Import of Linux/MIPS 1.3.0

1 files changed, 288 insertions, 0 deletions

diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
new file mode 100644
index 000000000..a5e8777bf
--- /dev/null
+++ b/arch/i386/kernel/process.c
@@ -0,0 +1,288 @@
+/*
+ *  linux/arch/i386/kernel/process.c
+ *
+ *  Copyright (C) 1995  Linus Torvalds
+ */
+
+/*
+ * 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/ldt.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+
+#include <asm/segment.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/io.h>
+
+asmlinkage void ret_from_sys_call(void) __asm__("ret_from_sys_call");
+
+static int hlt_counter=0;
+
+void disable_hlt(void)
+{
+	hlt_counter++;
+}
+
+void enable_hlt(void)
+{
+	hlt_counter--;
+}
+
+asmlinkage int sys_pipe(unsigned long * fildes)
+{
+	int fd[2];
+	int error;
+
+	error = verify_area(VERIFY_WRITE,fildes,8);
+	if (error)
+		return error;
+	error = do_pipe(fd);
+	if (error)
+		return error;
+	put_fs_long(fd[0],0+fildes);
+	put_fs_long(fd[1],1+fildes);
+	return 0;
+}
+
+/*
+ * The idle loop on a i386..
+ */
+asmlinkage int sys_idle(void)
+{
+	int i;
+	pmd_t * pmd;
+
+	if (current->pid != 0)
+		return -EPERM;
+
+	/* Map out the low memory: it's no longer needed */
+	pmd = pmd_offset(swapper_pg_dir, 0);
+	for (i = 0 ; i < 768 ; i++)
+		pmd_clear(pmd++);
+
+	/* endless idle loop with no priority at all */
+	current->counter = -100;
+	for (;;) {
+		if (hlt_works_ok && !hlt_counter && !need_resched)
+			__asm__("hlt");
+		schedule();
+	}
+}
+
+/*
+ * This routine reboots the machine by asking the keyboard
+ * controller to pulse the reset-line low. We try that for a while,
+ * and if it doesn't work, we do some other stupid things.
+ */
+static long no_idt[2] = {0, 0};
+
+static inline void kb_wait(void)
+{
+	int i;
+
+	for (i=0; i<0x10000; i++)
+		if ((inb_p(0x64) & 0x02) == 0)
+			break;
+}
+
+void hard_reset_now(void)
+{
+	int i, j;
+
+	sti();
+/* rebooting needs to touch the page at absolute addr 0 */
+	pg0[0] = 7;
+	*((unsigned short *)0x472) = 0x1234;
+	for (;;) {
+		for (i=0; i<100; i++) {
+			kb_wait();
+			for(j = 0; j < 100000 ; j++)
+				/* nothing */;
+			outb(0xfe,0x64);	 /* pulse reset low */
+		}
+		__asm__ __volatile__("\tlidt %0": "=m" (no_idt));
+	}
+}
+
+void show_regs(struct pt_regs * regs)
+{
+	printk("\n");
+	printk("EIP: %04x:%08lx",0xffff & regs->cs,regs->eip);
+	if (regs->cs & 3)
+		printk(" ESP: %04x:%08lx",0xffff & regs->ss,regs->esp);
+	printk(" EFLAGS: %08lx\n",regs->eflags);
+	printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
+		regs->eax,regs->ebx,regs->ecx,regs->edx);
+	printk("ESI: %08lx EDI: %08lx EBP: %08lx",
+		regs->esi, regs->edi, regs->ebp);
+	printk(" DS: %04x ES: %04x FS: %04x GS: %04x\n",
+		0xffff & regs->ds,0xffff & regs->es,
+		0xffff & regs->fs,0xffff & regs->gs);
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+	/* forget local segments */
+	__asm__ __volatile__("mov %w0,%%fs ; mov %w0,%%gs ; lldt %w0"
+		: /* no outputs */
+		: "r" (0));
+	current->tss.ldt = 0;
+	if (current->ldt) {
+		void * ldt = current->ldt;
+		current->ldt = NULL;
+		vfree(ldt);
+	}
+}
+
+void flush_thread(void)
+{
+	int i;
+
+	if (current->ldt) {
+		free_page((unsigned long) current->ldt);
+		current->ldt = NULL;
+		for (i=1 ; i<NR_TASKS ; i++) {
+			if (task[i] == current)  {
+				set_ldt_desc(gdt+(i<<1)+
+					     FIRST_LDT_ENTRY,&default_ldt, 1);
+				load_ldt(i);
+			}
+		}	
+	}
+
