summaryrefslogtreecommitdiffstats
path: root/arch/mips/include/asm/barrier.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/include/asm/barrier.h')
-rw-r--r--arch/mips/include/asm/barrier.h142
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h
new file mode 100644
index 000000000..49ff172a7
--- /dev/null
+++ b/arch/mips/include/asm/barrier.h
@@ -0,0 +1,142 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2006 by Ralf Baechle (ralf@linux-mips.org)
+ */
+#ifndef __ASM_BARRIER_H
+#define __ASM_BARRIER_H
+
+#include <asm/addrspace.h>
+#include <asm/sync.h>
+
+static inline void __sync(void)
+{
+ asm volatile(__SYNC(full, always) ::: "memory");
+}
+
+static inline void rmb(void)
+{
+ asm volatile(__SYNC(rmb, always) ::: "memory");
+}
+#define rmb rmb
+
+static inline void wmb(void)
+{
+ asm volatile(__SYNC(wmb, always) ::: "memory");
+}
+#define wmb wmb
+
+#define fast_mb() __sync()
+
+#define __fast_iob() \
+ __asm__ __volatile__( \
+ ".set push\n\t" \
+ ".set noreorder\n\t" \
+ "lw $0,%0\n\t" \
+ "nop\n\t" \
+ ".set pop" \
+ : /* no output */ \
+ : "m" (*(int *)CKSEG1) \
+ : "memory")
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+# define fast_iob() do { } while (0)
+#else /* ! CONFIG_CPU_CAVIUM_OCTEON */
+# ifdef CONFIG_SGI_IP28
+# define fast_iob() \
+ __asm__ __volatile__( \
+ ".set push\n\t" \
+ ".set noreorder\n\t" \
+ "lw $0,%0\n\t" \
+ "sync\n\t" \
+ "lw $0,%0\n\t" \
+ ".set pop" \
+ : /* no output */ \
+ : "m" (*(int *)CKSEG1ADDR(0x1fa00004)) \
+ : "memory")
+# else
+# define fast_iob() \
+ do { \
+ __sync(); \
+ __fast_iob(); \
+ } while (0)
+# endif
+#endif /* CONFIG_CPU_CAVIUM_OCTEON */
+
+#ifdef CONFIG_CPU_HAS_WB
+
+#include <asm/wbflush.h>
+
+#define mb() wbflush()
+#define iob() wbflush()
+
+#else /* !CONFIG_CPU_HAS_WB */
+
+#define mb() fast_mb()
+#define iob() fast_iob()
+
+#endif /* !CONFIG_CPU_HAS_WB */
+
+#if defined(CONFIG_WEAK_ORDERING)
+# define __smp_mb() __sync()
+# define __smp_rmb() rmb()
+# define __smp_wmb() wmb()
+#else
+# define __smp_mb() barrier()
+# define __smp_rmb() barrier()
+# define __smp_wmb() barrier()
+#endif
+
+/*
+ * When LL/SC does imply order, it must also be a compiler barrier to avoid the
+ * compiler from reordering where the CPU will not. When it does not imply
+ * order, the compiler is also free to reorder across the LL/SC loop and
+ * ordering will be done by smp_llsc_mb() and friends.
+ */
+#if defined(CONFIG_WEAK_REORDERING_BEYOND_LLSC) && defined(CONFIG_SMP)
+# define __WEAK_LLSC_MB sync
+# define smp_llsc_mb() \
+ __asm__ __volatile__(__stringify(__WEAK_LLSC_MB) : : :"memory")
+# define __LLSC_CLOBBER
+#else
+# define __WEAK_LLSC_MB
+# define smp_llsc_mb() do { } while (0)
+# define __LLSC_CLOBBER "memory"
+#endif
+
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+#define smp_mb__before_llsc() smp_wmb()
+#define __smp_mb__before_llsc() __smp_wmb()
+/* Cause previous writes to become visible on all CPUs as soon as possible */
+#define nudge_writes() __asm__ __volatile__(".set push\n\t" \
+ ".set arch=octeon\n\t" \
+ "syncw\n\t" \
+ ".set pop" : : : "memory")
+#else
+#define smp_mb__before_llsc() smp_llsc_mb()
+#define __smp_mb__before_llsc() smp_llsc_mb()
+#define nudge_writes() mb()
+#endif
+
+/*
+ * In the Loongson3 LL/SC workaround case, all of our LL/SC loops already have
+ * a completion barrier immediately preceding the LL instruction. Therefore we
+ * can skip emitting a barrier from __smp_mb__before_atomic().
+ */
+#ifdef CONFIG_CPU_LOONGSON3_WORKAROUNDS
+# define __smp_mb__before_atomic()
+#else
+# define __smp_mb__before_atomic() __smp_mb__before_llsc()
+#endif
+
+#define __smp_mb__after_atomic() smp_llsc_mb()
+
+static inline void sync_ginv(void)
+{
+ asm volatile(__SYNC(ginv, always));
+}
+
+#include <asm-generic/barrier.h>
+
+#endif /* __ASM_BARRIER_H */