Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

With the removal of IPKDB on arm, the undefined stack is only used to

Browse Source 
bounce into SVC32 mode, there is no per-process data stored on it.

We can therefore use the undefined stack setup by the platform machdep.c
as a system wide undefined stack.

This removes the need for a per-process undefined stack, and the processor
mode switching overhead it causes in cpu_switchto.

The space freed in the USPACE is used to increase the per process kernel
stack size.
This commit is contained in:
chris 2008-01-19 15:04:09 +00:00
parent 3618b9ac2c
commit 4e4f6b2828
6 changed files with 11 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
sys/arch/arm/arm32/arm32_machdep.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: arm32_machdep.c,v 1.54 2008/01/19 13:11:09 chris Exp $ */
/* $NetBSD: arm32_machdep.c,v 1.55 2008/01/19 15:04:09 chris Exp $ */
/*
* Copyright (c) 1994-1998 Mark Brinicombe.
@ -42,7 +42,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: arm32_machdep.c,v 1.54 2008/01/19 13:11:09 chris Exp $");
__KERNEL_RCSID(0, "$NetBSD: arm32_machdep.c,v 1.55 2008/01/19 15:04:09 chris Exp $");
#include "opt_md.h"
#include "opt_pmap_debug.h"
@ -273,8 +273,6 @@ cpu_startup()
curpcb = &lwp0.l_addr->u_pcb;
curpcb->pcb_flags = 0;
curpcb->pcb_un.un_32.pcb32_und_sp = (u_int)lwp0.l_addr +
USPACE_UNDEF_STACK_TOP;
curpcb->pcb_un.un_32.pcb32_sp = (u_int)lwp0.l_addr +
USPACE_SVC_STACK_TOP;

20
sys/arch/arm/arm32/cpuswitch.S
View File

@ -1,4 +1,4 @@
/* $NetBSD: cpuswitch.S,v 1.53 2008/01/13 02:43:53 chris Exp $ */
/* $NetBSD: cpuswitch.S,v 1.54 2008/01/19 15:04:10 chris Exp $ */
/*
* Copyright 2003 Wasabi Systems, Inc.
@ -230,15 +230,6 @@ ENTRY(cpu_switchto)
/* Get the user structure for the new process in r9 */
ldr r9, [r6, #(L_ADDR)]
/* fetch sp for the undefined instruction trap. */
mrs r3, cpsr
orr r2, r3, #(PSR_UND32_MODE | I32_bit)
msr cpsr_c, r2
str sp, [r8, #(PCB_UND_SP)]
msr cpsr_c, r3 /* Restore the old mode */
/* What else needs to be saved? Only FPA stuff when that is supported */
/* Restore saved context */
@ -258,15 +249,6 @@ ENTRY(cpu_switchto)
/* rem: r9 = new PCB */
/* rem: interrupts are enabled */
/* set sp for the undefined instruction trap. */
mrs r3, cpsr
orr r2, r3, #(PSR_UND32_MODE | I32_bit)
msr cpsr_c, r2
ldr sp, [r9, #(PCB_UND_SP)]
msr cpsr_c, r3 /* Restore the old mode */
/* Restore all the saved registers */
#ifndef __XSCALE__
add r7, r9, #PCB_R8

3
sys/arch/arm/arm32/genassym.cf
View File

@ -1,4 +1,4 @@
# $NetBSD: genassym.cf,v 1.37 2008/01/08 02:07:50 matt Exp $
# $NetBSD: genassym.cf,v 1.38 2008/01/19 15:04:10 chris Exp $
# Copyright (c) 1982, 1990 The Regents of the University of California.
# All rights reserved.
@ -102,7 +102,6 @@ define PCB_R12 offsetof(struct pcb, pcb_un.un_32.pcb32_r12)
define PCB_SP offsetof(struct pcb, pcb_un.un_32.pcb32_sp)
define PCB_LR offsetof(struct pcb, pcb_un.un_32.pcb32_lr)
define PCB_PC offsetof(struct pcb, pcb_un.un_32.pcb32_pc)
define PCB_UND_SP offsetof(struct pcb, pcb_un.un_32.pcb32_und_sp)
define PCB_ONFAULT offsetof(struct pcb, pcb_onfault)
define PCB_NOALIGNFLT PCB_NOALIGNFLT

