Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * arc_hostlink.c: Pseudo-driver for Metaware provided "hostlink" facility
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Allows Linux userland access to host in absence of any peripherals.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/fs.h>		/* file_operations */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/miscdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/mm.h>		/* VM_IO */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) static unsigned char __HOSTLINK__[4 * PAGE_SIZE] __aligned(PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 			       vma->vm_end - vma->vm_start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 			       vma->vm_page_prot)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 		pr_warn("Hostlink buffer mmap ERROR\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 		return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static long arc_hl_ioctl(struct file *file, unsigned int cmd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 			unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	/* we only support, returning the physical addr to mmap in user space */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	put_user((unsigned int)__HOSTLINK__, (int __user *)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static const struct file_operations arc_hl_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	.unlocked_ioctl	= arc_hl_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	.mmap		= arc_hl_mmap,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) static struct miscdevice arc_hl_dev = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	.minor	= MISC_DYNAMIC_MINOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	.name	= "hostlink",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	.fops	= &arc_hl_fops
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) static int __init arc_hl_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	pr_info("ARC Hostlink driver mmap at 0x%p\n", __HOSTLINK__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	return misc_register(&arc_hl_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) module_init(arc_hl_init);