parisc: Add assembly implementations for memset, strlen, strcpy, strn…

…cpy and strcat

Add performance-optimized versions of some string functions.

Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: Sven Schnelle <svens@stackframe.org>

arch/parisc/include/asm/string.h

@@ -8,4 +8,19 @@ extern void * memset(void *, int, size_t);
 #define __HAVE_ARCH_MEMCPY
 void * memcpy(void * dest,const void *src,size_t count);
 
+#define __HAVE_ARCH_STRLEN
+extern size_t strlen(const char *s);
+
+#define __HAVE_ARCH_STRCPY
+extern char *strcpy(char *dest, const char *src);
+
+#define __HAVE_ARCH_STRNCPY
+extern char *strncpy(char *dest, const char *src, size_t count);
+
+#define __HAVE_ARCH_STRCAT
+extern char *strcat(char *dest, const char *src);
+
+#define __HAVE_ARCH_MEMSET
+extern void *memset(void *, int, size_t);
+
 #endif

arch/parisc/kernel/parisc_ksyms.c

@@ -17,6 +17,10 @@
 
 #include <linux/string.h>
 EXPORT_SYMBOL(memset);
+EXPORT_SYMBOL(strlen);
+EXPORT_SYMBOL(strcpy);
+EXPORT_SYMBOL(strncpy);
+EXPORT_SYMBOL(strcat);
 
 #include <linux/atomic.h>
 EXPORT_SYMBOL(__xchg8);

arch/parisc/lib/Makefile

@@ -3,7 +3,7 @@
 # Makefile for parisc-specific library files
 #
 
-lib-y	:= lusercopy.o bitops.o checksum.o io.o memset.o memcpy.o \
-	   ucmpdi2.o delay.o
+lib-y	:= lusercopy.o bitops.o checksum.o io.o memcpy.o \
+	   ucmpdi2.o delay.o string.o
 
 obj-y	:= iomap.o

arch/parisc/lib/string.S

@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *    PA-RISC assembly string functions
+ *
+ *    Copyright (C) 2019 Helge Deller <deller@gmx.de>
+ */
+
+#include <asm/assembly.h>
+#include <linux/linkage.h>
+
+	.section .text.hot
+	.level PA_ASM_LEVEL
+
+	t0 = r20
+	t1 = r21
+	t2 = r22
+
+ENTRY_CFI(strlen, frame=0,no_calls)
+	or,COND(<>) arg0,r0,ret0
+	b,l,n	.Lstrlen_null_ptr,r0
+	depwi	0,31,2,ret0
+	cmpb,COND(<>) arg0,ret0,.Lstrlen_not_aligned
+	ldw,ma	4(ret0),t0
+	cmpib,tr 0,r0,.Lstrlen_loop
+	uxor,nbz r0,t0,r0
+.Lstrlen_not_aligned:
+	uaddcm	arg0,ret0,t1
+	shladd	t1,3,r0,t1
+	mtsar	t1
+	depwi	-1,%sar,32,t0
+	uxor,nbz r0,t0,r0
+.Lstrlen_loop:
+	b,l,n	.Lstrlen_end_loop,r0
+	ldw,ma	4(ret0),t0
+	cmpib,tr 0,r0,.Lstrlen_loop
+	uxor,nbz r0,t0,r0
+.Lstrlen_end_loop:
+	extrw,u,<> t0,7,8,r0
+	addib,tr,n -3,ret0,.Lstrlen_out
+	extrw,u,<> t0,15,8,r0
+	addib,tr,n -2,ret0,.Lstrlen_out
+	extrw,u,<> t0,23,8,r0
+	addi	-1,ret0,ret0
+.Lstrlen_out:
+	bv r0(rp)
+	uaddcm ret0,arg0,ret0
+.Lstrlen_null_ptr:
+	bv,n r0(rp)
+ENDPROC_CFI(strlen)
+
+
+ENTRY_CFI(strcpy, frame=0,no_calls)
+	ldb	0(arg1),t0
+	stb	t0,0(arg0)
+	ldo	0(arg0),ret0
+	ldo	1(arg1),t1
+	cmpb,=	r0,t0,2f
+	ldo	1(arg0),t2
+1:	ldb	0(t1),arg1
+	stb	arg1,0(t2)
+	ldo	1(t1),t1
+	cmpb,<> r0,arg1,1b
+	ldo	1(t2),t2
+2:	bv,n	r0(rp)
+ENDPROC_CFI(strcpy)
+
+
+ENTRY_CFI(strncpy, frame=0,no_calls)
+	ldb	0(arg1),t0
+	stb	t0,0(arg0)
+	ldo	1(arg1),t1
+	ldo	0(arg0),ret0
+	cmpb,=	r0,t0,2f
+	ldo	1(arg0),arg1
+1:	ldo	-1(arg2),arg2
+	cmpb,COND(=),n r0,arg2,2f
+	ldb	0(t1),arg0
+	stb	arg0,0(arg1)
+	ldo	1(t1),t1
+	cmpb,<> r0,arg0,1b
+	ldo	1(arg1),arg1
+2:	bv,n	r0(rp)
+ENDPROC_CFI(strncpy)
+
+
+ENTRY_CFI(strcat, frame=0,no_calls)
+	ldb	0(arg0),t0
+	cmpb,=	t0,r0,2f
+	ldo	0(arg0),ret0
+	ldo	1(arg0),arg0
+1:	ldb	0(arg0),t1
+	cmpb,<>,n r0,t1,1b
+	ldo	1(arg0),arg0
+2:	ldb	0(arg1),t2
+	stb	t2,0(arg0)
+	ldo	1(arg0),arg0
+	ldb	0(arg1),t0
+	cmpb,<>	r0,t0,2b
+	ldo	1(arg1),arg1
+	bv,n	r0(rp)
+ENDPROC_CFI(strcat)
+
+
+ENTRY_CFI(memset, frame=0,no_calls)
+	copy	arg0,ret0
+	cmpb,COND(=) r0,arg0,4f
+	copy	arg0,t2
+	cmpb,COND(=) r0,arg2,4f
+	ldo	-1(arg2),arg3
+	subi	-1,arg3,t0
+	subi	0,t0,t1
+	cmpiclr,COND(>=) 0,t1,arg2
+	ldo	-1(t1),arg2
+	extru arg2,31,2,arg0
+2:	stb	arg1,0(t2)
+	ldo	1(t2),t2
+	addib,>= -1,arg0,2b
+	ldo	-1(arg3),arg3
+	cmpiclr,COND(<=) 4,arg2,r0
+	b,l,n	4f,r0
+#ifdef CONFIG_64BIT
+	depd,*	r0,63,2,arg2
+#else
+	depw	r0,31,2,arg2
+#endif
+	ldo	1(t2),t2
+3:	stb	arg1,-1(t2)
+	stb	arg1,0(t2)
+	stb	arg1,1(t2)
+	stb	arg1,2(t2)
+	addib,COND(>) -4,arg2,3b
+	ldo	4(t2),t2
+4:	bv,n	r0(rp)
+ENDPROC_CFI(memset)
+
+	.end