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Commit de398406 authored by Yoshinori Sato's avatar Yoshinori Sato Committed by Paul Mundt
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sh: Exception vector rework and SH-2/SH-2A support. 

This splits out common bits from the existing exception handler for
use between SH-2/SH-2A and SH-3/4, and adds support for the SH-2/2A
exceptions.
Signed-off-by: default avatarYoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 0983b318
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Showing with 767 additions and 332 deletions
arch/sh/kernel/cpu/sh2/entry.S 0 → 100644
View file @ de398406
/*
* arch/sh/kernel/cpu/sh2/entry.S
*
* The SH-2 exception entry
*
* Copyright (C) 2005,2006 Yoshinori Sato
* Copyright (C) 2005 AXE,Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/cpu/mmu_context.h>
#include <asm/unistd.h>
#include <asm/errno.h>
#include <asm/page.h>
/* Offsets to the stack */
OFF_R0 = 0 /* Return value. New ABI also arg4 */
OFF_R1 = 4 /* New ABI: arg5 */
OFF_R2 = 8 /* New ABI: arg6 */
OFF_R3 = 12 /* New ABI: syscall_nr */
OFF_R4 = 16 /* New ABI: arg0 */
OFF_R5 = 20 /* New ABI: arg1 */
OFF_R6 = 24 /* New ABI: arg2 */
OFF_R7 = 28 /* New ABI: arg3 */
OFF_SP = (15*4)
OFF_PC = (16*4)
OFF_SR = (16*4+2*4)
OFF_TRA = (16*4+6*4)
#include <asm/entry-macros.S>
ENTRY(exception_handler)
! already saved r0/r1
mov.l r2,@-sp
mov.l r3,@-sp
mov r0,r1
cli
mov.l $cpu_mode,r2
mov.l @r2,r0
mov.l @(5*4,r15),r3 ! previous SR
shll2 r3 ! set "S" flag
rotl r0 ! T <- "S" flag
rotl r0 ! "S" flag is LSB
rotcr r3 ! T -> r3:b30
shlr r3
shlr r0
bt/s 1f
mov.l r3,@(5*4,r15) ! copy cpu mode to SR
! switch to kernel mode
mov #1,r0
rotr r0
rotr r0
mov.l r0,@r2 ! enter kernel mode
mov.l $current_thread_info,r2
mov.l @r2,r2
mov #0x20,r0
shll8 r0
add r2,r0
mov r15,r2 ! r2 = user stack top
mov r0,r15 ! switch kernel stack
add #-4,r15 ! dummy
mov.l r1,@-r15 ! TRA
sts.l macl, @-r15
sts.l mach, @-r15
stc.l gbr, @-r15
mov.l @(4*4,r2),r0
mov.l @(5*4,r2),r1
mov.l r1,@-r15 ! original SR
sts.l pr,@-r15
mov.l r0,@-r15 ! original PC
mov r2,r3
add #(4+2)*4,r3 ! rewind r0 - r3 + exception frame
mov.l r3,@-r15 ! original SP
mov.l r14,@-r15
mov.l r13,@-r15
mov.l r12,@-r15
mov.l r11,@-r15
mov.l r10,@-r15
mov.l r9,@-r15
mov.l r8,@-r15
mov.l r7,@-r15
mov.l r6,@-r15
mov.l r5,@-r15
mov.l r4,@-r15
mov r2,r8 ! copy user -> kernel stack
mov.l @r8+,r3
mov.l r3,@-r15
mov.l @r8+,r2
mov.l r2,@-r15
mov.l @r8+,r1
mov.l r1,@-r15
mov.l @r8+,r0
bra 2f
mov.l r0,@-r15
1:
! in kernel exception
mov #(22-4-4-1)*4+4,r0
mov r15,r2
sub r0,r15
mov.l @r2+,r0 ! old R3
mov.l r0,@-r15
mov.l @r2+,r0 ! old R2
mov.l r0,@-r15
mov.l @r2+,r0 ! old R1
mov.l r0,@-r15
mov.l @r2+,r0 ! old R0
mov.l r0,@-r15
mov.l @r2+,r3 ! old PC
mov.l @r2+,r0 ! old SR
