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132 lines
4.1 KiB
132 lines
4.1 KiB
/* |
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Copyright (c) 2013, Raspberry Pi Foundation |
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Copyright (c) 2013, RISC OS Open Ltd |
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All rights reserved. |
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Redistribution and use in source and binary forms, with or without |
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modification, are permitted provided that the following conditions are met: |
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* Redistributions of source code must retain the above copyright |
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notice, this list of conditions and the following disclaimer. |
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* Redistributions in binary form must reproduce the above copyright |
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notice, this list of conditions and the following disclaimer in the |
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documentation and/or other materials provided with the distribution. |
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* Neither the name of the copyright holder nor the |
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names of its contributors may be used to endorse or promote products |
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derived from this software without specific prior written permission. |
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |
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ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY |
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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#include <linux/linkage.h> |
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#include "arm-mem.h" |
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/* Prevent the stack from becoming executable */ |
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#if defined(__linux__) && defined(__ELF__) |
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.section .note.GNU-stack,"",%progbits |
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#endif |
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.text |
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.arch armv6 |
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.object_arch armv4 |
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.arm |
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.altmacro |
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.p2align 2 |
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/* |
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* void *memset(void *s, int c, size_t n); |
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* On entry: |
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* a1 = pointer to buffer to fill |
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* a2 = byte pattern to fill with (caller-narrowed) |
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* a3 = number of bytes to fill |
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* On exit: |
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* a1 preserved |
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*/ |
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ENTRY(mmioset) |
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ENTRY(memset) |
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ENTRY(__memset) |
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S .req a1 |
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DAT0 .req a2 |
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N .req a3 |
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DAT1 .req a4 |
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DAT2 .req ip |
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DAT3 .req lr |
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orr DAT0, DAT0, DAT0, lsl #8 |
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orr DAT0, DAT0, DAT0, lsl #16 |
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ENTRY(__memset32) |
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mov DAT1, DAT0 |
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ENTRY(__memset64) |
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push {S, lr} |
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/* See if we're guaranteed to have at least one 16-byte aligned 16-byte write */ |
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cmp N, #31 |
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blo 170f |
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161: sub N, N, #16 /* simplifies inner loop termination */ |
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/* Leading words and bytes */ |
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tst S, #15 |
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beq 164f |
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rsb DAT3, S, #0 /* bits 0-3 = number of leading bytes until aligned */ |
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movs DAT2, DAT3, lsl #31 |
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submi N, N, #1 |
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strmib DAT0, [S], #1 |
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subcs N, N, #2 |
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strcsh DAT0, [S], #2 |
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movs DAT2, DAT3, lsl #29 |
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submi N, N, #4 |
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strmi DAT0, [S], #4 |
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subcs N, N, #8 |
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stmcsia S!, {DAT0, DAT1} |
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164: /* Delayed set up of DAT2 and DAT3 so we could use them as scratch registers above */ |
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mov DAT2, DAT0 |
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mov DAT3, DAT1 |
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/* Now the inner loop of 16-byte stores */ |
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165: stmia S!, {DAT0, DAT1, DAT2, DAT3} |
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subs N, N, #16 |
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bhs 165b |
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166: /* Trailing words and bytes */ |
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movs N, N, lsl #29 |
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stmcsia S!, {DAT0, DAT1} |
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strmi DAT0, [S], #4 |
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movs N, N, lsl #2 |
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strcsh DAT0, [S], #2 |
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strmib DAT0, [S] |
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199: pop {S, pc} |
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170: /* Short case */ |
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mov DAT2, DAT0 |
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mov DAT3, DAT1 |
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tst S, #3 |
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beq 174f |
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172: subs N, N, #1 |
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blo 199b |
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strb DAT0, [S], #1 |
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tst S, #3 |
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bne 172b |
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174: tst N, #16 |
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stmneia S!, {DAT0, DAT1, DAT2, DAT3} |
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b 166b |
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.unreq S |
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.unreq DAT0 |
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.unreq N |
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.unreq DAT1 |
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.unreq DAT2 |
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.unreq DAT3 |
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ENDPROC(__memset64) |
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ENDPROC(__memset32) |
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ENDPROC(__memset) |
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ENDPROC(memset) |
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ENDPROC(mmioset)
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