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author | Vineet Gupta <vgupta@synopsys.com> | 2013-01-18 15:12:25 +0530 |
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committer | Vineet Gupta <vgupta@synopsys.com> | 2013-02-15 23:16:10 +0530 |
commit | cbe056f76a386708f3807b274322f78269aee0f6 (patch) | |
tree | a64ad404b3f912c3885881b32aba3b5559b3333a /arch/arc/kernel/arc_hostlink.c | |
parent | 8b5850f8ac8d9b809db4588b80b568faca5aaaaf (diff) | |
download | talos-op-linux-cbe056f76a386708f3807b274322f78269aee0f6.tar.gz talos-op-linux-cbe056f76a386708f3807b274322f78269aee0f6.zip |
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: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel/arc_hostlink.c')
-rw-r--r-- | arch/arc/kernel/arc_hostlink.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/arc/kernel/arc_hostlink.c b/arch/arc/kernel/arc_hostlink.c new file mode 100644 index 000000000000..47b2a17cc52a --- /dev/null +++ b/arch/arc/kernel/arc_hostlink.c @@ -0,0 +1,58 @@ +/* + * 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); |