add #-4,r2 ! exception frame stub (sr)
mov.l r1,@-r2 ! TRA
sts.l macl, @-r2
sts.l mach, @-r2
stc.l gbr, @-r2
mov.l r0,@-r2 ! save old SR
sts.l pr,@-r2
mov.l r3,@-r2 ! save old PC
mov r2,r0
add #8*4,r0
mov.l r0,@-r2 ! save old SP
mov.l r14,@-r2
mov.l r13,@-r2
mov.l r12,@-r2
mov.l r11,@-r2
mov.l r10,@-r2
mov.l r9,@-r2
mov.l r8,@-r2
mov.l r7,@-r2
mov.l r6,@-r2
mov.l r5,@-r2
mov.l r4,@-r2
mov.l @(OFF_R0,r15),r0
mov.l @(OFF_R1,r15),r1
mov.l @(OFF_R2,r15),r2
mov.l @(OFF_R3,r15),r3
2:
mov #OFF_TRA,r8
add r15,r8
mov.l @r8,r9
mov #64,r8
cmp/hs r8,r9
bt interrupt_entry ! vec >= 64 is interrupt
mov #32,r8
cmp/hs r8,r9
bt trap_entry ! 64 > vec >= 32 is trap
mov.l 4f,r8
mov r9,r4
shll2 r9
add r9,r8
mov.l @r8,r8
mov #0,r9
cmp/eq r9,r8
bf 3f
mov.l 8f,r8 ! unhandled exception
3:
mov.l 5f,r10
jmp @r8
lds r10,pr
interrupt_entry:
mov r9,r4
mov.l 6f,r9
mov.l 7f,r8
jmp @r8
lds r9,pr
.align 2
4: .long exception_handling_table
5: .long ret_from_exception
6: .long ret_from_irq
7: .long do_IRQ
8: .long do_exception_error
trap_entry:
add #-0x10,r9
shll2 r9 ! TRA
mov #OFF_TRA,r8
add r15,r8
mov.l r9,@r8
mov r9,r8
sti
bra system_call
nop
.align 2
1: .long syscall_exit
2: .long break_point_trap_software
3: .long NR_syscalls
4: .long sys_call_table
#if defined(CONFIG_SH_STANDARD_BIOS)
/* Unwind the stack and jmp to the debug entry */
debug_kernel_fw:
mov r15,r0
add #(22-4)*4-4,r0
ldc.l @r0+,gbr
lds.l @r0+,mach
lds.l @r0+,macl
mov r15,r0
mov.l @(OFF_SP,r0),r1
mov #OFF_SR,r2
mov.l @(r0,r2),r3
mov.l r3,@-r1
mov #OFF_SP,r2
mov.l @(r0,r2),r3
mov.l r3,@-r1
mov r15,r0
add #(22-4)*4-8,r0
mov.l 1f,r2
mov.l @r2,r2
stc sr,r3
mov.l r2,@r0
mov.l r3,@r0
mov.l r1,@(8,r0)
mov.l @r15+, r0
mov.l @r15+, r1
mov.l @r15+, r2
mov.l @r15+, r3
mov.l @r15+, r4
mov.l @r15+, r5
mov.l @r15+, r6
mov.l @r15+, r7
mov.l @r15+, r8
mov.l @r15+, r9
mov.l @r15+, r10
mov.l @r15+, r11
mov.l @r15+, r12
mov.l @r15+, r13
mov.l @r15+, r14
add #8,r15
lds.l @r15+, pr
rte
mov.l @r15+,r15
.align 2
1: .long gdb_vbr_vector
#endif /* CONFIG_SH_STANDARD_BIOS */
ENTRY(address_error_handler)
mov r15,r4 ! regs
add #4,r4
mov #OFF_PC,r0
mov.l @(r0,r15),r6 ! pc
mov.l 1f,r0
jmp @r0
mov #0,r5 ! writeaccess is unknown
.align 2
1: .long do_address_error
restore_all:
cli
mov r15,r0
mov.l $cpu_mode,r2
mov #OFF_SR,r3
mov.l @(r0,r3),r1
mov.l r1,@r2
shll2 r1 ! clear MD bit
shlr2 r1
mov.l @(OFF_SP,r0),r2
add #-8,r2
mov.l r2,@(OFF_SP,r0) ! point exception frame top
mov.l r1,@(4,r2) ! set sr
mov #OFF_PC,r3
mov.l @(r0,r3),r1
mov.l r1,@r2 ! set pc
add #4*16+4,r0
lds.l @r0+,pr
add #4,r0 ! skip sr
ldc.l @r0+,gbr
lds.l @r0+,mach
lds.l @r0+,macl
get_current_thread_info r0, r1
mov.l $current_thread_info,r1
mov.l r0,@r1
mov.l @r15+,r0
mov.l @r15+,r1
mov.l @r15+,r2
mov.l @r15+,r3
mov.l @r15+,r4
mov.l @r15+,r5
mov.l @r15+,r6
mov.l @r15+,r7
mov.l @r15+,r8
