patch-2.3.16 linux/arch/sh/kernel/process.c

• Lines: 305
• Date: Mon Aug 30 18:12:59 1999
• Orig file: v2.3.15/linux/arch/sh/kernel/process.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.15/linux/arch/sh/kernel/process.c linux/arch/sh/kernel/process.c
@@ -0,0 +1,304 @@
+/*
+ *  linux/arch/sh/kernel/process.c
+ *
+ *  Copyright (C) 1995  Linus Torvalds
+ *
+ *  SuperH version:  Copyright (C) 1999  Niibe Yutaka
+ */
+
+/*
+ * This file handles the architecture-dependent parts of process handling..
+ */
+
+#define __KERNEL_SYSCALLS__
+#include <stdarg.h>
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/stddef.h>
+#include <linux/ptrace.h>
+#include <linux/malloc.h>
+#include <linux/vmalloc.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/interrupt.h>
+#include <linux/config.h>
+#include <linux/unistd.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/mmu_context.h>
+#include <asm/elf.h>
+
+#include <linux/irq.h>
+
+static int hlt_counter=0;
+
+#define HARD_IDLE_TIMEOUT (HZ / 3)
+
+void disable_hlt(void)
+{
+	hlt_counter++;
+}
+
+void enable_hlt(void)
+{
+	hlt_counter--;
+}
+
+/*
+ * The idle loop on a uniprocessor i386..
+ */ 
+void cpu_idle(void *unused)
+{
+	/* endless idle loop with no priority at all */
+	init_idle();
+	current->priority = 0;
+	current->counter = -100;
+
+	while (1) {
+		while (!current->need_resched) {
+			if (hlt_counter)
+				continue;
+			__sti();
+			asm volatile("sleep" : : : "memory");
+		}
+		schedule();
+		check_pgt_cache();
+	}
+}
+
+void machine_restart(char * __unused)
+{ /* Need to set MMU_TTB?? */
+}
+
+void machine_halt(void)
+{
+}
+
+void machine_power_off(void)
+{
+}
+
+void show_regs(struct pt_regs * regs)
+{
+	printk("\n");
+	printk("PC: [<%08lx>]", regs->pc);
+	printk(" SP: %08lx", regs->u_regs[UREG_SP]);
+	printk(" SR: %08lx\n", regs->sr);
+	printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
+	       regs->u_regs[0],regs->u_regs[1],
+	       regs->u_regs[2],regs->u_regs[3]);
+	printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
+	       regs->u_regs[4],regs->u_regs[5],
+	       regs->u_regs[6],regs->u_regs[7]);
+	printk("R8 : %08lx R9 : %08lx R10: %08lx R11: %08lx\n",
+	       regs->u_regs[8],regs->u_regs[9],
+	       regs->u_regs[10],regs->u_regs[11]);
+	printk("R12: %08lx R13: %08lx R14: %08lx\n",
+	       regs->u_regs[12],regs->u_regs[13],
+	       regs->u_regs[14]);
+	printk("MACH: %08lx MACL: %08lx GBR: %08lx PR: %08lx",
+	       regs->mach, regs->macl, regs->gbr, regs->pr);
+}
+
+struct task_struct * alloc_task_struct(void)
+{
+	/* Get two pages */
+	return (struct task_struct *) __get_free_pages(GFP_KERNEL,1);
+}
+
+void free_task_struct(struct task_struct *p)
+{
+	free_pages((unsigned long) p, 1);
+}
+
+/*
+ * Create a kernel thread
+ */
+
+/*
+ * This is the mechanism for creating a new kernel thread.
+ *
+ * NOTE! Only a kernel-only process(ie the swapper or direct descendants
+ * who haven't done an "execve()") should use this: it will work within
+ * a system call from a "real" process, but the process memory space will
+ * not be free'd until both the parent and the child have exited.
