From e4e3929325ac368d9f5802592997bdc5e088631e Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Fri, 7 Dec 2001 09:04:30 +0000
Subject: [PATCH] Initial version

---
 include/iatomic.h | 889 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 889 insertions(+)
 create mode 100644 include/iatomic.h

diff --git a/include/iatomic.h b/include/iatomic.h
new file mode 100644
index 00000000..88a50492
--- /dev/null
+++ b/include/iatomic.h
@@ -0,0 +1,889 @@
+#ifndef __ALSA_IATOMIC__
+#define __ALSA_IATOMIC__
+
+#ifdef __i386__
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc..
+ */
+
+#define LOCK "lock ; "
+
+/*
+ * Make sure gcc doesn't try to be clever and move things around
+ * on us. We need to use _exactly_ the address the user gave us,
+ * not some alias that contains the same information.
+ */
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i)	{ (i) }
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ * 
+ * Atomically reads the value of @v.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */ 
+#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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */ 
+#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.  Note that the guaranteed useful range
+ * of an atomic_t is only 24 bits.
+ */
+static __inline__ void atomic_add(int i, atomic_t *v)
+{
+	__asm__ __volatile__(
+		LOCK "addl %1,%0"
+		:"=m" (v->counter)
+		:"ir" (i), "m" (v->counter));
+}
+
+/**
+ * atomic_sub - subtract the atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ * 
+ * Atomically subtracts @i from @v.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+static __inline__ void atomic_sub(int i, atomic_t *v)
+{
+	__asm__ __volatile__(
+		LOCK "subl %1,%0"
+		:"=m" (v->counter)
+		:"ir" (i), "m" (v->counter));
+}
+
+/**
+ * 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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
+{
+	unsigned char c;
+
+	__asm__ __volatile__(
+		LOCK "subl %2,%0; sete %1"
+		:"=m" (v->counter), "=qm" (c)
+		:"ir" (i), "m" (v->counter) : "memory");
+	return c;
+}
+
+/**
+ * atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ * 
+ * Atomically increments @v by 1.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */ 
+static __inline__ void atomic_inc(atomic_t *v)
+{
+	__asm__ __volatile__(
+		LOCK "incl %0"
+		:"=m" (v->counter)
+		:"m" (v->counter));
+}
+
+/**
+ * atomic_dec - decrement atomic variable
+ * @v: pointer of type atomic_t
+ * 
+ * Atomically decrements @v by 1.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */ 
+static __inline__ void atomic_dec(atomic_t *v)
+{
+	__asm__ __volatile__(
+		LOCK "decl %0"
+		:"=m" (v->counter)
+		:"m" (v->counter));
+}
+
+/**
+ * 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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */ 
+static __inline__ int atomic_dec_and_test(atomic_t *v)
+{
+	unsigned char c;
+
+	__asm__ __volatile__(
+		LOCK "decl %0; sete %1"
+		:"=m" (v->counter), "=qm" (c)
+		:"m" (v->counter) : "memory");
+	return c != 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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */ 
+static __inline__ int atomic_inc_and_test(atomic_t *v)
+{
+	unsigned char c;
+
+	__asm__ __volatile__(
+		LOCK "incl %0; sete %1"
+		:"=m" (v->counter), "=qm" (c)
+		:"m" (v->counter) : "memory");
+	return c != 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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */ 
+static __inline__ int atomic_add_negative(int i, atomic_t *v)
+{
+	unsigned char c;
+
+	__asm__ __volatile__(
+		LOCK "addl %2,%0; sets %1"
+		:"=m" (v->counter), "=qm" (c)
+		:"ir" (i), "m" (v->counter) : "memory");
+	return c;
+}
+
+/* These are x86-specific, used by some header files */
+#define atomic_clear_mask(mask, addr) \
+__asm__ __volatile__(LOCK "andl %0,%1" \
+: : "r" (~(mask)),"m" (*addr) : "memory")
+
+#define atomic_set_mask(mask, addr) \
+__asm__ __volatile__(LOCK "orl %0,%1" \
+: : "r" (mask),"m" (*addr) : "memory")
+
+#endif /* __i386__ */
+
+#ifdef __ia64__
+
+/*
+ * On IA-64, counter must always be volatile to ensure that that the
+ * memory accesses are ordered.
