1 /* $Id: processor.h,v 1.25 2000/02/05 06:47:37 ralf Exp $
2 *
3 * This file is subject to the terms and conditions of the GNU General Public
4 * License. See the file "COPYING" in the main directory of this archive
5 * for more details.
6 *
7 * Copyright (C) 1994 Waldorf GMBH
8 * Copyright (C) 1995, 1996, 1997, 1998 Ralf Baechle
9 * Copyright (C) 1996 Paul M. Antoine
10 * Copyright (C) 1999 Silicon Graphics, Inc.
11 */
12 #ifndef _ASM_PROCESSOR_H
13 #define _ASM_PROCESSOR_H
14
15 #include <linux/config.h>
16
17 #include <asm/isadep.h>
18
19 /*
20 * Default implementation of macro that returns current
21 * instruction pointer ("program counter").
22 */
23 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
24
25 #if !defined (_LANGUAGE_ASSEMBLY)
26 #include <linux/threads.h>
27 #include <asm/cachectl.h>
28 #include <asm/mipsregs.h>
29 #include <asm/reg.h>
30 #include <asm/system.h>
31
32 struct mips_cpuinfo {
33 unsigned long *pgd_quick;
34 unsigned long *pte_quick;
35 unsigned long pgtable_cache_sz;
36 };
37
38 /*
39 * System setup and hardware flags..
40 * XXX: Should go into mips_cpuinfo.
41 */
42 extern void (*cpu_wait)(void); /* only available on R4[26]00 and R3081 */
43 extern void r3081_wait(void);
44 extern void r4k_wait(void);
45 extern char cyclecounter_available; /* only available from R4000 upwards. */
46 extern char dedicated_iv_available; /* some embedded MIPS like Nevada */
47 extern char vce_available; /* Supports VCED / VCEI exceptions */
48
49 extern struct mips_cpuinfo boot_cpu_data;
50 extern unsigned int vced_count, vcei_count;
51
52 #ifdef CONFIG_SMP
53 extern struct mips_cpuinfo cpu_data[];
54 #define current_cpu_data cpu_data[smp_processor_id()]
55 #else
56 #define cpu_data &boot_cpu_data
57 #define current_cpu_data boot_cpu_data
58 #endif
59
60 /*
61 * Bus types (default is ISA, but people can check others with these..)
62 * MCA_bus hardcoded to 0 for now.
63 *
64 * This needs to be extended since MIPS systems are being delivered with
65 * numerous different types of bus systems.
66 */
67 extern int EISA_bus;
68 #define MCA_bus 0
69 #define MCA_bus__is_a_macro /* for versions in ksyms.c */
70
71 /*
72 * MIPS has no problems with write protection
73 */
74 #define wp_works_ok 1
75 #define wp_works_ok__is_a_macro /* for versions in ksyms.c */
76
77 /* Lazy FPU handling on uni-processor */
78 extern struct task_struct *last_task_used_math;
79
80 /*
81 * User space process size: 2GB. This is hardcoded into a few places,
82 * so don't change it unless you know what you are doing. TASK_SIZE
83 * for a 64 bit kernel expandable to 8192EB, of which the current MIPS
84 * implementations will "only" be able to use 1TB ...
85 */
86 #define TASK_SIZE (0x80000000UL)
87
88 /* This decides where the kernel will search for a free chunk of vm
89 * space during mmap's.
90 */
91 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
92
93 /*
94 * Size of io_bitmap in longwords: 32 is ports 0-0x3ff.
95 */
96 #define IO_BITMAP_SIZE 32
97
98 #define NUM_FPU_REGS 32
99
100 struct mips_fpu_hard_struct {
101 unsigned int fp_regs[NUM_FPU_REGS];
102 unsigned int control;
103 } __attribute__((aligned(8)));
104
105 /*
106 * FIXME: no fpu emulator yet (but who cares anyway?)
107 */
108 struct mips_fpu_soft_struct {
109 long dummy;
110 };
111
112 union mips_fpu_union {
113 struct mips_fpu_hard_struct hard;
114 struct mips_fpu_soft_struct soft;
115 };
116
117 #define INIT_FPU { \
118 {{0,},} \
119 }
120
121 typedef struct {
122 unsigned long seg;
123 } mm_segment_t;
124
125 /*
126 * If you change thread_struct remember to change the #defines below too!
