Disintegrate asm/system.h for M68K
Disintegrate asm/system.h for M68K.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
cc: linux-m68k@lists.linux-m68k.org
diff --git a/arch/m68k/include/asm/cmpxchg.h b/arch/m68k/include/asm/cmpxchg.h
new file mode 100644
index 0000000..5c81d0e
--- /dev/null
+++ b/arch/m68k/include/asm/cmpxchg.h
@@ -0,0 +1,141 @@
+#ifndef __ARCH_M68K_CMPXCHG__
+#define __ARCH_M68K_CMPXCHG__
+
+#include <linux/irqflags.h>
+
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x) ((volatile struct __xchg_dummy *)(x))
+
+extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
+
+#ifndef CONFIG_RMW_INSNS
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+ unsigned long flags, tmp;
+
+ local_irq_save(flags);
+
+ switch (size) {
+ case 1:
+ tmp = *(u8 *)ptr;
+ *(u8 *)ptr = x;
+ x = tmp;
+ break;
+ case 2:
+ tmp = *(u16 *)ptr;
+ *(u16 *)ptr = x;
+ x = tmp;
+ break;
+ case 4:
+ tmp = *(u32 *)ptr;
+ *(u32 *)ptr = x;
+ x = tmp;
+ break;
+ default:
+ tmp = __invalid_xchg_size(x, ptr, size);
+ break;
+ }
+
+ local_irq_restore(flags);
+ return x;
+}
+#else
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+ switch (size) {
+ case 1:
+ __asm__ __volatile__
+ ("moveb %2,%0\n\t"
+ "1:\n\t"
+ "casb %0,%1,%2\n\t"
+ "jne 1b"
+ : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
+ break;
+ case 2:
+ __asm__ __volatile__
+ ("movew %2,%0\n\t"
+ "1:\n\t"
+ "casw %0,%1,%2\n\t"
+ "jne 1b"
+ : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
+ break;
+ case 4:
+ __asm__ __volatile__
+ ("movel %2,%0\n\t"
+ "1:\n\t"
+ "casl %0,%1,%2\n\t"
+ "jne 1b"
+ : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
+ break;
+ default:
+ x = __invalid_xchg_size(x, ptr, size);
+ break;
+ }
+ return x;
+}
+#endif
+
+#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+#include <asm-generic/cmpxchg-local.h>
+
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+extern unsigned long __invalid_cmpxchg_size(volatile void *,
+ unsigned long, unsigned long, int);
+
+/*
+ * Atomic compare and exchange. Compare OLD with MEM, if identical,
+ * store NEW in MEM. Return the initial value in MEM. Success is
+ * indicated by comparing RETURN with OLD.
+ */
+#ifdef CONFIG_RMW_INSNS
+#define __HAVE_ARCH_CMPXCHG 1
+
+static inline unsigned long __cmpxchg(volatile void *p, unsigned long old,
+ unsigned long new, int size)
+{
+ switch (size) {
+ case 1:
+ __asm__ __volatile__ ("casb %0,%2,%1"
+ : "=d" (old), "=m" (*(char *)p)
+ : "d" (new), "0" (old), "m" (*(char *)p));
+ break;
+ case 2:
+ __asm__ __volatile__ ("casw %0,%2,%1"
+ : "=d" (old), "=m" (*(short *)p)
+ : "d" (new), "0" (old), "m" (*(short *)p));
+ break;
+ case 4:
+ __asm__ __volatile__ ("casl %0,%2,%1"
+ : "=d" (old), "=m" (*(int *)p)
+ : "d" (new), "0" (old), "m" (*(int *)p));
+ break;
+ default:
+ old = __invalid_cmpxchg_size(p, old, new, size);
+ break;
+ }
+ return old;
+}
+
+#define cmpxchg(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))))
+#else
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
+ (unsigned long)(n), sizeof(*(ptr))))
+
+#include <asm-generic/cmpxchg.h>
+
+#endif
+
+#endif /* __ARCH_M68K_CMPXCHG__ */