+ */
+typedef struct { volatile __s32 counter; } atomic_t;
+
+#define ATOMIC_INIT(i)		((atomic_t) { (i) })
+
+#define atomic_read(v)		((v)->counter)
+#define atomic_set(v,i)		(((v)->counter) = (i))
+
+static __inline__ int
+ia64_atomic_add (int i, atomic_t *v)
+{
+	__s32 old, new;
+	CMPXCHG_BUGCHECK_DECL
+
+	do {
+		CMPXCHG_BUGCHECK(v);
+		old = atomic_read(v);
+		new = old + i;
+	} while (ia64_cmpxchg("acq", v, old, old + i, sizeof(atomic_t)) != old);
+	return new;
+}
+
+static __inline__ int
+ia64_atomic_sub (int i, atomic_t *v)
+{
+	__s32 old, new;
+	CMPXCHG_BUGCHECK_DECL
+
+	do {
+		CMPXCHG_BUGCHECK(v);
+		old = atomic_read(v);
+		new = old - i;
+	} while (ia64_cmpxchg("acq", v, old, new, sizeof(atomic_t)) != old);
+	return new;
+}
+
+/*
+ * Atomically add I to V and return TRUE if the resulting value is
+ * negative.
+ */
+static __inline__ int
+atomic_add_negative (int i, atomic_t *v)
+{
+	return ia64_atomic_add(i, v) < 0;
+}
+
+#define atomic_add_return(i,v)						\
+	((__builtin_constant_p(i) &&					\
+	  (   (i ==  1) || (i ==  4) || (i ==  8) || (i ==  16)		\
+	   || (i == -1) || (i == -4) || (i == -8) || (i == -16)))	\
+	 ? ia64_fetch_and_add(i, &(v)->counter)				\
+	 : ia64_atomic_add(i, v))
+
+#define atomic_sub_return(i,v)						\
+	((__builtin_constant_p(i) &&					\
+	  (   (i ==  1) || (i ==  4) || (i ==  8) || (i ==  16)		\
+	   || (i == -1) || (i == -4) || (i == -8) || (i == -16)))	\
+	 ? ia64_fetch_and_add(-(i), &(v)->counter)			\
+	 : ia64_atomic_sub(i, v))
+
+#define atomic_dec_return(v)		atomic_sub_return(1, (v))
+#define atomic_inc_return(v)		atomic_add_return(1, (v))
+
+#define atomic_sub_and_test(i,v)	(atomic_sub_return((i), (v)) == 0)
+#define atomic_dec_and_test(v)		(atomic_sub_return(1, (v)) == 0)
+#define atomic_inc_and_test(v)		(atomic_add_return(1, (v)) != 0)
+
+#define atomic_add(i,v)			atomic_add_return((i), (v))
+#define atomic_sub(i,v)			atomic_sub_return((i), (v))
+#define atomic_inc(v)			atomic_add(1, (v))
+#define atomic_dec(v)			atomic_sub(1, (v))
+
+#endif __ia64__
+
+#ifdef __alpha__
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc...
+ *
+ * But use these as seldom as possible since they are much slower
+ * than regular operations.
+ */
+
+
+/*
+ * Counter is volatile to make sure gcc doesn't try to be clever
+ * and move things around on us. We need to use _exactly_ the address
+ * the user gave us, not some alias that contains the same information.
+ */
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i)	( (atomic_t) { (i) } )
+
+#define atomic_read(v)		((v)->counter)
+#define atomic_set(v,i)		((v)->counter = (i))
+
+/*
+ * To get proper branch prediction for the main line, we must branch
+ * forward to code at the end of this object's .text section, then
+ * branch back to restart the operation.
