patch-1.3.94 linux/arch/m68k/kernel/process.c

• Lines: 201
• Date: Mon Apr 1 21:40:27 1996
• Orig file: v1.3.93/linux/arch/m68k/kernel/process.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.93/linux/arch/m68k/kernel/process.c linux/arch/m68k/kernel/process.c
@@ -0,0 +1,200 @@
+/*
+ *  linux/arch/m68k/kernel/process.c
+ *
+ *  Copyright (C) 1995  Hamish Macdonald
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/malloc.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+
+#include <asm/segment.h>
+#include <asm/system.h>
+#include <asm/traps.h>
+#include <asm/machdep.h>
+
+asmlinkage void ret_from_exception(void);
+
+/*
+ * The idle loop on an m68k..
+ */
+asmlinkage int sys_idle(void)
+{
+	if (current->pid != 0)
+		return -EPERM;
+
+	/* endless idle loop with no priority at all */
+	current->counter = -100;
+	for (;;)
+		schedule();
+}
+
+void hard_reset_now(void)
+{
+	if (mach_reset)
+		mach_reset();
+}
+
+void show_regs(struct pt_regs * regs)
+{
+	printk("\n");
+	printk("Format %02x  Vector: %04x  PC: %08lx  Status: %04x\n",
+	       regs->format, regs->vector, regs->pc, regs->sr);
+	printk("ORIG_D0: %08lx  D0: %08lx  A1: %08lx\n",
+	       regs->orig_d0, regs->d0, regs->a1);
+	printk("A0: %08lx  D5: %08lx  D4: %08lx\n",
+	       regs->a0, regs->d5, regs->d4);
+	printk("D3: %08lx  D2: %08lx  D1: %08lx\n",
+	       regs->d3, regs->d2, regs->d1);
+	if (!(regs->sr & PS_S))
+		printk("USP: %08lx\n", rdusp());
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+}
+
+void flush_thread(void)
+{
+	set_fs(USER_DS);
+	current->tss.fs = USER_DS;
+}
+
+/*
+ * "m68k_fork()".. By the time we get here, the
+ * non-volatile registers have also been saved on the
+ * stack. We do some ugly pointer stuff here.. (see
+ * also copy_thread)
+ */
+
+asmlinkage int m68k_fork(struct pt_regs *regs)
+{
+	return do_fork(SIGCHLD, rdusp(), regs);
+}
+
+asmlinkage int m68k_clone(struct pt_regs *regs)
+{
+	unsigned long clone_flags;
+	unsigned long newsp;
+
+	/* syscall2 puts clone_flags in d1 and usp in d2 */
+	clone_flags = regs->d1;
+	newsp = regs->d2;
+	if (!newsp)
+	  newsp  = rdusp();
+	return do_fork(clone_flags, newsp, regs);
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+}
+
+void copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
+		 struct task_struct * p, struct pt_regs * regs)
+{
+	struct pt_regs * childregs;
+	struct switch_stack * childstack, *stack;
+	unsigned long stack_offset, *retp;
+
+	stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
+	childregs = (struct pt_regs *) (p->kernel_stack_page + stack_offset);
+
+	*childregs = *regs;
+	childregs->d0 = 0;
+
+	retp = ((unsigned long *) regs);
+	stack = ((struct switch_stack *) retp) - 1;
+
+	childstack = ((struct switch_stack *) childregs) - 1;
+	*childstack = *stack;
+	childstack->retpc = (unsigned long) ret_from_exception;
+
+	p->tss.usp = usp;
+	p->tss.ksp = (unsigned long)childstack;
+
+	/* Copy the current fpu state */
+	asm volatile ("fsave %0" : : "m" (p->tss.fpstate[0]) : "memory");
+	if (p->tss.fpstate[0])
+	  asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
+			"fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
+			: : "m" (p->tss.fp[0]), "m" (p->tss.fpcntl[0])
+			: "memory");
+	/* Restore the state in case the fpu was busy */
+	asm volatile ("frestore %0" : : "m" (p->tss.fpstate[0]));
+}
+
+/* Fill in the fpu structure for a core dump.  */
+
+int dump_fpu (struct user_m68kfp_struct *fpu)
+{
+  char fpustate[216];
+
+  /* First dump the fpu context to avoid protocol violation.  */
+  asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
+  if (!fpustate[0])
+    return 0;
+
+  asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
+		:: "m" (fpu->fpcntl[0])
+		: "memory");
+  asm volatile ("fmovemx %/fp0-%/fp7,%0"
+		:: "m" (fpu->fpregs[0])
+		: "memory");
+  return 1;
+}
+
+/*
+ * fill in the user structure for a core dump..
+ */
+void dump_thread(struct pt_regs * regs, struct user * dump)
+{
+/* changed the size calculations - should hopefully work better. lbt */
+	dump->magic = CMAGIC;
+	dump->start_code = 0;
+	dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
+	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
+	dump->u_dsize = ((unsigned long) (current->mm->brk +
+					  (PAGE_SIZE-1))) >> PAGE_SHIFT;
+	dump->u_dsize -= dump->u_tsize;
+	dump->u_ssize = 0;
+
+	if (dump->start_stack < TASK_SIZE)
+		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
+
+	dump->u_ar0 = (struct pt_regs *)(((int)(&dump->regs)) -((int)(dump)));
+	dump->regs = *regs;
+	dump->regs2 = ((struct switch_stack *)regs)[-1];
+	/* dump floating point stuff */
+	dump->u_fpvalid = dump_fpu (&dump->m68kfp);
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(char *name, char **argv, char **envp)
+{
+	int error;
+	char * filename;
+	struct pt_regs *regs = (struct pt_regs *) &name;
+
+	error = getname(name, &filename);
+	if (error)
+		return error;
+	error = do_execve(filename, argv, envp, regs);
+	putname(filename);
+	return error;
+}