/* * include/asm-m68knommu/processor.h * * Copyright (C) 1995 Hamish Macdonald */ #ifndef __ASM_M68K_PROCESSOR_H #define __ASM_M68K_PROCESSOR_H /* * Default implementation of macro that returns current * instruction pointer ("program counter"). */ #define current_text_addr() ({ __label__ _l; _l: &&_l;}) #include <linux/compiler.h> #include <linux/threads.h> #include <asm/types.h> #include <asm/segment.h> #include <asm/fpu.h> #include <asm/ptrace.h> #include <asm/current.h> static inline unsigned long rdusp(void) { #ifdef CONFIG_COLDFIRE extern unsigned int sw_usp; return(sw_usp); #else unsigned long usp; __asm__ __volatile__("move %/usp,%0" : "=a" (usp)); return usp; #endif } static inline void wrusp(unsigned long usp) { #ifdef CONFIG_COLDFIRE extern unsigned int sw_usp; sw_usp = usp; #else __asm__ __volatile__("move %0,%/usp" : : "a" (usp)); #endif } /* * 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) /* * This decides where the kernel will search for a free chunk of vm * space during mmap's. We won't be using it */ #define TASK_UNMAPPED_BASE 0 /* * 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_THREAD { \ sizeof(init_stack) + (unsigned long) init_stack, 0, \ PS_S, __KERNEL_DS, \ {0, 0}, 0, {0,}, {0, 0, 0}, {0,}, \ } /* * Coldfire stacks need to be re-aligned on trap exit, conventional * 68k can handle this case cleanly. */ #if defined(CONFIG_COLDFIRE) #define reformat(_regs) do { (_regs)->format = 0x4; } while(0) #else #define reformat(_regs) do { } while (0) #endif /* * Do necessary setup to start up a newly executed thread. * * pass the data segment into user programs if it exists, * it can't hurt anything as far as I can tell */ #define start_thread(_regs, _pc, _usp) \ do { \ set_fs(USER_DS); /* reads from user space */ \ (_regs)->pc = (_pc); \ ((struct switch_stack *)(_regs))[-1].a6 = 0; \ reformat(_regs); \ if (current->mm) \ (_regs)->d5 = current->mm->start_data; \ (_regs)->sr &= ~0x2000; \ wrusp(_usp); \ } while(0) /* Forward declaration, a strange C thing */ struct task_struct; /* Free all resources held by a thread. */ static inline void release_thread(struct task_struct *dead_task) { } /* Prepare to copy thread state - unlazy all lazy status */ #define prepare_to_copy(tsk) do { } while (0) extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); /* * Free current thread data structures etc.. */ static inline void exit_thread(void) { } unsigned long thread_saved_pc(struct task_struct *tsk); unsigned long get_wchan(struct task_struct *p); #define KSTK_EIP(tsk) \ ({ \ unsigned long eip = 0; \ if ((tsk)->thread.esp0 > PAGE_SIZE && \ (virt_addr_valid((tsk)->thread.esp0))) \ eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ eip; }) #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) #define cpu_relax() barrier() #endif