mov.l @r15+,r9
mov.l @r15+,r10
mov.l @r15+,r11
mov.l @r15+,r12
mov.l @r15+,r13
mov.l @r15+,r14
mov.l @r15,r15
rte
nop
2:
mov.l 1f,r8
mov.l 2f,r9
jmp @r9
lds r8,pr
.align 2
$current_thread_info:
.long __current_thread_info
$cpu_mode:
.long __cpu_mode
! common exception handler
#include "../../entry-common.S"
.data
! cpu operation mode
! bit30 = MD (compatible SH3/4)
__cpu_mode:
.long 0x40000000
.section .bss
__current_thread_info:
.long 0
ENTRY(exception_handling_table)
.space 4*32
arch/sh/kernel/cpu/sh2/ex.S 0 → 100644
View file @ de398406
/*
* arch/sh/kernel/cpu/sh2/ex.S
*
* The SH-2 exception vector table
*
* Copyright (C) 2005 Yoshinori Sato
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/linkage.h>
!
! convert Exception Vector to Exception Number
!
exception_entry:
no = 0
.rept 256
mov.l r0,@-sp
mov #no,r0
bra exception_trampoline
and #0xff,r0
no = no + 1
.endr
exception_trampoline:
mov.l r1,@-sp
mov.l $exception_handler,r1
jmp @r1
.align 2
$exception_entry:
.long exception_entry
$exception_handler:
.long exception_handler
!
! Exception Vector Base
!
.align 2
ENTRY(vbr_base)
vector = 0
.rept 256
.long exception_entry + vector * 8
vector = vector + 1
.endr
arch/sh/kernel/cpu/sh3/Makefile
View file @ de398406
......@@ -2,7 +2,7 @@
# Makefile for the Linux/SuperH SH-3 backends.
#
obj-y := ex.o probe.o
obj-y := ex.o probe.o entry.o
# CPU subtype setup
obj-$(CONFIG_CPU_SUBTYPE_SH7705) += setup-sh7705.o
......
arch/sh/kernel/entry.S → arch/sh/kernel/cpu/sh3/entry.S
View file @ de398406
/*
* linux/arch/sh/entry.S
* arch/sh/kernel/entry.S
*
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
* Copyright (C) 2003 - 2006 Paul Mundt
......@@ -7,7 +7,6 @@
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
*/
#include <linux/sys.h>
#include <linux/errno.h>
......@@ -81,6 +80,8 @@ OFF_TRA = (16*4+6*4)
#define k_g_imask r6_bank /* r6_bank1 */
#define current r7 /* r7_bank1 */
#include <asm/entry-macros.S>
/*
* Kernel mode register usage:
* k0 scratch
......@@ -107,26 +108,6 @@ OFF_TRA = (16*4+6*4)
! this first version depends *much* on C implementation.
!
#define CLI() \
stc sr, r0; \
or #0xf0, r0; \
ldc r0, sr
#define STI() \
mov.l __INV_IMASK, r11; \
stc sr, r10; \
and r11, r10; \
stc k_g_imask, r11; \
or r11, r10; \
ldc r10, sr
#if defined(CONFIG_PREEMPT)
# define preempt_stop() CLI()
#else
# define preempt_stop()
# define resume_kernel restore_all
#endif
#if defined(CONFIG_MMU)
.align 2
ENTRY(tlb_miss_load)
......@@ -168,7 +149,7 @@ call_dpf:
lds r10, pr
rts
nop
0: STI()
0: sti
mov.l 3f, r0
mov r9, r6
mov r8, r5
......@@ -203,32 +184,6 @@ call_dae:
2: .long do_address_error
#endif /* CONFIG_MMU */
#if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
! Handle kernel debug if either kgdb (SW) or gdb-stub (FW) is present.
