v=0.97#L122">122</a> }
<a name=L123 href="source/kernel/chr_drv/mem.c?v=0.97#L123">123</a> 
<a name=L124 href="source/kernel/chr_drv/mem.c?v=0.97#L124">124</a> static int <a href="ident?v=0.97;i=write_kmem">write_kmem</a>(struct <a href="ident?v=0.97;i=inode">inode</a> * <a href="ident?v=0.97;i=inode">inode</a>, struct <a href="ident?v=0.97;i=file">file</a> * <a href="ident?v=0.97;i=file">file</a>,char * <a href="ident?v=0.97;i=buf">buf</a>, int <a href="ident?v=0.97;i=count">count</a>)
<a name=L125 href="source/kernel/chr_drv/mem.c?v=0.97#L125">125</a> {
<a name=L126 href="source/kernel/chr_drv/mem.c?v=0.97#L126">126</a>         unsigned long p = <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos;
<a name=L127 href="source/kernel/chr_drv/mem.c?v=0.97#L127">127</a> 
<a name=L128 href="source/kernel/chr_drv/mem.c?v=0.97#L128">128</a>         if (<a href="ident?v=0.97;i=count">count</a> &lt; 0)
<a name=L129 href="source/kernel/chr_drv/mem.c?v=0.97#L129">129</a>                 return -<a href="ident?v=0.97;i=EINVAL">EINVAL</a>;
<a name=L130 href="source/kernel/chr_drv/mem.c?v=0.97#L130">130</a>         if (p &gt;= <a href="ident?v=0.97;i=high_memory">high_memory</a>)
<a name=L131 href="source/kernel/chr_drv/mem.c?v=0.97#L131">131</a>                 return 0;
<a name=L132 href="source/kernel/chr_drv/mem.c?v=0.97#L132">132</a>         if (<a href="ident?v=0.97;i=count">count</a> &gt; <a href="ident?v=0.97;i=high_memory">high_memory</a> - p)
<a name=L133 href="source/kernel/chr_drv/mem.c?v=0.97#L133">133</a>                 <a href="ident?v=0.97;i=count">count</a> = <a href="ident?v=0.97;i=high_memory">high_memory</a> - p;
<a name=L134 href="source/kernel/chr_drv/mem.c?v=0.97#L134">134</a>         <a href="ident?v=0.97;i=memcpy_fromfs">memcpy_fromfs</a>((void *) p,<a href="ident?v=0.97;i=buf">buf</a>,<a href="ident?v=0.97;i=count">count</a>);
<a name=L135 href="source/kernel/chr_drv/mem.c?v=0.97#L135">135</a>         <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos += <a href="ident?v=0.97;i=count">count</a>;
<a name=L136 href="source/kernel/chr_drv/mem.c?v=0.97#L136">136</a>         return <a href="ident?v=0.97;i=count">count</a>;
<a name=L137 href="source/kernel/chr_drv/mem.c?v=0.97#L137">137</a> }
<a name=L138 href="source/kernel/chr_drv/mem.c?v=0.97#L138">138</a> 
<a name=L139 href="source/kernel/chr_drv/mem.c?v=0.97#L139">139</a> static int <a href="ident?v=0.97;i=read_port">read_port</a>(struct <a href="ident?v=0.97;i=inode">inode</a> * <a href="ident?v=0.97;i=inode">inode</a>,struct <a href="ident?v=0.97;i=file">file</a> * <a href="ident?v=0.97;i=file">file</a>,char * <a href="ident?v=0.97;i=buf">buf</a>, int <a href="ident?v=0.97;i=count">count</a>)
<a name=L140 href="source/kernel/chr_drv/mem.c?v=0.97#L140">140</a> {
<a name=L141 href="source/kernel/chr_drv/mem.c?v=0.97#L141">141</a>         unsigned int i = <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos;
<a name=L142 href="source/kernel/chr_drv/mem.c?v=0.97#L142">142</a>         char * tmp = <a href="ident?v=0.97;i=buf">buf</a>;
<a name=L143 href="source/kernel/chr_drv/mem.c?v=0.97#L143">143</a> 
<a name=L144 href="source/kernel/chr_drv/mem.c?v=0.97#L144">144</a>         while (<a href="ident?v=0.97;i=count">count</a>-- &gt; 0 &amp;&amp; i &lt; 65536) {
<a name=L145 href="source/kernel/chr_drv/mem.c?v=0.97#L145">145</a>                 <a href="ident?v=0.97;i=put_fs_byte">put_fs_byte</a>(<a href="ident?v=0.97;i=inb">inb</a>(i),tmp);
<a name=L146 href="source/kernel/chr_drv/mem.c?v=0.97#L146">146</a>                 i++;
