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Vineet Gupta3be80aa2013-01-18 15:12:17 +05301/*
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/arcregs.h> /* for STATUS_E1_MASK et all */
Vineet Gupta16f9afe2013-05-27 21:43:41 +053022#include <asm/ptrace.h>
Vineet Gupta3be80aa2013-01-18 15:12:17 +053023
24/* Arch specific stuff which needs to be saved per task.
25 * However these items are not so important so as to earn a place in
26 * struct thread_info
27 */
28struct thread_struct {
29 unsigned long ksp; /* kernel mode stack pointer */
30 unsigned long callee_reg; /* pointer to callee regs */
31 unsigned long fault_address; /* dbls as brkpt holder as well */
Vineet Guptabf90e1e2013-01-18 15:12:18 +053032#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
33 struct arc_fpu fpu;
34#endif
Vineet Gupta3be80aa2013-01-18 15:12:17 +053035};
36
37#define INIT_THREAD { \
38 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
39}
40
41/* Forward declaration, a strange C thing */
42struct task_struct;
43
44/*
45 * Return saved PC of a blocked thread.
46 */
47unsigned long thread_saved_pc(struct task_struct *t);
48
49#define task_pt_regs(p) \
Vineet Gupta283237a2013-05-28 09:34:45 +053050 ((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
Vineet Gupta3be80aa2013-01-18 15:12:17 +053051
52/* Free all resources held by a thread. */
53#define release_thread(thread) do { } while (0)
54
55/* Prepare to copy thread state - unlazy all lazy status */
56#define prepare_to_copy(tsk) do { } while (0)
57
Vineet Gupta41195d22013-01-18 15:12:23 +053058/*
59 * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
60 * get optimised away by gcc
61 */
62#ifdef CONFIG_SMP
63#define cpu_relax() __asm__ __volatile__ ("" : : : "memory")
64#else
Vineet Gupta3be80aa2013-01-18 15:12:17 +053065#define cpu_relax() do { } while (0)
Vineet Gupta41195d22013-01-18 15:12:23 +053066#endif
Vineet Gupta3be80aa2013-01-18 15:12:17 +053067
Vineet Gupta3be80aa2013-01-18 15:12:17 +053068#define copy_segments(tsk, mm) do { } while (0)
69#define release_segments(mm) do { } while (0)
70
71#define KSTK_EIP(tsk) (task_pt_regs(tsk)->ret)
72
73/*
74 * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
Vineet Gupta16f9afe2013-05-27 21:43:41 +053075 * Look in process.c for details of kernel stack layout
Vineet Gupta3be80aa2013-01-18 15:12:17 +053076 */
77#define KSTK_ESP(tsk) (tsk->thread.ksp)
Vineet Gupta16f9afe2013-05-27 21:43:41 +053078
79#define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \
80 sizeof(struct callee_regs) + off)))
81
82#define KSTK_BLINK(tsk) KSTK_REG(tsk, 4)
83#define KSTK_FP(tsk) KSTK_REG(tsk, 0)
Vineet Gupta3be80aa2013-01-18 15:12:17 +053084
85/*
86 * Do necessary setup to start up a newly executed thread.
87 *
88 * E1,E2 so that Interrupts are enabled in user mode
89 * L set, so Loop inhibited to begin with
90 * lp_start and lp_end seeded with bogus non-zero values so to easily catch
91 * the ARC700 sr to lp_start hardware bug
92 */
93#define start_thread(_regs, _pc, _usp) \
94do { \
95 set_fs(USER_DS); /* reads from user space */ \
96 (_regs)->ret = (_pc); \
97 /* Interrupts enabled in User Mode */ \
98 (_regs)->status32 = STATUS_U_MASK | STATUS_L_MASK \
99 | STATUS_E1_MASK | STATUS_E2_MASK; \
100 (_regs)->sp = (_usp); \
101 /* bogus seed values for debugging */ \
102 (_regs)->lp_start = 0x10; \
103 (_regs)->lp_end = 0x80; \
104} while (0)
105
106extern unsigned int get_wchan(struct task_struct *p);
107
108/*
109 * Default implementation of macro that returns current
110 * instruction pointer ("program counter").
111 * Should the PC register be read instead ? This macro does not seem to
112 * be used in many places so this wont be all that bad.
113 */
114#define current_text_addr() ({ __label__ _l; _l: &&_l; })
115
116#endif /* !__ASSEMBLY__ */
117
118/* Kernels Virtual memory area.
119 * Unlike other architectures(MIPS, sh, cris ) ARC 700 does not have a
120 * "kernel translated" region (like KSEG2 in MIPS). So we use a upper part
121 * of the translated bottom 2GB for kernel virtual memory and protect
122 * these pages from user accesses by disabling Ru, Eu and Wu.
123 */
124#define VMALLOC_SIZE (0x10000000) /* 256M */
125#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
126#define VMALLOC_END (PAGE_OFFSET)
127
128/* Most of the architectures seem to be keeping some kind of padding between
129 * userspace TASK_SIZE and PAGE_OFFSET. i.e TASK_SIZE != PAGE_OFFSET.
130 */
131#define USER_KERNEL_GUTTER 0x10000000
132
133/* User address space:
134 * On ARC700, CPU allows the entire lower half of 32 bit address space to be
135 * translated. Thus potentially 2G (0:0x7FFF_FFFF) could be User vaddr space.
136 * However we steal 256M for kernel addr (0x7000_0000:0x7FFF_FFFF) and another
137 * 256M (0x6000_0000:0x6FFF_FFFF) is gutter between user/kernel spaces
138 * Thus total User vaddr space is (0:0x5FFF_FFFF)
139 */
140#define TASK_SIZE (PAGE_OFFSET - VMALLOC_SIZE - USER_KERNEL_GUTTER)
141
142#define STACK_TOP TASK_SIZE
143#define STACK_TOP_MAX STACK_TOP
144
145/* This decides where the kernel will search for a free chunk of vm
146 * space during mmap's.
147 */
148#define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
149
150#endif /* __KERNEL__ */
151
152#endif /* __ASM_ARC_PROCESSOR_H */