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[tpg/acess2.git] / Kernel / arch / arm7 / include / lock.h

diff --git a/Kernel/arch/arm7/include/lock.h b/Kernel/arch/arm7/include/lock.h
new file mode 100644 (file)
index 0000000..9b289d1
--- /dev/null
+++ b/Kernel/arch/arm7/include/lock.h
@@ -0,0 +1,50 @@
+/*
+ * Acess2
+ * ARM7 Architecture
+ *
+ * lock.h - Hardware level spinlocks
+ */
+#ifndef _LOCK_H_
+#define _LOCK_H_
+
+// === CODE ===
+struct sShortSpinlock {
+        int    Lock;
+};
+
+// --- Spinlocks ---
+static inline int IS_LOCKED(struct sShortSpinlock *Lock)
+{
+       return !!Lock->Lock;
+}
+
+static inline int CPU_HAS_LOCK(struct sShortSpinlock *Lock)
+{
+       // TODO: Handle multiple CPUs
+       return !!Lock->Lock;
+}
+
+static inline int SHORTLOCK(struct sShortSpinlock *Lock)
+{
+       // Shamelessly copied from linux (/arch/arm/include/asm/spinlock.h) until I can fix stuff
+       Uint    tmp;
+       __asm__ __volatile__ (
+       "1:     ldrex   %0, [%1]\n"
+       "       teq     %0, #0\n"
+       "       strexeq %0, %2, [%1]\n" // Magic? TODO: Look up
+       "       teqeq   %0, #0\n"
+       "       bne     1b"
+               : "=&r" (tmp)   // Temp
+               : "r" (&Lock->Lock), "r" (1)
+               : "cc"  // Condition codes clobbered
+               );
+       return 1;
+}
+
+static inline void SHORTREL(struct sShortSpinlock *Lock)
+{
+       Lock->Lock = 0;
+}
+
+#endif
+