[PATCH v4 5/8] bitops: wrap non-atomic bitops with a transparent macro

From: Alexander Lobakin
Date: Tue Jun 21 2022 - 15:17:38 EST


In preparation for altering the non-atomic bitops with a macro, wrap
them in a transparent definition. This requires prepending one more
'_' to their names in order to be able to do that seamlessly. It is
a simple change, given that all the non-prefixed definitions are now
in asm-generic.
sparc32 already has several triple-underscored functions, so I had
to rename them ('___' -> 'sp32_').

Signed-off-by: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
arch/sparc/include/asm/bitops_32.h | 18 ++++++------
arch/sparc/lib/atomic32.c | 12 ++++----
.../bitops/instrumented-non-atomic.h | 28 +++++++++----------
.../bitops/non-instrumented-non-atomic.h | 14 +++++-----
include/linux/bitops.h | 18 +++++++++++-
tools/include/asm-generic/bitops/non-atomic.h | 24 ++++++++--------
tools/include/linux/bitops.h | 16 +++++++++++
7 files changed, 81 insertions(+), 49 deletions(-)

diff --git a/arch/sparc/include/asm/bitops_32.h b/arch/sparc/include/asm/bitops_32.h
index 889afa9f990f..3448c191b484 100644
--- a/arch/sparc/include/asm/bitops_32.h
+++ b/arch/sparc/include/asm/bitops_32.h
@@ -19,9 +19,9 @@
#error only <linux/bitops.h> can be included directly
#endif

-unsigned long ___set_bit(unsigned long *addr, unsigned long mask);
-unsigned long ___clear_bit(unsigned long *addr, unsigned long mask);
-unsigned long ___change_bit(unsigned long *addr, unsigned long mask);
+unsigned long sp32___set_bit(unsigned long *addr, unsigned long mask);
+unsigned long sp32___clear_bit(unsigned long *addr, unsigned long mask);
+unsigned long sp32___change_bit(unsigned long *addr, unsigned long mask);

/*
* Set bit 'nr' in 32-bit quantity at address 'addr' where bit '0'
@@ -36,7 +36,7 @@ static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *add
ADDR = ((unsigned long *) addr) + (nr >> 5);
mask = 1 << (nr & 31);

- return ___set_bit(ADDR, mask) != 0;
+ return sp32___set_bit(ADDR, mask) != 0;
}

static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
@@ -46,7 +46,7 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
ADDR = ((unsigned long *) addr) + (nr >> 5);
mask = 1 << (nr & 31);

- (void) ___set_bit(ADDR, mask);
+ (void) sp32___set_bit(ADDR, mask);
}

static inline int test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
@@ -56,7 +56,7 @@ static inline int test_and_clear_bit(unsigned long nr, volatile unsigned long *a
ADDR = ((unsigned long *) addr) + (nr >> 5);
mask = 1 << (nr & 31);

- return ___clear_bit(ADDR, mask) != 0;
+ return sp32___clear_bit(ADDR, mask) != 0;
}

static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
@@ -66,7 +66,7 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
ADDR = ((unsigned long *) addr) + (nr >> 5);
mask = 1 << (nr & 31);

- (void) ___clear_bit(ADDR, mask);
+ (void) sp32___clear_bit(ADDR, mask);
}

static inline int test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
@@ -76,7 +76,7 @@ static inline int test_and_change_bit(unsigned long nr, volatile unsigned long *
ADDR = ((unsigned long *) addr) + (nr >> 5);
mask = 1 << (nr & 31);

- return ___change_bit(ADDR, mask) != 0;
+ return sp32___change_bit(ADDR, mask) != 0;
}

static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
@@ -86,7 +86,7 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
ADDR = ((unsigned long *) addr) + (nr >> 5);
mask = 1 << (nr & 31);

