2 files changed, 136 insertions, 0 deletions

diff --git a/include/asm-generic/checksum.h b/include/asm-generic/checksum.h
index 4647c76..c084767 100644
--- a/include/asm-generic/checksum.h
+++ b/include/asm-generic/checksum.h
@@ -33,8 +33,10 @@ extern __wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
 					int len, __wsum sum, int *csum_err);
 
+#ifndef csum_partial_copy_nocheck
 #define csum_partial_copy_nocheck(src, dst, len, sum)	\
 	csum_partial_copy((src), (dst), (len), (sum))
+#endif
 
 /*
  * This is a version of ip_compute_csum() optimized for IP headers,
@@ -63,12 +65,14 @@ csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
 		unsigned short proto, __wsum sum);
 #endif
 
+#ifndef csum_tcpudp_magic
 static inline __sum16
 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
 		  unsigned short proto, __wsum sum)
 {
 	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
 }
+#endif
 
 /*
  * this routine is used for miscellaneous IP-like checksums, mainly
diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h
new file mode 100644
index 0000000..bb1e2cd
--- /dev/null
+++ b/include/asm-generic/rwsem.h
@@ -0,0 +1,132 @@
+#ifndef _ASM_POWERPC_RWSEM_H
+#define _ASM_POWERPC_RWSEM_H
+
+#ifndef _LINUX_RWSEM_H
+#error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead."
+#endif
+
+#ifdef __KERNEL__
+
+/*
+ * R/W semaphores for PPC using the stuff in lib/rwsem.c.
+ * Adapted largely from include/asm-i386/rwsem.h
+ * by Paul Mackerras <paulus@samba.org>.
+ */
+
+/*
+ * the semaphore definition
+ */
+#ifdef CONFIG_PPC64
+# define RWSEM_ACTIVE_MASK		0xffffffffL
+#else
+# define RWSEM_ACTIVE_MASK		0x0000ffffL
+#endif
+
+#define RWSEM_UNLOCKED_VALUE		0x00000000L
+#define RWSEM_ACTIVE_BIAS		0x00000001L
+#define RWSEM_WAITING_BIAS		(-RWSEM_ACTIVE_MASK-1)
+#define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS
+#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+
+/*
+ * lock for reading
+ */
+static inline void __down_read(struct rw_semaphore *sem)
+{
+	if (unlikely(atomic_long_inc_return((atomic_long_t *)&sem->count) <= 0))
+		rwsem_down_read_failed(sem);
+}
+
+static inline int __down_read_trylock(struct rw_semaphore *sem)
+{
+	long tmp;
+
+	while ((tmp = sem->count) >= 0) {
+		if (tmp == cmpxchg(&sem->count, tmp,
+				   tmp + RWSEM_ACTIVE_READ_BIAS)) {
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * lock for writing
+ */
+static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
+{
+	long tmp;
+
+	tmp = atomic_long_add_return(RWSEM_ACTIVE_WRITE_BIAS,
+				     (atomic_long_t *)&sem->count);
+	if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS))
+		rwsem_down_write_failed(sem);
+}
+
+static inline void __down_write(struct rw_semaphore *sem)
+{
+	__down_write_nested(sem, 0);
+}
+
+static inline int __down_write_trylock(struct rw_semaphore *sem)
+{
+	long tmp;
+
+	tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
+		      RWSEM_ACTIVE_WRITE_BIAS);
+	return tmp == RWSEM_UNLOCKED_VALUE;
+}
+
+/*
+ * unlock after reading
+ */
+static inline void __up_read(struct rw_semaphore *sem)
+{
+	long tmp;
+
+	tmp = atomic_long_dec_return((atomic_long_t *)&sem->count);
+	if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0))
+		rwsem_wake(sem);
+}
+
+/*
+ * unlock after writing
+ */
+static inline void __up_write(struct rw_semaphore *sem)
+{
+	if (unlikely(atomic_long_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
+				 (atomic_long_t *)&sem->count) < 0))
+		rwsem_wake(sem);
+}
+
+/*
+ * implement atomic add functionality
+ */
+static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
+{
+	atomic_long_add(delta, (atomic_long_t *)&sem->count);
+}
+
+/*
+ * downgrade write lock to read lock
+ */
+static inline void __downgrade_write(struct rw_semaphore *sem)
+{
+	long tmp;
+
+	tmp = atomic_long_add_return(-RWSEM_WAITING_BIAS,
+				     (atomic_long_t *)&sem->count);
+	if (tmp < 0)
+		rwsem_downgrade_wake(sem);
+}
+
+/*
+ * implement exchange and add functionality
+ */
+static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
+{
+	return atomic_long_add_return(delta, (atomic_long_t *)&sem->count);
+}
+
+#endif	/* __KERNEL__ */
+#endif	/* _ASM_POWERPC_RWSEM_H */