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- /* $Id: processor.h,v 1.18 1998/10/14 20:31:12 ralf Exp $
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 1994 Waldorf GMBH
- * Copyright (C) 1995, 1996, 1997, 1998 Ralf Baechle
- * Modified further for R[236]000 compatibility by Paul M. Antoine
- */
- #ifndef __ASM_MIPS_PROCESSOR_H
- #define __ASM_MIPS_PROCESSOR_H
-
- #if !defined (_LANGUAGE_ASSEMBLY)
- #include <asm/cachectl.h>
- #include <asm/mipsregs.h>
- #include <asm/reg.h>
- #include <asm/system.h>
-
- struct mips_cpuinfo {
- unsigned long *pgd_quick;
- unsigned long *pte_quick;
- unsigned long pgtable_cache_sz;
- };
-
- /*
- * System setup and hardware flags..
- * XXX: Should go into mips_cpuinfo.
- */
- extern char wait_available; /* only available on R4[26]00 */
- extern char cyclecounter_available; /* only available from R4000 upwards. */
- extern char dedicated_iv_available; /* some embedded MIPS like Nevada */
- extern char vce_available; /* Supports VCED / VCEI exceptions */
-
- extern struct mips_cpuinfo boot_cpu_data;
- extern unsigned int vced_count, vcei_count;
-
- #ifdef __SMP__
- extern struct mips_cpuinfo cpu_data[];
- #define current_cpu_data cpu_data[smp_processor_id()]
- #else
- #define cpu_data &boot_cpu_data
- #define current_cpu_data boot_cpu_data
- #endif
-
- /*
- * Bus types (default is ISA, but people can check others with these..)
- * MCA_bus hardcoded to 0 for now.
- *
- * This needs to be extended since MIPS systems are being delivered with
- * numerous different types of bus systems.
- */
- extern int EISA_bus;
- #define MCA_bus 0
- #define MCA_bus__is_a_macro /* for versions in ksyms.c */
-
- /*
- * MIPS has no problems with write protection
- */
- #define wp_works_ok 1
- #define wp_works_ok__is_a_macro /* for versions in ksyms.c */
-
- /* Lazy FPU handling on uni-processor */
- extern struct task_struct *last_task_used_math;
-
- /*
- * User space process size: 2GB. This is hardcoded into a few places,
- * so don't change it unless you know what you are doing. TASK_SIZE
- * for a 64 bit kernel expandable to 8192EB, of which the current MIPS
- * implementations will "only" be able to use 1TB ...
- */
- #define TASK_SIZE (0x80000000UL)
-
- /* This decides where the kernel will search for a free chunk of vm
- * space during mmap's.
- */
- #define TASK_UNMAPPED_BASE (TASK_SIZE / 3)
-
- /*
- * Size of io_bitmap in longwords: 32 is ports 0-0x3ff.
- */
- #define IO_BITMAP_SIZE 32
-
- #define NUM_FPU_REGS 32
-
- struct mips_fpu_hard_struct {
- double fp_regs[NUM_FPU_REGS];
- unsigned int control;
- };
-
- /*
- * FIXME: no fpu emulator yet (but who cares anyway?)
- */
- struct mips_fpu_soft_struct {
- long dummy;
- };
-
- union mips_fpu_union {
- struct mips_fpu_hard_struct hard;
- struct mips_fpu_soft_struct soft;
- };
-
- #define INIT_FPU { \
- {{0,},} \
- }
-
- typedef struct {
- unsigned long seg;
- } mm_segment_t;
-
- /*
- * If you change thread_struct remember to change the #defines below too!
