mirror of
https://github.com/torvalds/linux.git
synced 2024-11-27 06:31:52 +00:00
cbe056f76a
This allows ARC Target to do I/O to host in absence of any peripherals whatsoever, assisted by Metaware Hostlink facility. Further we have a FUSE based filesystem which makes us mount/access host filesystem on target and do fops. Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
59 lines
1.6 KiB
C
59 lines
1.6 KiB
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);
|