forked from luck/tmp_suning_uos_patched
1efe4ce3ca
This implements kernel-level atomic rollback built on top of gUSA, as an alternative non-IRQ based atomicity method. This is generally a faster method for platforms that are lacking the LL/SC pairs that SH-4A and later use, and is only supportable on legacy cores. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
41 lines
796 B
C
41 lines
796 B
C
#ifndef __ASM_SH_CMPXCHG_IRQ_H
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#define __ASM_SH_CMPXCHG_IRQ_H
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static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
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{
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unsigned long flags, retval;
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local_irq_save(flags);
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retval = *m;
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*m = val;
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local_irq_restore(flags);
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return retval;
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}
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static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
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{
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unsigned long flags, retval;
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local_irq_save(flags);
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retval = *m;
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*m = val & 0xff;
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local_irq_restore(flags);
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return retval;
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}
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static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
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unsigned long new)
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{
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__u32 retval;
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unsigned long flags;
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local_irq_save(flags);
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retval = *m;
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if (retval == old)
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*m = new;
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local_irq_restore(flags); /* implies memory barrier */
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return retval;
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}
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#endif /* __ASM_SH_CMPXCHG_IRQ_H */
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