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kernel_samsung_sm7125/arch/tile/include/asm/bitops_64.h

96 lines
2.7 KiB

/*
* Copyright 2011 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#ifndef _ASM_TILE_BITOPS_64_H
#define _ASM_TILE_BITOPS_64_H
#include <linux/compiler.h>
tile: rework <asm/cmpxchg.h> The macrology in cmpxchg.h was designed to allow arbitrary pointer and integer values to be passed through the routines. To support cmpxchg() on 64-bit values on the 32-bit tilepro architecture, we used the idiom "(typeof(val))(typeof(val-val))". This way, in the "size 8" branch of the switch, when the underlying cmpxchg routine returns a 64-bit quantity, we cast it first to a typeof(val-val) quantity (i.e. size_t if "val" is a pointer) with no warnings about casting between pointers and integers of different sizes, then cast onwards to typeof(val), again with no warnings. If val is not a pointer type, the additional cast is a no-op. We can't replace the typeof(val-val) cast with (for example) unsigned long, since then if "val" is really a 64-bit type, we cast away the high bits. HOWEVER, this fails with current gcc (through 4.7 at least) if "val" is a pointer to an incomplete type. Unfortunately gcc isn't smart enough to realize that "val - val" will always be a size_t type even if it's an incomplete type pointer. Accordingly, I've reworked the way we handle the casting. We have given up the ability to use cmpxchg() on 64-bit values on tilepro, which is OK in the kernel since we should use cmpxchg64() explicitly on such values anyway. As a result, I can just use simple "unsigned long" casts internally. As I reworked it, I realized it would be cleaner to move the architecture-specific conditionals for cmpxchg and xchg out of the atomic.h headers and into cmpxchg, and then use the cmpxchg() and xchg() primitives directly in atomic.h and elsewhere. This allowed the cmpxchg.h header to stand on its own without relying on the implicit include of it that is performed by <asm/atomic.h>. It also allowed collapsing the atomic_xchg/atomic_cmpxchg routines from atomic_{32,64}.h into atomic.h. I improved the tests that guard the allowed size of the arguments to the routines to use a __compiletime_error() test. (By avoiding the use of BUILD_BUG, I could include cmpxchg.h into bitops.h as well and use the macros there, which is otherwise impossible due to include order dependency issues.) The tilepro _atomic_xxx internal methods were previously set up to take atomic_t and atomic64_t arguments, which isn't as convenient with the new model, so I modified them to take int or u64 arguments, which is consistent with how they used the arguments internally anyway, so provided some nice simplification there too. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
11 years ago
#include <asm/cmpxchg.h>
/* See <asm/bitops.h> for API comments. */
static inline void set_bit(unsigned nr, volatile unsigned long *addr)
{
unsigned long mask = (1UL << (nr % BITS_PER_LONG));
__insn_fetchor((void *)(addr + nr / BITS_PER_LONG), mask);
}
static inline void clear_bit(unsigned nr, volatile unsigned long *addr)
{
unsigned long mask = (1UL << (nr % BITS_PER_LONG));
__insn_fetchand((void *)(addr + nr / BITS_PER_LONG), ~mask);
}
static inline void change_bit(unsigned nr, volatile unsigned long *addr)
{
unsigned long mask = (1UL << (nr % BITS_PER_LONG));
unsigned long guess, oldval;
addr += nr / BITS_PER_LONG;
oldval = *addr;
do {
guess = oldval;
tile: rework <asm/cmpxchg.h> The macrology in cmpxchg.h was designed to allow arbitrary pointer and integer values to be passed through the routines. To support cmpxchg() on 64-bit values on the 32-bit tilepro architecture, we used the idiom "(typeof(val))(typeof(val-val))". This way, in the "size 8" branch of the switch, when the underlying cmpxchg routine returns a 64-bit quantity, we cast it first to a typeof(val-val) quantity (i.e. size_t if "val" is a pointer) with no warnings about casting between pointers and integers of different sizes, then cast onwards to typeof(val), again with no warnings. If val is not a pointer type, the additional cast is a no-op. We can't replace the typeof(val-val) cast with (for example) unsigned long, since then if "val" is really a 64-bit type, we cast away the high bits. HOWEVER, this fails with current gcc (through 4.7 at least) if "val" is a pointer to an incomplete type. Unfortunately gcc isn't smart enough to realize that "val - val" will always be a size_t type even if it's an incomplete type pointer. Accordingly, I've reworked the way we handle the casting. We have given up the ability to use cmpxchg() on 64-bit values on tilepro, which is OK in the kernel since we should use cmpxchg64() explicitly on such values anyway. As a result, I can just use simple "unsigned long" casts internally. As I reworked it, I realized it would be cleaner to move the architecture-specific conditionals for cmpxchg and xchg out of the atomic.h headers and into cmpxchg, and then use the cmpxchg() and xchg() primitives directly in atomic.h and elsewhere. This allowed the cmpxchg.h header to stand on its own without relying on the implicit include of it that is performed by <asm/atomic.h>. It also allowed collapsing the atomic_xchg/atomic_cmpxchg routines from atomic_{32,64}.h into atomic.h. I improved the tests that guard the allowed size of the arguments to the routines to use a __compiletime_error() test. (By avoiding the use of BUILD_BUG, I could include cmpxchg.h into bitops.h as well and use the macros there, which is otherwise impossible due to include order dependency issues.) The tilepro _atomic_xxx internal methods were previously set up to take atomic_t and atomic64_t arguments, which isn't as convenient with the new model, so I modified them to take int or u64 arguments, which is consistent with how they used the arguments internally anyway, so provided some nice simplification there too. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
11 years ago
oldval = cmpxchg(addr, guess, guess ^ mask);
} while (guess != oldval);
}
/*
* The test_and_xxx_bit() routines require a memory fence before we
* start the operation, and after the operation completes. We use
* smp_mb() before, and rely on the "!= 0" comparison, plus a compiler
* barrier(), to block until the atomic op is complete.