- (void) ___change_bit(ADDR, mask);
+ (void) sp32___change_bit(ADDR, mask);
}

#include <asm-generic/bitops/non-atomic.h>
diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c
index 8b81d0f00c97..cf80d1ae352b 100644
--- a/arch/sparc/lib/atomic32.c
+++ b/arch/sparc/lib/atomic32.c
@@ -120,7 +120,7 @@ void arch_atomic_set(atomic_t *v, int i)
}
EXPORT_SYMBOL(arch_atomic_set);

-unsigned long ___set_bit(unsigned long *addr, unsigned long mask)
+unsigned long sp32___set_bit(unsigned long *addr, unsigned long mask)
{
unsigned long old, flags;

@@ -131,9 +131,9 @@ unsigned long ___set_bit(unsigned long *addr, unsigned long mask)

return old & mask;
}
-EXPORT_SYMBOL(___set_bit);
+EXPORT_SYMBOL(sp32___set_bit);

-unsigned long ___clear_bit(unsigned long *addr, unsigned long mask)
+unsigned long sp32___clear_bit(unsigned long *addr, unsigned long mask)
{
unsigned long old, flags;

@@ -144,9 +144,9 @@ unsigned long ___clear_bit(unsigned long *addr, unsigned long mask)

return old & mask;
}
-EXPORT_SYMBOL(___clear_bit);
+EXPORT_SYMBOL(sp32___clear_bit);

-unsigned long ___change_bit(unsigned long *addr, unsigned long mask)
+unsigned long sp32___change_bit(unsigned long *addr, unsigned long mask)
{
unsigned long old, flags;

@@ -157,7 +157,7 @@ unsigned long ___change_bit(unsigned long *addr, unsigned long mask)

return old & mask;
}
-EXPORT_SYMBOL(___change_bit);
+EXPORT_SYMBOL(sp32___change_bit);

unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
{
diff --git a/include/asm-generic/bitops/instrumented-non-atomic.h b/include/asm-generic/bitops/instrumented-non-atomic.h
index b019f77ef21c..988a3bbfba34 100644
--- a/include/asm-generic/bitops/instrumented-non-atomic.h
+++ b/include/asm-generic/bitops/instrumented-non-atomic.h
@@ -14,7 +14,7 @@
#include <linux/instrumented.h>

/**
- * __set_bit - Set a bit in memory
+ * ___set_bit - Set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
@@ -23,14 +23,14 @@
* succeeds.
*/
static __always_inline void
-__set_bit(unsigned long nr, volatile unsigned long *addr)
+___set_bit(unsigned long nr, volatile unsigned long *addr)
{
instrument_write(addr + BIT_WORD(nr), sizeof(long));
arch___set_bit(nr, addr);
}

/**
- * __clear_bit - Clears a bit in memory
+ * ___clear_bit - Clears a bit in memory
* @nr: the bit to clear
* @addr: the address to start counting from
*
@@ -39,14 +39,14 @@ __set_bit(unsigned long nr, volatile unsigned long *addr)
* succeeds.
*/
static __always_inline void
-__clear_bit(unsigned long nr, volatile unsigned long *addr)
+___clear_bit(unsigned long nr, volatile unsigned long *addr)
{
instrument_write(addr + BIT_WORD(nr), sizeof(long));
arch___clear_bit(nr, addr);
}

/**
- * __change_bit - Toggle a bit in memory
+ * ___change_bit - Toggle a bit in memory
* @nr: the bit to change
* @addr: the address to start counting from
*
@@ -55,7 +55,7 @@ __clear_bit(unsigned long nr, volatile unsigned long *addr)
* succeeds.
*/
static __always_inline void
-__change_bit(unsigned long nr, volatile unsigned long *addr)
+___change_bit(unsigned long nr, volatile unsigned long *addr)
{
instrument_write(addr + BIT_WORD(nr), sizeof(long));
arch___change_bit(nr, addr);
@@ -86,7 +86,7 @@ static __always_inline void __instrument_read_write_bitop(long nr, volatile unsi
}

