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authorChris Zankel <chris@zankel.net>2008-11-06 06:40:46 -0800
committerChris Zankel <chris@zankel.net>2008-11-06 10:25:09 -0800
commit367b8112fe2ea5c39a7bb4d263dcdd9b612fae18 (patch)
tree9f3349189718dd2c5678faf0ab38f389786b6925 /arch/xtensa/include/asm/atomic.h
parent206ead28377fee86b129637edada8c77816cc0d6 (diff)
xtensa: move headers files to arch/xtensa/include
Move all header files for xtensa to arch/xtensa/include and platform and variant header files to the appropriate arch/xtensa/platforms/ and arch/xtensa/variants/ directories. Moving the files gets also rid of all uses of symlinks in the Makefile. This has been completed already for the majority of the architectures and xtensa is one out of six missing. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa/include/asm/atomic.h')
-rw-r--r--arch/xtensa/include/asm/atomic.h300
1 files changed, 300 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
new file mode 100644
index 00000000000..b3b23540f14
--- /dev/null
+++ b/arch/xtensa/include/asm/atomic.h
@@ -0,0 +1,300 @@
+/*
+ * include/asm-xtensa/atomic.h
+ *
+ * Atomic operations that C can't guarantee us. Useful for resource counting..
+ *
+ * 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) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_ATOMIC_H
+#define _XTENSA_ATOMIC_H
+
+#include <linux/stringify.h>
+
+typedef struct { volatile int counter; } atomic_t;
+
+#ifdef __KERNEL__
+#include <asm/processor.h>
+#include <asm/system.h>
+
+#define ATOMIC_INIT(i) { (i) }
+
+/*
+ * This Xtensa implementation assumes that the right mechanism
+ * for exclusion is for locking interrupts to level 1.
+ *
+ * Locking interrupts looks like this:
+ *
+ * rsil a15, 1
+ * <code>
+ * wsr a15, PS
+ * rsync
+ *
+ * Note that a15 is used here because the register allocation
+ * done by the compiler is not guaranteed and a window overflow
+ * may not occur between the rsil and wsr instructions. By using
+ * a15 in the rsil, the machine is guaranteed to be in a state
+ * where no register reference will cause an overflow.
+ */
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+#define atomic_read(v) ((v)->counter)
+
+/**
+ * atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ */
+#define atomic_set(v,i) ((v)->counter = (i))
+
+/**
+ * atomic_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v.
+ */
+static inline void atomic_add(int i, atomic_t * v)
+{
+ unsigned int vval;
+
+ __asm__ __volatile__(
+ "rsil a15, "__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %2, 0 \n\t"
+ "add %0, %0, %1 \n\t"
+ "s32i %0, %2, 0 \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n"
+ : "=&a" (vval)
+ : "a" (i), "a" (v)
+ : "a15", "memory"
+ );
+}
+
+/**
+ * atomic_sub - subtract the atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v.
+ */
+static inline void atomic_sub(int i, atomic_t *v)
+{
+ unsigned int vval;
+
+ __asm__ __volatile__(
+ "rsil a15, "__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %2, 0 \n\t"
+ "sub %0, %0, %1 \n\t"
+ "s32i %0, %2, 0 \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n"
+ : "=&a" (vval)
+ : "a" (i), "a" (v)
+ : "a15", "memory"
+ );
+}
+
+/*
+ * We use atomic_{add|sub}_return to define other functions.
+ */
+
+static inline int atomic_add_return(int i, atomic_t * v)
+{
+ unsigned int vval;
+
+ __asm__ __volatile__(
+ "rsil a15,"__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %2, 0 \n\t"
+ "add %0, %0, %1 \n\t"
+ "s32i %0, %2, 0 \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n"
+ : "=&a" (vval)
+ : "a" (i), "a" (v)
+ : "a15", "memory"
+ );
+
+ return vval;
+}
+
+static inline int atomic_sub_return(int i, atomic_t * v)
+{
+ unsigned int vval;
+
+ __asm__ __volatile__(
+ "rsil a15,"__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %2, 0 \n\t"
+ "sub %0, %0, %1 \n\t"
+ "s32i %0, %2, 0 \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n"
+ : "=&a" (vval)
+ : "a" (i), "a" (v)
+ : "a15", "memory"
+ );
+
+ return vval;
+}
+
+/**
+ * atomic_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+#define atomic_sub_and_test(i,v) (atomic_sub_return((i),(v)) == 0)
+
+/**
+ * atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1.
+ */
+#define atomic_inc(v) atomic_add(1,(v))
+
+/**
+ * atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1.
+ */
+#define atomic_inc_return(v) atomic_add_return(1,(v))
+
+/**
+ * atomic_dec - decrement atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1.
+ */
+#define atomic_dec(v) atomic_sub(1,(v))
+
+/**
+ * atomic_dec_return - decrement atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1.
+ */
+#define atomic_dec_return(v) atomic_sub_return(1,(v))
+
+/**
+ * atomic_dec_and_test - decrement and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+#define atomic_dec_and_test(v) (atomic_sub_return(1,(v)) == 0)
+
+/**
+ * atomic_inc_and_test - increment and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#define atomic_inc_and_test(v) (atomic_add_return(1,(v)) == 0)
+
+/**
+ * atomic_add_negative - add and test if negative
+ * @v: pointer of type atomic_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+#define atomic_add_negative(i,v) (atomic_add_return((i),(v)) < 0)
+
+#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+/**
+ * atomic_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
+{
+ int c, old;
+ c = atomic_read(v);
+ for (;;) {
+ if (unlikely(c == (u)))
+ break;
+ old = atomic_cmpxchg((v), c, c + (a));
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+ return c != (u);
+}
+
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
+static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
+{
+ unsigned int all_f = -1;
+ unsigned int vval;
+
+ __asm__ __volatile__(
+ "rsil a15,"__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %2, 0 \n\t"
+ "xor %1, %4, %3 \n\t"
+ "and %0, %0, %4 \n\t"
+ "s32i %0, %2, 0 \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n"
+ : "=&a" (vval), "=a" (mask)
+ : "a" (v), "a" (all_f), "1" (mask)
+ : "a15", "memory"
+ );
+}
+
+static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
+{
+ unsigned int vval;
+
+ __asm__ __volatile__(
+ "rsil a15,"__stringify(LOCKLEVEL)"\n\t"
+ "l32i %0, %2, 0 \n\t"
+ "or %0, %0, %1 \n\t"
+ "s32i %0, %2, 0 \n\t"
+ "wsr a15, "__stringify(PS)" \n\t"
+ "rsync \n"
+ : "=&a" (vval)
+ : "a" (mask), "a" (v)
+ : "a15", "memory"
+ );
+}
+
+/* Atomic operations are already serializing */
+#define smp_mb__before_atomic_dec() barrier()
+#define smp_mb__after_atomic_dec() barrier()
+#define smp_mb__before_atomic_inc() barrier()
+#define smp_mb__after_atomic_inc() barrier()
+
+#include <asm-generic/atomic.h>
+#endif /* __KERNEL__ */
+
+#endif /* _XTENSA_ATOMIC_H */
+