1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994 Waldorf GMBH
7 * Copyright (C) 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2003 Ralf Baechle
8 * Copyright (C) 1996 Paul M. Antoine
9 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
10 */
11#ifndef _ASM_PROCESSOR_H
12#define _ASM_PROCESSOR_H
13
14#include <linux/cpumask.h>
15#include <linux/threads.h>
16
17#include <asm/cachectl.h>
18#include <asm/cpu.h>
19#include <asm/cpu-info.h>
20#include <asm/mipsregs.h>
21#include <asm/prefetch.h>
22#include <asm/system.h>
23
24/*
25 * Return current * instruction pointer ("program counter").
26 */
27#define current_text_addr() ({ __label__ _l; _l: &&_l;})
28
29/*
30 * System setup and hardware flags..
31 */
32extern void (*cpu_wait)(void);
33
34extern unsigned int vced_count, vcei_count;
35
36#ifdef CONFIG_32BIT
37/*
38 * User space process size: 2GB. This is hardcoded into a few places,
39 * so don't change it unless you know what you are doing.
40 */
41#define TASK_SIZE	0x7fff8000UL
42#define STACK_TOP	TASK_SIZE
43
44/*
45 * This decides where the kernel will search for a free chunk of vm
46 * space during mmap's.
47 */
48#define TASK_UNMAPPED_BASE	((TASK_SIZE / 3) & ~(PAGE_SIZE))
49#endif
50
51#ifdef CONFIG_64BIT
52/*
53 * User space process size: 1TB. This is hardcoded into a few places,
54 * so don't change it unless you know what you are doing.  TASK_SIZE
55 * is limited to 1TB by the R4000 architecture; R10000 and better can
56 * support 16TB; the architectural reserve for future expansion is
57 * 8192EB ...
58 */
59#define TASK_SIZE32	0x7fff8000UL
60#define TASK_SIZE	0x10000000000UL
61#define STACK_TOP	\
62      (test_thread_flag(TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE)
63
64/*
65 * This decides where the kernel will search for a free chunk of vm
66 * space during mmap's.
67 */
68#define TASK_UNMAPPED_BASE						\
69	(test_thread_flag(TIF_32BIT_ADDR) ?				\
70		PAGE_ALIGN(TASK_SIZE32 / 3) : PAGE_ALIGN(TASK_SIZE / 3))
71#define TASK_SIZE_OF(tsk)						\
72	(test_tsk_thread_flag(tsk, TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE)
73#endif
74
75#ifdef __KERNEL__
76#define STACK_TOP_MAX	TASK_SIZE
77#endif
78
79#define NUM_FPU_REGS	32
80
81typedef __u64 fpureg_t;
82
83/*
84 * It would be nice to add some more fields for emulator statistics, but there
85 * are a number of fixed offsets in offset.h and elsewhere that would have to
86 * be recalculated by hand.  So the additional information will be private to
87 * the FPU emulator for now.  See asm-mips/fpu_emulator.h.
88 */
89
90struct mips_fpu_struct {
91	fpureg_t	fpr[NUM_FPU_REGS];
92	unsigned int	fcr31;
93};
94
95#define NUM_DSP_REGS   6
96
97typedef __u32 dspreg_t;
98
99struct mips_dsp_state {
100	dspreg_t        dspr[NUM_DSP_REGS];
101	unsigned int    dspcontrol;
102};
103
104#define INIT_CPUMASK { \
105	{0,} \
106}
107
108typedef struct {
109	unsigned long seg;
110} mm_segment_t;
111
112#define ARCH_MIN_TASKALIGN	8
113
114struct mips_abi;
115
116/*
117 * If you change thread_struct remember to change the #defines below too!
