You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
179 lines
4.0 KiB
179 lines
4.0 KiB
############################################################################### |
|
# |
|
# MN10300 Context switch operation |
|
# |
|
# Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
|
# Written by David Howells (dhowells@redhat.com) |
|
# |
|
# This program is free software; you can redistribute it and/or |
|
# modify it under the terms of the GNU General Public Licence |
|
# as published by the Free Software Foundation; either version |
|
# 2 of the Licence, or (at your option) any later version. |
|
# |
|
############################################################################### |
|
#include <linux/sys.h> |
|
#include <linux/linkage.h> |
|
#include <asm/thread_info.h> |
|
#include <asm/cpu-regs.h> |
|
#ifdef CONFIG_SMP |
|
#include <proc/smp-regs.h> |
|
#endif /* CONFIG_SMP */ |
|
|
|
.text |
|
|
|
############################################################################### |
|
# |
|
# struct task_struct *__switch_to(struct thread_struct *prev, |
|
# struct thread_struct *next, |
|
# struct task_struct *prev_task) |
|
# |
|
############################################################################### |
|
ENTRY(__switch_to) |
|
movm [d2,d3,a2,a3,exreg1],(sp) |
|
or EPSW_NMID,epsw |
|
|
|
mov (44,sp),d2 |
|
|
|
mov d0,a0 |
|
mov d1,a1 |
|
|
|
# save prev context |
|
mov __switch_back,d0 |
|
mov sp,a2 |
|
mov a2,(THREAD_SP,a0) |
|
mov a3,(THREAD_A3,a0) |
|
|
|
#ifdef CONFIG_KGDB |
|
btst 0xff,(kgdb_single_step) |
|
bne __switch_to__lift_sstep_bp |
|
__switch_to__continue: |
|
#endif |
|
mov d0,(THREAD_PC,a0) |
|
|
|
mov (THREAD_A3,a1),a3 |
|
mov (THREAD_SP,a1),a2 |
|
|
|
# switch |
|
mov a2,sp |
|
|
|
# load next context |
|
GET_THREAD_INFO a2 |
|
mov a2,(__current_ti) |
|
mov (TI_task,a2),a2 |
|
mov a2,(__current) |
|
#ifdef CONFIG_MN10300_CURRENT_IN_E2 |
|
mov a2,e2 |
|
#endif |
|
|
|
mov (THREAD_PC,a1),a2 |
|
mov d2,d0 # for ret_from_fork |
|
mov d0,a0 # for __switch_to |
|
|
|
jmp (a2) |
|
|
|
__switch_back: |
|
and ~EPSW_NMID,epsw |
|
ret [d2,d3,a2,a3,exreg1],32 |
|
|
|
#ifdef CONFIG_KGDB |
|
############################################################################### |
|
# |
|
# Lift the single-step breakpoints when the task being traced is switched out |
|
# A0 = prev |
|
# A1 = next |
|
# |
|
############################################################################### |
|
__switch_to__lift_sstep_bp: |
|
add -12,sp |
|
mov a0,e4 |
|
mov a1,e5 |
|
|
|
# Clear the single-step flag to prevent us coming this way until we get |
|
# switched back in |
|
bclr 0xff,(kgdb_single_step) |
|
|
|
# Remove first breakpoint |
|
mov (kgdb_sstep_bp_addr),a2 |
|
cmp 0,a2 |
|
beq 1f |
|
movbu (kgdb_sstep_bp),d0 |
|
movbu d0,(a2) |
|
#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) |
|
mov a2,d0 |
|
mov a2,d1 |
|
add 1,d1 |
|
calls flush_icache_range |
|
#endif |
|
1: |
|
|
|
# Remove second breakpoint |
|
mov (kgdb_sstep_bp_addr+4),a2 |
|
cmp 0,a2 |
|
beq 2f |
|
movbu (kgdb_sstep_bp+1),d0 |
|
movbu d0,(a2) |
|
#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) |
|
mov a2,d0 |
|
mov a2,d1 |
|
add 1,d1 |
|
calls flush_icache_range |
|
#endif |
|
2: |
|
|
|
# Change the resumption address and return |
|
mov __switch_back__reinstall_sstep_bp,d0 |
|
mov e4,a0 |
|
mov e5,a1 |
|
add 12,sp |
|
bra __switch_to__continue |
|
|
|
############################################################################### |
|
# |
|
# Reinstall the single-step breakpoints when the task being traced is switched |
|
# back in (A1 points to the new thread_struct). |
|
# |
|
############################################################################### |
|
__switch_back__reinstall_sstep_bp: |
|
add -12,sp |
|
mov a0,e4 # save the return value |
|
mov 0xff,d3 |
|
|
|
# Reinstall first breakpoint |
|
mov (kgdb_sstep_bp_addr),a2 |
|
cmp 0,a2 |
|
beq 1f |
|
movbu (a2),d0 |
|
movbu d0,(kgdb_sstep_bp) |
|
movbu d3,(a2) |
|
#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) |
|
mov a2,d0 |
|
mov a2,d1 |
|
add 1,d1 |
|
calls flush_icache_range |
|
#endif |
|
1: |
|
|
|
# Reinstall second breakpoint |
|
mov (kgdb_sstep_bp_addr+4),a2 |
|
cmp 0,a2 |
|
beq 2f |
|
movbu (a2),d0 |
|
movbu d0,(kgdb_sstep_bp+1) |
|
movbu d3,(a2) |
|
#if defined(CONFIG_MN10300_CACHE_FLUSH_ICACHE) || defined(CONFIG_MN10300_CACHE_INV_ICACHE) |
|
mov a2,d0 |
|
mov a2,d1 |
|
add 1,d1 |
|
calls flush_icache_range |
|
#endif |
|
2: |
|
|
|
mov d3,(kgdb_single_step) |
|
|
|
# Restore the return value (the previous thread_struct pointer) |
|
mov e4,a0 |
|
mov a0,d0 |
|
add 12,sp |
|
bra __switch_back |
|
|
|
#endif /* CONFIG_KGDB */
|
|
|