m68k: merge the MMU and non-MMU versions of process.c

The MMU and non-MMU varients of the m68k arch process.c code are pretty
much the same. Only a few minor details differ between the two. The
majority of the difference is to deal with having or wanting hardware FPU
support. So merge them back into a single process.c file.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 377 insertions, 2 deletions

diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index 6cf4bd6e34f8..f053e245bd40 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -1,5 +1,380 @@
+/*
+ *  linux/arch/m68k/kernel/process.c
+ *
+ *  Copyright (C) 1995  Hamish Macdonald
+ *
+ *  68060 fixes by Jesper Skov
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/reboot.h>
+#include <linux/init_task.h>
+#include <linux/mqueue.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/traps.h>
+#include <asm/machdep.h>
+#include <asm/setup.h>
+#include <asm/pgtable.h>
+
+
+asmlinkage void ret_from_fork(void);
+
+
+/*
+ * Return saved PC from a blocked thread
+ */
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+	struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
+	/* Check whether the thread is blocked in resume() */
+	if (in_sched_functions(sw->retpc))
+		return ((unsigned long *)sw->a6)[1];
+	else
+		return sw->retpc;
+}
+
+/*
+ * The idle loop on an m68k..
+ */
+static void default_idle(void)
+{
+	if (!need_resched())
+#if defined(MACH_ATARI_ONLY)
+		/* block out HSYNC on the atari (falcon) */
+		__asm__("stop #0x2200" : : : "cc");
+#else
+		__asm__("stop #0x2000" : : : "cc");
+#endif
+}
+
+void (*idle)(void) = default_idle;
+
+/*
+ * The idle thread. There's no useful work to be
+ * done, so just try to conserve power and have a
+ * low exit latency (ie sit in a loop waiting for
+ * somebody to say that they'd like to reschedule)
+ */
+void cpu_idle(void)
+{
+	/* endless idle loop with no priority at all */
+	while (1) {
+		while (!need_resched())
+			idle();
+		preempt_enable_no_resched();
+		schedule();
+		preempt_disable();
+	}
+}
+
+void machine_restart(char * __unused)
+{
+	if (mach_reset)
+		mach_reset();
+	for (;;);
+}
+
+void machine_halt(void)
+{
+	if (mach_halt)
+		mach_halt();
+	for (;;);
+}
+
+void machine_power_off(void)
+{
+	if (mach_power_off)
+		mach_power_off();
+	for (;;);
+}
+
+void (*pm_power_off)(void) = machine_power_off;
+EXPORT_SYMBOL(pm_power_off);
+
+void show_regs(struct pt_regs * regs)
+{
+	printk("\n");
+	printk("Format %02x  Vector: %04x  PC: %08lx  Status: %04x    %s\n",
+	       regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
+	printk("ORIG_D0: %08lx  D0: %08lx  A2: %08lx  A1: %08lx\n",
+	       regs->orig_d0, regs->d0, regs->a2, 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());
+}
+
+/*
+ * Create a kernel thread
+ */
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
+{
+	int pid;
+	mm_segment_t fs;
+
+	fs = get_fs();
+	set_fs (KERNEL_DS);
+
+	{
+	register long retval __asm__ ("d0");
+	register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
+
+	retval = __NR_clone;
+	__asm__ __volatile__
+	  ("clrl %%d2\n\t"
+	   "trap #0\n\t"		/* Linux/m68k system call */
+	   "tstl %0\n\t"		/* child or parent */
+	   "jne 1f\n\t"			/* parent - jump */
+#ifdef CONFIG_MMU
+	   "lea %%sp@(%c7),%6\n\t"	/* reload current */
+	   "movel %6@,%6\n\t"
+#endif
+	   "movel %3,%%sp@-\n\t"	/* push argument */
+	   "jsr %4@\n\t"		/* call fn */
+	   "movel %0,%%d1\n\t"		/* pass exit value */
+	   "movel %2,%%d0\n\t"		/* exit */
+	   "trap #0\n"
+	   "1:"
+	   : "+d" (retval)
+	   : "i" (__NR_clone), "i" (__NR_exit),
+	     "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
+	     "i" (-THREAD_SIZE)
+	   : "d2");
+
+	pid = retval;
+	}
+
+	set_fs (fs);
+	return pid;
+}
+EXPORT_SYMBOL(kernel_thread);
+
+void flush_thread(void)
+{
+	current->thread.fs = __USER_DS;
+#ifdef CONFIG_FPU
+	if (!FPU_IS_EMU) {
+		unsigned long zero = 0;
+		asm volatile("frestore %0": :"m" (zero));
+	}
+#endif
+}
+
+/*
+ * "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)
+{
 #ifdef CONFIG_MMU
-#include "process_mm.c"
+	return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
 #else
-#include "process_no.c"
+	return -EINVAL;
 #endif
+}
+
+asmlinkage int m68k_vfork(struct pt_regs *regs)
+{
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
