/* *  linux/kernel/chr_drv/mem.c * *  Copyright (C) 1991, 1992  Linus Torvalds */#include <linux/config.h>#include <linux/types.h>#include <linux/errno.h>#include <linux/sched.h>#include <linux/kernel.h>#include <linux/major.h>#include <linux/tty.h>#include <linux/mouse.h>#include <linux/tpqic02.h>#include <linux/malloc.h>#include <linux/mman.h>#include <asm/segment.h>#include <asm/io.h>#ifdef CONFIG_SOUNDextern long soundcard_init(long mem_start);#endifstatic int read_ram(struct inode * inode, struct file * file,char * buf, int count){	return -EIO;}static int write_ram(struct inode * inode, struct file * file,char * buf, int count){	return -EIO;}static int read_mem(struct inode * inode, struct file * file,char * buf, int count){	unsigned long p = file->f_pos;	int read;	if (count < 0)		return -EINVAL;	if (p >= high_memory)		return 0;	if (count > high_memory - p)		count = high_memory - p;	read = 0;	while (p < PAGE_SIZE && count > 0) {		put_fs_byte(0,buf);		buf++;		p++;		count--;		read++;	}	memcpy_tofs(buf,(void *) p,count);	read += count;	file->f_pos += read;	return read;}static int write_mem(struct inode * inode, struct file * file,char * buf, int count){	unsigned long p = file->f_pos;	int written;	if (count < 0)		return -EINVAL;	if (p >= high_memory)		return 0;	if (count > high_memory - p)		count = high_memory - p;	written = 0;	while (p < PAGE_SIZE && count > 0) {		/* Hmm. Do something? */		buf++;		p++;		count--;		written++;	}	memcpy_fromfs((void *) p,buf,count);	written += count;	file->f_pos += written;	return count;}static int mmap_mem(struct inode * inode, struct file * file,	unsigned long addr, size_t len, int prot, unsigned long off){	struct vm_area_struct * mpnt;	if (off & 0xfff || off + len < off)		return -ENXIO;	if (x86 > 3 && off >= high_memory)		prot |= PAGE_PCD;	if (remap_page_range(addr, off, len, prot))		return -EAGAIN;/* try to create a dummy vmm-structure so that the rest of the kernel knows we are here */	mpnt = (struct vm_area_struct * ) kmalloc(sizeof(struct vm_area_struct), GFP_KERNEL);	if (!mpnt)		return 0;	mpnt->vm_task = current;	mpnt->vm_start = addr;	mpnt->vm_end = addr + len;	mpnt->vm_page_prot = prot;	mpnt->vm_share = NULL;	mpnt->vm_inode = inode;	inode->i_count++;	mpnt->vm_offset = off;	mpnt->vm_ops = NULL;	insert_vm_struct(current, mpnt);	merge_segments(current->mmap, NULL, NULL);	return 0;}static int read_kmem(struct inode *inode, struct file *file, char *buf, int count){	int read1, read2;	read1 = read_mem(inode, file, buf, count);	if (read1 < 0)		return read1;	read2 = vread(buf + read1, (char *) file->f_pos, count - read1);	if (read2 < 0)		return read2;	file->f_pos += read2;	return read1 + read2;}static int read_port(struct inode * inode,struct file * file,char * buf, int count){	unsigned int i = file->f_pos;	char * tmp = buf;	while (count-- > 0 && i < 65536) {		put_fs_byte(inb(i),tmp);		i++;		tmp++;	}	file->f_pos = i;	return tmp-buf;}static int write_port(struct inode * inode,struct file * file,char * buf, int count){	unsigned int i = file->f_pos;	char * tmp = buf;	while (count-- > 0 && i < 65536) {		outb(get_fs_byte(tmp),i);		i++;		tmp++;	}	file->f_pos = i;	return tmp-buf;}static int read_null(struct inode * node,struct file * file,char * buf,int count){	return 0;}static int write_null(struct inode * inode,struct file * file,char * buf, int count){	return count;}static int read_zero(struct inode * node,struct file * file,char * buf,int count){	int left;	for (left = count; left > 0; left--) {		put_fs_byte(0,buf);		buf++;	}	return count;}static int mmap_zero(struct inode * inode, struct file * file,	unsigned long addr, size_t len, int prot, unsigned long off){	struct vm_area_struct *mpnt;	if (prot & PAGE_RW)		return -EINVAL;	if (zeromap_page_range(addr, len, prot))		return -EAGAIN;	/*	 * try to create a dummy vmm-structure so that the	 * rest of the kernel knows we are here	 */	mpnt = (struct vm_area_struct *)kmalloc(sizeof(*mpnt), GFP_KERNEL);	if (!mpnt)		return 0;	mpnt->vm_task = current;	mpnt->vm_start = addr;	mpnt->vm_end = addr + len;	mpnt->vm_page_prot = prot;	mpnt->vm_share = NULL;	mpnt->vm_inode = NULL;	mpnt->vm_offset = off;	mpnt->vm_ops = NULL;	insert_vm_struct(current, mpnt);	merge_segments(current->mmap, ignoff_mergep, inode);	return 0;}static int read_full(struct inode * node,struct file * file,char * buf,int count){	return count;}static int write_full(struct inode * inode,struct file * file,char * buf, int count){	return -ENOSPC;}/* * Special lseek() function for /dev/null and /dev/zero.  Most notably, you can fopen() * both devices with "a" now.  