15
sys/arch/arm/arm32/vm_machdep.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: vm_machdep.c,v 1.41 2008/01/12 20:50:24 skrll Exp $ */
/* $NetBSD: vm_machdep.c,v 1.42 2008/01/19 15:04:10 chris Exp $ */
/*
* Copyright (c) 1994-1998 Mark Brinicombe.
@ -44,7 +44,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.41 2008/01/12 20:50:24 skrll Exp $");
__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.42 2008/01/19 15:04:10 chris Exp $");
#include "opt_armfpe.h"
#include "opt_pmap_debug.h"
@ -144,17 +144,12 @@ cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
*pcb = l1->l_addr->u_pcb;
/*
* Set up the undefined stack for the process.
* Set up the stack for the process.
* Note: this stack is not in use if we are forking from p1
*/
pcb->pcb_un.un_32.pcb32_und_sp = (u_int)l2->l_addr +
USPACE_UNDEF_STACK_TOP;
pcb->pcb_un.un_32.pcb32_sp = (u_int)l2->l_addr + USPACE_SVC_STACK_TOP;
#ifdef STACKCHECKS
/* Fill the undefined stack with a known pattern */
memset(((u_char *)l2->l_addr) + USPACE_UNDEF_STACK_BOTTOM, 0xdd,
(USPACE_UNDEF_STACK_TOP - USPACE_UNDEF_STACK_BOTTOM));
/* Fill the kernel stack with a known pattern */
memset(((u_char *)l2->l_addr) + USPACE_SVC_STACK_BOTTOM, 0xdd,
(USPACE_SVC_STACK_TOP - USPACE_SVC_STACK_BOTTOM));
@ -218,10 +213,6 @@ cpu_lwp_free(struct lwp *l, int proc)
u_char *ptr;
int loop;
ptr = ((u_char *)p2->p_addr) + USPACE_UNDEF_STACK_BOTTOM;
for (loop = 0; loop < (USPACE_UNDEF_STACK_TOP - USPACE_UNDEF_STACK_BOTTOM)
&& *ptr == 0xdd; ++loop, ++ptr) ;
log(LOG_INFO, "%d bytes of undefined stack fill pattern\n", loop);
ptr = ((u_char *)p2->p_addr) + USPACE_SVC_STACK_BOTTOM;
for (loop = 0; loop < (USPACE_SVC_STACK_TOP - USPACE_SVC_STACK_BOTTOM)
&& *ptr == 0xdd; ++loop, ++ptr) ;

11
sys/arch/arm/include/arm32/param.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: param.h,v 1.12 2005/12/11 12:16:47 christos Exp $ */
/* $NetBSD: param.h,v 1.13 2008/01/19 15:04:10 chris Exp $ */
/*
* Copyright (c) 1994,1995 Mark Brinicombe.
@ -86,18 +86,15 @@
* 1. the user structure for the process
* 2. the fp context for FP emulation
* 3. the kernel (svc) stack
* 4. the undefined instruction stack
*
* The layout of the area looks like this
*
* | user area | FP context | undefined stack | kernel stack |
* | user area | FP context | kernel stack |
*
* The size of the user area is known.
* The size of the FP context is variable depending of the FP emulator
* in use and whether there is hardware FP support. However we can put
* an upper limit on it.
* The undefined stack needs to be at least 512 bytes. This is a requirement
* if the FP emulators
* The kernel stack should be at least 4K is size.
*
* The stack top addresses are used to set the stack pointers. The stack bottom
@ -107,9 +104,7 @@
#define FPCONTEXTSIZE (0x100)
#define USPACE_SVC_STACK_TOP (USPACE)
#define USPACE_SVC_STACK_BOTTOM (USPACE_SVC_STACK_TOP - 0x1000)
#define USPACE_UNDEF_STACK_TOP (USPACE_SVC_STACK_BOTTOM - 0x10)
#define USPACE_UNDEF_STACK_BOTTOM (sizeof(struct user) + FPCONTEXTSIZE + 10)
#define USPACE_SVC_STACK_BOTTOM (sizeof(struct user) + FPCONTEXTSIZE + 10)
#define arm_btop(x) ((x) >> PGSHIFT)
#define arm_ptob(x) ((x) << PGSHIFT)

3
sys/arch/arm/include/pcb.h
View File

@ -1,4 +1,4 @@
/* $NetBSD: pcb.h,v 1.16 2007/10/17 19:53:41 garbled Exp $ */
/* $NetBSD: pcb.h,v 1.17 2008/01/19 15:04:10 chris Exp $ */
/*
* Copyright (c) 2001 Matt Thomas <matt@3am-software.com>.
@ -57,7 +57,6 @@ struct pcb_arm32 {
u_int pcb32_sp; /* used */
u_int pcb32_lr;
u_int pcb32_pc;
u_int pcb32_und_sp;
};
#define pcb_pagedir pcb_un.un_32.pcb32_pagedir
#define pcb_pl1vec pcb_un.un_32.pcb32_pl1vec