Module Name:    src
Committed By:   rin
Date:           Tue Oct  4 13:45:50 UTC 2022

Modified Files:
        src/sys/arch/powerpc/ibm4xx: copyinstr.c copyoutstr.c trap.c

Log Message:
copy{in,out}{,str}: Drop needless dcbst.

Data cache is purely physical for 40[53] with 16KB pages, and therefore
no need to flush cache before context switch.

This significantly improves copy{in,out} against small data; for example,
bytebench on DHT becomes:

-Pipe Throughput        12440.0          8826.1          7.1
+Pipe Throughput        12440.0         18364.8         14.8

No performance/ATF regression observed on 405. 403 boots successfully
into multiuser mode, and builds some packages.


To generate a diff of this commit:
cvs rdiff -u -r1.18 -r1.19 src/sys/arch/powerpc/ibm4xx/copyinstr.c \
    src/sys/arch/powerpc/ibm4xx/copyoutstr.c
cvs rdiff -u -r1.99 -r1.100 src/sys/arch/powerpc/ibm4xx/trap.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/arch/powerpc/ibm4xx/copyinstr.c
diff -u src/sys/arch/powerpc/ibm4xx/copyinstr.c:1.18 src/sys/arch/powerpc/ibm4xx/copyinstr.c:1.19
--- src/sys/arch/powerpc/ibm4xx/copyinstr.c:1.18	Mon Oct  3 23:41:28 2022
+++ src/sys/arch/powerpc/ibm4xx/copyinstr.c	Tue Oct  4 13:45:50 2022
@@ -1,4 +1,4 @@
-/*	$NetBSD: copyinstr.c,v 1.18 2022/10/03 23:41:28 rin Exp $	*/
+/*	$NetBSD: copyinstr.c,v 1.19 2022/10/04 13:45:50 rin Exp $	*/
 
 /*
  * Copyright 2001 Wasabi Systems, Inc.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: copyinstr.c,v 1.18 2022/10/03 23:41:28 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: copyinstr.c,v 1.19 2022/10/04 13:45:50 rin Exp $");
 
 #include <sys/param.h>
 #include <uvm/uvm_extern.h>
@@ -92,7 +92,6 @@ copyinstr(const void *uaddr, void *kaddr
 		MTPID(%[pid])
 		"isync;"
 		"stb %[data],0(%[kaddr]);"	/* Store kernel byte */
-		"dcbst 0,%[kaddr];"
 		"addi %[kaddr],%[kaddr],1;"
 		"or. %[data],%[data],%[data];"
 		"sync;"
Index: src/sys/arch/powerpc/ibm4xx/copyoutstr.c
diff -u src/sys/arch/powerpc/ibm4xx/copyoutstr.c:1.18 src/sys/arch/powerpc/ibm4xx/copyoutstr.c:1.19
--- src/sys/arch/powerpc/ibm4xx/copyoutstr.c:1.18	Mon Oct  3 23:41:28 2022
+++ src/sys/arch/powerpc/ibm4xx/copyoutstr.c	Tue Oct  4 13:45:50 2022
@@ -1,4 +1,4 @@
-/*	$NetBSD: copyoutstr.c,v 1.18 2022/10/03 23:41:28 rin Exp $	*/
+/*	$NetBSD: copyoutstr.c,v 1.19 2022/10/04 13:45:50 rin Exp $	*/
 
 /*
  * Copyright 2001 Wasabi Systems, Inc.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: copyoutstr.c,v 1.18 2022/10/03 23:41:28 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: copyoutstr.c,v 1.19 2022/10/04 13:45:50 rin Exp $");
 
 #include <sys/param.h>
 #include <uvm/uvm_extern.h>
@@ -94,7 +94,6 @@ copyoutstr(const void *kaddr, void *uadd
 		"isync;"
 
 		"stb %[data],0(%[uaddr]);"	/* Store byte */
-		"dcbst 0,%[uaddr];"
 		"addi %[uaddr],%[uaddr],1;"
 
 		"or. %[data],%[data],%[data];"

Index: src/sys/arch/powerpc/ibm4xx/trap.c
diff -u src/sys/arch/powerpc/ibm4xx/trap.c:1.99 src/sys/arch/powerpc/ibm4xx/trap.c:1.100
--- src/sys/arch/powerpc/ibm4xx/trap.c:1.99	Mon Sep 12 08:06:36 2022
+++ src/sys/arch/powerpc/ibm4xx/trap.c	Tue Oct  4 13:45:50 2022
@@ -1,4 +1,4 @@
-/*	$NetBSD: trap.c,v 1.99 2022/09/12 08:06:36 rin Exp $	*/
+/*	$NetBSD: trap.c,v 1.100 2022/10/04 13:45:50 rin Exp $	*/
 
 /*
  * Copyright 2001 Wasabi Systems, Inc.
@@ -69,7 +69,7 @@
 #define	__UFETCHSTORE_PRIVATE
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.99 2022/09/12 08:06:36 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.100 2022/10/04 13:45:50 rin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -481,7 +481,6 @@ copyin(const void *uaddr, void *kaddr, s
 #else
 		"stw	%[tmp],0(%[kaddr]);"
 #endif
-		"dcbst	0,%[kaddr];"		/* flush cache */
 		"addi	%[kaddr],%[kaddr],0x4;"	/* next kaddr word */
 		"sync;"
 		"bdnz	1b;"			/* repeat */
@@ -498,7 +497,6 @@ copyin(const void *uaddr, void *kaddr, s
 		MTPID(%[pid])
 		"isync;"
 		"stswx	%[tmp],0,%[kaddr];"	/* Store kernel bytes */
-		"dcbst	0,%[kaddr];"		/* flush cache */
 		"sync;"
 
 	"10:"	"mtmsr	%[msr];"		/* Restore MSR */
@@ -601,7 +599,6 @@ copyout(const void *kaddr, void *uaddr, 
 #else
 		"stw	%[tmp],0(%[uaddr]);"
 #endif
-		"dcbst	0,%[uaddr];"		/* flush cache */
 		"addi	%[uaddr],%[uaddr],0x4;"	/* next uaddr word */
 		"sync;"
 
@@ -619,7 +616,6 @@ copyout(const void *kaddr, void *uaddr, 
 		MTPID(%[ctx])
 		"isync;"
 		"stswx	%[tmp],0,%[uaddr];"	/* Store user bytes */
-		"dcbst	0,%[uaddr];"		/* flush cache */
 		"sync;"
 
 		MTPID(%[pid])			/* Restore PID and MSR */

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