Kernel/x86 - Debugging SMP bugs, lead to some fixes and cleanups

[tpg/acess2.git] / Kernel / arch / x86 / lib.c

diff --git a/Kernel/arch/x86/lib.c b/Kernel/arch/x86/lib.c
index 5a86e44..ecc575c 100644 (file)
--- a/Kernel/arch/x86/lib.c
+++ b/Kernel/arch/x86/lib.c
@@ -22,6 +22,7 @@ extern struct sShortSpinlock  glThreadListLock;
 extern int     GetCPUNum(void);
 
 // === PROTOTYPES ==
+Uint64 __divmod64(Uint64 Num, Uint64 Den, Uint64 *Rem);
 Uint64 __udivdi3(Uint64 Num, Uint64 Den);
 Uint64 __umoddi3(Uint64 Num, Uint64 Den);
 
@@ -79,12 +80,16 @@ void SHORTLOCK(struct sShortSpinlock *Lock)
        }
        #endif
        
+       __ASM__("cli");
+       
        // Wait for another CPU to release
-       while(v) {
-               __ASM__("xchgl %%eax, (%%edi)":"=a"(v):"a"(cpu),"D"(&Lock->Lock));
-       }
+       __ASM__(
+               "1: lock cmpxchgl %2, (%3)\n\t"
+               "jnz 1b"
+               : "=a"(v)
+               : "a"(0), "r"(cpu), "r"(&Lock->Lock)
+               );
        
-       __ASM__("cli");
        Lock->IF = IF;
        
        #if TRACE_LOCKS
@@ -326,9 +331,12 @@ void *memcpyd(void *Dest, const void *Src, size_t Num)
        return Dest;
 }
 
+#include "../helpers.h"
+
+DEF_DIVMOD(64);
+
 Uint64 DivMod64U(Uint64 Num, Uint64 Div, Uint64 *Rem)
 {
-       Uint64  ret;
        if( Div < 0x100000000ULL && Num < 0xFFFFFFFF * Div ) {
                Uint32  rem, ret_32;
                __asm__ __volatile__(
@@ -340,9 +348,7 @@ Uint64 DivMod64U(Uint64 Num, Uint64 Div, Uint64 *Rem)
                return ret_32;
        }
 
-       ret = __udivdi3(Num, Div);
-       if(Rem) *Rem = __umoddi3(Num, Div);
-       return ret;
+       return __divmod64(Num, Div, Rem);
 }
 
 /**
@@ -351,11 +357,10 @@ Uint64 DivMod64U(Uint64 Num, Uint64 Div, Uint64 *Rem)
  */
 Uint64 __udivdi3(Uint64 Num, Uint64 Den)
 {
-       Uint64  P[2];
-       Uint64  q = 0;
-        int    i;
-       
-       if(Den == 0)    __asm__ __volatile__ ("int $0x0");
+       if(Den == 0) {
+               __asm__ __volatile__ ("int $0x0");
+               return -1;
+       }
        // Common speedups
        if(Num <= 0xFFFFFFFF && Den <= 0xFFFFFFFF)
                return (Uint32)Num / (Uint32)Den;
@@ -371,46 +376,8 @@ Uint64 __udivdi3(Uint64 Num, Uint64 Den)
        if(Num < Den)   return 0;
        if(Num < Den*2) return 1;
        if(Num == Den*2)        return 2;
-       
-       #if 1
-       i = 0;  // Shut up
-       P[0] = Num;
-       P[1] = Den;
-       __asm__ __volatile__ (
-               "fildq %2\n\t"  // Num
-               "fildq %1\n\t"  // Den
-               "fdivp\n\t"
-               "fistpq %0"
-               : "=m" (q)
-               : "m" (P[0]), "m" (P[1])
-               );
-               
-       //Log("%llx / %llx = %llx\n", Num, Den, q);
-       #else
-       // Restoring division, from wikipedia
-       // http://en.wikipedia.org/wiki/Division_(digital)
-       P[0] = Num;     P[1] = 0;
-       for( i = 64; i--; )
-       {
-               // P <<= 1;
-               P[1] = (P[1] << 1) | (P[0] >> 63);
-               P[0] = P[0] << 1;
-               
-               // P -= Den << 64
-               P[1] -= Den;
-               
-               // P >= 0
-               if( !(P[1] & (1ULL<<63)) ) {
-                       q |= (Uint64)1 << (63-i);
-               }
-               else {
-                       //q |= 0 << (63-i);
-                       P[1] += Den;
-               }
-       }
-       #endif
-       
-       return q;
+
+       return __divmod64(Num, Den, NULL);
 }
 
 /**
@@ -419,7 +386,11 @@ Uint64 __udivdi3(Uint64 Num, Uint64 Den)
  */
 Uint64 __umoddi3(Uint64 Num, Uint64 Den)
 {
-       if(Den == 0)    __asm__ __volatile__ ("int $0x0");      // Call Div by Zero Error
+       Uint64  ret = 0;
+       if(Den == 0) {
+               __asm__ __volatile__ ("int $0x0");      // Call Div by Zero Error
+               return -1;
+       }
        if(Den == 1)    return 0;       // Speed Hacks
        if(Den == 2)    return Num & 1; // Speed Hacks
        if(Den == 4)    return Num & 3; // Speed Hacks
@@ -433,7 +404,8 @@ Uint64 __umoddi3(Uint64 Num, Uint64 Den)
        if(Num >> 32 == 0 && Den >> 32 == 0)
                return (Uint32)Num % (Uint32)Den;
        
-       return Num - __udivdi3(Num, Den) * Den;
+       __divmod64(Num, Den, &ret);
+       return ret;
 }