forked from Minki/linux
1c83af5f9d
The more modern ColdFire parts (even if based on older version cores) have separate user and supervisor stack pointers (a7 register). Modify the ColdFire CPU setup and exception code to enable and use this on parts that have it. Signed-off-by: Greg Ungerer <gerg@uclinux.org>
180 lines
4.3 KiB
C
180 lines
4.3 KiB
C
/*
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* include/asm-m68k/processor.h
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*
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* Copyright (C) 1995 Hamish Macdonald
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*/
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#ifndef __ASM_M68K_PROCESSOR_H
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#define __ASM_M68K_PROCESSOR_H
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/*
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* Default implementation of macro that returns current
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* instruction pointer ("program counter").
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*/
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#define current_text_addr() ({ __label__ _l; _l: &&_l;})
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#include <linux/thread_info.h>
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#include <asm/segment.h>
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#include <asm/fpu.h>
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#include <asm/ptrace.h>
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static inline unsigned long rdusp(void)
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{
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#ifdef CONFIG_COLDFIRE_SW_A7
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extern unsigned int sw_usp;
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return sw_usp;
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#else
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register unsigned long usp __asm__("a0");
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/* move %usp,%a0 */
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__asm__ __volatile__(".word 0x4e68" : "=a" (usp));
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return usp;
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#endif
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}
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static inline void wrusp(unsigned long usp)
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{
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#ifdef CONFIG_COLDFIRE_SW_A7
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extern unsigned int sw_usp;
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sw_usp = usp;
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#else
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register unsigned long a0 __asm__("a0") = usp;
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/* move %a0,%usp */
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__asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
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#endif
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}
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/*
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* User space process size: 3.75GB. This is hardcoded into a few places,
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* so don't change it unless you know what you are doing.
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*/
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#ifdef CONFIG_MMU
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#ifndef CONFIG_SUN3
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#define TASK_SIZE (0xF0000000UL)
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#else
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#define TASK_SIZE (0x0E000000UL)
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#endif
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#else
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#define TASK_SIZE (0xFFFFFFFFUL)
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#endif
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#ifdef __KERNEL__
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#define STACK_TOP TASK_SIZE
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#define STACK_TOP_MAX STACK_TOP
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#endif
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/* This decides where the kernel will search for a free chunk of vm
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* space during mmap's.
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*/
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#ifdef CONFIG_MMU
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#ifndef CONFIG_SUN3
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#define TASK_UNMAPPED_BASE 0xC0000000UL
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#else
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#define TASK_UNMAPPED_BASE 0x0A000000UL
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#endif
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#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
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#else
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#define TASK_UNMAPPED_BASE 0
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#endif
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struct thread_struct {
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unsigned long ksp; /* kernel stack pointer */
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unsigned long usp; /* user stack pointer */
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unsigned short sr; /* saved status register */
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unsigned short fs; /* saved fs (sfc, dfc) */
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unsigned long crp[2]; /* cpu root pointer */
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unsigned long esp0; /* points to SR of stack frame */
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unsigned long faddr; /* info about last fault */
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int signo, code;
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unsigned long fp[8*3];
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unsigned long fpcntl[3]; /* fp control regs */
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unsigned char fpstate[FPSTATESIZE]; /* floating point state */
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struct thread_info info;
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};
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#define INIT_THREAD { \
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.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
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.sr = PS_S, \
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.fs = __KERNEL_DS, \
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.info = INIT_THREAD_INFO(init_task), \
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}
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#ifdef CONFIG_MMU
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/*
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* Do necessary setup to start up a newly executed thread.
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*/
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static inline void start_thread(struct pt_regs * regs, unsigned long pc,
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unsigned long usp)
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{
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/* reads from user space */
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set_fs(USER_DS);
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regs->pc = pc;
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regs->sr &= ~0x2000;
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wrusp(usp);
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}
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#else
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/*
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* Coldfire stacks need to be re-aligned on trap exit, conventional
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* 68k can handle this case cleanly.
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*/
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#ifdef CONFIG_COLDFIRE
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#define reformat(_regs) do { (_regs)->format = 0x4; } while(0)
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#else
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#define reformat(_regs) do { } while (0)
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#endif
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#define start_thread(_regs, _pc, _usp) \
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do { \
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set_fs(USER_DS); /* reads from user space */ \
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(_regs)->pc = (_pc); \
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((struct switch_stack *)(_regs))[-1].a6 = 0; \
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reformat(_regs); \
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if (current->mm) \
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(_regs)->d5 = current->mm->start_data; \
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(_regs)->sr &= ~0x2000; \
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wrusp(_usp); \
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} while(0)
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#endif
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/* Forward declaration, a strange C thing */
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struct task_struct;
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/* Free all resources held by a thread. */
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static inline void release_thread(struct task_struct *dead_task)
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{
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}
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/* Prepare to copy thread state - unlazy all lazy status */
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#define prepare_to_copy(tsk) do { } while (0)
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extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
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/*
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* Free current thread data structures etc..
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*/
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static inline void exit_thread(void)
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{
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}
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extern unsigned long thread_saved_pc(struct task_struct *tsk);
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unsigned long get_wchan(struct task_struct *p);
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#define KSTK_EIP(tsk) \
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({ \
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unsigned long eip = 0; \
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if ((tsk)->thread.esp0 > PAGE_SIZE && \
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(virt_addr_valid((tsk)->thread.esp0))) \
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eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
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eip; })
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#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
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#define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
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#define cpu_relax() barrier()
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#endif
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