+ */
+
+static __inline__ void atomic_add(int i, atomic_t * v)
+{
+	unsigned long temp;
+	__asm__ __volatile__(
+	"1:	ldl_l %0,%1\n"
+	"	addl %0,%2,%0\n"
+	"	stl_c %0,%1\n"
+	"	beq %0,2f\n"
+	".subsection 2\n"
+	"2:	br 1b\n"
+	".previous"
+	:"=&r" (temp), "=m" (v->counter)
+	:"Ir" (i), "m" (v->counter));
+}
+
+static __inline__ void atomic_sub(int i, atomic_t * v)
+{
+	unsigned long temp;
+	__asm__ __volatile__(
+	"1:	ldl_l %0,%1\n"
+	"	subl %0,%2,%0\n"
+	"	stl_c %0,%1\n"
+	"	beq %0,2f\n"
+	".subsection 2\n"
+	"2:	br 1b\n"
+	".previous"
+	:"=&r" (temp), "=m" (v->counter)
+	:"Ir" (i), "m" (v->counter));
+}
+
+/*
+ * Same as above, but return the result value
+ */
+static __inline__ long atomic_add_return(int i, atomic_t * v)
+{
+	long temp, result;
+	__asm__ __volatile__(
+	"1:	ldl_l %0,%1\n"
+	"	addl %0,%3,%2\n"
+	"	addl %0,%3,%0\n"
+	"	stl_c %0,%1\n"
+	"	beq %0,2f\n"
+	"	mb\n"
+	".subsection 2\n"
+	"2:	br 1b\n"
+	".previous"
+	:"=&r" (temp), "=m" (v->counter), "=&r" (result)
+	:"Ir" (i), "m" (v->counter) : "memory");
+	return result;
+}
+
+static __inline__ long atomic_sub_return(int i, atomic_t * v)
+{
+	long temp, result;
+	__asm__ __volatile__(
+	"1:	ldl_l %0,%1\n"
+	"	subl %0,%3,%2\n"
+	"	subl %0,%3,%0\n"
+	"	stl_c %0,%1\n"
+	"	beq %0,2f\n"
+	"	mb\n"
+	".subsection 2\n"
+	"2:	br 1b\n"
+	".previous"
+	:"=&r" (temp), "=m" (v->counter), "=&r" (result)
+	:"Ir" (i), "m" (v->counter) : "memory");
+	return result;
+}
+
+#define atomic_dec_return(v) atomic_sub_return(1,(v))
+#define atomic_inc_return(v) atomic_add_return(1,(v))
+
+#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
+#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
+
+#define atomic_inc(v) atomic_add(1,(v))
+#define atomic_dec(v) atomic_sub(1,(v))
+
+#endif /* __alpha__ */
+
+#ifdef __ppc__
+
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i)	{ (i) }
+
+#define atomic_read(v)		((v)->counter)
+#define atomic_set(v,i)		(((v)->counter) = (i))
+
+extern void atomic_clear_mask(unsigned long mask, unsigned long *addr);
+extern void atomic_set_mask(unsigned long mask, unsigned long *addr);
+
+#define SMP_ISYNC	"\n\tisync"
+
+static __inline__ void atomic_add(int a, atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%3		# atomic_add\n\
+	add	%0,%2,%0\n\
+	stwcx.	%0,0,%3\n\
+	bne-	1b"
+	: "=&r" (t), "=m" (v->counter)
+	: "r" (a), "r" (&v->counter), "m" (v->counter)
+	: "cc");
+}
+
+static __inline__ int atomic_add_return(int a, atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%2		# atomic_add_return\n\
+	add	%0,%1,%0\n\
+	stwcx.	%0,0,%2\n\
+	bne-	1b"
+	SMP_ISYNC
+	: "=&r" (t)
+	: "r" (a), "r" (&v->counter)
+	: "cc", "memory");
+
+	return t;
+}
+
+static __inline__ void atomic_sub(int a, atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%3		# atomic_sub\n\
+	subf	%0,%2,%0\n\
+	stwcx.	%0,0,%3\n\
+	bne-	1b"
+	: "=&r" (t), "=m" (v->counter)
+	: "r" (a), "r" (&v->counter), "m" (v->counter)
+	: "cc");
+}
+
+static __inline__ int atomic_sub_return(int a, atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%2		# atomic_sub_return\n\
+	subf	%0,%1,%0\n\
+	stwcx.	%0,0,%2\n\
+	bne-	1b"
+	SMP_ISYNC
+	: "=&r" (t)
+	: "r" (a), "r" (&v->counter)
+	: "cc", "memory");
+
+	return t;
+}
+
+static __inline__ void atomic_inc(atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%2		# atomic_inc\n\
+	addic	%0,%0,1\n\
+	stwcx.	%0,0,%2\n\
+	bne-	1b"
+	: "=&r" (t), "=m" (v->counter)
+	: "r" (&v->counter), "m" (v->counter)
+	: "cc");
+}
+
+static __inline__ int atomic_inc_return(atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%1		# atomic_inc_return\n\
+	addic	%0,%0,1\n\
+	stwcx.	%0,0,%1\n\
+	bne-	1b"
+	SMP_ISYNC
+	: "=&r" (t)
+	: "r" (&v->counter)
+	: "cc", "memory");
+
+	return t;
+}
+
+static __inline__ void atomic_dec(atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%2		# atomic_dec\n\
+	addic	%0,%0,-1\n\
+	stwcx.	%0,0,%2\n\
+	bne-	1b"
+	: "=&r" (t), "=m" (v->counter)
+	: "r" (&v->counter), "m" (v->counter)
+	: "cc");
+}
+
+static __inline__ int atomic_dec_return(atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%1		# atomic_dec_return\n\
+	addic	%0,%0,-1\n\
+	stwcx.	%0,0,%1\n\
+	bne-	1b"
+	SMP_ISYNC
+	: "=&r" (t)
+	: "r" (&v->counter)
+	: "cc", "memory");
+
+	return t;
+}
+
+#define atomic_sub_and_test(a, v)	(atomic_sub_return((a), (v)) == 0)
+#define atomic_dec_and_test(v)		(atomic_dec_return((v)) == 0)
+
+/*
+ * Atomically test *v and decrement if it is greater than 0.
