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/slab.h>
12 #include <linux/cache.h>
13
arc_uncached_addr_space(phys_addr_t paddr)14 static inline bool arc_uncached_addr_space(phys_addr_t paddr)
15 {
16 if (is_isa_arcompact()) {
17 if (paddr >= ARC_UNCACHED_ADDR_SPACE)
18 return true;
19 } else if (paddr >= perip_base && paddr <= perip_end) {
20 return true;
21 }
22
23 return false;
24 }
25
ioremap(phys_addr_t paddr,unsigned long size)26 void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
27 {
28 phys_addr_t end;
29
30 /* Don't allow wraparound or zero size */
31 end = paddr + size - 1;
32 if (!size || (end < paddr))
33 return NULL;
34
35 /*
36 * If the region is h/w uncached, MMU mapping can be elided as optim
37 * The cast to u32 is fine as this region can only be inside 4GB
38 */
39 if (arc_uncached_addr_space(paddr))
40 return (void __iomem *)(u32)paddr;
41
42 return ioremap_prot(paddr, size, PAGE_KERNEL_NO_CACHE);
43 }
44 EXPORT_SYMBOL(ioremap);
45
46 /*
47 * ioremap with access flags
48 * Cache semantics wise it is same as ioremap - "forced" uncached.
49 * However unlike vanilla ioremap which bypasses ARC MMU for addresses in
50 * ARC hardware uncached region, this one still goes thru the MMU as caller
51 * might need finer access control (R/W/X)
52 */
ioremap_prot(phys_addr_t paddr,unsigned long size,unsigned long flags)53 void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
54 unsigned long flags)
55 {
56 unsigned int off;
57 unsigned long vaddr;
58 struct vm_struct *area;
59 phys_addr_t end;
60 pgprot_t prot = __pgprot(flags);
61
62 /* Don't allow wraparound, zero size */
63 end = paddr + size - 1;
64 if ((!size) || (end < paddr))
65 return NULL;
66
67 /* An early platform driver might end up here */
68 if (!slab_is_available())
69 return NULL;
70
71 /* force uncached */
72 prot = pgprot_noncached(prot);
73
74 /* Mappings have to be page-aligned */
75 off = paddr & ~PAGE_MASK;
76 paddr &= PAGE_MASK_PHYS;
77 size = PAGE_ALIGN(end + 1) - paddr;
78
79 /*
80 * Ok, go for it..
81 */
82 area = get_vm_area(size, VM_IOREMAP);
83 if (!area)
84 return NULL;
85 area->phys_addr = paddr;
86 vaddr = (unsigned long)area->addr;
87 if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) {
88 vunmap((void __force *)vaddr);
89 return NULL;
90 }
91 return (void __iomem *)(off + (char __iomem *)vaddr);
92 }
93 EXPORT_SYMBOL(ioremap_prot);
94
95
iounmap(const volatile void __iomem * addr)96 void iounmap(const volatile void __iomem *addr)
97 {
98 /* weird double cast to handle phys_addr_t > 32 bits */
99 if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
100 return;
101
102 vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
103 }
104 EXPORT_SYMBOL(iounmap);
105