+ */
+int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
+{	/* Don't use this in BL=1(cli).  Or else, CPU resets! */
+	register unsigned long __sc0 __asm__ ("r0") = __NR_clone;
+	register unsigned long __sc4 __asm__ ("r4") = (long) flags | CLONE_VM;
+	register unsigned long __sc5 __asm__ ("r5") = 0;
+	register unsigned long __sc8 __asm__ ("r8") = (long) arg;
+	register unsigned long __sc9 __asm__ ("r9") = (long) fn;
+	__asm__ __volatile__(
+		"trapa	#0\n\t" 	/* Linux/SH system call */
+		"tst	#0xff,r0\n\t"	/* child or parent? */
+		"bf	1f\n\t"		/* parent - jump */
+		"jsr	@r9\n\t"	/* call fn */
+		" mov	r8,r4\n\t"	/* push argument */
+		"mov	r0,r4\n\t"	/* return value to arg of exit */
+		"mov	%2,r0\n\t"	/* exit */
+		"trapa	#0\n"
+		"1:"
+		:"=z" (__sc0)
+		:"0" (__sc0), "i" (__NR_exit),
+		 "r" (__sc4), "r" (__sc5), "r" (__sc8), "r" (__sc9)
+		:"memory");
+	return __sc0;
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+	/* nothing to do ... */
+}
+
+void flush_thread(void)
+{
+	/* do nothing */
+	/* Possibly, set clear debug registers */
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+	/* do nothing */
+}
+
+/* Fill in the fpu structure for a core dump.. */
+int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
+{
+	return 0; /* Task didn't use the fpu at all. */
+}
+
+asmlinkage void ret_from_fork(void);
+
+int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
+		struct task_struct *p, struct pt_regs *regs)
+{
+	struct pt_regs *childregs;
+
+	childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long) p)) - 1;
+
+	*childregs = *regs;
+	if (user_mode(regs)) {
+		childregs->u_regs[UREG_SP] = usp;
+	} else {
+		childregs->u_regs[UREG_SP] = (unsigned long)p+2*PAGE_SIZE;
+	}
+	childregs->u_regs[0] = 0; /* Set return value for child */
+
+	p->thread.sp = (unsigned long) childregs;
+	p->thread.pc = (unsigned long) ret_from_fork;
+	if (p->mm)
+		p->mm->context = NO_CONTEXT;
+
+	return 0;
+}
+
+/*
+ * 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 = regs->u_regs[UREG_SP] & ~(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;
+	/* Debug registers will come here. */
+
+	if (dump->start_stack < TASK_SIZE)
+		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
+
+	dump->regs = *regs;
+}
+
+/*
+ *	switch_to(x,y) should switch tasks from x to y.
+ *
+ */
+void __switch_to(struct task_struct *prev, struct task_struct *next)
+{
+	/*
+	 * Restore the kernel stack onto kernel mode register
+	 *   	k4 (r4_bank1)
+	 */
+	asm volatile("ldc	%0,r4_bank"
+		     : /* no output */
+		     :"r" ((unsigned long)next+8192));
+}
+
+asmlinkage int sys_fork(unsigned long r4, unsigned long r5,
+			unsigned long r6, unsigned long r7,
+			struct pt_regs regs)
+{
+	return do_fork(SIGCHLD, regs.u_regs[UREG_SP], &regs);
+}
+
+asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
+			 unsigned long r6, unsigned long r7,
+			 struct pt_regs regs)
+{
+	if (!newsp)
+		newsp = regs.u_regs[UREG_SP];
+	return do_fork(clone_flags, newsp, &regs);
+}
+
+/*
+ * This is trivial, and on the face of it looks like it
+ * could equally well be done in user mode.
+ *
+ * Not so, for quite unobvious reasons - register pressure.
+ * In user mode vfork() cannot have a stack frame, and if
+ * done by calling the "clone()" system call directly, you
+ * do not have enough call-clobbered registers to hold all
+ * the information you need.
+ */
+asmlinkage int sys_vfork(unsigned long r4, unsigned long r5,
+			 unsigned long r6, unsigned long r7,
+			 struct pt_regs regs)
+{
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
+		       regs.u_regs[UREG_SP], &regs);
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(char *ufilename, char **uargv,
+			  char **uenvp, unsigned long r7,
+			  struct pt_regs regs)
+{
+	int error;
+	char *filename;
+
+	lock_kernel();
+	filename = getname(ufilename);
+	error = PTR_ERR(filename);
+	if (IS_ERR(filename))
+		goto out;
+	error = do_execve(filename, uargv, uenvp, &regs);
+	if (error == 0)
+		current->flags &= ~PF_DTRACE;
+	putname(filename);
+out:
+	unlock_kernel();
+	return error;
+}