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Diffstat (limited to 'arch/hexagon/mm/strnlen_user.S')
-rw-r--r--arch/hexagon/mm/strnlen_user.S139
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/hexagon/mm/strnlen_user.S b/arch/hexagon/mm/strnlen_user.S
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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