/**
- * __test_and_set_bit - Set a bit and return its old value
+ * ___test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
@@ -94,14 +94,14 @@ static __always_inline void __instrument_read_write_bitop(long nr, volatile unsi
* can appear to succeed but actually fail.
*/
static __always_inline bool
-__test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
+___test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
{
__instrument_read_write_bitop(nr, addr);
return arch___test_and_set_bit(nr, addr);
}

/**
- * __test_and_clear_bit - Clear a bit and return its old value
+ * ___test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
@@ -109,14 +109,14 @@ __test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
* can appear to succeed but actually fail.
*/
static __always_inline bool
-__test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
+___test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
{
__instrument_read_write_bitop(nr, addr);
return arch___test_and_clear_bit(nr, addr);
}

/**
- * __test_and_change_bit - Change a bit and return its old value
+ * ___test_and_change_bit - Change a bit and return its old value
* @nr: Bit to change
* @addr: Address to count from
*
@@ -124,19 +124,19 @@ __test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
* can appear to succeed but actually fail.
*/
static __always_inline bool
-__test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
+___test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
{
__instrument_read_write_bitop(nr, addr);
return arch___test_and_change_bit(nr, addr);
}

/**
- * test_bit - Determine whether a bit is set
+ * _test_bit - Determine whether a bit is set
* @nr: bit number to test
* @addr: Address to start counting from
*/
static __always_inline bool
-test_bit(unsigned long nr, const volatile unsigned long *addr)
+_test_bit(unsigned long nr, const volatile unsigned long *addr)
{
instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long));
return arch_test_bit(nr, addr);
diff --git a/include/asm-generic/bitops/non-instrumented-non-atomic.h b/include/asm-generic/bitops/non-instrumented-non-atomic.h
index e0fd7bf72a56..bdb9b1ffaee9 100644
--- a/include/asm-generic/bitops/non-instrumented-non-atomic.h
+++ b/include/asm-generic/bitops/non-instrumented-non-atomic.h
@@ -3,14 +3,14 @@
#ifndef __ASM_GENERIC_BITOPS_NON_INSTRUMENTED_NON_ATOMIC_H
#define __ASM_GENERIC_BITOPS_NON_INSTRUMENTED_NON_ATOMIC_H

-#define __set_bit arch___set_bit
-#define __clear_bit arch___clear_bit
-#define __change_bit arch___change_bit
+#define ___set_bit arch___set_bit
+#define ___clear_bit arch___clear_bit
+#define ___change_bit arch___change_bit

-#define __test_and_set_bit arch___test_and_set_bit
-#define __test_and_clear_bit arch___test_and_clear_bit
-#define __test_and_change_bit arch___test_and_change_bit
+#define ___test_and_set_bit arch___test_and_set_bit
+#define ___test_and_clear_bit arch___test_and_clear_bit
+#define ___test_and_change_bit arch___test_and_change_bit

-#define test_bit arch_test_bit
+#define _test_bit arch_test_bit

#endif /* __ASM_GENERIC_BITOPS_NON_INSTRUMENTED_NON_ATOMIC_H */
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index d393297287d5..3c3afbae1533 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -26,8 +26,24 @@ extern unsigned int __sw_hweight16(unsigned int w);
extern unsigned int __sw_hweight32(unsigned int w);
extern unsigned long __sw_hweight64(__u64 w);

+/*
+ * Defined here because those may be needed by architecture-specific static
+ * inlines.
+ */
+
#include <asm-generic/bitops/generic-non-atomic.h>

+#define bitop(op, nr, addr) \
+ op(nr, addr)
+
+#define __set_bit(nr, addr) bitop(___set_bit, nr, addr)
+#define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr)
+#define __change_bit(nr, addr) bitop(___change_bit, nr, addr)
+#define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr)
+#define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr)
+#define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr)
+#define test_bit(nr, addr) bitop(_test_bit, nr, addr)
+
/*
* Include this here because some architectures need generic_ffs/fls in
* scope
@@ -38,7 +54,7 @@ extern unsigned long __sw_hweight64(__u64 w);
#define __check_bitop_pr(name) \
static_assert(__same_type(arch_##name, generic_##name) && \
__same_type(const_##name, generic_##name) && \
- __same_type(name, generic_##name))
+ __same_type(_##name, generic_##name))

