Kernel/arch/x86_64/lib.c

   1 /*
   2  */
   3 #include <acess.h>
   4 #include <arch.h>
   5
   6 // === IMPORTS ===
   7 extern int      GetCPUNum(void);
   8 extern void     *Proc_GetCurThread(void);
   9
  10 // === CODE ===
  11 /**
  12  * \brief Determine if a short spinlock is locked
  13  * \param Lock  Lock pointer
  14  */
  15 int IS_LOCKED(struct sShortSpinlock *Lock)
  16 {
  17         return !!Lock->Lock;
  18 }
  19
  20 /**
  21  * \brief Check if the current CPU has the lock
  22  * \param Lock  Lock pointer
  23  */
  24 int CPU_HAS_LOCK(struct sShortSpinlock *Lock)
  25 {
  26         #if STACKED_LOCKS == 1
  27         return Lock->Lock == GetCPUNum() + 1;
  28         #elif STACKED_LOCKS == 2
  29         return Lock->Lock == Proc_GetCurThread();
  30         #else
  31         return 0;
  32         #endif
  33 }
  34
  35 /**
  36  * \brief Acquire a Short Spinlock
  37  * \param Lock  Lock pointer
  38  *
  39  * This type of mutex should only be used for very short sections of code,
  40  * or in places where a Mutex_* would be overkill, such as appending
  41  * an element to linked list (usually two assignement lines in C)
  42  *
  43  * \note This type of lock halts interrupts, so ensure that no timing
  44  * functions are called while it is held. As a matter of fact, spend as
  45  * little time as possible with this lock held
  46  * \note If \a STACKED_LOCKS is set, this type of spinlock can be nested
  47  */
  48 void SHORTLOCK(struct sShortSpinlock *Lock)
  49 {
  50          int    v = 1;
  51         #if LOCK_DISABLE_INTS
  52          int    IF;
  53         #endif
  54         #if STACKED_LOCKS == 1
  55          int    cpu = GetCPUNum() + 1;
  56         #elif STACKED_LOCKS == 2
  57         void    *thread = Proc_GetCurThread();
  58         #endif
  59
  60         #if LOCK_DISABLE_INTS
  61         // Save interrupt state and clear interrupts
  62         __ASM__ ("pushf;\n\tpop %0" : "=r"(IF));
  63         IF &= 0x200;    // AND out all but the interrupt flag
  64         #endif
  65
  66         #if STACKED_LOCKS == 1
  67         if( Lock->Lock == cpu ) {
  68                 Lock->Depth ++;
  69                 return ;
  70         }
  71         #elif STACKED_LOCKS == 2
  72         if( Lock->Lock == thread ) {
  73                 Lock->Depth ++;
  74                 return ;
  75         }
  76         #endif
  77
  78         // Wait for another CPU to release
  79         while(v) {
  80                 // CMPXCHG:
  81                 //  If r/m32 == EAX, set ZF and set r/m32 = r32
  82                 //  Else, clear ZF and set EAX = r/m32
  83                 #if STACKED_LOCKS == 1
  84                 __ASM__("lock cmpxchgl %2, (%3)"
  85                         : "=a"(v)
  86                         : "a"(0), "r"(cpu), "r"(&Lock->Lock)
  87                         );
  88                 #elif STACKED_LOCKS == 2
  89                 __ASM__("lock cmpxchgq %2, (%3)"
  90                         : "=a"(v)
  91                         : "a"(0), "r"(thread), "r"(&Lock->Lock)
  92                         );
  93                 #else
  94                 __ASM__("xchgl %0, (%2)":"=a"(v):"a"(1),"D"(&Lock->Lock));
  95                 #endif
  96
  97                 #if LOCK_DISABLE_INTS
  98                 if( v ) __ASM__("sti"); // Re-enable interrupts
  99                 #endif
 100         }
 101
 102         #if LOCK_DISABLE_INTS
 103         __ASM__("cli");
 104         Lock->IF = IF;
 105         #endif
 106 }
 107 /**
 108  * \brief Release a short lock
 109  * \param Lock  Lock pointer
 110  */
 111 void SHORTREL(struct sShortSpinlock *Lock)
 112 {
 113         #if STACKED_LOCKS
 114         if( Lock->Depth ) {
 115                 Lock->Depth --;
 116                 return ;
 117         }
 118         #endif
 119
 120         #if LOCK_DISABLE_INTS
 121         // Lock->IF can change anytime once Lock->Lock is zeroed
 122         if(Lock->IF) {
 123                 Lock->Lock = 0;
 124                 __ASM__ ("sti");
 125         }
 126         else {
 127                 Lock->Lock = 0;
 128         }
 129         #else
 130         Lock->Lock = 0;
 131         #endif
 132 }
 133
 134 void outb(Uint16 Port, Uint8 Data)
 135 {
 136         __asm__ __volatile__ ("outb %%al, %%dx"::"d"(Port),"a"(Data));
 137 }
 138 void outw(Uint16 Port, Uint16 Data)
 139 {
 140         __asm__ __volatile__ ("outw %%ax, %%dx"::"d"(Port),"a"(Data));
 141 }
 142 void outd(Uint16 Port, Uint32 Data)
 143 {
 144         __asm__ __volatile__ ("outl %%eax, %%dx"::"d"(Port),"a"(Data));
 145 }
 146 Uint8 inb(Uint16 Port)
 147 {
 148         Uint8   ret;
 149         __asm__ __volatile__ ("inb %%dx, %%al":"=a"(ret):"d"(Port));
 150         return ret;
 151 }
 152 Uint16 inw(Uint16 Port)
 153 {
 154         Uint16  ret;
 155         __asm__ __volatile__ ("inw %%dx, %%ax":"=a"(ret):"d"(Port));
