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Commit cbe056f7 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: Hostlink Pseudo-Driver for Metaware Debugger 



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: default avatarVineet Gupta <vgupta@synopsys.com>
parent 8b5850f8

arch/arc/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -389,6 +389,15 @@ config HZ 
	int "Timer Frequency"

	default 100



config ARC_METAWARE_HLINK

	bool "Support for Metaware debugger assisted Host access"

	default n

	help

	  This options allows a Linux userland apps to directly access

	  host file system (open/creat/read/write etc) with help from

	  Metaware Debugger. This can come in handy for Linux-host communication

	  when there is no real usable peripheral such as EMAC.



menuconfig ARC_DBG

	bool "ARC debugging"

	default y

arch/arc/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ obj-$(CONFIG_ARC_DW2_UNWIND) += unwind.o 
obj-$(CONFIG_KPROBES)      		+= kprobes.o

obj-$(CONFIG_ARC_MISALIGN_ACCESS) 	+= unaligned.o

obj-$(CONFIG_KGDB)			+= kgdb.o

obj-$(CONFIG_ARC_METAWARE_HLINK)	+= arc_hostlink.o



obj-$(CONFIG_ARC_FPU_SAVE_RESTORE)	+= fpu.o

CFLAGS_fpu.o   += -mdpfp

arch/arc/kernel/arc_hostlink.c

0 → 100644
+58 −0
Original line number Diff line number Diff line 
/*

 * 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);