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#ifndef __ASSEMBLY__
18
19#include <asm/ptrace.h>
20
21#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
22/* These DPFP regs need to be saved/restored across ctx-sw */
23struct arc_fpu {
24 struct {
25 unsigned int l, h;
26 } aux_dpfp[2];
27};
28#endif
29
30/* Arch specific stuff which needs to be saved per task.
31 * However these items are not so important so as to earn a place in
32 * struct thread_info
33 */
34struct thread_struct {
35 unsigned long ksp; /* kernel mode stack pointer */
36 unsigned long callee_reg; /* pointer to callee regs */
37 unsigned long fault_address; /* dbls as brkpt holder as well */
38#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
39 struct arc_fpu fpu;
40#endif
41};
42
43#define INIT_THREAD { \
44 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
45}
46
47/* Forward declaration, a strange C thing */
48struct task_struct;
49
50/* Return saved PC of a blocked thread */
51unsigned long thread_saved_pc(struct task_struct *t);
52
53#define task_pt_regs(p) \
54 ((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
55
56/* Free all resources held by a thread */
57#define release_thread(thread) do { } while (0)
58
59/* Prepare to copy thread state - unlazy all lazy status */
60#define prepare_to_copy(tsk) do { } while (0)
61
62/*
63 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
64 * get optimised away by gcc
65 */
66#ifdef CONFIG_SMP
67#define cpu_relax() __asm__ __volatile__ ("" : : : "memory")
68#else
69#define cpu_relax() do { } while (0)
70#endif
71
72#define cpu_relax_lowlatency() cpu_relax()
73
74#define copy_segments(tsk, mm) do { } while (0)
75#define release_segments(mm) do { } while (0)
76
77#define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret)
78
79/*
80 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
81 * Look in process.c for details of kernel stack layout
82 */
83#define KSTK_ESP(tsk) (tsk->thread.ksp)
84
85#define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \
86 sizeof(struct callee_regs) + off)))
87
88#define KSTK_BLINK(tsk) KSTK_REG(tsk, 4)
89#define KSTK_FP(tsk) KSTK_REG(tsk, 0)
90
91extern void start_thread(struct pt_regs * regs, unsigned long pc,
92 unsigned long usp);
93
94extern unsigned int get_wchan(struct task_struct *p);
95
96/*
97 * Default implementation of macro that returns current
98 * instruction pointer ("program counter").
99 * Should the PC register be read instead ? This macro does not seem to
100 * be used in many places so this wont be all that bad.
101 */
102#define current_text_addr() ({ __label__ _l; _l: &&_l; })
103
104#endif /* !__ASSEMBLY__ */
105
106/* Kernels Virtual memory area.
107 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a
108 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part
109 * of the translated bottom 2GB for kernel virtual memory and protect
110 * these pages from user accesses by disabling Ru, Eu and Wu.
111 */
112#define VMALLOC_SIZE (0x10000000) /* 256M */
113#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
114#define VMALLOC_END (PAGE_OFFSET)
115
116/* Most of the architectures seem to be keeping some kind of padding between
117 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET.
118 */
119#define USER_KERNEL_GUTTER 0x10000000
120
121/* User address space:
122 * On ARC700, CPU allows the entire lower half of 32 bit address space to be
123 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space.
124 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another
125 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces
126 * Thus total User vaddr space is (0:0x5FFF_FFFF)
127 */
128#define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER)
129
130#define STACK_TOP TASK_SIZE
131#define STACK_TOP_MAX STACK_TOP
132
133/* This decides where the kernel will search for a free chunk of vm
134 * space during mmap's.
135 */
136#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
137
138#endif /* __ASM_ARC_PROCESSOR_H */