+/**
+ * \brief Short Spinlock structure
+ */
+struct sShortSpinlock {
+ volatile int Lock; //!< Lock value
+ int IF; //!< Interrupt state on call to SHORTLOCK
+};
+/**
+ * \brief Determine if a short spinlock is locked
+ * \param Lock Lock pointer
+ */
+static inline int IS_LOCKED(struct sShortSpinlock *Lock) {
+ return !!Lock->Lock;
+}
+/**
+ * \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.
+ */
+static inline void SHORTLOCK(struct sShortSpinlock *Lock) {
+ int v = 1;
+
+ // Save interrupt state
+ __ASM__ ("pushf;\n\tpop %%rax" : "=a"(Lock->IF));
+ Lock->IF &= 0x200;
+
+ // Stop interrupts
+ __ASM__ ("cli");
+
+ // Wait for another CPU to release
+ while(v)
+ __ASM__("xchgl %%eax, (%%rdi)":"=a"(v):"a"(1),"D"(&Lock->Lock));
+}
+/**
+ * \brief Release a short lock
+ * \param Lock Lock pointer
+ */
+static inline void SHORTREL(struct sShortSpinlock *Lock) {
+ Lock->Lock = 0;
+ #if 0 // Which is faster?, meh the test is simpler
+ __ASM__ ("pushf;\n\tor %0, (%%rsp);\n\tpopf" : : "a"(Lock->IF));
+ #else
+ if(Lock->IF) __ASM__ ("sti");
+ #endif
+}
+