! If both are configured, handle the debug traps (breakpoints) in SW,
! but still allow BIOS traps to FW.
.align 2
debug_kernel:
#if defined(CONFIG_SH_STANDARD_BIOS) && defined(CONFIG_SH_KGDB)
/* Force BIOS call to FW (debug_trap put TRA in r8) */
mov r8,r0
shlr2 r0
cmp/eq #0x3f,r0
bt debug_kernel_fw
#endif /* CONFIG_SH_STANDARD_BIOS && CONFIG_SH_KGDB */
debug_enter:
#if defined(CONFIG_SH_KGDB)
/* Jump to kgdb, pass stacked regs as arg */
debug_kernel_sw:
mov.l 3f, r0
jmp @r0
mov r15, r4
.align 2
3: .long kgdb_handle_exception
#endif /* CONFIG_SH_KGDB */
#if defined(CONFIG_SH_STANDARD_BIOS)
/* Unwind the stack and jmp to the debug entry */
debug_kernel_fw:
......@@ -269,276 +224,6 @@ debug_kernel_fw:
2: .long gdb_vbr_vector
#endif /* CONFIG_SH_STANDARD_BIOS */
#endif /* CONFIG_SH_STANDARD_BIOS || CONFIG_SH_KGDB */
.align 2
debug_trap:
#if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
shll r0
shll r0 ! kernel space?
bt/s debug_kernel
#endif
mov.l @r15, r0 ! Restore R0 value
mov.l 1f, r8
jmp @r8
nop
.align 2
ENTRY(exception_error)
!
STI()
mov.l 2f, r0
jmp @r0
nop
!
.align 2
1: .long break_point_trap_software
2: .long do_exception_error
.align 2
ret_from_exception:
preempt_stop()
ENTRY(ret_from_irq)
!
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
shll r0
shll r0 ! kernel space?
bt/s resume_kernel ! Yes, it's from kernel, go back soon
GET_THREAD_INFO(r8)
#ifdef CONFIG_PREEMPT
bra resume_userspace
nop
ENTRY(resume_kernel)
mov.l @(TI_PRE_COUNT,r8), r0 ! current_thread_info->preempt_count
tst r0, r0
bf noresched
need_resched:
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_NEED_RESCHED, r0 ! need_resched set?
bt noresched
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
and #0xf0, r0 ! interrupts off (exception path)?
cmp/eq #0xf0, r0
bt noresched
mov.l 1f, r0
mov.l r0, @(TI_PRE_COUNT,r8)
STI()
mov.l 2f, r0
jsr @r0
nop
mov #0, r0
mov.l r0, @(TI_PRE_COUNT,r8)
CLI()
bra need_resched
nop
noresched:
bra restore_all
nop
.align 2
1: .long PREEMPT_ACTIVE
2: .long schedule
#endif
ENTRY(resume_userspace)
! r8: current_thread_info
CLI()
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_WORK_MASK, r0
bt/s restore_all
tst #_TIF_NEED_RESCHED, r0
.align 2
work_pending:
! r0: current_thread_info->flags
! r8: current_thread_info
! t: result of "tst #_TIF_NEED_RESCHED, r0"
bf/s work_resched
tst #(_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), r0
work_notifysig:
bt/s restore_all
mov r15, r4
mov r12, r5 ! set arg1(save_r0)
mov r0, r6
mov.l 2f, r1
mova restore_all, r0
jmp @r1
lds r0, pr
work_resched:
#ifndef CONFIG_PREEMPT
! gUSA handling
mov.l @(OFF_SP,r15), r0 ! get user space stack pointer
mov r0, r1
shll r0
bf/s 1f
shll r0
bf/s 1f
mov #OFF_PC, r0
! SP >= 0xc0000000 : gUSA mark
mov.l @(r0,r15), r2 ! get user space PC (program counter)
mov.l @(OFF_R0,r15), r3 ! end point
cmp/hs r3, r2 ! r2 >= r3?
bt 1f
add r3, r1 ! rewind point #2
mov.l r1, @(r0,r15) ! reset PC to rewind point #2
!
