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Fiddling with threading code to attempt to fix this ____ bug
[tpg/acess2.git]
/
Kernel
/
arch
/
x86
/
include
/
arch.h
diff --git
a/Kernel/arch/x86/include/arch.h
b/Kernel/arch/x86/include/arch.h
index
464023e
..
b3f7545
100644
(file)
--- a/
Kernel/arch/x86/include/arch.h
+++ b/
Kernel/arch/x86/include/arch.h
@@
-10,6
+10,9
@@
#define KERNEL_BASE 0xC0000000
#define BITS 32
#define KERNEL_BASE 0xC0000000
#define BITS 32
+// Allow nested spinlocks?
+#define STACKED_LOCKS 1
+
// - Processor/Machine Specific Features
#if ARCH != i386 && ARCH != i486 && ARCH != i586
# error "Unknown architecture '" #ARCH "'"
// - Processor/Machine Specific Features
#if ARCH != i386 && ARCH != i486 && ARCH != i586
# error "Unknown architecture '" #ARCH "'"
@@
-36,6
+39,9
@@
struct sShortSpinlock {
volatile int Lock; //!< Lock value
int IF; //!< Interrupt state on call to SHORTLOCK
struct sShortSpinlock {
volatile int Lock; //!< Lock value
int IF; //!< Interrupt state on call to SHORTLOCK
+ #if STACKED_LOCKS
+ int Depth;
+ #endif
};
/**
* \brief Determine if a short spinlock is locked
};
/**
* \brief Determine if a short spinlock is locked
@@
-53,20
+59,42
@@
static inline int IS_LOCKED(struct sShortSpinlock *Lock) {
* an element to linked list (usually two assignement lines in C)
*
* \note This type of lock halts interrupts, so ensure that no timing
* an element to linked list (usually two assignement lines in C)
*
* \note This type of lock halts interrupts, so ensure that no timing
- * functions are called while it is held.
+ * functions are called while it is held. As a matter of fact, spend as
+ * little time as possible with this lock held
*/
static inline void SHORTLOCK(struct sShortSpinlock *Lock) {
int v = 1;
int IF;
*/
static inline void SHORTLOCK(struct sShortSpinlock *Lock) {
int v = 1;
int IF;
- // int cpu = GetCPUNum() + 1;
+ #if STACKED_LOCKS
+ extern int GetCPUNum(void);
+ int cpu = GetCPUNum() + 1;
+ #endif
// Save interrupt state and clear interrupts
__ASM__ ("pushf;\n\tpop %%eax\n\tcli" : "=a"(IF));
IF &= 0x200; // AND out all but the interrupt flag
// Save interrupt state and clear interrupts
__ASM__ ("pushf;\n\tpop %%eax\n\tcli" : "=a"(IF));
IF &= 0x200; // AND out all but the interrupt flag
+ #if STACKED_LOCKS
+ if( Lock->Lock == cpu ) {
+ Lock->Depth ++;
+ return ;
+ }
+ #endif
+
// Wait for another CPU to release
// Wait for another CPU to release
- while(v)
+ while(v) {
+ #if STACKED_LOCKS
+ // CMPXCHG:
+ // If r/m32 == EAX, set ZF and set r/m32 = r32
+ // Else, clear ZF and set EAX = r/m32
+ __ASM__("lock cmpxchgl %%ecx, (%%edi)"
+ : "=a"(v)
+ : "a"(0), "c"(cpu), "D"(&Lock->Lock)
+ );
+ #else
__ASM__("xchgl %%eax, (%%edi)":"=a"(v):"a"(1),"D"(&Lock->Lock));
__ASM__("xchgl %%eax, (%%edi)":"=a"(v):"a"(1),"D"(&Lock->Lock));
+ #endif
+ }
Lock->IF = IF;
}
Lock->IF = IF;
}
@@
-75,6
+103,12
@@
static inline void SHORTLOCK(struct sShortSpinlock *Lock) {
* \param Lock Lock pointer
*/
static inline void SHORTREL(struct sShortSpinlock *Lock) {
* \param Lock Lock pointer
*/
static inline void SHORTREL(struct sShortSpinlock *Lock) {
+ #if STACKED_LOCKS
+ if( Lock->Depth ) {
+ Lock->Depth --;
+ return ;
+ }
+ #endif
// Lock->IF can change anytime once Lock->Lock is zeroed
if(Lock->IF) {
Lock->Lock = 0;
// Lock->IF can change anytime once Lock->Lock is zeroed
if(Lock->IF) {
Lock->Lock = 0;
UCC
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