+	for (i=0 ; i<8 ; i++)
+		current->debugreg[i] = 0;
+}
+
+void copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
+	struct task_struct * p, struct pt_regs * regs)
+{
+	int i;
+	struct pt_regs * childregs;
+
+	p->tss.es = KERNEL_DS;
+	p->tss.cs = KERNEL_CS;
+	p->tss.ss = KERNEL_DS;
+	p->tss.ds = KERNEL_DS;
+	p->tss.fs = USER_DS;
+	p->tss.gs = KERNEL_DS;
+	p->tss.ss0 = KERNEL_DS;
+	p->tss.esp0 = p->kernel_stack_page + PAGE_SIZE;
+	p->tss.tr = _TSS(nr);
+	childregs = ((struct pt_regs *) (p->kernel_stack_page + PAGE_SIZE)) - 1;
+	p->tss.esp = (unsigned long) childregs;
+	p->tss.eip = (unsigned long) ret_from_sys_call;
+	*childregs = *regs;
+	childregs->eax = 0;
+	childregs->esp = esp;
+	p->tss.back_link = 0;
+	p->tss.eflags = regs->eflags & 0xffffcfff;	/* iopl is always 0 for a new process */
+	p->tss.ldt = _LDT(nr);
+	if (p->ldt) {
+		p->ldt = (struct desc_struct*) vmalloc(LDT_ENTRIES*LDT_ENTRY_SIZE);
+		if (p->ldt != NULL)
+			memcpy(p->ldt, current->ldt, LDT_ENTRIES*LDT_ENTRY_SIZE);
+	}
+	set_tss_desc(gdt+(nr<<1)+FIRST_TSS_ENTRY,&(p->tss));
+	if (p->ldt)
+		set_ldt_desc(gdt+(nr<<1)+FIRST_LDT_ENTRY,p->ldt, 512);
+	else
+		set_ldt_desc(gdt+(nr<<1)+FIRST_LDT_ENTRY,&default_ldt, 1);
+	p->tss.bitmap = offsetof(struct thread_struct,io_bitmap);
+	for (i = 0; i < IO_BITMAP_SIZE+1 ; i++) /* IO bitmap is actually SIZE+1 */
+		p->tss.io_bitmap[i] = ~0;
+	if (last_task_used_math == current)
+		__asm__("clts ; fnsave %0 ; frstor %0":"=m" (p->tss.i387));
+}
+
+/*
+ * fill in the user structure for a core dump..
+ */
+void dump_thread(struct pt_regs * regs, struct user * dump)
+{
+	int i;
+
+/* changed the size calculations - should hopefully work better. lbt */
+	dump->magic = CMAGIC;
+	dump->start_code = 0;
+	dump->start_stack = regs->esp & ~(PAGE_SIZE - 1);
+	dump->u_tsize = ((unsigned long) current->mm->end_code) >> 12;
+	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> 12;
+	dump->u_dsize -= dump->u_tsize;
+	dump->u_ssize = 0;
+	for (i = 0; i < 8; i++)
+		dump->u_debugreg[i] = current->debugreg[i];  
+
+	if (dump->start_stack < TASK_SIZE)
+		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> 12;
+
+	dump->regs = *regs;
+
+/* Flag indicating the math stuff is valid. We don't support this for the
+   soft-float routines yet */
+	if (hard_math) {
+		if ((dump->u_fpvalid = current->used_math) != 0) {
+			if (last_task_used_math == current)
+				__asm__("clts ; fnsave %0": :"m" (dump->i387));
+			else
+				memcpy(&dump->i387,&current->tss.i387.hard,sizeof(dump->i387));
+		}
+	} else {
+		/* we should dump the emulator state here, but we need to
+		   convert it into standard 387 format first.. */
+		dump->u_fpvalid = 0;
+	}
+}
+
+asmlinkage int sys_fork(struct pt_regs regs)
+{
+	return do_fork(COPYVM | SIGCHLD, regs.esp, &regs);
+}
+
+asmlinkage int sys_clone(struct pt_regs regs)
+{
+#ifdef CLONE_ACTUALLY_WORKS_OK
+	unsigned long clone_flags;
+	unsigned long newsp;
+
+	newsp = regs.ebx;
+	clone_flags = regs.ecx;
+	if (!newsp)
+		newsp = regs.esp;
+	if (newsp == regs.esp)
+		clone_flags |= COPYVM;
+	return do_fork(clone_flags, newsp, &regs);
+#else
+	return -ENOSYS;
+#endif
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(struct pt_regs regs)
+{
+	int error;
+	char * filename;
+
+	error = getname((char *) regs.ebx, &filename);
+	if (error)
+		return error;
+	error = do_execve(filename, (char **) regs.ecx, (char **) regs.edx, &regs);
+	putname(filename);
+	return error;
+}