Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * vineetg: March 2009
9 * -Implemented task_pt_regs( )
10 *
11 * Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004
12 */
13
14#ifndef __ASM_ARC_PROCESSOR_H
15#define __ASM_ARC_PROCESSOR_H
16
17#ifdef __KERNEL__
18
19#ifndef __ASSEMBLY__
20
21#include <asm/ptrace.h>
22
23/* Arch specific stuff which needs to be saved per task.
24 * However these items are not so important so as to earn a place in
25 * struct thread_info
26 */
27struct thread_struct {
28 unsigned long ksp; /* kernel mode stack pointer */
29 unsigned long callee_reg; /* pointer to callee regs */
30 unsigned long fault_address; /* dbls as brkpt holder as well */
31#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
32 struct arc_fpu fpu;
33#endif
34};
35
36#define INIT_THREAD { \
37 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
38}
39
40/* Forward declaration, a strange C thing */
41struct task_struct;
42
43/* Return saved PC of a blocked thread */
44unsigned long thread_saved_pc(struct task_struct *t);
45
46#define task_pt_regs(p) \
47 ((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
48
49/* Free all resources held by a thread */
50#define release_thread(thread) do { } while (0)
51
52/* Prepare to copy thread state - unlazy all lazy status */
53#define prepare_to_copy(tsk) do { } while (0)
54
55/*
56 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
57 * get optimised away by gcc
58 */
59#ifdef CONFIG_SMP
60#define cpu_relax() __asm__ __volatile__ ("" : : : "memory")
61#else
62#define cpu_relax() do { } while (0)
63#endif
64
65#define cpu_relax_lowlatency() cpu_relax()
66
67#define copy_segments(tsk, mm) do { } while (0)
68#define release_segments(mm) do { } while (0)
69
70#define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret)
71
72/*
73 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
74 * Look in process.c for details of kernel stack layout
75 */
76#define KSTK_ESP(tsk) (tsk->thread.ksp)
77
78#define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \
79 sizeof(struct callee_regs) + off)))
80
81#define KSTK_BLINK(tsk) KSTK_REG(tsk, 4)
82#define KSTK_FP(tsk) KSTK_REG(tsk, 0)
83
84extern void start_thread(struct pt_regs * regs, unsigned long pc,
85 unsigned long usp);
86
87extern unsigned int get_wchan(struct task_struct *p);
88
89/*
90 * Default implementation of macro that returns current
91 * instruction pointer ("program counter").
92 * Should the PC register be read instead ? This macro does not seem to
93 * be used in many places so this wont be all that bad.
94 */
95#define current_text_addr() ({ __label__ _l; _l: &&_l; })
96
97#endif /* !__ASSEMBLY__ */
98
99/* Kernels Virtual memory area.
100 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a
101 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part
102 * of the translated bottom 2GB for kernel virtual memory and protect
103 * these pages from user accesses by disabling Ru, Eu and Wu.
104 */
105#define VMALLOC_SIZE (0x10000000) /* 256M */
106#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
107#define VMALLOC_END (PAGE_OFFSET)
108
109/* Most of the architectures seem to be keeping some kind of padding between
110 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET.
111 */
112#define USER_KERNEL_GUTTER 0x10000000
113
114/* User address space:
115 * On ARC700, CPU allows the entire lower half of 32 bit address space to be
116 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space.
117 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another
118 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces
119 * Thus total User vaddr space is (0:0x5FFF_FFFF)
120 */
121#define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER)
122
123#define STACK_TOP TASK_SIZE
124#define STACK_TOP_MAX STACK_TOP
125
126/* This decides where the kernel will search for a free chunk of vm
127 * space during mmap's.
128 */
129#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
130
131#endif /* __KERNEL__ */
132
133#endif /* __ASM_ARC_PROCESSOR_H */