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>
71 lines
2.0 KiB
C
71 lines
2.0 KiB
C
#ifndef __ASM_SH_CMPXCHG_GRB_H
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#define __ASM_SH_CMPXCHG_GRB_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 retval;
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__asm__ __volatile__ (
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" .align 2 \n\t"
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" mova 1f, r0 \n\t" /* r0 = end point */
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" nop \n\t"
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" mov r15, r1 \n\t" /* r1 = saved sp */
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" mov #-4, r15 \n\t" /* LOGIN */
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" mov.l @%1, %0 \n\t" /* load old value */
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" mov.l %2, @%1 \n\t" /* store new value */
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"1: mov r1, r15 \n\t" /* LOGOUT */
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: "=&r" (retval),
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"+r" (m)
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: "r" (val)
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: "memory", "r0", "r1");
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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 retval;
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__asm__ __volatile__ (
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" .align 2 \n\t"
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" mova 1f, r0 \n\t" /* r0 = end point */
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" mov r15, r1 \n\t" /* r1 = saved sp */
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" mov #-6, r15 \n\t" /* LOGIN */
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" mov.b @%1, %0 \n\t" /* load old value */
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" extu.b %0, %0 \n\t" /* extend as unsigned */
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" mov.b %2, @%1 \n\t" /* store new value */
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"1: mov r1, r15 \n\t" /* LOGOUT */
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: "=&r" (retval),
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"+r" (m)
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: "r" (val)
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: "memory" , "r0", "r1");
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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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unsigned long retval;
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__asm__ __volatile__ (
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" .align 2 \n\t"
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" mova 1f, r0 \n\t" /* r0 = end point */
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" nop \n\t"
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" mov r15, r1 \n\t" /* r1 = saved sp */
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" mov #-8, r15 \n\t" /* LOGIN */
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" mov.l @%1, %0 \n\t" /* load old value */
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" cmp/eq %0, %2 \n\t"
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" bf 1f \n\t" /* if not equal */
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" mov.l %2, @%1 \n\t" /* store new value */
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"1: mov r1, r15 \n\t" /* LOGOUT */
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: "=&r" (retval),
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"+r" (m)
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: "r" (new)
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: "memory" , "r0", "r1", "t");
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return retval;
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}
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#endif /* __ASM_SH_CMPXCHG_GRB_H */
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