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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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7d9794e752
Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to reconstruct the state prior to modification). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-sh@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
#ifndef __ASM_SH_ATOMIC_IRQ_H
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#define __ASM_SH_ATOMIC_IRQ_H
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#include <linux/irqflags.h>
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/*
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* To get proper branch prediction for the main line, we must branch
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* forward to code at the end of this object's .text section, then
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* branch back to restart the operation.
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*/
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#define ATOMIC_OP(op, c_op) \
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static inline void atomic_##op(int i, atomic_t *v) \
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{ \
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unsigned long flags; \
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\
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raw_local_irq_save(flags); \
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v->counter c_op i; \
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raw_local_irq_restore(flags); \
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}
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#define ATOMIC_OP_RETURN(op, c_op) \
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static inline int atomic_##op##_return(int i, atomic_t *v) \
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{ \
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unsigned long temp, flags; \
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\
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raw_local_irq_save(flags); \
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temp = v->counter; \
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temp c_op i; \
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v->counter = temp; \
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raw_local_irq_restore(flags); \
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\
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return temp; \
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}
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#define ATOMIC_FETCH_OP(op, c_op) \
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static inline int atomic_fetch_##op(int i, atomic_t *v) \
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{ \
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unsigned long temp, flags; \
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\
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raw_local_irq_save(flags); \
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temp = v->counter; \
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v->counter c_op i; \
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raw_local_irq_restore(flags); \
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\
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return temp; \
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}
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#define ATOMIC_OPS(op, c_op) \
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ATOMIC_OP(op, c_op) \
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ATOMIC_OP_RETURN(op, c_op) \
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ATOMIC_FETCH_OP(op, c_op)
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ATOMIC_OPS(add, +=)
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ATOMIC_OPS(sub, -=)
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#undef ATOMIC_OPS
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#define ATOMIC_OPS(op, c_op) \
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ATOMIC_OP(op, c_op) \
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ATOMIC_FETCH_OP(op, c_op)
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ATOMIC_OPS(and, &=)
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ATOMIC_OPS(or, |=)
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ATOMIC_OPS(xor, ^=)
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#undef ATOMIC_OPS
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#undef ATOMIC_FETCH_OP
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#undef ATOMIC_OP_RETURN
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#undef ATOMIC_OP
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#endif /* __ASM_SH_ATOMIC_IRQ_H */
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