 156         return ret;
 157 }
 158 Uint32 ind(Uint16 Port)
 159 {
 160         Uint32  ret;
 161         __asm__ __volatile__ ("inl %%dx, %%eax":"=a"(ret):"d"(Port));
 162         return ret;
 163 }
 164
 165 // === Endianness ===
 166 Uint32 BigEndian32(Uint32 Value)
 167 {
 168         Uint32  ret;
 169         ret = (Value >> 24);
 170         ret |= ((Value >> 16) & 0xFF) << 8;
 171         ret |= ((Value >>  8) & 0xFF) << 16;
 172         ret |= ((Value >>  0) & 0xFF) << 24;
 173         return ret;
 174 }
 175
 176 Uint16 BigEndian16(Uint16 Value)
 177 {
 178         return  (Value>>8)|(Value<<8);
 179 }
 180
 181 // === Memory Manipulation ===
 182 int memcmp(const void *__dest, const void *__src, size_t __count)
 183 {
 184         if( ((tVAddr)__dest & 7) != ((tVAddr)__src & 7) ) {
 185                 const Uint8     *src = __src, *dst = __dest;
 186                 while(__count)
 187                 {
 188                         if( *src != *dst )
 189                                 return *dst - *src;
 190                         src ++; dst ++; __count --;
 191                 }
 192                 return 0;
 193         }
 194         else {
 195                 const Uint8     *src = __src;
 196                 const Uint8     *dst = __dest;
 197                 const Uint64    *src64, *dst64;
 198
 199                 while( (tVAddr)src & 7 && __count ) {
 200                         if( *src != *dst )
 201                                 return *dst - *src;
 202                         dst ++; src ++; __count --;
 203                 }
 204
 205                 src64 = (void*)src;
 206                 dst64 = (void*)dst;
 207
 208                 while( __count >= 8 )
 209                 {
 210                         if( *src64 != *dst64 )
 211                         {
 212                                 src = (void*)src64;
 213                                 dst = (void*)dst64;
 214                                 if(src[0] != dst[0])    return dst[0]-src[0];
 215                                 if(src[1] != dst[1])    return dst[1]-src[1];
 216                                 if(src[2] != dst[2])    return dst[2]-src[2];
 217                                 if(src[3] != dst[3])    return dst[3]-src[3];
 218                                 if(src[4] != dst[4])    return dst[4]-src[4];
 219                                 if(src[5] != dst[5])    return dst[5]-src[5];
 220                                 if(src[6] != dst[6])    return dst[6]-src[6];
 221                                 if(src[7] != dst[7])    return dst[7]-src[7];
 222                                 return -1;      // This should never happen
 223                         }
 224                         __count -= 8;
 225                         src64 ++;
 226                         dst64 ++;
 227                 }
 228
 229                 src = (void*)src64;
 230                 dst = (void*)dst64;
 231                 while( __count-- )
 232                 {
 233                         if(*dst != *src)        return *dst - *src;
 234                         dst ++;
 235                         src ++;
 236                 }
 237         }
 238         return 0;
 239 }
 240
 241 void *memcpy(void *__dest, const void *__src, size_t __count)
 242 {
 243         if( ((tVAddr)__dest & 7) != ((tVAddr)__src & 7) )
 244                 __asm__ __volatile__ ("rep movsb" : : "D"(__dest),"S"(__src),"c"(__count));
 245         else {
 246                 const Uint8     *src = __src;
 247                 Uint8   *dst = __dest;
 248                 while( (tVAddr)src & 7 && __count ) {
 249                         *dst++ = *src++;
 250                         __count --;
 251                 }
 252
 253                 __asm__ __volatile__ ("rep movsq" : : "D"(dst),"S"(src),"c"(__count/8));
 254                 src += __count & ~7;
 255                 dst += __count & ~7;
 256                 __count = __count & 7;
 257                 while( __count-- )
 258                         *dst++ = *src++;
 259         }
 260         return __dest;
 261 }
 262
 263 void *memset(void *__dest, int __val, size_t __count)
 264 {
 265         if( __val != 0 || ((tVAddr)__dest & 7) != 0 )
 266                 __asm__ __volatile__ ("rep stosb" : : "D"(__dest),"a"(__val),"c"(__count));
 267         else {
 268                 Uint8   *dst = __dest;
 269
 270                 __asm__ __volatile__ ("rep stosq" : : "D"(dst),"a"(0),"c"(__count/8));
 271                 dst += __count & ~7;
 272                 __count = __count & 7;
 273                 while( __count-- )
 274                         *dst++ = 0;
 275         }
 276         return __dest;
 277 }
 278
 279 void *memsetd(void *__dest, Uint32 __val, size_t __count)
 280 {
 281         __asm__ __volatile__ ("rep stosl" : : "D"(__dest),"a"(__val),"c"(__count));
 282         return __dest;
 283 }
 284