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