+		       NULL, NULL);
+}
+
+asmlinkage int m68k_clone(struct pt_regs *regs)
+{
+	unsigned long clone_flags;
+	unsigned long newsp;
+	int __user *parent_tidptr, *child_tidptr;
+
+	/* syscall2 puts clone_flags in d1 and usp in d2 */
+	clone_flags = regs->d1;
+	newsp = regs->d2;
+	parent_tidptr = (int __user *)regs->d3;
+	child_tidptr = (int __user *)regs->d4;
+	if (!newsp)
+		newsp = rdusp();
+	return do_fork(clone_flags, newsp, regs, 0,
+		       parent_tidptr, child_tidptr);
+}
+
+int copy_thread(unsigned long clone_flags, unsigned long usp,
+		 unsigned long unused,
+		 struct task_struct * p, struct pt_regs * regs)
+{
+	struct pt_regs * childregs;
+	struct switch_stack * childstack, *stack;
+	unsigned long *retp;
+
+	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
+
+	*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_fork;
+
+	p->thread.usp = usp;
+	p->thread.ksp = (unsigned long)childstack;
+
+	if (clone_flags & CLONE_SETTLS)
+		task_thread_info(p)->tp_value = regs->d5;
+
+	/*
+	 * Must save the current SFC/DFC value, NOT the value when
+	 * the parent was last descheduled - RGH  10-08-96
+	 */
+	p->thread.fs = get_fs().seg;
+
+#ifdef CONFIG_FPU
+	if (!FPU_IS_EMU) {
+		/* Copy the current fpu state */
+		asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
+
+		if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
+			if (CPU_IS_COLDFIRE) {
+				asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
+					      "fmovel %/fpiar,%1\n\t"
+					      "fmovel %/fpcr,%2\n\t"
+					      "fmovel %/fpsr,%3"
+					      :
+					      : "m" (p->thread.fp[0]),
+						"m" (p->thread.fpcntl[0]),
+						"m" (p->thread.fpcntl[1]),
+						"m" (p->thread.fpcntl[2])
+					      : "memory");
+			} else {
+				asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
+					      "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
+					      :
+					      : "m" (p->thread.fp[0]),
+						"m" (p->thread.fpcntl[0])
+					      : "memory");
+			}
+		}
+
+		/* Restore the state in case the fpu was busy */
+		asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
+	}
+#endif /* CONFIG_FPU */
+
+	return 0;
+}
+
+/* Fill in the fpu structure for a core dump.  */
+#ifdef CONFIG_FPU
+int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
+{
+	char fpustate[216];
+
+	if (FPU_IS_EMU) {
+		int i;
+
+		memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
+		memcpy(fpu->fpregs, current->thread.fp, 96);
+		/* Convert internal fpu reg representation
+		 * into long double format
+		 */
+		for (i = 0; i < 24; i += 3)
+			fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
+			                 ((fpu->fpregs[i] & 0x0000ffff) << 16);
+		return 1;
+	}
+
+	/* First dump the fpu context to avoid protocol violation.  */
+	asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
+	if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
+		return 0;
+
+	if (CPU_IS_COLDFIRE) {
+		asm volatile ("fmovel %/fpiar,%0\n\t"
+			      "fmovel %/fpcr,%1\n\t"
+			      "fmovel %/fpsr,%2\n\t"
+			      "fmovemd %/fp0-%/fp7,%3"
+			      :
+			      : "m" (fpu->fpcntl[0]),
+				"m" (fpu->fpcntl[1]),
+				"m" (fpu->fpcntl[2]),
+				"m" (fpu->fpregs[0])
+			      : "memory");
+	} else {
+		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;
+}
+EXPORT_SYMBOL(dump_fpu);
+#endif /* CONFIG_FPU */
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(const char __user *name,
+			  const char __user *const __user *argv,
+			  const char __user *const __user *envp)
+{
+	int error;
+	char * filename;
+	struct pt_regs *regs = (struct pt_regs *) &name;
+
+	filename = getname(name);
+	error = PTR_ERR(filename);
+	if (IS_ERR(filename))
+		return error;
+	error = do_execve(filename, argv, envp, regs);
+	putname(filename);
+	return error;
+}
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	unsigned long fp, pc;
+	unsigned long stack_page;
+	int count = 0;
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+
+	stack_page = (unsigned long)task_stack_page(p);
+	fp = ((struct switch_stack *)p->thread.ksp)->a6;
+	do {
+		if (fp < stack_page+sizeof(struct thread_info) ||
+		    fp >= 8184+stack_page)
+			return 0;
+		pc = ((unsigned long *)fp)[1];
+		if (!in_sched_functions(pc))
+			return pc;
+		fp = *(unsigned long *) fp;
+	} while (count++ < 16);
+	return 0;
+}