1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#include <linux/vmalloc.h>
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/io.h>
10#include <linux/mm.h>
11#include <linux/cache.h>
12
13static inline bool arc_uncached_addr_space(phys_addr_t paddr)
14{
15	if (is_isa_arcompact()) {
16		if (paddr >= ARC_UNCACHED_ADDR_SPACE)
17			return true;
18	} else if (paddr >= perip_base && paddr <= perip_end) {
19		return true;
20	}
21
22	return false;
23}
24
25void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
26{
27	/*
28	 * If the region is h/w uncached, MMU mapping can be elided as optim
29	 * The cast to u32 is fine as this region can only be inside 4GB
30	 */
31	if (arc_uncached_addr_space(paddr))
32		return (void __iomem *)(u32)paddr;
33
34	return ioremap_prot(paddr, size,
35			    pgprot_val(pgprot_noncached(PAGE_KERNEL)));
36}
37EXPORT_SYMBOL(ioremap);
38
39/*
40 * ioremap with access flags
41 * Cache semantics wise it is same as ioremap - "forced" uncached.
42 * However unlike vanilla ioremap which bypasses ARC MMU for addresses in
43 * ARC hardware uncached region, this one still goes thru the MMU as caller
44 * might need finer access control (R/W/X)
45 */
46void __iomem *ioremap_prot(phys_addr_t paddr, size_t size,
47			   unsigned long flags)
48{
49	pgprot_t prot = __pgprot(flags);
50
51	/* force uncached */
52	return generic_ioremap_prot(paddr, size, pgprot_noncached(prot));
53}
54EXPORT_SYMBOL(ioremap_prot);
55
56void iounmap(volatile void __iomem *addr)
57{
58	/* weird double cast to handle phys_addr_t > 32 bits */
59	if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
60		return;
61
62	generic_iounmap(addr);
63}
64EXPORT_SYMBOL(iounmap);
65