*/
static inline int test_and_set_bit(unsigned nr, volatile unsigned long *addr)
{
int val;
unsigned long mask = (1UL << (nr % BITS_PER_LONG));
smp_mb(); /* barrier for proper semantics */
val = (__insn_fetchor((void *)(addr + nr / BITS_PER_LONG), mask)
& mask) != 0;
barrier();
return val;
}
static inline int test_and_clear_bit(unsigned nr, volatile unsigned long *addr)
{
int val;
unsigned long mask = (1UL << (nr % BITS_PER_LONG));
smp_mb(); /* barrier for proper semantics */
val = (__insn_fetchand((void *)(addr + nr / BITS_PER_LONG), ~mask)
& mask) != 0;
barrier();
return val;
}
static inline int test_and_change_bit(unsigned nr,
volatile unsigned long *addr)
{
unsigned long mask = (1UL << (nr % BITS_PER_LONG));
unsigned long guess, oldval;
addr += nr / BITS_PER_LONG;
oldval = *addr;
do {
guess = oldval;
tile: rework <asm/cmpxchg.h> The macrology in cmpxchg.h was designed to allow arbitrary pointer and integer values to be passed through the routines. To support cmpxchg() on 64-bit values on the 32-bit tilepro architecture, we used the idiom "(typeof(val))(typeof(val-val))". This way, in the "size 8" branch of the switch, when the underlying cmpxchg routine returns a 64-bit quantity, we cast it first to a typeof(val-val) quantity (i.e. size_t if "val" is a pointer) with no warnings about casting between pointers and integers of different sizes, then cast onwards to typeof(val), again with no warnings. If val is not a pointer type, the additional cast is a no-op. We can't replace the typeof(val-val) cast with (for example) unsigned long, since then if "val" is really a 64-bit type, we cast away the high bits. HOWEVER, this fails with current gcc (through 4.7 at least) if "val" is a pointer to an incomplete type. Unfortunately gcc isn't smart enough to realize that "val - val" will always be a size_t type even if it's an incomplete type pointer. Accordingly, I've reworked the way we handle the casting. We have given up the ability to use cmpxchg() on 64-bit values on tilepro, which is OK in the kernel since we should use cmpxchg64() explicitly on such values anyway. As a result, I can just use simple "unsigned long" casts internally. As I reworked it, I realized it would be cleaner to move the architecture-specific conditionals for cmpxchg and xchg out of the atomic.h headers and into cmpxchg, and then use the cmpxchg() and xchg() primitives directly in atomic.h and elsewhere. This allowed the cmpxchg.h header to stand on its own without relying on the implicit include of it that is performed by <asm/atomic.h>. It also allowed collapsing the atomic_xchg/atomic_cmpxchg routines from atomic_{32,64}.h into atomic.h. I improved the tests that guard the allowed size of the arguments to the routines to use a __compiletime_error() test. (By avoiding the use of BUILD_BUG, I could include cmpxchg.h into bitops.h as well and use the macros there, which is otherwise impossible due to include order dependency issues.) The tilepro _atomic_xxx internal methods were previously set up to take atomic_t and atomic64_t arguments, which isn't as convenient with the new model, so I modified them to take int or u64 arguments, which is consistent with how they used the arguments internally anyway, so provided some nice simplification there too. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
11 years ago
oldval = cmpxchg(addr, guess, guess ^ mask);
} while (guess != oldval);
return (oldval & mask) != 0;
}
#include <asm-generic/bitops/ext2-atomic-setbit.h>
#endif /* _ASM_TILE_BITOPS_64_H */