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Diffstat (limited to 'include/asm-m68k/processor.h')
-rw-r--r-- | include/asm-m68k/processor.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/include/asm-m68k/processor.h b/include/asm-m68k/processor.h new file mode 100644 index 000000000..d228816af --- /dev/null +++ b/include/asm-m68k/processor.h @@ -0,0 +1,92 @@ +/* + * include/asm-m68k/processor.h + * + * Copyright (C) 1995 Hamish Macdonald + */ + +#ifndef __ASM_M68K_PROCESSOR_H +#define __ASM_M68K_PROCESSOR_H + +#include <asm/segment.h> + +/* + * User space process size: 3.75GB. This is hardcoded into a few places, + * so don't change it unless you know what you are doing. + */ +#define TASK_SIZE (0xF0000000UL) + +/* + * Bus types + */ +#define EISA_bus 0 +#define MCA_bus 0 + +/* MAX floating point unit state size (FSAVE/FRESTORE) */ +#define FPSTATESIZE (216/sizeof(unsigned char)) + +/* + * if you change this structure, you must change the code and offsets + * in m68k/machasm.S + */ + +struct thread_struct { + unsigned long ksp; /* kernel stack pointer */ + unsigned long usp; /* user stack pointer */ + unsigned short sr; /* saved status register */ + unsigned short fs; /* saved fs (sfc, dfc) */ + unsigned long crp[2]; /* cpu root pointer */ + unsigned long esp0; /* points to SR of stack frame */ + unsigned long fp[8*3]; + unsigned long fpcntl[3]; /* fp control regs */ + unsigned char fpstate[FPSTATESIZE]; /* floating point state */ +}; + +#define INIT_MMAP { &init_mm, 0, 0x40000000, __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED), VM_READ | VM_WRITE | VM_EXEC } + +#define INIT_TSS { \ + sizeof(init_kernel_stack) + (long) init_kernel_stack, 0, \ + PS_S, KERNEL_DS, \ + {0, 0}, 0, {0,}, {0, 0, 0}, {0,}, \ +} + +#define alloc_kernel_stack() __get_free_page(GFP_KERNEL) +#define free_kernel_stack(page) free_page((page)) + +/* + * Do necessary setup to start up a newly executed thread. + */ +static inline void start_thread(struct pt_regs * regs, unsigned long pc, + unsigned long usp) +{ + unsigned long nilstate = 0; + + /* clear floating point state */ + __asm__ __volatile__ ("frestore %0@" : : "a" (&nilstate)); + + /* reads from user space */ + set_fs(USER_DS); + + regs->pc = pc; + regs->sr &= ~0x2000; + wrusp(usp); +} + +/* + * Return saved PC of a blocked thread. + */ +extern inline unsigned long thread_saved_pc(struct thread_struct *t) +{ + return ((unsigned long *)((struct switch_stack *)t->ksp)->a6)[1]; +} + +/* + * 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 the GCC + * aborts compilation on some CPUs. It's simply not possible to unwind + * some CPU's stackframes. + */ +#define return_address() __builtin_return_address(0) + +#endif |