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