| 1 | |
| 2 | |
| 3 | * arc_hostlink.c: Pseudo-driver for Metaware provided "hostlink" facility
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| 4 | *
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| 5 | * Allows Linux userland access to host in absence of any peripherals.
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| 6 | *
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| 7 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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| 8 |
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| 9 |
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| 10 | #include <linux/fs.h>
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| 11 | #include <linux/miscdevice.h>
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| 12 | #include <linux/mm.h>
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| 13 | #include <linux/module.h>
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| 14 | #include <linux/uaccess.h>
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| 15 |
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| 16 | static unsigned char __HOSTLINK__[4 * PAGE_SIZE] __aligned(PAGE_SIZE);
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| 17 |
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| 18 | static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma)
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| 19 | {
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| 20 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
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| 21 |
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| 22 | if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
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| 23 | vma->vm_end - vma->vm_start,
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| 24 | vma->vm_page_prot)) {
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| 25 | pr_warn("Hostlink buffer mmap ERROR\n");
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| 26 | return -EAGAIN;
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| 27 | }
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| 28 | return 0;
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| 29 | }
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| 30 |
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| 31 | static long arc_hl_ioctl(struct file *file, unsigned int cmd,
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| 32 | unsigned long arg)
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| 33 | {
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| 34 |
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| 35 | put_user((unsigned int)__HOSTLINK__, (int __user *)arg);
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| 36 | return 0;
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| 37 | }
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| 38 |
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| 39 | static const struct file_operations arc_hl_fops = {
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| 40 | .unlocked_ioctl = arc_hl_ioctl,
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| 41 | .mmap = arc_hl_mmap,
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| 42 | };
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| 43 |
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| 44 | static struct miscdevice arc_hl_dev = {
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| 45 | .minor = MISC_DYNAMIC_MINOR,
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| 46 | .name = "hostlink",
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| 47 | .fops = &arc_hl_fops
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| 48 | };
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| 49 |
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| 50 | static int __init arc_hl_init(void)
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| 51 | {
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| 52 | pr_info("ARC Hostlink driver mmap at 0x%p\n", __HOSTLINK__);
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| 53 | return misc_register(&arc_hl_dev);
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| 54 | }
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| 55 | module_init(arc_hl_init);
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