118 */
119struct thread_struct {
120	/* Saved main processor registers. */
121	unsigned long reg16;
122	unsigned long reg17, reg18, reg19, reg20, reg21, reg22, reg23;
123	unsigned long reg29, reg30, reg31;
124
125	/* Saved cp0 stuff. */
126	unsigned long cp0_status;
127
128	/* Saved fpu/fpu emulator stuff. */
129	struct mips_fpu_struct fpu;
130#ifdef CONFIG_MIPS_MT_FPAFF
131	/* Emulated instruction count */
132	unsigned long emulated_fp;
133	/* Saved per-thread scheduler affinity mask */
134	cpumask_t user_cpus_allowed;
135#endif /* CONFIG_MIPS_MT_FPAFF */
136
137	/* Saved state of the DSP ASE, if available. */
138	struct mips_dsp_state dsp;
139
140	/* Other stuff associated with the thread. */
141	unsigned long cp0_badvaddr;	/* Last user fault */
142	unsigned long cp0_baduaddr;	/* Last kernel fault accessing USEG */
143	unsigned long error_code;
144	unsigned long trap_no;
145	unsigned long irix_trampoline;  /* Wheee... */
146	unsigned long irix_oldctx;
147	struct mips_abi *abi;
148};
149
150#ifdef CONFIG_MIPS_MT_FPAFF
151#define FPAFF_INIT						\
152	.emulated_fp			= 0,			\
153	.user_cpus_allowed		= INIT_CPUMASK,
154#else
155#define FPAFF_INIT
156#endif /* CONFIG_MIPS_MT_FPAFF */
157
158#define INIT_THREAD  {						\
159        /*							\
160         * Saved main processor registers			\
161         */							\
162	.reg16			= 0,				\
163	.reg17			= 0,				\
164	.reg18			= 0,				\
165	.reg19			= 0,				\
166	.reg20			= 0,				\
167	.reg21			= 0,				\
168	.reg22			= 0,				\
169	.reg23			= 0,				\
170	.reg29			= 0,				\
171	.reg30			= 0,				\
172	.reg31			= 0,				\
173	/*							\
174	 * Saved cp0 stuff					\
175	 */							\
176	.cp0_status		= 0,				\
177	/*							\
178	 * Saved FPU/FPU emulator stuff				\
179	 */							\
180	.fpu			= {				\
181		.fpr		= {0,},				\
182		.fcr31		= 0,				\
183	},							\
184	/*							\
185	 * FPU affinity state (null if not FPAFF)		\
186	 */							\
187	FPAFF_INIT						\
188	/*							\
189	 * Saved DSP stuff					\
190	 */							\
191	.dsp			= {				\
192		.dspr		= {0, },			\
193		.dspcontrol	= 0,				\
194	},							\
195	/*							\
196	 * Other stuff associated with the process		\
197	 */							\
198	.cp0_badvaddr		= 0,				\
199	.cp0_baduaddr		= 0,				\
200	.error_code		= 0,				\
201	.trap_no		= 0,				\
202	.irix_trampoline	= 0,				\
203	.irix_oldctx		= 0,				\
204}
205
206struct task_struct;
207
208/* Free all resources held by a thread. */
209#define release_thread(thread) do { } while(0)
210
211/* Prepare to copy thread state - unlazy all lazy status */
212#define prepare_to_copy(tsk)	do { } while (0)
213
214extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
215
216extern unsigned long thread_saved_pc(struct task_struct *tsk);
217
218/*
219 * Do necessary setup to start up a newly executed thread.
220 */
221extern void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp);
222
223unsigned long get_wchan(struct task_struct *p);
224
225#define __KSTK_TOS(tsk) ((unsigned long)task_stack_page(tsk) + THREAD_SIZE - 32)
226#define task_pt_regs(tsk) ((struct pt_regs *)__KSTK_TOS(tsk) - 1)
227#define KSTK_EIP(tsk) (task_pt_regs(tsk)->cp0_epc)
228#define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[29])
229#define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status)
230
231#define cpu_relax()	barrier()
232
233/*
234 * Return_address is a replacement for __builtin_return_address(count)
235 * which on certain architectures cannot reasonably be implemented in GCC
236 * (MIPS, Alpha) or is unuseable with -fomit-frame-pointer (i386).
237 * Note that __builtin_return_address(x>=1) is forbidden because GCC
238 * aborts compilation on some CPUs.  It's simply not possible to unwind
239 * some CPU's stackframes.
240 *
241 * __builtin_return_address works only for non-leaf functions.  We avoid the
242 * overhead of a function call by forcing the compiler to save the return
243 * address register on the stack.
244 */
245#define return_address() ({__asm__ __volatile__("":::"$31");__builtin_return_address(0);})
246
247#ifdef CONFIG_CPU_HAS_PREFETCH
248
249#define ARCH_HAS_PREFETCH
250
251static inline void prefetch(const void *addr)
252{
253	__asm__ __volatile__(
254	"	.set	mips4		\n"
255	"	pref	%0, (%1)	\n"
256	"	.set	mips0		\n"
257	:
258	: "i" (Pref_Load), "r" (addr));
259}
260
261#endif
262
263#endif /* _ASM_PROCESSOR_H */
264