- */
- struct thread_struct {
- /* Saved main processor registers. */
- unsigned long reg16;
- unsigned long reg17, reg18, reg19, reg20, reg21, reg22, reg23;
- unsigned long reg29, reg30, reg31;
-
- /* Saved cp0 stuff. */
- unsigned long cp0_status;
-
- /* Saved fpu/fpu emulator stuff. */
- union mips_fpu_union fpu;
-
- /* Other stuff associated with the thread. */
- unsigned long cp0_badvaddr; /* Last user fault */
- unsigned long cp0_baduaddr; /* Last kernel fault accessing USEG */
- unsigned long error_code;
- unsigned long trap_no;
- unsigned long pg_dir; /* used in tlb refill */
- #define MF_FIXADE 1 /* Fix address errors in software */
- #define MF_LOGADE 2 /* Log address errors to syslog */
- unsigned long mflags;
- mm_segment_t current_ds;
- unsigned long irix_trampoline; /* Wheee... */
- unsigned long irix_oldctx;
- };
-
- #endif /* !defined (_LANGUAGE_ASSEMBLY) */
-
- #define INIT_MMAP { &init_mm, KSEG0, KSEG1, NULL, PAGE_SHARED, \
- VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
-
- #define INIT_TSS { \
- /* \
- * saved main processor registers \
- */ \
- 0, 0, 0, 0, 0, 0, 0, 0, \
- 0, 0, 0, \
- /* \
- * saved cp0 stuff \
- */ \
- 0, \
- /* \
- * saved fpu/fpu emulator stuff \
- */ \
- INIT_FPU, \
- /* \
- * Other stuff associated with the process \
- */ \
- 0, 0, 0, 0, (unsigned long) swapper_pg_dir, \
- /* \
- * For now the default is to fix address errors \
- */ \
- MF_FIXADE, { 0 }, 0, 0 \
- }
-
- #ifdef __KERNEL__
-
- #define KERNEL_STACK_SIZE 8192
-
- #if !defined (_LANGUAGE_ASSEMBLY)
-
- /* Free all resources held by a thread. */
- extern void release_thread(struct task_struct *);
-
- /* Copy and release all segment info associated with a VM */
- #define copy_segments(nr, p, mm) do { } while(0)
- #define release_segments(mm) do { } while(0)
- #define forget_segments() do { } while (0)
-
- /*
- * Return saved PC of a blocked thread.
- */
- extern inline unsigned long thread_saved_pc(struct thread_struct *t)
- {
- extern void ret_from_sys_call(void);
-
- /* New born processes are a special case */
- if (t->reg31 == (unsigned long) ret_from_sys_call)
- return t->reg31;
-
- return ((unsigned long*)t->reg29)[17];
- }
-
- extern int (*user_mode)(struct pt_regs *);
-
- /*
- * Do necessary setup to start up a newly executed thread.
- */
- extern void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp);
-
- /* Allocation and freeing of basic task resources. */
- /*
- * NOTE! The task struct and the stack go together
- */
- #define alloc_task_struct() \
- ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
- #define free_task_struct(p) free_pages((unsigned long)(p),1)
-
- #define init_task (init_task_union.task)
- #define init_stack (init_task_union.stack)
-
- #endif /* !defined (_LANGUAGE_ASSEMBLY) */
- #endif /* __KERNEL__ */
-
- /*
- * Return_address is a replacement for __builtin_return_address(count)
- * which on certain architectures cannot reasonably be implemented in GCC
- * (MIPS, Alpha) or is unuseable with -fomit-frame-pointer (i386).
- * Note that __builtin_return_address(x>=1) is forbidden because GCC
- * aborts compilation on some CPUs. It's simply not possible to unwind
- * some CPU's stackframes.
- */
- #if (__GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8))
- /*
- * __builtin_return_address works only for non-leaf functions. We avoid the
- * overhead of a function call by forcing the compiler to save the return
- * address register on the stack.
- */
- #define return_address() ({__asm__ __volatile__("":::"$31");__builtin_return_address(0);})
- #else
- /*
- * __builtin_return_address is not implemented at all. Calling it
- * will return senseless values. Return NULL which at least is an obviously
- * senseless value.
- */
- #define return_address() NULL
- #endif
-
- #endif /* __ASM_MIPS_PROCESSOR_H */
-