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- #ifndef __SH4A__
- #include "atomic.h"
- #include "libc.h"
- /* gusa is a hack in the kernel which lets you create a sequence of instructions
- * which will be restarted if the process is preempted in the middle of the
- * sequence. It will do for implementing atomics on non-smp systems. ABI is:
- * r0 = address of first instruction after the atomic sequence
- * r1 = original stack pointer
- * r15 = -1 * length of atomic sequence in bytes
- */
- #define GUSA_CLOBBERS "r0", "r1", "memory"
- #define GUSA_START(mem,old,nop) \
- " .align 2\n" \
- " mova 1f, r0\n" \
- nop \
- " mov r15, r1\n" \
- " mov #(0f-1f), r15\n" \
- "0: mov.l @" mem ", " old "\n"
- /* the target of mova must be 4 byte aligned, so we may need a nop */
- #define GUSA_START_ODD(mem,old) GUSA_START(mem,old,"")
- #define GUSA_START_EVEN(mem,old) GUSA_START(mem,old,"\tnop\n")
- #define GUSA_END(mem,new) \
- " mov.l " new ", @" mem "\n" \
- "1: mov r1, r15\n"
- #define CPU_HAS_LLSC 0x0040
- int __sh_cas(volatile int *p, int t, int s)
- {
- if (__hwcap & CPU_HAS_LLSC) return __sh_cas_llsc(p, t, s);
- int old;
- __asm__ __volatile__(
- GUSA_START_EVEN("%1", "%0")
- " cmp/eq %0, %2\n"
- " bf 1f\n"
- GUSA_END("%1", "%3")
- : "=&r"(old) : "r"(p), "r"(t), "r"(s) : GUSA_CLOBBERS, "t");
- return old;
- }
- int __sh_swap(volatile int *x, int v)
- {
- if (__hwcap & CPU_HAS_LLSC) return __sh_swap_llsc(x, v);
- int old;
- __asm__ __volatile__(
- GUSA_START_EVEN("%1", "%0")
- GUSA_END("%1", "%2")
- : "=&r"(old) : "r"(x), "r"(v) : GUSA_CLOBBERS);
- return old;
- }
- int __sh_fetch_add(volatile int *x, int v)
- {
- if (__hwcap & CPU_HAS_LLSC) return __sh_fetch_add_llsc(x, v);
- int old, dummy;
- __asm__ __volatile__(
- GUSA_START_EVEN("%2", "%0")
- " mov %0, %1\n"
- " add %3, %1\n"
- GUSA_END("%2", "%1")
- : "=&r"(old), "=&r"(dummy) : "r"(x), "r"(v) : GUSA_CLOBBERS);
- return old;
- }
- void __sh_store(volatile int *p, int x)
- {
- if (__hwcap & CPU_HAS_LLSC) return __sh_store_llsc(p, x);
- __asm__ __volatile__(
- " mov.l %1, @%0\n"
- : : "r"(p), "r"(x) : "memory");
- }
- void __sh_and(volatile int *x, int v)
- {
- if (__hwcap & CPU_HAS_LLSC) return __sh_and_llsc(x, v);
- int dummy;
- __asm__ __volatile__(
- GUSA_START_ODD("%1", "%0")
- " and %2, %0\n"
- GUSA_END("%1", "%0")
- : "=&r"(dummy) : "r"(x), "r"(v) : GUSA_CLOBBERS);
- }
- void __sh_or(volatile int *x, int v)
- {
- if (__hwcap & CPU_HAS_LLSC) return __sh_or_llsc(x, v);
- int dummy;
- __asm__ __volatile__(
- GUSA_START_ODD("%1", "%0")
- " or %2, %0\n"
- GUSA_END("%1", "%0")
- : "=&r"(dummy) : "r"(x), "r"(v) : GUSA_CLOBBERS);
- }
- #endif
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