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c042be02d7
Rather than using custom SZLONG_LOG & SZLONG_MASK macros to shift & mask
a bit index to form word & bit offsets respectively, make use of the
standard BIT_WORD() & BITS_PER_LONG macros for the same purpose.
volatile is added to the definition of pointers to the long-sized word
we'll operate on, in order to prevent the compiler complaining that we
cast away the volatile qualifier of the addr argument. This should have
no effect on generated code, which in the LL/SC case is inline asm
anyway & in the non-LLSC case access is constrained by compiler barriers
provided by raw_local_irq_{save,restore}().
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-kernel@vger.kernel.org
148 lines
3.8 KiB
C
148 lines
3.8 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (c) 1994-1997, 99, 2000, 06, 07 Ralf Baechle (ralf@linux-mips.org)
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* Copyright (c) 1999, 2000 Silicon Graphics, Inc.
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*/
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#include <linux/bitops.h>
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#include <linux/bits.h>
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#include <linux/irqflags.h>
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#include <linux/export.h>
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/**
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* __mips_set_bit - Atomically set a bit in memory. This is called by
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* set_bit() if it cannot find a faster solution.
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* @nr: the bit to set
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* @addr: the address to start counting from
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*/
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void __mips_set_bit(unsigned long nr, volatile unsigned long *addr)
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{
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volatile unsigned long *a = &addr[BIT_WORD(nr)];
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unsigned int bit = nr % BITS_PER_LONG;
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unsigned long mask;
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unsigned long flags;
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mask = 1UL << bit;
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raw_local_irq_save(flags);
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*a |= mask;
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raw_local_irq_restore(flags);
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}
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EXPORT_SYMBOL(__mips_set_bit);
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/**
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* __mips_clear_bit - Clears a bit in memory. This is called by clear_bit() if
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* it cannot find a faster solution.
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* @nr: Bit to clear
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* @addr: Address to start counting from
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*/
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void __mips_clear_bit(unsigned long nr, volatile unsigned long *addr)
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{
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volatile unsigned long *a = &addr[BIT_WORD(nr)];
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unsigned int bit = nr % BITS_PER_LONG;
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unsigned long mask;
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unsigned long flags;
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mask = 1UL << bit;
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raw_local_irq_save(flags);
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*a &= ~mask;
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raw_local_irq_restore(flags);
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}
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EXPORT_SYMBOL(__mips_clear_bit);
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/**
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* __mips_change_bit - Toggle a bit in memory. This is called by change_bit()
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* if it cannot find a faster solution.
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* @nr: Bit to change
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* @addr: Address to start counting from
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*/
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void __mips_change_bit(unsigned long nr, volatile unsigned long *addr)
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{
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volatile unsigned long *a = &addr[BIT_WORD(nr)];
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unsigned int bit = nr % BITS_PER_LONG;
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unsigned long mask;
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unsigned long flags;
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mask = 1UL << bit;
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raw_local_irq_save(flags);
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*a ^= mask;
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raw_local_irq_restore(flags);
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}
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EXPORT_SYMBOL(__mips_change_bit);
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/**
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* __mips_test_and_set_bit_lock - Set a bit and return its old value. This is
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* called by test_and_set_bit_lock() if it cannot find a faster solution.
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* @nr: Bit to set
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* @addr: Address to count from
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*/
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int __mips_test_and_set_bit_lock(unsigned long nr,
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volatile unsigned long *addr)
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{
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volatile unsigned long *a = &addr[BIT_WORD(nr)];
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unsigned int bit = nr % BITS_PER_LONG;
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unsigned long mask;
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unsigned long flags;
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int res;
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mask = 1UL << bit;
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raw_local_irq_save(flags);
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res = (mask & *a) != 0;
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*a |= mask;
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raw_local_irq_restore(flags);
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return res;
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}
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EXPORT_SYMBOL(__mips_test_and_set_bit_lock);
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/**
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* __mips_test_and_clear_bit - Clear a bit and return its old value. This is
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* called by test_and_clear_bit() if it cannot find a faster solution.
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* @nr: Bit to clear
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* @addr: Address to count from
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*/
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int __mips_test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
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{
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volatile unsigned long *a = &addr[BIT_WORD(nr)];
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unsigned int bit = nr % BITS_PER_LONG;
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unsigned long mask;
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unsigned long flags;
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int res;
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mask = 1UL << bit;
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raw_local_irq_save(flags);
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res = (mask & *a) != 0;
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*a &= ~mask;
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raw_local_irq_restore(flags);
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return res;
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}
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EXPORT_SYMBOL(__mips_test_and_clear_bit);
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/**
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* __mips_test_and_change_bit - Change a bit and return its old value. This is
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* called by test_and_change_bit() if it cannot find a faster solution.
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* @nr: Bit to change
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* @addr: Address to count from
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*/
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int __mips_test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
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{
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volatile unsigned long *a = &addr[BIT_WORD(nr)];
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unsigned int bit = nr % BITS_PER_LONG;
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unsigned long mask;
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unsigned long flags;
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int res;
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mask = 1UL << bit;
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raw_local_irq_save(flags);
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res = (mask & *a) != 0;
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*a ^= mask;
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raw_local_irq_restore(flags);
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return res;
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}
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EXPORT_SYMBOL(__mips_test_and_change_bit);
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