+ * The function returns the old value of *v minus 1.
+ */
+static __inline__ int atomic_dec_if_positive(atomic_t *v)
+{
+	int t;
+
+	__asm__ __volatile__(
+"1:	lwarx	%0,0,%1		# atomic_dec_if_positive\n\
+	addic.	%0,%0,-1\n\
+	blt-	2f\n\
+	stwcx.	%0,0,%1\n\
+	bne-	1b"
+	SMP_ISYNC
+	"\n\
+2:"	: "=&r" (t)
+	: "r" (&v->counter)
+	: "cc", "memory");
+
+	return t;
+}
+
+#endif /* __ppc__ */
+
+#ifdef __mips__
+
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i)    { (i) }
+
+/*
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_set(v,i)	((v)->counter = (i))
+
+#ifndef CONFIG_CPU_HAS_LLSC
+
+/*
+ * The MIPS I implementation is only atomic with respect to
+ * interrupts.  R3000 based multiprocessor machines are rare anyway ...
+ *
+ * atomic_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v.  Note that the guaranteed useful range
+ * of an atomic_t is only 24 bits.
+ */
+extern __inline__ void atomic_add(int i, atomic_t * v)
+{
+	int	flags;
+
+	save_flags(flags);
+	cli();
+	v->counter += i;
+	restore_flags(flags);
+}
+
+/*
+ * atomic_sub - subtract the atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+extern __inline__ void atomic_sub(int i, atomic_t * v)
+{
+	int	flags;
+
+	save_flags(flags);
+	cli();
+	v->counter -= i;
+	restore_flags(flags);
+}
+
+extern __inline__ int atomic_add_return(int i, atomic_t * v)
+{
+	int	temp, flags;
+
+	save_flags(flags);
+	cli();
+	temp = v->counter;
+	temp += i;
+	v->counter = temp;
+	restore_flags(flags);
+
+	return temp;
+}
+
+extern __inline__ int atomic_sub_return(int i, atomic_t * v)
+{
+	int	temp, flags;
+
+	save_flags(flags);
+	cli();
+	temp = v->counter;
+	temp -= i;
+	v->counter = temp;
+	restore_flags(flags);
+
+	return temp;
+}
+
+#else
+
+/*
+ * ... while for MIPS II and better we can use ll/sc instruction.  This
+ * implementation is SMP safe ...
+ */
+
+/*
+ * atomic_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v.  Note that the guaranteed useful range
+ * of an atomic_t is only 24 bits.