__check_bitop_pr(__set_bit);
__check_bitop_pr(__clear_bit);
diff --git a/tools/include/asm-generic/bitops/non-atomic.h b/tools/include/asm-generic/bitops/non-atomic.h
index e5e78e42e57b..0c472a833408 100644
--- a/tools/include/asm-generic/bitops/non-atomic.h
+++ b/tools/include/asm-generic/bitops/non-atomic.h
@@ -5,7 +5,7 @@
#include <linux/bits.h>

/**
- * __set_bit - Set a bit in memory
+ * ___set_bit - Set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
@@ -14,7 +14,7 @@
* may be that only one operation succeeds.
*/
static __always_inline void
-__set_bit(unsigned long nr, volatile unsigned long *addr)
+___set_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
@@ -23,7 +23,7 @@ __set_bit(unsigned long nr, volatile unsigned long *addr)
}

static __always_inline void
-__clear_bit(unsigned long nr, volatile unsigned long *addr)
+___clear_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
@@ -32,7 +32,7 @@ __clear_bit(unsigned long nr, volatile unsigned long *addr)
}

/**
- * __change_bit - Toggle a bit in memory
+ * ___change_bit - Toggle a bit in memory
* @nr: the bit to change
* @addr: the address to start counting from
*
@@ -41,7 +41,7 @@ __clear_bit(unsigned long nr, volatile unsigned long *addr)
* may be that only one operation succeeds.
*/
static __always_inline void
-__change_bit(unsigned long nr, volatile unsigned long *addr)
+___change_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
@@ -50,7 +50,7 @@ __change_bit(unsigned long nr, volatile unsigned long *addr)
}

/**
- * __test_and_set_bit - Set a bit and return its old value
+ * ___test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
@@ -59,7 +59,7 @@ __change_bit(unsigned long nr, volatile unsigned long *addr)
* but actually fail. You must protect multiple accesses with a lock.
*/
static __always_inline bool
-__test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
+___test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
@@ -70,7 +70,7 @@ __test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
}

/**
- * __test_and_clear_bit - Clear a bit and return its old value
+ * ___test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
@@ -79,7 +79,7 @@ __test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
* but actually fail. You must protect multiple accesses with a lock.
*/
static __always_inline bool
-__test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
+___test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
@@ -91,7 +91,7 @@ __test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)

/* WARNING: non atomic and it can be reordered! */
static __always_inline bool
-__test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
+___test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned long mask = BIT_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
@@ -102,12 +102,12 @@ __test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
}

/**
- * test_bit - Determine whether a bit is set
+ * _test_bit - Determine whether a bit is set
* @nr: bit number to test
* @addr: Address to start counting from
*/
static __always_inline bool
-test_bit(unsigned long nr, const volatile unsigned long *addr)
+_test_bit(unsigned long nr, const volatile unsigned long *addr)
{
return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
}
diff --git a/tools/include/linux/bitops.h b/tools/include/linux/bitops.h
index 5fca38fe1ba8..f18683b95ea6 100644
--- a/tools/include/linux/bitops.h
+++ b/tools/include/linux/bitops.h
@@ -25,6 +25,22 @@ extern unsigned int __sw_hweight16(unsigned int w);
extern unsigned int __sw_hweight32(unsigned int w);
extern unsigned long __sw_hweight64(__u64 w);

+/*
+ * Defined here because those may be needed by architecture-specific static
+ * inlines.
+ */
+
+#define bitop(op, nr, addr) \
+ op(nr, addr)
+
+#define __set_bit(nr, addr) bitop(___set_bit, nr, addr)
+#define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr)
+#define __change_bit(nr, addr) bitop(___change_bit, nr, addr)
+#define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr)
+#define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr)
+#define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr)
+#define test_bit(nr, addr) bitop(_test_bit, nr, addr)
+
/*
* Include this here because some architectures need generic_ffs/fls in
* scope
--
2.36.1