<a name=L147 href="source/kernel/chr_drv/mem.c?v=0.97#L147">147</a>                 tmp++;
<a name=L148 href="source/kernel/chr_drv/mem.c?v=0.97#L148">148</a>         }
<a name=L149 href="source/kernel/chr_drv/mem.c?v=0.97#L149">149</a>         <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos = i;
<a name=L150 href="source/kernel/chr_drv/mem.c?v=0.97#L150">150</a>         return tmp-<a href="ident?v=0.97;i=buf">buf</a>;
<a name=L151 href="source/kernel/chr_drv/mem.c?v=0.97#L151">151</a> }
<a name=L152 href="source/kernel/chr_drv/mem.c?v=0.97#L152">152</a> 
<a name=L153 href="source/kernel/chr_drv/mem.c?v=0.97#L153">153</a> static int <a href="ident?v=0.97;i=write_port">write_port</a>(struct <a href="ident?v=0.97;i=inode">inode</a> * <a href="ident?v=0.97;i=inode">inode</a>,struct <a href="ident?v=0.97;i=file">file</a> * <a href="ident?v=0.97;i=file">file</a>,char * <a href="ident?v=0.97;i=buf">buf</a>, int <a href="ident?v=0.97;i=count">count</a>)
<a name=L154 href="source/kernel/chr_drv/mem.c?v=0.97#L154">154</a> {
<a name=L155 href="source/kernel/chr_drv/mem.c?v=0.97#L155">155</a>         unsigned int i = <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos;
<a name=L156 href="source/kernel/chr_drv/mem.c?v=0.97#L156">156</a>         char * tmp = <a href="ident?v=0.97;i=buf">buf</a>;
<a name=L157 href="source/kernel/chr_drv/mem.c?v=0.97#L157">157</a> 
<a name=L158 href="source/kernel/chr_drv/mem.c?v=0.97#L158">158</a>         while (<a href="ident?v=0.97;i=count">count</a>-- &gt; 0 &amp;&amp; i &lt; 65536) {
<a name=L159 href="source/kernel/chr_drv/mem.c?v=0.97#L159">159</a>                 <a href="ident?v=0.97;i=outb">outb</a>(<a href="ident?v=0.97;i=get_fs_byte">get_fs_byte</a>(tmp),i);
<a name=L160 href="source/kernel/chr_drv/mem.c?v=0.97#L160">160</a>                 i++;
<a name=L161 href="source/kernel/chr_drv/mem.c?v=0.97#L161">161</a>                 tmp++;
<a name=L162 href="source/kernel/chr_drv/mem.c?v=0.97#L162">162</a>         }
<a name=L163 href="source/kernel/chr_drv/mem.c?v=0.97#L163">163</a>         <a href="ident?v=0.97;i=file">file</a>-&gt;f_pos = i;
<a name=L164 href="source/kernel/chr_drv/mem.c?v=0.97#L164">164</a>         return tmp-<a href="ident?v=0.97;i=buf">buf</a>;
<a name=L165 href="source/kernel/chr_drv/mem.c?v=0.97#L165">165</a> }
<a name=L166 href="source/kernel/chr_drv/mem.c?v=0.97#L166">166</a> 
<a name=L167 href="source/kernel/chr_drv/mem.c?v=0.97#L167">167</a> static int <a href="ident?v=0.97;i=read_zero">read_zero</a>(struct <a href="ident?v=0.97;i=inode">inode</a> *node,struct <a href="ident?v=0.97;i=file">file</a> *<a href="ident?v=0.97;i=file">file</a>,char *<a href="ident?v=0.97;i=buf">buf</a>,int <a href="ident?v=0.97;i=count">count</a>)
<a name=L168 href="source/kernel/chr_drv/mem.c?v=0.97#L168">168</a> {
<a name=L169 href="source/kernel/chr_drv/mem.c?v=0.97#L169">169</a>         int left;
<a name=L170 href="source/kernel/chr_drv/mem.c?v=0.97#L170">170</a> 
<a name=L171 href="source/kernel/chr_drv/mem.c?v=0.97#L171">171</a>         for (left = <a href="ident?v=0.97;i=count">count</a>; left &gt; 0; left--) {
<a name=L172 href="source/kernel/chr_drv/mem.c?v=0.97#L172">172</a>                 <a href="ident?v=0.97;i=put_fs_byte">put_fs_byte</a>(0,<a href="ident?v=0.97;i=buf">buf</a>);
<a name=L173 href="source/kernel/chr_drv/mem.c?v=0.97#L173">173</a>                 <a href="ident?v=0.97;i=buf">buf</a>++;
<a name=L174 href="source/kernel/chr_drv/mem.c?v=0.97#L174">174</a>         }