x86: unify smp parts of system.h

[sfrench/cifs-2.6.git] / include / asm-x86 / system_32.h

diff --git a/include/asm-x86/system_32.h b/include/asm-x86/system_32.h
index c05568290add5f058f678e047ffd797cf83d7677..7da0716fb317b0082c3b660a6a6665628bd8ac7f 100644 (file)
--- a/include/asm-x86/system_32.h
+++ b/include/asm-x86/system_32.h
@@ -36,105 +36,6 @@ extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struc
 #endif /* __KERNEL__ */
 
 
-/*
- * Force strict CPU ordering.
- * And yes, this is required on UP too when we're talking
- * to devices.
- *
- * For now, "wmb()" doesn't actually do anything, as all
- * Intel CPU's follow what Intel calls a *Processor Order*,
- * in which all writes are seen in the program order even
- * outside the CPU.
- *
- * I expect future Intel CPU's to have a weaker ordering,
- * but I'd also expect them to finally get their act together
- * and add some real memory barriers if so.
- *
- * Some non intel clones support out of order store. wmb() ceases to be a
- * nop for these.
- */
- 
-
-#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
-#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
-#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
-
-/**
- * read_barrier_depends - Flush all pending reads that subsequents reads
- * depend on.
- *
- * No data-dependent reads from memory-like regions are ever reordered
- * over this barrier.  All reads preceding this primitive are guaranteed
- * to access memory (but not necessarily other CPUs' caches) before any
- * reads following this primitive that depend on the data return by
- * any of the preceding reads.  This primitive is much lighter weight than
- * rmb() on most CPUs, and is never heavier weight than is
- * rmb().
- *
- * These ordering constraints are respected by both the local CPU
- * and the compiler.
- *
- * Ordering is not guaranteed by anything other than these primitives,
- * not even by data dependencies.  See the documentation for
- * memory_barrier() for examples and URLs to more information.
- *
- * For example, the following code would force ordering (the initial
- * value of "a" is zero, "b" is one, and "p" is "&a"):
- *
- * <programlisting>
- *     CPU 0                           CPU 1
- *
- *     b = 2;
- *     memory_barrier();
- *     p = &b;                         q = p;
- *                                     read_barrier_depends();
- *                                     d = *q;
- * </programlisting>
- *
- * because the read of "*q" depends on the read of "p" and these
- * two reads are separated by a read_barrier_depends().  However,
- * the following code, with the same initial values for "a" and "b":
- *
- * <programlisting>
- *     CPU 0                           CPU 1
- *
- *     a = 2;
- *     memory_barrier();
- *     b = 3;                          y = b;
- *                                     read_barrier_depends();
- *                                     x = a;
- * </programlisting>
- *
- * does not enforce ordering, since there is no data dependency between
- * the read of "a" and the read of "b".  Therefore, on some CPUs, such
- * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
- * in cases like this where there are no data dependencies.
- **/
-
-#define read_barrier_depends() do { } while(0)
-
-#ifdef CONFIG_SMP
-#define smp_mb()       mb()
-#ifdef CONFIG_X86_PPRO_FENCE
-# define smp_rmb()     rmb()
-#else
-# define smp_rmb()     barrier()
-#endif
-#ifdef CONFIG_X86_OOSTORE
-# define smp_wmb()     wmb()
-#else
-# define smp_wmb()     barrier()
-#endif
-#define smp_read_barrier_depends()     read_barrier_depends()
-#define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
-#else
-#define smp_mb()       barrier()
-#define smp_rmb()      barrier()
-#define smp_wmb()      barrier()
-#define smp_read_barrier_depends()     do { } while(0)
-#define set_mb(var, value) do { var = value; barrier(); } while (0)
-#endif
-
 #include <linux/irqflags.h>
 
 /*