+ */
+extern __inline__ void atomic_add(int i, atomic_t * v)
+{
+	unsigned long temp;
+
+	__asm__ __volatile__(
+		"1:   ll      %0, %1      # atomic_add\n"
+		"     addu    %0, %2                  \n"
+		"     sc      %0, %1                  \n"
+		"     beqz    %0, 1b                  \n"
+		: "=&r" (temp), "=m" (v->counter)
+		: "Ir" (i), "m" (v->counter));
+}
+
+/*
+ * atomic_sub - subtract the atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+extern __inline__ void atomic_sub(int i, atomic_t * v)
+{
+	unsigned long temp;
+
+	__asm__ __volatile__(
+		"1:   ll      %0, %1      # atomic_sub\n"
+		"     subu    %0, %2                  \n"
+		"     sc      %0, %1                  \n"
+		"     beqz    %0, 1b                  \n"
+		: "=&r" (temp), "=m" (v->counter)
+		: "Ir" (i), "m" (v->counter));
+}
+
+/*
+ * Same as above, but return the result value
+ */
+extern __inline__ int atomic_add_return(int i, atomic_t * v)
+{
+	unsigned long temp, result;
+
+	__asm__ __volatile__(
+		".set push               # atomic_add_return\n"
+		".set noreorder                             \n"
+		"1:   ll      %1, %2                        \n"
+		"     addu    %0, %1, %3                    \n"
+		"     sc      %0, %2                        \n"
+		"     beqz    %0, 1b                        \n"
+		"     addu    %0, %1, %3                    \n"
+		".set pop                                   \n"
+		: "=&r" (result), "=&r" (temp), "=m" (v->counter)
+		: "Ir" (i), "m" (v->counter)
+		: "memory");
+
+	return result;
+}
+
+extern __inline__ int atomic_sub_return(int i, atomic_t * v)
+{
+	unsigned long temp, result;
+
+	__asm__ __volatile__(
+		".set push                                   \n"
+		".set noreorder           # atomic_sub_return\n"
+		"1:   ll    %1, %2                           \n"
+		"     subu  %0, %1, %3                       \n"
+		"     sc    %0, %2                           \n"
+		"     beqz  %0, 1b                           \n"
+		"     subu  %0, %1, %3                       \n"
+		".set pop                                    \n"
+		: "=&r" (result), "=&r" (temp), "=m" (v->counter)
+		: "Ir" (i), "m" (v->counter)
+		: "memory");
+
+	return result;
+}
+#endif
+
+#define atomic_dec_return(v) atomic_sub_return(1,(v))
+#define atomic_inc_return(v) atomic_add_return(1,(v))
+
+/*
+ * 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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_inc_and_test(v) (atomic_inc_return(1, (v)) == 0)
+
+/*
+ * atomic_dec_and_test - decrement by 1 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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
+
+/*
+ * atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_inc(v) atomic_add(1,(v))
+
+/*
+ * atomic_dec - decrement and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_dec(v) atomic_sub(1,(v))
+
+/*
+ * 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.  Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ *
+ * Currently not implemented for MIPS.
+ */
+
+#endif __mips__
+
+#ifdef __arm__
+
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i)	{ (i) }
+
+#define atomic_read(v)	((v)->counter)
+#define atomic_set(v,i)	(((v)->counter) = (i))
+
+static __inline__ void atomic_add(int i, volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	__save_flags_cli(flags);
+	v->counter += i;
+	__restore_flags(flags);
+}
+
+static __inline__ void atomic_sub(int i, volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	__save_flags_cli(flags);
+	v->counter -= i;
+	__restore_flags(flags);
+}
+
+static __inline__ void atomic_inc(volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	__save_flags_cli(flags);
+	v->counter += 1;
+	__restore_flags(flags);
+}
+
+static __inline__ void atomic_dec(volatile atomic_t *v)
+{
+	unsigned long flags;
+
+	__save_flags_cli(flags);
+	v->counter -= 1;
+	__restore_flags(flags);
+}
+
+static __inline__ int atomic_dec_and_test(volatile atomic_t *v)
+{
+	unsigned long flags;
+	int result;
+
+	__save_flags_cli(flags);
+	v->counter -= 1;
+	result = (v->counter == 0);
+	__restore_flags(flags);
+
+	return result;
+}
+
+static inline int atomic_add_negative(int i, volatile atomic_t *v)
+{
+	unsigned long flags;
+	int result;
+
+	__save_flags_cli(flags);
+	v->counter += i;
+	result = (v->counter < 0);
+	__restore_flags(flags);
+
+	return result;
+}
+
+static __inline__ void atomic_clear_mask(unsigned long mask, unsigned long *addr)
+{
+	unsigned long flags;
+
+	__save_flags_cli(flags);
+	*addr &= ~mask;
+	__restore_flags(flags);
+}
+
+#endif /* __arm__ */
+
+#endif /* __ALSA_IATOMIC__ */
-- 
2.47.1