diff options
Diffstat (limited to 'kernel/arch/frv/lib/memcpy.S')
| -rw-r--r-- | kernel/arch/frv/lib/memcpy.S | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/kernel/arch/frv/lib/memcpy.S b/kernel/arch/frv/lib/memcpy.S new file mode 100644 index 000000000..9c5965273 --- /dev/null +++ b/kernel/arch/frv/lib/memcpy.S @@ -0,0 +1,135 @@ +/* memcpy.S: optimised assembly memcpy + * + * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + + + .text + .p2align 4 + +############################################################################### +# +# void *memcpy(void *to, const char *from, size_t count) +# +# - NOTE: must not use any stack. exception detection performs function return +# to caller's fixup routine, aborting the remainder of the copy +# +############################################################################### + .globl memcpy,__memcpy_end + .type memcpy,@function +memcpy: + or.p gr8,gr9,gr4 + orcc gr10,gr0,gr0,icc3 + or.p gr10,gr4,gr4 + beqlr icc3,#0 + + # optimise based on best common alignment for to, from & count + andicc.p gr4,#0x0f,gr0,icc0 + setlos #8,gr11 + andicc.p gr4,#0x07,gr0,icc1 + beq icc0,#0,memcpy_16 + andicc.p gr4,#0x03,gr0,icc0 + beq icc1,#0,memcpy_8 + andicc.p gr4,#0x01,gr0,icc1 + beq icc0,#0,memcpy_4 + setlos.p #1,gr11 + beq icc1,#0,memcpy_2 + + # do byte by byte copy + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: ldubu.p @(gr9,gr11),gr4 + subicc gr10,#1,gr10,icc0 + stbu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do halfword by halfword copy +memcpy_2: + setlos #2,gr11 + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: lduhu.p @(gr9,gr11),gr4 + subicc gr10,#2,gr10,icc0 + sthu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do word by word copy +memcpy_4: + setlos #4,gr11 + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: ldu.p @(gr9,gr11),gr4 + subicc gr10,#4,gr10,icc0 + stu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do double-word by double-word copy +memcpy_8: + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: lddu.p @(gr9,gr11),gr4 + subicc gr10,#8,gr10,icc0 + stdu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do quad-word by quad-word copy +memcpy_16: + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: lddu @(gr9,gr11),gr4 + lddu.p @(gr9,gr11),gr6 + subicc gr10,#16,gr10,icc0 + stdu gr4,@(gr3,gr11) + stdu.p gr6,@(gr3,gr11) + bne icc0,#2,0b + bralr +__memcpy_end: + + .size memcpy, __memcpy_end-memcpy + +############################################################################### +# +# copy to/from userspace +# - return the number of bytes that could not be copied (0 on complete success) +# +# long __memcpy_user(void *dst, const void *src, size_t count) +# +############################################################################### + .globl __memcpy_user, __memcpy_user_error_lr, __memcpy_user_error_handler + .type __memcpy_user,@function +__memcpy_user: + movsg lr,gr7 + subi.p sp,#8,sp + add gr8,gr10,gr6 ; calculate expected end address + stdi gr6,@(sp,#0) + + # abuse memcpy to do the dirty work + call memcpy +__memcpy_user_error_lr: + ldi.p @(sp,#4),gr7 + setlos #0,gr8 + jmpl.p @(gr7,gr0) + addi sp,#8,sp + + # deal any exception generated by memcpy + # GR8 - memcpy's current dest address + # GR11 - memset's step value (index register for store insns) +__memcpy_user_error_handler: + lddi.p @(sp,#0),gr4 ; load GR4 with dst+count, GR5 with ret addr + add gr11,gr3,gr7 + sub.p gr4,gr7,gr8 + + addi sp,#8,sp + jmpl @(gr5,gr0) + + .size __memcpy_user, .-__memcpy_user |