xref: /linux/arch/openrisc/include/asm/processor.h (revision 59e6295fac26b8e85c1ea859cdd89fa1e47519d7)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * OpenRISC Linux
4  *
5  * Linux architectural port borrowing liberally from similar works of
6  * others.  All original copyrights apply as per the original source
7  * declaration.
8  *
9  * OpenRISC implementation:
10  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12  * et al.
13  */
14 
15 #ifndef __ASM_OPENRISC_PROCESSOR_H
16 #define __ASM_OPENRISC_PROCESSOR_H
17 
18 #include <asm/spr_defs.h>
19 #include <asm/page.h>
20 #include <asm/ptrace.h>
21 
22 #define STACK_TOP       TASK_SIZE
23 #define STACK_TOP_MAX	STACK_TOP
24 /* Kernel and user SR register setting */
25 #define KERNEL_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_ICE \
26 		   | SPR_SR_DCE | SPR_SR_SM)
27 #define USER_SR   (SPR_SR_DME | SPR_SR_IME | SPR_SR_ICE \
28 		   | SPR_SR_DCE | SPR_SR_IEE | SPR_SR_TEE)
29 /* SR bits user space may change via sigreturn, the rest stay kernel owned */
30 #define SPR_SR_USER_MASK  (SPR_SR_F | SPR_SR_CY | SPR_SR_OV)
31 
32 /*
33  * User space process size. This is hardcoded into a few places,
34  * so don't change it unless you know what you are doing.
35  */
36 
37 #define TASK_SIZE       (0x80000000UL)
38 
39 /* This decides where the kernel will search for a free chunk of vm
40  * space during mmap's.
41  */
42 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 8 * 3)
43 
44 #ifndef __ASSEMBLER__
45 
46 struct task_struct;
47 
48 struct thread_struct {
49 	long fpcsr;		/* Floating point control status register. */
50 };
51 
52 /*
53  * At user->kernel entry, the pt_regs struct is stacked on the top of the
54  * kernel-stack.  This macro allows us to find those regs for a task.
55  * Notice that subsequent pt_regs stackings, like recursive interrupts
56  * occurring while we're in the kernel, won't affect this - only the first
57  * user->kernel transition registers are reached by this (i.e. not regs
58  * for running signal handler)
59  */
60 #define user_regs(thread_info)  (((struct pt_regs *)((unsigned long)(thread_info) + THREAD_SIZE - STACK_FRAME_OVERHEAD)) - 1)
61 
62 /*
63  * Dito but for the currently running task
64  */
65 
66 #define task_pt_regs(task) user_regs(task_thread_info(task))
67 
68 #define INIT_SP         (sizeof(init_stack) + (unsigned long) &init_stack)
69 
70 #define INIT_THREAD  { }
71 
72 
73 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->pc)
74 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
75 
76 
77 void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp);
78 unsigned long __get_wchan(struct task_struct *p);
79 void show_registers(struct pt_regs *regs);
80 
81 #define cpu_relax()     barrier()
82 
83 #endif /* __ASSEMBLER__ */
84 #endif /* __ASM_OPENRISC_PROCESSOR_H */
85