1:
#endif
mov.l 1f, r1
jsr @r1 ! schedule
nop
CLI()
!
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_WORK_MASK, r0
bt restore_all
bra work_pending
tst #_TIF_NEED_RESCHED, r0
.align 2
1: .long schedule
2: .long do_notify_resume
.align 2
syscall_exit_work:
! r0: current_thread_info->flags
! r8: current_thread_info
tst #_TIF_SYSCALL_TRACE, r0
bt/s work_pending
tst #_TIF_NEED_RESCHED, r0
STI()
! XXX setup arguments...
mov.l 4f, r0 ! do_syscall_trace
jsr @r0
nop
bra resume_userspace
nop
.align 2
syscall_trace_entry:
! Yes it is traced.
! XXX setup arguments...
mov.l 4f, r11 ! Call do_syscall_trace which notifies
jsr @r11 ! superior (will chomp R[0-7])
nop
! Reload R0-R4 from kernel stack, where the
! parent may have modified them using
! ptrace(POKEUSR). (Note that R0-R2 are
! used by the system call handler directly
! from the kernel stack anyway, so don't need
! to be reloaded here.) This allows the parent
! to rewrite system calls and args on the fly.
mov.l @(OFF_R4,r15), r4 ! arg0
mov.l @(OFF_R5,r15), r5
mov.l @(OFF_R6,r15), r6
mov.l @(OFF_R7,r15), r7 ! arg3
mov.l @(OFF_R3,r15), r3 ! syscall_nr
! Arrange for do_syscall_trace to be called
! again as the system call returns.
mov.l 2f, r10 ! Number of syscalls
cmp/hs r10, r3
bf syscall_call
mov #-ENOSYS, r0
bra syscall_exit
mov.l r0, @(OFF_R0,r15) ! Return value
/*
* Syscall interface:
*
* Syscall #: R3
* Arguments #0 to #3: R4--R7
* Arguments #4 to #6: R0, R1, R2
* TRA: (number of arguments + 0x10) x 4
*
* This code also handles delegating other traps to the BIOS/gdb stub
* according to:
*
* Trap number
* (TRA>>2) Purpose
* -------- -------
* 0x0-0xf old syscall ABI
* 0x10-0x1f new syscall ABI
* 0x20-0xff delegated through debug_trap to BIOS/gdb stub.
*
* Note: When we're first called, the TRA value must be shifted
* right 2 bits in order to get the value that was used as the "trapa"
* argument.
*/
.align 2
.globl ret_from_fork
ret_from_fork:
mov.l 1f, r8
jsr @r8
mov r0, r4
bra syscall_exit
nop
.align 2
1: .long schedule_tail
!
ENTRY(system_call)
mov.l 1f, r9
mov.l @r9, r8 ! Read from TRA (Trap Address) Register
!
! Is the trap argument >= 0x20? (TRA will be >= 0x80)
mov #0x7f, r9
cmp/hi r9, r8
bt/s 0f
mov #OFF_TRA, r9
add r15, r9
!
mov.l r8, @r9 ! set TRA value to tra
STI()
! Call the system call handler through the table.
! First check for bad syscall number
mov r3, r9
mov.l 2f, r8 ! Number of syscalls
cmp/hs r8, r9
bf/s good_system_call
GET_THREAD_INFO(r8)
syscall_badsys: ! Bad syscall number
mov #-ENOSYS, r0
bra resume_userspace
mov.l r0, @(OFF_R0,r15) ! Return value
!
0:
bra debug_trap
nop
!
good_system_call: ! Good syscall number
mov.l @(TI_FLAGS,r8), r8
mov #_TIF_SYSCALL_TRACE, r10
tst r10, r8
bf syscall_trace_entry
!
syscall_call:
shll2 r9 ! x4
mov.l 3f, r8 ! Load the address of sys_call_table
add r8, r9
mov.l @r9, r8
jsr @r8 ! jump to specific syscall handler
nop
mov.l @(OFF_R0,r15), r12 ! save r0
mov.l r0, @(OFF_R0,r15) ! save the return value
!
syscall_exit:
CLI()
!