This was previously impossible.  SRB. */static int null_lseek(struct inode * inode, struct file * file, off_t offset, int orig){	return file->f_pos=0;}/* * The memory devices use the full 32 bits of the offset, and so we cannot * check against negative addresses: they are ok. The return value is weird, * though, in that case (0). * * also note that seeking relative to the "end of file" isn't supported: * it has no meaning, so it returns -EINVAL. */static int memory_lseek(struct inode * inode, struct file * file, off_t offset, int orig){	switch (orig) {		case 0:			file->f_pos = offset;			return file->f_pos;		case 1:			file->f_pos += offset;			return file->f_pos;		default:			return -EINVAL;	}	if (file->f_pos < 0)		return 0;	return file->f_pos;}#define write_kmem	write_mem#define mmap_kmem	mmap_mem#define zero_lseek	null_lseek#define write_zero	write_nullstatic struct file_operations ram_fops = {	memory_lseek,	read_ram,	write_ram,	NULL,		/* ram_readdir */	NULL,		/* ram_select */	NULL,		/* ram_ioctl */	NULL,		/* ram_mmap */	NULL,		/* no special open code */	NULL,		/* no special release code */	NULL		/* fsync */};static struct file_operations mem_fops = {	memory_lseek,	read_mem,	write_mem,	NULL,		/* mem_readdir */	NULL,		/* mem_select */	NULL,		/* mem_ioctl */	mmap_mem,	NULL,		/* no special open code */	NULL,		/* no special release code */	NULL		/* fsync */};static struct file_operations kmem_fops = {	memory_lseek,	read_kmem,	write_kmem,	NULL,		/* kmem_readdir */	NULL,		/* kmem_select */	NULL,		/* kmem_ioctl */	mmap_kmem,	NULL,		/* no special open code */	NULL,		/* no special release code */	NULL		/* fsync */};static struct file_operations null_fops = {	null_lseek,	read_null,	write_null,	NULL,		/* null_readdir */	NULL,		/* null_select */	NULL,		/* null_ioctl */	NULL,		/* null_mmap */	NULL,		/* no special open code */	NULL,		/* no special release code */	NULL		/* fsync */};static struct file_operations port_fops = {	memory_lseek,	read_port,	write_port,	NULL,		/* port_readdir */	NULL,		/* port_select */	NULL,		/* port_ioctl */	NULL,		/* port_mmap */	NULL,		/* no special open code */	NULL,		/* no special release code */	NULL		/* fsync */};static struct file_operations zero_fops = {	zero_lseek,	read_zero,	write_zero,	NULL,		/* zero_readdir */	NULL,		/* zero_select */	NULL,		/* zero_ioctl */	mmap_zero,	NULL,		/* no special open code */	NULL		/* no special release code */};static struct file_operations full_fops = {	memory_lseek,	read_full,	write_full,	NULL,		/* full_readdir */	NULL,		/* full_select */	NULL,		/* full_ioctl */		NULL,		/* full_mmap */	NULL,		/* no special open code */	NULL		/* no special release code */};static int memory_open(struct inode * inode, struct file * filp){	switch (MINOR(inode->i_rdev)) {		case 0:			filp->f_op = &ram_fops;			break;		case 1:			filp->f_op = &mem_fops;			break;		case 2:			filp->f_op = &kmem_fops;			break;		case 3:			filp->f_op = &null_fops;			break;		case 4:			filp->f_op = &port_fops;			break;		case 5:			filp->f_op = &zero_fops;			break;		case 7:			filp->f_op = &full_fops;			break;		default:			return -ENODEV;	}	if (filp->f_op && filp->f_op->open)		return filp->f_op->open(inode,filp);	return 0;}static struct file_operations memory_fops = {	NULL,		/* lseek */	NULL,		/* read */	NULL,		/* write */	NULL,		/* readdir */	NULL,		/* select */	NULL,		/* ioctl */	NULL,		/* mmap */	memory_open,	/* just a selector for the real open */	NULL,		/* release */	NULL		/* fsync */};#ifdef CONFIG_FTAPEchar* ftape_big_buffer;#endiflong chr_dev_init(long mem_start, long mem_end){	if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))		printk("unable to get major %d for memory devs\n", MEM_MAJOR);	mem_start = tty_init(mem_start);#ifdef CONFIG_PRINTER	mem_start = lp_init(mem_start);#endif#if defined (CONFIG_BUSMOUSE) || defined (CONFIG_82C710_MOUSE) || \    defined (CONFIG_PSMOUSE) || defined (CONFIG_MS_BUSMOUSE) || \    defined (CONFIG_ATIXL_BUSMOUSE)	mem_start = mouse_init(mem_start);#endif#ifdef CONFIG_SOUND	mem_start = soundcard_init(mem_start);#endif#if CONFIG_TAPE_QIC02	mem_start = tape_qic02_init(mem_start);#endif/* *      Rude way to allocate kernel memory buffer for tape device */#ifdef CONFIG_FTAPE        /* allocate NR_FTAPE_BUFFERS 32Kb buffers at aligned address */        ftape_big_buffer= (char*) ((mem_start + 0x7fff) & ~0x7fff);        printk( "ftape: allocated %d buffers alligned at: %p\n",               NR_FTAPE_BUFFERS, ftape_big_buffer);        mem_start = (long) ftape_big_buffer + NR_FTAPE_BUFFERS * 0x8000;#endif 	return mem_start;}