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
arc_uncached_addr_space(phys_addr_t paddr)13 static 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
ioremap(phys_addr_t paddr,unsigned long size)25 void __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 }
37 EXPORT_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 */
ioremap_prot(phys_addr_t paddr,size_t size,unsigned long flags)46 void __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 }
54 EXPORT_SYMBOL(ioremap_prot);
55
iounmap(volatile void __iomem * addr)56 void 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 }
64 EXPORT_SYMBOL(iounmap);
65