GET_THREAD_INFO(r8)
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_ALLWORK_MASK, r0
bf syscall_exit_work
restore_all:
mov.l @r15+, r0
mov.l @r15+, r1
......@@ -606,7 +291,9 @@ skip_restore:
!
! Calculate new SR value
mov k3, k2 ! original SR value
mov.l 9f, k1
mov #0xf0, k1
extu.b k1, k1
not k1, k1
and k1, k2 ! Mask orignal SR value
!
mov k3, k0 ! Calculate IMASK-bits
......@@ -632,16 +319,12 @@ skip_restore:
nop
.align 2
1: .long TRA
2: .long NR_syscalls
3: .long sys_call_table
4: .long do_syscall_trace
5: .long 0x00001000 ! DSP
7: .long 0x30000000
9:
__INV_IMASK:
.long 0xffffff0f ! ~(IMASK)
! common exception handler
#include "../../entry.S"
! Exception Vector Base
!
! Should be aligned page boundary.
......@@ -761,7 +444,7 @@ skip_save:
! Save the user registers on the stack.
mov.l k2, @-r15 ! EXPEVT
mov #-1, k4
mov #-1, k4
mov.l k4, @-r15 ! set TRA (default: -1)
!
sts.l macl, @-r15
......
arch/sh/kernel/cpu/sh4/Makefile
View file @ de398406
......@@ -2,7 +2,8 @@
# Makefile for the Linux/SuperH SH-4 backends.
#
obj-y := ex.o probe.o
obj-y := ex.o probe.o common.o
common-y += $(addprefix ../sh3/, entry.o)
obj-$(CONFIG_SH_FPU) += fpu.o
obj-$(CONFIG_SH_STORE_QUEUES) += sq.o
......
arch/sh/kernel/entry-common.S 0 → 100644
View file @ de398406
/* $Id: entry.S,v 1.37 2004/06/11 13:02:46 doyu Exp $
*
* linux/arch/sh/entry.S
*
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
* Copyright (C) 2003 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
*/
! NOTE:
! GNU as (as of 2.9.1) changes bf/s into bt/s and bra, when the address
! to be jumped is too far, but it causes illegal slot exception.
/*
* entry.S contains the system-call and fault low-level handling routines.
* This also contains the timer-interrupt handler, as well as all interrupts
* and faults that can result in a task-switch.
*
* NOTE: This code handles signal-recognition, which happens every time
* after a timer-interrupt and after each system call.
*
* NOTE: This code uses a convention that instructions in the delay slot
* of a transfer-control instruction are indented by an extra space, thus:
*
* jmp @k0 ! control-transfer instruction
* ldc k1, ssr ! delay slot
*
* Stack layout in 'ret_from_syscall':
* ptrace needs to have all regs on the stack.
* if the order here is changed, it needs to be
* updated in ptrace.c and ptrace.h
*
* r0
* ...
* r15 = stack pointer
* spc
* pr
* ssr
* gbr
* mach
* macl
* syscall #
*
*/
#if defined(CONFIG_PREEMPT)
# define preempt_stop() cli
#else
# define preempt_stop()
# define resume_kernel __restore_all
#endif
#if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
! Handle kernel debug if either kgdb (SW) or gdb-stub (FW) is present.
! If both are configured, handle the debug traps (breakpoints) in SW,
! but still allow BIOS traps to FW.
.align 2
debug_kernel:
#if defined(CONFIG_SH_STANDARD_BIOS) && defined(CONFIG_SH_KGDB)
/* Force BIOS call to FW (debug_trap put TRA in r8) */
mov r8,r0
shlr2 r0
cmp/eq #0x3f,r0
bt debug_kernel_fw
#endif /* CONFIG_SH_STANDARD_BIOS && CONFIG_SH_KGDB */
debug_enter:
#if defined(CONFIG_SH_KGDB)
/* Jump to kgdb, pass stacked regs as arg */
debug_kernel_sw:
mov.l 3f, r0
jmp @r0
mov r15, r4
.align 2
3: .long kgdb_handle_exception
#endif /* CONFIG_SH_KGDB */
#endif /* CONFIG_SH_STANDARD_BIOS || CONFIG_SH_KGDB */
.align 2
debug_trap:
#if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
shll r0
shll r0 ! kernel space?
bt/s debug_kernel
#endif
mov.l @r15, r0 ! Restore R0 value
mov.l 1f, r8
jmp @r8
nop
.align 2
ENTRY(exception_error)
!
sti
mov.l 2f, r0
jmp @r0
nop
!
