mirror of https://gitee.com/openkylin/linux.git
92 lines
1.7 KiB
ArmAsm
92 lines
1.7 KiB
ArmAsm
/*
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* String handling functions.
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*
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* Copyright IBM Corp. 2012
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*/
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#include <linux/linkage.h>
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#include <asm/export.h>
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/*
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* memset implementation
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*
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* This code corresponds to the C construct below. We do distinguish
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* between clearing (c == 0) and setting a memory array (c != 0) simply
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* because nearly all memset invocations in the kernel clear memory and
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* the xc instruction is preferred in such cases.
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*
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* void *memset(void *s, int c, size_t n)
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* {
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* if (likely(c == 0))
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* return __builtin_memset(s, 0, n);
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* return __builtin_memset(s, c, n);
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* }
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*/
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ENTRY(memset)
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ltgr %r4,%r4
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bzr %r14
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ltgr %r3,%r3
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jnz .Lmemset_fill
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aghi %r4,-1
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srlg %r3,%r4,8
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ltgr %r3,%r3
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lgr %r1,%r2
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jz .Lmemset_clear_rest
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.Lmemset_clear_loop:
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xc 0(256,%r1),0(%r1)
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la %r1,256(%r1)
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brctg %r3,.Lmemset_clear_loop
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.Lmemset_clear_rest:
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larl %r3,.Lmemset_xc
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ex %r4,0(%r3)
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br %r14
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.Lmemset_fill:
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stc %r3,0(%r2)
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cghi %r4,1
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lgr %r1,%r2
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ber %r14
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aghi %r4,-2
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srlg %r3,%r4,8
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ltgr %r3,%r3
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jz .Lmemset_fill_rest
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.Lmemset_fill_loop:
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mvc 1(256,%r1),0(%r1)
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la %r1,256(%r1)
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brctg %r3,.Lmemset_fill_loop
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.Lmemset_fill_rest:
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larl %r3,.Lmemset_mvc
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ex %r4,0(%r3)
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br %r14
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.Lmemset_xc:
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xc 0(1,%r1),0(%r1)
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.Lmemset_mvc:
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mvc 1(1,%r1),0(%r1)
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EXPORT_SYMBOL(memset)
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/*
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* memcpy implementation
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*
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* void *memcpy(void *dest, const void *src, size_t n)
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*/
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ENTRY(memcpy)
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ltgr %r4,%r4
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bzr %r14
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aghi %r4,-1
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srlg %r5,%r4,8
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ltgr %r5,%r5
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lgr %r1,%r2
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jnz .Lmemcpy_loop
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.Lmemcpy_rest:
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larl %r5,.Lmemcpy_mvc
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ex %r4,0(%r5)
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br %r14
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.Lmemcpy_loop:
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mvc 0(256,%r1),0(%r3)
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la %r1,256(%r1)
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la %r3,256(%r3)
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brctg %r5,.Lmemcpy_loop
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j .Lmemcpy_rest
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.Lmemcpy_mvc:
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mvc 0(1,%r1),0(%r3)
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EXPORT_SYMBOL(memcpy)
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