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1#ifndef __ASM_SH_PROCESSOR_64_H
2#define __ASM_SH_PROCESSOR_64_H
3
4/*
5 * include/asm-sh/processor_64.h
6 *
7 * Copyright (C) 2000, 2001 Paolo Alberelli
8 * Copyright (C) 2003 Paul Mundt
9 * Copyright (C) 2004 Richard Curnow
10 *
11 * This file is subject to the terms and conditions of the GNU General Public
12 * License. See the file "COPYING" in the main directory of this archive
13 * for more details.
14 */
15#ifndef __ASSEMBLY__
16
17#include <linux/compiler.h>
18#include <asm/page.h>
19#include <asm/types.h>
20#include <cpu/registers.h>
21
22#endif
23
24/*
25 * User space process size: 2GB - 4k.
26 */
27#define TASK_SIZE 0x7ffff000UL
28
29#define STACK_TOP TASK_SIZE
30#define STACK_TOP_MAX STACK_TOP
31
32/* This decides where the kernel will search for a free chunk of vm
33 * space during mmap's.
34 */
35#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
36
37/*
38 * Bit of SR register
39 *
40 * FD-bit:
41 * When it's set, it means the processor doesn't have right to use FPU,
42 * and it results exception when the floating operation is executed.
43 *
44 * IMASK-bit:
45 * Interrupt level mask
46 *
47 * STEP-bit:
48 * Single step bit
49 *
50 */
51#if defined(CONFIG_SH64_SR_WATCH)
52#define SR_MMU 0x84000000
53#else
54#define SR_MMU 0x80000000
55#endif
56
57#define SR_IMASK 0x000000f0
58#define SR_FD 0x00008000
59#define SR_SSTEP 0x08000000
60
61#ifndef __ASSEMBLY__
62
63/*
64 * FPU structure and data : require 8-byte alignment as we need to access it
65 with fld.p, fst.p
66 */
67
68struct sh_fpu_hard_struct {
69 unsigned long fp_regs[64];
70 unsigned int fpscr;
71 /* long status; * software status information */
72};
73
74/* Dummy fpu emulator */
75struct sh_fpu_soft_struct {
76 unsigned long fp_regs[64];
77 unsigned int fpscr;
78 unsigned char lookahead;
79 unsigned long entry_pc;
80};
81
82union thread_xstate {
83 struct sh_fpu_hard_struct hardfpu;
84 struct sh_fpu_soft_struct softfpu;
85 /*
86 * The structure definitions only produce 32 bit alignment, yet we need
87 * to access them using 64 bit load/store as well.
88 */
89 unsigned long long alignment_dummy;
90};
91
92struct thread_struct {
93 unsigned long sp;
94 unsigned long pc;
95
96 /* Various thread flags, see SH_THREAD_xxx */
97 unsigned long flags;
98
99 /* This stores the address of the pt_regs built during a context
100 switch, or of the register save area built for a kernel mode
101 exception. It is used for backtracing the stack of a sleeping task
102 or one that traps in kernel mode. */
103 struct pt_regs *kregs;
104 /* This stores the address of the pt_regs constructed on entry from
105 user mode. It is a fixed value over the lifetime of a process, or
106 NULL for a kernel thread. */
107 struct pt_regs *uregs;
108
109 unsigned long address;
110 /* Hardware debugging registers may come here */
111
112 /* floating point info */
113 union thread_xstate *xstate;
114
115 /*
116 * fpu_counter contains the number of consecutive context switches
117 * that the FPU is used. If this is over a threshold, the lazy fpu
118 * saving becomes unlazy to save the trap. This is an unsigned char
119 * so that after 256 times the counter wraps and the behavior turns
120 * lazy again; this to deal with bursty apps that only use FPU for
121 * a short time
122 */
123 unsigned char fpu_counter;
124};
125
126#define INIT_MMAP \
127{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
128
129#define INIT_THREAD { \
130 .sp = sizeof(init_stack) + \
131 (long) &init_stack, \
132 .pc = 0, \
133 .kregs = &fake_swapper_regs, \
134 .uregs = NULL, \
135 .address = 0, \
136 .flags = 0, \
137}
138
139/*
140 * Do necessary setup to start up a newly executed thread.
141 */
142#define SR_USER (SR_MMU | SR_FD)
143
144#define start_thread(_regs, new_pc, new_sp) \
145 _regs->sr = SR_USER; /* User mode. */ \
146 _regs->pc = new_pc - 4; /* Compensate syscall exit */ \
147 _regs->pc |= 1; /* Set SHmedia ! */ \
148 _regs->regs[18] = 0; \
149 _regs->regs[15] = new_sp
150
151/* Forward declaration, a strange C thing */
152struct task_struct;
153struct mm_struct;
154
155/* Free all resources held by a thread. */
156extern void release_thread(struct task_struct *);
157
158/*
159 * FPU lazy state save handling.
160 */
161
162static inline void disable_fpu(void)
163{
164 unsigned long long __dummy;
165
166 /* Set FD flag in SR */
167 __asm__ __volatile__("getcon " __SR ", %0\n\t"
168 "or %0, %1, %0\n\t"
169 "putcon %0, " __SR "\n\t"
170 : "=&r" (__dummy)
171 : "r" (SR_FD));
172}
173
174static inline void enable_fpu(void)
175{
176 unsigned long long __dummy;
177
178 /* Clear out FD flag in SR */
179 __asm__ __volatile__("getcon " __SR ", %0\n\t"
180 "and %0, %1, %0\n\t"
181 "putcon %0, " __SR "\n\t"
182 : "=&r" (__dummy)
183 : "r" (~SR_FD));
184}
185
186/* Round to nearest, no exceptions on inexact, overflow, underflow,
187 zero-divide, invalid. Configure option for whether to flush denorms to
188 zero, or except if a denorm is encountered. */
189#if defined(CONFIG_SH64_FPU_DENORM_FLUSH)
190#define FPSCR_INIT 0x00040000
191#else
192#define FPSCR_INIT 0x00000000
193#endif
194
195#ifdef CONFIG_SH_FPU
196/* Initialise the FP state of a task */
197void fpinit(struct sh_fpu_hard_struct *fpregs);
198#else
199#define fpinit(fpregs) do { } while (0)
200#endif
201
202extern struct task_struct *last_task_used_math;
203
204/*
205 * Return saved PC of a blocked thread.
206 */
207#define thread_saved_pc(tsk) (tsk->thread.pc)
208
209extern unsigned long get_wchan(struct task_struct *p);
210
211#define KSTK_EIP(tsk) ((tsk)->thread.pc)
212#define KSTK_ESP(tsk) ((tsk)->thread.sp)
213
214#endif /* __ASSEMBLY__ */
215#endif /* __ASM_SH_PROCESSOR_64_H */