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
6 * Copyright (C) 1994 Waldorf GMBH
7 * Copyright (C) 1995, 1996, 1997, 1998, 1999, 2001 Ralf Baechle
8 * Copyright (C) 1996 Paul M. Antoine
9 * Copyright (C) 1999 Silicon Graphics, Inc.
11 #ifndef _ASM_PROCESSOR_H
12 #define _ASM_PROCESSOR_H
14 #include <linux/config.h>
15 #include <linux/cache.h>
16 #include <asm/isadep.h>
19 * Default implementation of macro that returns current
20 * instruction pointer ("program counter").
22 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
25 #include <linux/threads.h>
26 #include <asm/cachectl.h>
27 #include <asm/mipsregs.h>
29 #include <asm/system.h>
32 unsigned long udelay_val;
33 unsigned long *pgd_quick;
34 unsigned long *pte_quick;
35 unsigned long pgtable_cache_sz;
36 unsigned long asid_cache;
37 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
40 * System setup and hardware flags..
42 extern void (*cpu_wait)(void);
43 extern void r3081_wait(void);
44 extern void r39xx_wait(void);
45 extern void r4k_wait(void);
46 extern void au1k_wait(void);
48 extern struct cpuinfo_mips cpu_data[];
49 extern unsigned int vced_count, vcei_count;
52 #define current_cpu_data cpu_data[smp_processor_id()]
54 #define current_cpu_data cpu_data[0]
58 * Bus types (default is ISA, but people can check others with these..)
67 #define MCA_bus__is_a_macro /* for versions in ksyms.c */
70 * MIPS has no problems with write protection
73 #define wp_works_ok__is_a_macro /* for versions in ksyms.c */
75 /* Lazy FPU handling on uni-processor */
76 extern struct task_struct *last_task_used_math;
79 * User space process size: 2GB. This is hardcoded into a few places,
80 * so don't change it unless you know what you are doing. TASK_SIZE
81 * for a 64 bit kernel expandable to 8192EB, of which the current MIPS
82 * implementations will "only" be able to use 1TB ...
84 #define TASK_SIZE (0x7fff8000UL)
86 /* This decides where the kernel will search for a free chunk of vm
87 * space during mmap's.
89 #define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
92 * Size of io_bitmap in longwords: 32 is ports 0-0x3ff.
94 #define IO_BITMAP_SIZE 32
96 #define NUM_FPU_REGS 32
98 struct mips_fpu_hard_struct {
99 double fp_regs[NUM_FPU_REGS];
100 unsigned int control;
104 * It would be nice to add some more fields for emulator statistics, but there
105 * are a number of fixed offsets in offset.h and elsewhere that would have to
106 * be recalculated by hand. So the additional information will be private to
107 * the FPU emulator for now. See asm-mips/fpu_emulator.h.
109 typedef u64 fpureg_t;
110 struct mips_fpu_soft_struct {
111 fpureg_t regs[NUM_FPU_REGS];
115 union mips_fpu_union {
116 struct mips_fpu_hard_struct hard;
117 struct mips_fpu_soft_struct soft;
129 * If you change thread_struct remember to change the #defines below too!
131 struct thread_struct {
132 /* Saved main processor registers. */
134 unsigned long reg17, reg18, reg19, reg20, reg21, reg22, reg23;
135 unsigned long reg29, reg30, reg31;
137 /* Saved cp0 stuff. */
138 unsigned long cp0_status;
140 /* Saved fpu/fpu emulator stuff. */
141 union mips_fpu_union fpu;
143 /* Other stuff associated with the thread. */
144 unsigned long cp0_badvaddr; /* Last user fault */
145 unsigned long cp0_baduaddr; /* Last kernel fault accessing USEG */
146 unsigned long error_code;
147 unsigned long trap_no;
148 #define MF_FIXADE 1 /* Fix address errors in software */
149 #define MF_LOGADE 2 /* Log address errors to syslog */
150 unsigned long mflags;
151 mm_segment_t current_ds;
152 unsigned long irix_trampoline; /* Wheee... */
153 unsigned long irix_oldctx;
156 #endif /* !__ASSEMBLY__ */
158 #define INIT_THREAD { \
160 * saved main processor registers \
162 0, 0, 0, 0, 0, 0, 0, 0, \
169 * saved fpu/fpu emulator stuff \
173 * Other stuff associated with the process \
177 * For now the default is to fix address errors \
179 MF_FIXADE, { 0 }, 0, 0 \
184 #define KERNEL_STACK_SIZE 8192
188 /* Free all resources held by a thread. */
189 #define release_thread(thread) do { } while(0)
191 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
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)
198 * Return saved PC of a blocked thread.
200 static inline unsigned long thread_saved_pc(struct thread_struct *t)
202 extern void ret_from_fork(void);
204 /* New born processes are a special case */
205 if (t->reg31 == (unsigned long) ret_from_fork)
208 return ((unsigned long *)t->reg29)[13];
212 * Do necessary setup to start up a newly executed thread.
214 #define start_thread(regs, new_pc, new_sp) do { \
215 /* New thread loses kernel and FPU privileges. */ \
216 regs->cp0_status = (regs->cp0_status & ~(ST0_CU0|ST0_KSU|ST0_CU1)) | KU_USER;\
217 regs->cp0_epc = new_pc; \
218 regs->regs[29] = new_sp; \
219 current->thread.current_ds = USER_DS; \
222 unsigned long get_wchan(struct task_struct *p);
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])))
229 /* Allocation and freeing of basic task resources. */
231 * NOTE! The task struct and the stack go together
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)
239 #define init_task (init_task_union.task)
240 #define init_stack (init_task_union.stack)
242 #define cpu_relax() do { } while (0)
244 #endif /* !__ASSEMBLY__ */
245 #endif /* __KERNEL__ */
248 * Return_address is a replacement for __builtin_return_address(count)
249 * which on certain architectures cannot reasonably be implemented in GCC
250 * (MIPS, Alpha) or is unuseable with -fomit-frame-pointer (i386).
251 * Note that __builtin_return_address(x>=1) is forbidden because GCC
252 * aborts compilation on some CPUs. It's simply not possible to unwind
253 * some CPU's stackframes.
255 * __builtin_return_address works only for non-leaf functions. We avoid the
256 * overhead of a function call by forcing the compiler to save the return
257 * address register on the stack.
259 #define return_address() ({__asm__ __volatile__("":::"$31");__builtin_return_address(0);})
261 #endif /* _ASM_PROCESSOR_H */