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authorSam Ravnborg <sam@ravnborg.org>2008-07-27 23:00:59 +0200
committerSam Ravnborg <sam@ravnborg.org>2008-07-27 23:00:59 +0200
commita439fe51a1f8eb087c22dd24d69cebae4a3addac (patch)
treee32d1fa97a220ab598d8ab364205817c5bf2bd6f /arch/sparc/include/asm/smpprim.h
parent837b41b5de356aa67abb2cadb5eef3efc7776f91 (diff)
sparc, sparc64: use arch/sparc/include
The majority of this patch was created by the following script: *** ASM=arch/sparc/include/asm mkdir -p $ASM git mv include/asm-sparc64/ftrace.h $ASM git rm include/asm-sparc64/* git mv include/asm-sparc/* $ASM sed -ie 's/asm-sparc64/asm/g' $ASM/* sed -ie 's/asm-sparc/asm/g' $ASM/* *** The rest was an update of the top-level Makefile to use sparc for header files when sparc64 is being build. And a small fixlet to pick up the correct unistd.h from sparc64 code. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'arch/sparc/include/asm/smpprim.h')
-rw-r--r--arch/sparc/include/asm/smpprim.h54
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/smpprim.h b/arch/sparc/include/asm/smpprim.h
new file mode 100644
index 00000000000..eb849d862c6
--- /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) */