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author | Richard Kuo <rkuo@codeaurora.org> | 2011-10-31 18:48:07 -0500 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-11-01 07:34:20 -0700 |
commit | 7567746e1c0d66ac0ef8a9d8816ca694462c7370 (patch) | |
tree | 5812837c9a8024091e253496cbdbbe888c0f7ab9 /arch/hexagon/mm/strnlen_user.S | |
parent | dd472da380c3819740d740cfd70b7f8e700e834b (diff) | |
download | linux-7567746e1c0d66ac0ef8a9d8816ca694462c7370.tar.bz2 |
Hexagon: Add user access functions
Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/hexagon/mm/strnlen_user.S')
-rw-r--r-- | arch/hexagon/mm/strnlen_user.S | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/hexagon/mm/strnlen_user.S b/arch/hexagon/mm/strnlen_user.S new file mode 100644 index 000000000000..5c6a16c7c72a --- /dev/null +++ b/arch/hexagon/mm/strnlen_user.S @@ -0,0 +1,139 @@ +/* + * User string length functions for kernel + * + * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#define isrc r0 +#define max r1 /* Do not change! */ + +#define end r2 +#define tmp1 r3 + +#define obo r6 /* off-by-one */ +#define start r7 +#define mod8 r8 +#define dbuf r15:14 +#define dcmp r13:12 + +/* + * The vector mask version of this turned out *really* badly. + * The hardware loop version also turned out *really* badly. + * Seems straight pointer arithmetic basically wins here. + */ + +#define fname __strnlen_user + + .text + .global fname + .type fname, @function + .p2align 5 /* why? */ +fname: + { + mod8 = and(isrc,#7); + end = add(isrc,max); + start = isrc; + } + { + P0 = cmp.eq(mod8,#0); + mod8 = and(end,#7); + dcmp = #0; + if (P0.new) jump:t dw_loop; /* fire up the oven */ + } + +alignment_loop: +fail_1: { + tmp1 = memb(start++#1); + } + { + P0 = cmp.eq(tmp1,#0); + if (P0.new) jump:nt exit_found; + P1 = cmp.gtu(end,start); + mod8 = and(start,#7); + } + { + if (!P1) jump exit_error; /* hit the end */ + P0 = cmp.eq(mod8,#0); + } + { + if (!P0) jump alignment_loop; + } + + + +dw_loop: +fail_2: { + dbuf = memd(start); + obo = add(start,#1); + } + { + P0 = vcmpb.eq(dbuf,dcmp); + } + { + tmp1 = P0; + P0 = cmp.gtu(end,start); + } + { + tmp1 = ct0(tmp1); + mod8 = and(end,#7); + if (!P0) jump end_check; + } + { + P0 = cmp.eq(tmp1,#32); + if (!P0.new) jump:nt exit_found; + if (!P0.new) start = add(obo,tmp1); + } + { + start = add(start,#8); + jump dw_loop; + } /* might be nice to combine these jumps... */ + + +end_check: + { + P0 = cmp.gt(tmp1,mod8); + if (P0.new) jump:nt exit_error; /* neverfound! */ + start = add(obo,tmp1); + } + +exit_found: + { + R0 = sub(start,isrc); + jumpr R31; + } + +exit_error: + { + R0 = add(max,#1); + jumpr R31; + } + + /* Uh, what does the "fixup" return here? */ + .falign +fix_1: + { + R0 = #0; + jumpr R31; + } + + .size fname,.-fname + + +.section __ex_table,"a" +.long fail_1,fix_1 +.long fail_2,fix_1 +.previous |