Re: CVS commit: src/sys/arch/powerpc/powerpc

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

Hi,

On 2019/12/06 5:55, Andrew Doran wrote:
> Module Name:	src
> Committed By:	ad
> Date:		Thu Dec  5 20:55:24 UTC 2019
>
> Modified Files:
> 	src/sys/arch/powerpc/powerpc: powerpc_machdep.c
>
> Log Message:
> Need to call userret() from cpu_ast().
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.74 -r1.75 src/sys/arch/powerpc/powerpc/powerpc_machdep.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/powerpc/powerpc_machdep.c
> diff -u src/sys/arch/powerpc/powerpc/powerpc_machdep.c:1.74 src/sys/arch/powerpc/powerpc/powerpc_machdep.c:1.75
> --- src/sys/arch/powerpc/powerpc/powerpc_machdep.c:1.74	Sat Nov 23 19:40:36 2019
> +++ src/sys/arch/powerpc/powerpc/powerpc_machdep.c	Thu Dec  5 20:55:24 2019
> @@ -1,4 +1,4 @@
> -/*	$NetBSD: powerpc_machdep.c,v 1.74 2019/11/23 19:40:36 ad Exp $	*/
> +/*	$NetBSD: powerpc_machdep.c,v 1.75 2019/12/05 20:55:24 ad Exp $	*/
>   
>   /*
>    * Copyright (C) 1995, 1996 Wolfgang Solfrank.
> @@ -32,7 +32,7 @@
>    */
>   
>   #include <sys/cdefs.h>
> -__KERNEL_RCSID(0, "$NetBSD: powerpc_machdep.c,v 1.74 2019/11/23 19:40:36 ad Exp $");
> +__KERNEL_RCSID(0, "$NetBSD: powerpc_machdep.c,v 1.75 2019/12/05 20:55:24 ad Exp $");
>   
>   #include "opt_altivec.h"
>   #include "opt_ddb.h"
> @@ -373,6 +373,8 @@ void
>   cpu_ast(struct lwp *l, struct cpu_info *ci)
>   {
>   	l->l_md.md_astpending = 0;	/* we are about to do it */
> +	__insn_barrier();
> +	userret(l, l->l_md.md_utf);
>   
>   	if (l->l_pflag & LP_OWEUPC) {
>   		l->l_pflag &= ~LP_OWEUPC;
> @@ -400,7 +402,7 @@ cpu_need_resched(struct cpu_info *ci, st
>   		cpu_send_ipi(cpu_index(ci), IPI_AST);
>   #endif
>   	} else {
> -		l->l_md.md_astpending = 1;		/* force call to ast() */
> +		l->l_md.md_astpending = 1;	/* force call to cpu_ast() */
>   	}
>   }
>   

This commit makes userret() called twice with AST; cpu_ast() is
invoked from

booke/trap.c,
https://nxr.netbsd.org/xref/src/sys/arch/powerpc/booke/trap.c#815

ibm4xx/trap.c, and
https://nxr.netbsd.org/xref/src/sys/arch/powerpc/ibm4xx/trap.c#276

powerpc/trap.c.
https://nxr.netbsd.org/xref/src/sys/arch/powerpc/powerpc/trap.c#348

For all cases, userret() is called afterward. (Precisely speaking,
for ibm4xx, mi_userret(9) is used instead. This should probably be
replaced by userret().)

Also, other ports test (l->l_pflag & LP_OWEUPC) before mi_userret(9).

Thanks,
rin