alistair23-linux/arch/openrisc/include/asm/processor.h
David Howells 0500871f21 Construct init thread stack in the linker script rather than by union
Construct the init thread stack in the linker script rather than doing it
by means of a union so that ia64's init_task.c can be got rid of.

The following symbols are then made available from INIT_TASK_DATA() linker
script macro:

	init_thread_union
	init_stack

INIT_TASK_DATA() also expands the region to THREAD_SIZE to accommodate the
size of the init stack.  init_thread_union is given its own section so that
it can be placed into the stack space in the right order.  I'm assuming
that the ia64 ordering is correct and that the task_struct is first and the
thread_info second.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Will Deacon <will.deacon@arm.com> (arm64)
Tested-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2018-01-09 23:21:02 +00:00

91 lines
2.6 KiB
C

/*
* OpenRISC Linux
*
* Linux architectural port borrowing liberally from similar works of
* others. All original copyrights apply as per the original source
* declaration.
*
* OpenRISC implementation:
* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
* et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#ifndef __ASM_OPENRISC_PROCESSOR_H
#define __ASM_OPENRISC_PROCESSOR_H
#include <asm/spr_defs.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
/* Kernel and user SR register setting */
#define KERNEL_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_ICE \
| SPR_SR_DCE | SPR_SR_SM)
#define USER_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_ICE \
| SPR_SR_DCE | SPR_SR_IEE | SPR_SR_TEE)
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ __label__ _l; _l: &&_l; })
/*
* User space process size. This is hardcoded into a few places,
* so don't change it unless you know what you are doing.
*/
#define TASK_SIZE (0x80000000UL)
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE (TASK_SIZE / 8 * 3)
#ifndef __ASSEMBLY__
struct task_struct;
struct thread_struct {
};
/*
* At user->kernel entry, the pt_regs struct is stacked on the top of the
* kernel-stack. This macro allows us to find those regs for a task.
* Notice that subsequent pt_regs stackings, like recursive interrupts
* occurring while we're in the kernel, won't affect this - only the first
* user->kernel transition registers are reached by this (i.e. not regs
* for running signal handler)
*/
#define user_regs(thread_info) (((struct pt_regs *)((unsigned long)(thread_info) + THREAD_SIZE - STACK_FRAME_OVERHEAD)) - 1)
/*
* Dito but for the currently running task
*/
#define task_pt_regs(task) user_regs(task_thread_info(task))
#define INIT_SP (sizeof(init_stack) + (unsigned long) &init_stack)
#define INIT_THREAD { }
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp);
void release_thread(struct task_struct *);
unsigned long get_wchan(struct task_struct *p);
#define cpu_relax() barrier()
#endif /* __ASSEMBLY__ */
#endif /* __ASM_OPENRISC_PROCESSOR_H */