.align 2
1: .long break_point_trap_software
2: .long do_exception_error
.align 2
ret_from_exception:
preempt_stop()
ENTRY(ret_from_irq)
!
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
shll r0
shll r0 ! kernel space?
get_current_thread_info r8, r0
bt resume_kernel ! Yes, it's from kernel, go back soon
#ifdef CONFIG_PREEMPT
bra resume_userspace
nop
ENTRY(resume_kernel)
mov.l @(TI_PRE_COUNT,r8), r0 ! current_thread_info->preempt_count
tst r0, r0
bf noresched
need_resched:
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_NEED_RESCHED, r0 ! need_resched set?
bt noresched
mov #OFF_SR, r0
mov.l @(r0,r15), r0 ! get status register
and #0xf0, r0 ! interrupts off (exception path)?
cmp/eq #0xf0, r0
bt noresched
mov.l 1f, r0
mov.l r0, @(TI_PRE_COUNT,r8)
sti
mov.l 2f, r0
jsr @r0
nop
mov #0, r0
mov.l r0, @(TI_PRE_COUNT,r8)
cli
bra need_resched
nop
noresched:
bra __restore_all
nop
.align 2
1: .long PREEMPT_ACTIVE
2: .long schedule
#endif
ENTRY(resume_userspace)
! r8: current_thread_info
cli
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_WORK_MASK, r0
bt/s __restore_all
tst #_TIF_NEED_RESCHED, r0
.align 2
work_pending:
! r0: current_thread_info->flags
! r8: current_thread_info
! t: result of "tst #_TIF_NEED_RESCHED, r0"
bf/s work_resched
tst #(_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), r0
work_notifysig:
bt/s __restore_all
mov r15, r4
mov r12, r5 ! set arg1(save_r0)
mov r0, r6
mov.l 2f, r1
mov.l 3f, r0
jmp @r1
lds r0, pr
work_resched:
#ifndef CONFIG_PREEMPT
! gUSA handling
mov.l @(OFF_SP,r15), r0 ! get user space stack pointer
mov r0, r1
shll r0
bf/s 1f
shll r0
bf/s 1f
mov #OFF_PC, r0
! SP >= 0xc0000000 : gUSA mark
mov.l @(r0,r15), r2 ! get user space PC (program counter)
mov.l @(OFF_R0,r15), r3 ! end point
cmp/hs r3, r2 ! r2 >= r3?
bt 1f
add r3, r1 ! rewind point #2
mov.l r1, @(r0,r15) ! reset PC to rewind point #2
!
1:
#endif
mov.l 1f, r1
jsr @r1 ! schedule
nop
cli
!
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_WORK_MASK, r0
bt __restore_all
bra work_pending
tst #_TIF_NEED_RESCHED, r0
.align 2
1: .long schedule
2: .long do_notify_resume
3: .long restore_all
.align 2
syscall_exit_work:
! r0: current_thread_info->flags
! r8: current_thread_info
tst #_TIF_SYSCALL_TRACE, r0
bt/s work_pending
tst #_TIF_NEED_RESCHED, r0
sti
! XXX setup arguments...
mov.l 4f, r0 ! do_syscall_trace
jsr @r0
nop
bra resume_userspace
nop
.align 2
syscall_trace_entry:
! Yes it is traced.
! XXX setup arguments...
mov.l 4f, r11 ! Call do_syscall_trace which notifies
jsr @r11 ! superior (will chomp R[0-7])
nop
! Reload R0-R4 from kernel stack, where the
! parent may have modified them using
! ptrace(POKEUSR). (Note that R0-R2 are
! used by the system call handler directly
! from the kernel stack anyway, so don't need
! to be reloaded here.) This allows the parent
! to rewrite system calls and args on the fly.
mov.l @(OFF_R4,r15), r4 ! arg0
mov.l @(OFF_R5,r15), r5
mov.l @(OFF_R6,r15), r6
mov.l @(OFF_R7,r15), r7 ! arg3
mov.l @(OFF_R3,r15), r3 ! syscall_nr
! Arrange for do_syscall_trace to be called
! again as the system call returns.
