[deliverable/linux.git] / arch / arc / kernel / arc_hostlink.c

/*
 * arc_hostlink.c: Pseudo-driver for Metaware provided "hostlink" facility
 *
 * Allows Linux userland access to host in absence of any peripherals.
 *
 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/fs.h>		/* file_operations */
#include <linux/miscdevice.h>
#include <linux/mm.h>		/* VM_IO */
#include <linux/module.h>
#include <linux/uaccess.h>

static unsigned char __HOSTLINK__[4 * PAGE_SIZE] __aligned(PAGE_SIZE);

static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma)
{
	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
			       vma->vm_end - vma->vm_start,
			       vma->vm_page_prot)) {
		pr_warn("Hostlink buffer mmap ERROR\n");
		return -EAGAIN;
	}
	return 0;
}

static long arc_hl_ioctl(struct file *file, unsigned int cmd,
			unsigned long arg)
{
	/* we only support, returning the physical addr to mmap in user space */
	put_user((unsigned int)__HOSTLINK__, (int __user *)arg);
	return 0;
}

static const struct file_operations arc_hl_fops = {
	.unlocked_ioctl	= arc_hl_ioctl,
	.mmap		= arc_hl_mmap,
};

static struct miscdevice arc_hl_dev = {
	.minor	= MISC_DYNAMIC_MINOR,
	.name	= "hostlink",
	.fops	= &arc_hl_fops
};

static int __init arc_hl_init(void)
{
	pr_info("ARC Hostlink driver mmap at 0x%p\n", __HOSTLINK__);
	return misc_register(&arc_hl_dev);
}
module_init(arc_hl_init);
Commit	Line	Data
cbe056f7 VG	1	/*
	2	* arc_hostlink.c: Pseudo-driver for Metaware provided "hostlink" facility
	3	*
	4	* Allows Linux userland access to host in absence of any peripherals.
	5	*
	6	* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/fs.h> /* file_operations */
	14	#include <linux/miscdevice.h>
	15	#include <linux/mm.h> /* VM_IO */
	16	#include <linux/module.h>
	17	#include <linux/uaccess.h>
	18
	19	static unsigned char __HOSTLINK__[4 * PAGE_SIZE] __aligned(PAGE_SIZE);
	20
	21	static int arc_hl_mmap(struct file fp, struct vm_area_struct vma)
	22	{
	23	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
	24
	25	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
	26	vma->vm_end - vma->vm_start,
	27	vma->vm_page_prot)) {
	28	pr_warn("Hostlink buffer mmap ERROR\n");
	29	return -EAGAIN;
	30	}
	31	return 0;
	32	}
	33
	34	static long arc_hl_ioctl(struct file *file, unsigned int cmd,
	35	unsigned long arg)
	36	{
	37	/* we only support, returning the physical addr to mmap in user space */
	38	put_user((unsigned int)__HOSTLINK__, (int __user *)arg);
	39	return 0;
	40	}
	41
	42	static const struct file_operations arc_hl_fops = {
	43	.unlocked_ioctl = arc_hl_ioctl,
	44	.mmap = arc_hl_mmap,
	45	};
	46
	47	static struct miscdevice arc_hl_dev = {
	48	.minor = MISC_DYNAMIC_MINOR,
	49	.name = "hostlink",
	50	.fops = &arc_hl_fops
	51	};
	52
	53	static int __init arc_hl_init(void)
	54	{
	55	pr_info("ARC Hostlink driver mmap at 0x%p\n", __HOSTLINK__);
	56	return misc_register(&arc_hl_dev);
	57	}
	58	module_init(arc_hl_init);