sparc, sparc64: use arch/sparc/include

[pandora-kernel.git] / arch / sparc / include / asm / smpprim.h

diff --git a/arch/sparc/include/asm/smpprim.h b/arch/sparc/include/asm/smpprim.h
new file mode 100644 (file)
index 0000000..eb849d8
--- /dev/null
+++ b/arch/sparc/include/asm/smpprim.h
@@ -0,0 +1,54 @@
+/*
+ *  smpprim.h:  SMP locking primitives on the Sparc
+ *
+ *  God knows we won't be actually using this code for some time
+ *  but I thought I'd write it since I knew how.
+ *
+ *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ */
+
+#ifndef __SPARC_SMPPRIM_H
+#define __SPARC_SMPPRIM_H
+
+/* Test and set the unsigned byte at ADDR to 1.  Returns the previous
+ * value.  On the Sparc we use the ldstub instruction since it is
+ * atomic.
+ */
+
+static inline __volatile__ char test_and_set(void *addr)
+{
+       char state = 0;
+
+       __asm__ __volatile__("ldstub [%0], %1         ! test_and_set\n\t"
+                            "=r" (addr), "=r" (state) :
+                            "0" (addr), "1" (state) : "memory");
+
+       return state;
+}
+
+/* Initialize a spin-lock. */
+static inline __volatile__ smp_initlock(void *spinlock)
+{
+       /* Unset the lock. */
+       *((unsigned char *) spinlock) = 0;
+
+       return;
+}
+
+/* This routine spins until it acquires the lock at ADDR. */
+static inline __volatile__ smp_lock(void *addr)
+{
+       while(test_and_set(addr) == 0xff)
+               ;
+
+       /* We now have the lock */
+       return;
+}
+
+/* This routine releases the lock at ADDR. */
+static inline __volatile__ smp_unlock(void *addr)
+{
+       *((unsigned char *) addr) = 0;
+}
+
+#endif /* !(__SPARC_SMPPRIM_H) */