summaryrefslogtreecommitdiff
path: root/arch/mips/lib/strnlen_user.S
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/mips/lib/strnlen_user.S
Initial import
Diffstat (limited to 'arch/mips/lib/strnlen_user.S')
-rw-r--r--arch/mips/lib/strnlen_user.S83
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/mips/lib/strnlen_user.S b/arch/mips/lib/strnlen_user.S
new file mode 100644
index 000000000..77e64942f
--- /dev/null
+++ b/arch/mips/lib/strnlen_user.S
@@ -0,0 +1,83 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle
+ * Copyright (c) 1999 Silicon Graphics, Inc.
+ */
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/regdef.h>
+
+#define EX(insn,reg,addr,handler) \
+9: insn reg, addr; \
+ .section __ex_table,"a"; \
+ PTR 9b, handler; \
+ .previous
+
+/*
+ * Return the size of a string including the ending NUL character up to a
+ * maximum of a1 or 0 in case of error.
+ *
+ * Note: for performance reasons we deliberately accept that a user may
+ * make strlen_user and strnlen_user access the first few KSEG0
+ * bytes. There's nothing secret there. On 64-bit accessing beyond
+ * the maximum is a tad hairier ...
+ */
+ .macro __BUILD_STRNLEN_ASM func
+LEAF(__strnlen_\func\()_asm)
+ LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
+ and v0, a0
+ bnez v0, .Lfault\@
+
+FEXPORT(__strnlen_\func\()_nocheck_asm)
+ move v0, a0
+ PTR_ADDU a1, a0 # stop pointer
+1:
+#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
+ .set noat
+ li AT, 1
+#endif
+ beq v0, a1, 1f # limit reached?
+.ifeqs "\func", "kernel"
+ EX(lb, t0, (v0), .Lfault\@)
+.else
+ EX(lbe, t0, (v0), .Lfault\@)
+.endif
+ .set noreorder
+ bnez t0, 1b
+1:
+#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
+ PTR_ADDIU v0, 1
+#else
+ PTR_ADDU v0, AT
+ .set at
+#endif
+ .set reorder
+ PTR_SUBU v0, a0
+ jr ra
+ END(__strnlen_\func\()_asm)
+
+.Lfault\@:
+ move v0, zero
+ jr ra
+ .endm
+
+#ifndef CONFIG_EVA
+ /* Set aliases */
+ .global __strnlen_user_asm
+ .global __strnlen_user_nocheck_asm
+ .set __strnlen_user_asm, __strnlen_kernel_asm
+ .set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm
+#endif
+
+__BUILD_STRNLEN_ASM kernel
+
+#ifdef CONFIG_EVA
+
+ .set push
+ .set eva
+__BUILD_STRNLEN_ASM user
+ .set pop
+#endif