mov.l 2f, r10 ! Number of syscalls
cmp/hs r10, r3
bf syscall_call
mov #-ENOSYS, r0
bra syscall_exit
mov.l r0, @(OFF_R0,r15) ! Return value
__restore_all:
mov.l 1f,r0
jmp @r0
nop
.align 2
1: .long restore_all
/*
* Syscall interface:
*
* Syscall #: R3
* Arguments #0 to #3: R4--R7
* Arguments #4 to #6: R0, R1, R2
* TRA: (number of arguments + 0x10) x 4
*
* This code also handles delegating other traps to the BIOS/gdb stub
* according to:
*
* Trap number
* (TRA>>2) Purpose
* -------- -------
* 0x0-0xf old syscall ABI
* 0x10-0x1f new syscall ABI
* 0x20-0xff delegated through debug_trap to BIOS/gdb stub.
*
* Note: When we're first called, the TRA value must be shifted
* right 2 bits in order to get the value that was used as the "trapa"
* argument.
*/
.align 2
.globl ret_from_fork
ret_from_fork:
mov.l 1f, r8
jsr @r8
mov r0, r4
bra syscall_exit
nop
.align 2
1: .long schedule_tail
!
ENTRY(system_call)
#if !defined(CONFIG_CPU_SH2)
mov.l 1f, r9
mov.l @r9, r8 ! Read from TRA (Trap Address) Register
#endif
!
! Is the trap argument >= 0x20? (TRA will be >= 0x80)
mov #0x7f, r9
cmp/hi r9, r8
bt/s 0f
mov #OFF_TRA, r9
add r15, r9
!
mov.l r8, @r9 ! set TRA value to tra
sti
! Call the system call handler through the table.
! First check for bad syscall number
mov r3, r9
mov.l 2f, r8 ! Number of syscalls
cmp/hs r8, r9
get_current_thread_info r8, r10
bf good_system_call
syscall_badsys: ! Bad syscall number
mov #-ENOSYS, r0
bra resume_userspace
mov.l r0, @(OFF_R0,r15) ! Return value
!
0:
bra debug_trap
nop
!
good_system_call: ! Good syscall number
mov.l @(TI_FLAGS,r8), r8
mov #_TIF_SYSCALL_TRACE, r10
tst r10, r8
bf syscall_trace_entry
!
syscall_call:
shll2 r9 ! x4
mov.l 3f, r8 ! Load the address of sys_call_table
add r8, r9
mov.l @r9, r8
jsr @r8 ! jump to specific syscall handler
nop
mov.l @(OFF_R0,r15), r12 ! save r0
mov.l r0, @(OFF_R0,r15) ! save the return value
!
syscall_exit:
cli
!
get_current_thread_info r8, r0
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
tst #_TIF_ALLWORK_MASK, r0
bf syscall_exit_work
bra __restore_all
nop
.align 2
#if !defined(CONFIG_CPU_SH2)
1: .long TRA
#endif
2: .long NR_syscalls
3: .long sys_call_table
4: .long do_syscall_trace
arch/sh/kernel/head.S
View file @ de398406
......@@ -53,8 +53,10 @@ ENTRY(_stext)
ldc r0, sr
! Initialize global interrupt mask
mov #0, r0
#ifdef CONFIG_CPU_HAS_SR_RB
ldc r0, r6_bank
#endif
/*
* Prefetch if possible to reduce cache miss penalty.
*
......@@ -71,8 +73,10 @@ ENTRY(_stext)
mov #(THREAD_SIZE >> 8), r1
shll8 r1 ! r1 = THREAD_SIZE
sub r1, r0 !
#ifdef CONFIG_CPU_HAS_SR_RB
ldc r0, r7_bank ! ... and initial thread_info
#endif
! Clear BSS area
mov.l 3f, r1
add #4, r1
......@@ -95,7 +99,11 @@ ENTRY(_stext)
nop
.balign 4
#if defined(CONFIG_CPU_SH2)
1: .long 0x000000F0 ! IMASK=0xF
#else
1: .long 0x400080F0 ! MD=1, RB=0, BL=0, FD=1, IMASK=0xF
#endif
2: .long init_thread_union+THREAD_SIZE
3: .long __bss_start
4: .long _end
......
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