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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/hexagon/mm/strnlen_user.S | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/hexagon/mm/strnlen_user.S')
-rw-r--r-- | arch/hexagon/mm/strnlen_user.S | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/arch/hexagon/mm/strnlen_user.S b/arch/hexagon/mm/strnlen_user.S new file mode 100644 index 000000000..4b5574a7c --- /dev/null +++ b/arch/hexagon/mm/strnlen_user.S @@ -0,0 +1,126 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * User string length functions for kernel + * + * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. + */ + +#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 |