127 */
128 struct thread_struct {
129 /* Saved main processor registers. */
130 unsigned long reg16;
131 unsigned long reg17, reg18, reg19, reg20, reg21, reg22, reg23;
132 unsigned long reg29, reg30, reg31;
133
134 /* Saved cp0 stuff. */
135 unsigned long cp0_status;
136
137 /* Saved fpu/fpu emulator stuff. */
138 union mips_fpu_union fpu;
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 #define MF_FIXADE 1 /* Fix address errors in software */
146 #define MF_LOGADE 2 /* Log address errors to syslog */
147 unsigned long mflags;
148 mm_segment_t current_ds;
149 unsigned long irix_trampoline; /* Wheee... */
150 unsigned long irix_oldctx;
151 };
152
153 #endif /* !defined (_LANGUAGE_ASSEMBLY) */
154
155 #define INIT_MMAP { &init_mm, KSEG0, KSEG1, NULL, PAGE_SHARED, \
156 VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
157
158 #define INIT_THREAD { \
159 /* \
160 * saved main processor registers \
161 */ \
162 0, 0, 0, 0, 0, 0, 0, 0, \
163 0, 0, 0, \
164 /* \
165 * saved cp0 stuff \
166 */ \
167 0, \
168 /* \
169 * saved fpu/fpu emulator stuff \
170 */ \
171 INIT_FPU, \
172 /* \
173 * Other stuff associated with the process \
174 */ \
175 0, 0, 0, 0, \
176 /* \
177 * For now the default is to fix address errors \
178 */ \
179 MF_FIXADE, { 0 }, 0, 0 \
180 }
181
182 #ifdef __KERNEL__
183
184 #define KERNEL_STACK_SIZE 8192
185
186 #if !defined (_LANGUAGE_ASSEMBLY)
187
188 /* Free all resources held by a thread. */
189 #define release_thread(thread) do { } while(0)
190
191 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
192
193 /* Copy and release all segment info associated with a VM */
194 #define copy_segments(p, mm) do { } while(0)
195 #define release_segments(mm) do { } while(0)
196
197 /*
198 * Return saved PC of a blocked thread.
199 */
200 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
201 {
202 extern void ret_from_fork(void);
203
204 /* New born processes are a special case */
205 if (t->reg31 == (unsigned long) ret_from_fork)
206 return t->reg31;
207
208 return ((unsigned long *)t->reg29)[10];
209 }
210
211 /*
212 * Do necessary setup to start up a newly executed thread.
213 */
214 #define start_thread(regs, new_pc, new_sp) do { \
215 /* New thread looses kernel privileges. */ \
216 regs->cp0_status = (regs->cp0_status & ~(ST0_CU0|ST0_KSU)) | KU_USER;\
217 regs->cp0_epc = new_pc; \
218 regs->regs[29] = new_sp; \
219 current->thread.current_ds = USER_DS; \
220 } while (0)
221
222 unsigned long get_wchan(struct task_struct *p);
223
224 #define __PT_REG(reg) ((long)&((struct pt_regs *)0)->reg - sizeof(struct pt_regs))
225 #define __KSTK_TOS(tsk) ((unsigned long)(tsk) + KERNEL_STACK_SIZE - 32)
226 #define KSTK_EIP(tsk) (*(unsigned long *)(__KSTK_TOS(tsk) + __PT_REG(cp0_epc)))
227 #define KSTK_ESP(tsk) (*(unsigned long *)(__KSTK_TOS(tsk) + __PT_REG(regs[29])))
228
229 /* Allocation and freeing of basic task resources. */
230 /*
231 * NOTE! The task struct and the stack go together
232 */
233 #define THREAD_SIZE (2*PAGE_SIZE)
234 #define alloc_task_struct() \
235 ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
236 #define free_task_struct(p) free_pages((unsigned long)(p),1)
237 #define get_task_struct(tsk) atomic_inc(&virt_to_page(tsk)->count)
238
239 #define init_task (init_task_union.task)
240 #define init_stack (init_task_union.stack)
241
242 #endif /* !defined (_LANGUAGE_ASSEMBLY) */
243 #endif /* __KERNEL__ */
244
245 /*
246 * Return_address is a replacement for __builtin_return_address(count)
247 * which on certain architectures cannot reasonably be implemented in GCC
248 * (MIPS, Alpha) or is unuseable with -fomit-frame-pointer (i386).
249 * Note that __builtin_return_address(x>=1) is forbidden because GCC
250 * aborts compilation on some CPUs. It's simply not possible to unwind
251 * some CPU's stackframes.
252 *
253 * __builtin_return_address works only for non-leaf functions. We avoid the
254 * overhead of a function call by forcing the compiler to save the return
255 * address register on the stack.
256 */
257 #define return_address() ({__asm__ __volatile__("":::"$31");__builtin_return_address(0);})
258
259 #endif /* _ASM_PROCESSOR_H */
260
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.