Merge tag 'openrisc-for-linus' of git://github.com/openrisc/linux

Pull OpenRISC updates from Stafford Horne:
 "Highlights include:

   - optimized memset and memcpy routines, ~20% boot time saving

   - support for cpu idling

   - adding support for l.swa and l.lwa atomic operations (in spec from
     2014)

   - use atomics to implement: bitops, cmpxchg, futex

   - the atomics are in preparation for SMP support"

* tag 'openrisc-for-linus' of git://github.com/openrisc/linux: (25 commits)
  openrisc: head: Init r0 to 0 on start
  openrisc: Export ioremap symbols used by modules
  arch/openrisc/lib/memcpy.c: use correct OR1200 option
  openrisc: head: Remove unused strings
  openrisc: head: Move init strings to rodata section
  openrisc: entry: Fix delay slot detection
  openrisc: entry: Whitespace and comment cleanups
  scripts/checkstack.pl: Add openrisc support
  MAINTAINERS: Add the openrisc official repository
  openrisc: Add .gitignore
  openrisc: Add optimized memcpy routine
  openrisc: Add optimized memset
  openrisc: Initial support for the idle state
  openrisc: Fix the bitmask for the unit present register
  openrisc: remove unnecessary stddef.h include
  openrisc: add futex_atomic_* implementations
  openrisc: add optimized atomic operations
  openrisc: add cmpxchg and xchg implementations
  openrisc: add atomic bitops
  openrisc: add l.lwa/l.swa emulation
  ...

1 files changed, 83 insertions, 0 deletions

diff --git a/arch/openrisc/include/asm/cmpxchg.h b/arch/openrisc/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..5fcb9ac72693
--- /dev/null
+++ b/arch/openrisc/include/asm/cmpxchg.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#ifndef __ASM_OPENRISC_CMPXCHG_H
+#define __ASM_OPENRISC_CMPXCHG_H
+
+#include  <linux/types.h>
+
+/*
+ * This function doesn't exist, so you'll get a linker error
+ * if something tries to do an invalid cmpxchg().
+ */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+static inline unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
+{
+	if (size != 4) {
+		__cmpxchg_called_with_bad_pointer();
+		return old;
+	}
+
+	__asm__ __volatile__(
+		"1:	l.lwa %0, 0(%1)		\n"
+		"	l.sfeq %0, %2		\n"
+		"	l.bnf 2f		\n"
+		"	 l.nop			\n"
+		"	l.swa 0(%1), %3		\n"
+		"	l.bnf 1b		\n"
+		"	 l.nop			\n"
+		"2:				\n"
+		: "=&r"(old)
+		: "r"(ptr), "r"(old), "r"(new)
+		: "cc", "memory");
+
+	return old;
+}
+
+#define cmpxchg(ptr, o, n)						\
+	({								\
+		(__typeof__(*(ptr))) __cmpxchg((ptr),			\
+					       (unsigned long)(o),	\
+					       (unsigned long)(n),	\
+					       sizeof(*(ptr)));		\
+	})
+
+/*
+ * This function doesn't exist, so you'll get a linker error if
+ * something tries to do an invalidly-sized xchg().
+ */
+extern void __xchg_called_with_bad_pointer(void);
+
+static inline unsigned long __xchg(unsigned long val, volatile void *ptr,
+				   int size)
+{
+	if (size != 4) {
+		__xchg_called_with_bad_pointer();
+		return val;
+	}
+
+	__asm__ __volatile__(
+		"1:	l.lwa %0, 0(%1)		\n"
+		"	l.swa 0(%1), %2		\n"
+		"	l.bnf 1b		\n"
+		"	 l.nop			\n"
+		: "=&r"(val)
+		: "r"(ptr), "r"(val)
+		: "cc", "memory");
+
+	return val;
+}
+
+#define xchg(ptr, with) \
+	((typeof(*(ptr)))__xchg((unsigned long)(with), (ptr), sizeof(*(ptr))))
+
+#endif /* __ASM_OPENRISC_CMPXCHG_H */