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/*
23 * Default implementation of macro that returns current
24 * instruction pointer ("program counter").
25 */
26#define current_text_addr() ({ \
27void *pc; \
28unsigned long long __dummy = 0; \
29__asm__("gettr	tr0, %1\n\t" \
30	"pta	4, tr0\n\t" \
31	"gettr	tr0, %0\n\t" \
32	"ptabs	%1, tr0\n\t"	\
33	:"=r" (pc), "=r" (__dummy) \
34	: "1" (__dummy)); \
35pc; })
36
37#endif
38
39/*
40 * User space process size: 2GB - 4k.
41 */
42#define TASK_SIZE	0x7ffff000UL
43
44#define STACK_TOP	TASK_SIZE
45#define STACK_TOP_MAX	STACK_TOP
46
47/* This decides where the kernel will search for a free chunk of vm
48 * space during mmap's.
49 */
50#define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)
51
52/*
53 * Bit of SR register
54 *
55 * FD-bit:
56 *     When it's set, it means the processor doesn't have right to use FPU,
57 *     and it results exception when the floating operation is executed.
58 *
59 * IMASK-bit:
60 *     Interrupt level mask
61 *
62 * STEP-bit:
63 *     Single step bit
64 *
65 */
66#if defined(CONFIG_SH64_SR_WATCH)
67#define SR_MMU   0x84000000
68#else
69#define SR_MMU   0x80000000
70#endif
71
72#define SR_IMASK 0x000000f0
73#define SR_FD    0x00008000
74#define SR_SSTEP 0x08000000
75
76#ifndef __ASSEMBLY__
77
78/*
79 * FPU structure and data : require 8-byte alignment as we need to access it
80   with fld.p, fst.p
81 */
82
83struct sh_fpu_hard_struct {
84	unsigned long fp_regs[64];
85	unsigned int fpscr;
86	/* long status; * software status information */
87};
88
89/* Dummy fpu emulator  */
90struct sh_fpu_soft_struct {
91	unsigned long fp_regs[64];
92	unsigned int fpscr;
93	unsigned char lookahead;
94	unsigned long entry_pc;
95};
96
97union thread_xstate {
98	struct sh_fpu_hard_struct hardfpu;
99	struct sh_fpu_soft_struct softfpu;
100	/*
101	 * The structure definitions only produce 32 bit alignment, yet we need
102	 * to access them using 64 bit load/store as well.
103	 */
104	unsigned long long alignment_dummy;
105};
106
107struct thread_struct {
108	unsigned long sp;
109	unsigned long pc;
110
111	/* Various thread flags, see SH_THREAD_xxx */
112	unsigned long flags;
113
114	/* This stores the address of the pt_regs built during a context
115	   switch, or of the register save area built for a kernel mode
116	   exception.  It is used for backtracing the stack of a sleeping task
117	   or one that traps in kernel mode. */
118        struct pt_regs *kregs;
119	/* This stores the address of the pt_regs constructed on entry from
120	   user mode.  It is a fixed value over the lifetime of a process, or
121	   NULL for a kernel thread. */
122	struct pt_regs *uregs;
123
124	unsigned long address;
125	/* Hardware debugging registers may come here */
126
127	/* floating point info */
128	union thread_xstate *xstate;
129
130	/*
131	 * fpu_counter contains the number of consecutive context switches
132	 * that the FPU is used. If this is over a threshold, the lazy fpu
133	 * saving becomes unlazy to save the trap. This is an unsigned char
134	 * so that after 256 times the counter wraps and the behavior turns
135	 * lazy again; this to deal with bursty apps that only use FPU for
136	 * a short time
137	 */
138	unsigned char fpu_counter;
139};
140
141#define INIT_MMAP \
142{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
143
144#define INIT_THREAD  {				\
145	.sp		= sizeof(init_stack) +	\
146			  (long) &init_stack,	\
147	.pc		= 0,			\
148        .kregs		= &fake_swapper_regs,	\
149	.uregs	        = NULL,			\
150	.address	= 0,			\
151	.flags		= 0,			\
152}
153
154/*
155 * Do necessary setup to start up a newly executed thread.
156 */
157#define SR_USER (SR_MMU | SR_FD)
158
159#define start_thread(_regs, new_pc, new_sp)			\
160	_regs->sr = SR_USER;	/* User mode. */		\
161	_regs->pc = new_pc - 4;	/* Compensate syscall exit */	\
162	_regs->pc |= 1;		/* Set SHmedia ! */		\
163	_regs->regs[18] = 0;					\
164	_regs->regs[15] = new_sp
165
166/* Forward declaration, a strange C thing */
167struct task_struct;
168struct mm_struct;
169
170/* Free all resources held by a thread. */
171extern void release_thread(struct task_struct *);
172
173/* Copy and release all segment info associated with a VM */
174#define copy_segments(p, mm)	do { } while (0)
175#define release_segments(mm)	do { } while (0)
176#define forget_segments()	do { } while (0)
177/*
178 * FPU lazy state save handling.
179 */
180
181static inline void disable_fpu(void)
182{
183	unsigned long long __dummy;
184
185	/* Set FD flag in SR */
186	__asm__ __volatile__("getcon	" __SR ", %0\n\t"
187			     "or	%0, %1, %0\n\t"
188			     "putcon	%0, " __SR "\n\t"
189			     : "=&r" (__dummy)
190			     : "r" (SR_FD));
191}
192
193static inline void enable_fpu(void)
194{
195	unsigned long long __dummy;
196
197	/* Clear out FD flag in SR */
198	__asm__ __volatile__("getcon	" __SR ", %0\n\t"
199			     "and	%0, %1, %0\n\t"
200			     "putcon	%0, " __SR "\n\t"
201			     : "=&r" (__dummy)
202			     : "r" (~SR_FD));
203}
204
205/* Round to nearest, no exceptions on inexact, overflow, underflow,
206   zero-divide, invalid.  Configure option for whether to flush denorms to
207   zero, or except if a denorm is encountered.  */
208#if defined(CONFIG_SH64_FPU_DENORM_FLUSH)
209#define FPSCR_INIT  0x00040000
210#else
211#define FPSCR_INIT  0x00000000
212#endif
213
214#ifdef CONFIG_SH_FPU
215/* Initialise the FP state of a task */
216void fpinit(struct sh_fpu_hard_struct *fpregs);
217#else
218#define fpinit(fpregs)	do { } while (0)
219#endif
220
221extern struct task_struct *last_task_used_math;
222
223/*
224 * Return saved PC of a blocked thread.
225 */
226#define thread_saved_pc(tsk)	(tsk->thread.pc)
227
228extern unsigned long get_wchan(struct task_struct *p);
229
230#define KSTK_EIP(tsk)  ((tsk)->thread.pc)
231#define KSTK_ESP(tsk)  ((tsk)->thread.sp)
232
233#endif	/* __ASSEMBLY__ */
234#endif /* __ASM_SH_PROCESSOR_64_H */
235