MIPS: lib: strnlen_user: Add EVA support

In non-EVA mode, a strlen_user* alias is used for the
strlen_kernel* symbols since the code is identical. In EVA
mode, a new strlen_user* symbol is used which uses the EVA
specific instructions to load values from userspace.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

arch/mips/kernel/mips_ksyms.c

@@ -22,6 +22,8 @@ extern long __strncpy_from_user_asm(char *__to, const char *__from,
 				    long __len);
 extern long __strlen_user_nocheck_asm(const char *s);
 extern long __strlen_user_asm(const char *s);
+extern long __strnlen_kernel_nocheck_asm(const char *s);
+extern long __strnlen_kernel_asm(const char *s);
 extern long __strnlen_user_nocheck_asm(const char *s);
 extern long __strnlen_user_asm(const char *s);
 
@@ -48,6 +50,8 @@ EXPORT_SYMBOL(__strncpy_from_user_nocheck_asm);
 EXPORT_SYMBOL(__strncpy_from_user_asm);
 EXPORT_SYMBOL(__strlen_user_nocheck_asm);
 EXPORT_SYMBOL(__strlen_user_asm);
+EXPORT_SYMBOL(__strnlen_kernel_nocheck_asm);
+EXPORT_SYMBOL(__strnlen_kernel_asm);
 EXPORT_SYMBOL(__strnlen_user_nocheck_asm);
 EXPORT_SYMBOL(__strnlen_user_asm);
 

arch/mips/lib/strnlen_user.S

@@ -35,7 +35,11 @@ FEXPORT(__strnlen_\func\()_nocheck_asm)
 	move		v0, a0
 	PTR_ADDU	a1, a0			# stop pointer
 1:	beq		v0, a1, 1f		# limit reached?
+.ifeqs "\func", "kernel"
 	EX(lb, t0, (v0), .Lfault\@)
+.else
+	EX(lbe, t0, (v0), .Lfault\@)
+.endif
 	PTR_ADDIU	v0, 1
 	bnez		t0, 1b
 1:	PTR_SUBU	v0, a0
@@ -47,4 +51,20 @@ FEXPORT(__strnlen_\func\()_nocheck_asm)
 	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