Still some issues, but it seems to not crash anymore

[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 0afc51d..0126be3 100644 (file)
--- a/Kernel/arch/x86/include/arch.h
+++ b/Kernel/arch/x86/include/arch.h
@@ -6,35 +6,16 @@
 #ifndef _ARCH_H_
 #define _ARCH_H_
 
-// - Memory Layout
-#define        MM_USER_MIN     0x00200000
-#define        USER_STACK_SZ   0x00010000
-#define        USER_STACK_TOP  0x00800000
-#define        MM_USER_MAX     0xBC000000
-#define        MM_PPD_MIN      0xBC000000      // Per-Process Data
-#define        MM_PPD_VFS      0xBC000000      // 
-#define MM_PPD_CFG     0xBFFFF000      // 
-#define        MM_PPD_MAX      0xB0000000
+// - Base Defintions
 #define        KERNEL_BASE     0xC0000000
-#define        MM_KHEAP_BASE   0xC0400000      // C+4MiB
-#define        MM_KHEAP_MAX    0xCF000000      //
-#define MM_KERNEL_VFS  0xCF000000      // 
-#define MM_KUSER_CODE  0xCFFF0000      // 16 Pages
-#define        MM_MODULE_MIN   0xD0000000      // Lowest Module Address
-#define MM_MODULE_MAX  0xF0000000      // 512 MiB
-
 #define BITS   32
 
+// Allow nested spinlocks?
+#define STACKED_LOCKS  1
+#define LOCK_DISABLE_INTS      0
+
 // - Processor/Machine Specific Features
-#if ARCH == i386
-// Uses no advanced features
-# define       USE_MP  0
-# define       USE_PAE 0
-#elif ARCH == i586
-// All Enabled
-# define       USE_MP  1
-# define       USE_PAE 1
-#else
+#if ARCH != i386 && ARCH != i486 && ARCH != i586
 # error "Unknown architecture '" #ARCH "'"
 #endif
 
@@ -50,12 +31,127 @@
 # define       PHYS_BITS       32
 #endif
 
+#define __ASM__        __asm__ __volatile__
+
+// === Spinlocks ===
+/**
+ * \brief Short Spinlock structure
+ */
+struct sShortSpinlock {
+       volatile int    Lock;   //!< Lock value
+       #if LOCK_DISABLE_INTS
+        int    IF;     //!< Interrupt state on call to SHORTLOCK
+       #endif
+       #if STACKED_LOCKS
+        int    Depth;
+       #endif
+};
+/**
+ * \brief Determine if a short spinlock is locked
+ * \param Lock Lock pointer
+ */
+static inline int IS_LOCKED(struct sShortSpinlock *Lock) {
+       return !!Lock->Lock;
+}
+
+/**
+ * \brief Check if the current CPU has the lock
+ * \param Lock Lock pointer
+ */
+static inline int CPU_HAS_LOCK(struct sShortSpinlock *Lock) {
+       extern int      GetCPUNum(void);
+       return Lock->Lock == GetCPUNum() + 1;
+}
+
+/**
+ * \brief Acquire a Short Spinlock
+ * \param Lock Lock pointer
+ * 
+ * This type of mutex should only be used for very short sections of code,
+ * or in places where a Mutex_* would be overkill, such as appending
+ * 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. 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;
+       #if LOCK_DISABLE_INTS
+        int    IF;
+       #endif
+       #if STACKED_LOCKS
+       extern int      GetCPUNum(void);
+        int    cpu = GetCPUNum() + 1;
+       #endif
+       
+       #if LOCK_DISABLE_INTS
+       // Save interrupt state and clear interrupts
+       __ASM__ ("pushf;\n\tpop %%eax\n\tcli" : "=a"(IF));
+       IF &= 0x200;    // AND out all but the interrupt flag
+       #endif
+       
+       #if STACKED_LOCKS
+       if( Lock->Lock == cpu ) {
+               Lock->Depth ++;
+               return ;
+       }
+       #endif
+       
+       // Wait for another CPU to release
+       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 %2, (%3)"
+                       : "=a"(v)
+                       : "a"(0), "r"(cpu), "r"(&Lock->Lock)
+                       );
+               #else
+               __ASM__("xchgl %%eax, (%%edi)":"=a"(v):"a"(1),"D"(&Lock->Lock));
+               #endif
+       }
+       
+       #if LOCK_DISABLE_INTS
+       Lock->IF = IF;
+       #endif
+}
+/**
+ * \brief Release a short lock
+ * \param Lock Lock pointer
+ */
+static inline void SHORTREL(struct sShortSpinlock *Lock) {
+       #if STACKED_LOCKS
+       if( Lock->Depth ) {
+               Lock->Depth --;
+               return ;
+       }
+       #endif
+       
+       #if LOCK_DISABLE_INTS
+       // Lock->IF can change anytime once Lock->Lock is zeroed
+       if(Lock->IF) {
+               Lock->Lock = 0;
+               __ASM__ ("sti");
+       }
+       else {
+               Lock->Lock = 0;
+       }
+       #else
+       Lock->Lock = 0;
+       #endif
+}
+
 // === MACROS ===
-typedef volatile int   tSpinlock;
-#define LOCK(lockptr)  do {int v=1;\
-       while(v)__asm__ __volatile__("lock xchgl %%eax, (%%edi)":"=a"(v):"a"(1),"D"(lockptr));}while(0)
-#define        RELEASE(lockptr)        __asm__ __volatile__("lock andl $0, (%%edi)"::"D"(lockptr));
+/**
+ * \brief Halt the CPU
+ */
 #define        HALT()  __asm__ __volatile__ ("hlt")
+/**
+ * \brief Fire a magic breakpoint (bochs)
+ */
+#define        MAGIC_BREAK()   __asm__ __volatile__ ("xchg %bx, %bx")
 
 // === TYPES ===
 typedef unsigned int   Uint;   // Unsigned machine native integer
@@ -105,18 +201,6 @@ typedef struct {
        Uint    Resvd4[1];      // SS
 } tSyscallRegs;
 
-typedef struct {
-       Uint16  LimitLow;
-       Uint16  BaseLow;
-       Uint8   BaseMid;
-       Uint8   Access;
-       struct {
-               unsigned LimitHi:       4;
-               unsigned Flags:         4;
-       } __attribute__ ((packed));
-       Uint8   BaseHi;
-} __attribute__ ((packed)) tGDT;
-
 typedef struct {
        #if USE_PAE
        Uint    PDPT[4];