1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/cris/mm/ioremap.c
4 *
5 * Re-map IO memory to kernel address space so that we can access it.
6 * Needed for memory-mapped I/O devices mapped outside our normal DRAM
7 * window (that is, all memory-mapped I/O devices).
8 *
9 * (C) Copyright 1995 1996 Linus Torvalds
10 * CRIS-port by Axis Communications AB
11 */
12
13 #include <linux/vmalloc.h>
14 #include <linux/io.h>
15 #include <asm/pgalloc.h>
16 #include <arch/memmap.h>
17
18 /*
19 * Generic mapping function (not visible outside):
20 */
21
22 /*
23 * Remap an arbitrary physical address space into the kernel virtual
24 * address space. Needed when the kernel wants to access high addresses
25 * directly.
26 *
27 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
28 * have to convert them into an offset in a page-aligned mapping, but the
29 * caller shouldn't need to know that small detail.
30 */
__ioremap_prot(unsigned long phys_addr,unsigned long size,pgprot_t prot)31 void __iomem * __ioremap_prot(unsigned long phys_addr, unsigned long size, pgprot_t prot)
32 {
33 void __iomem * addr;
34 struct vm_struct * area;
35 unsigned long offset, last_addr;
36
37 /* Don't allow wraparound or zero size */
38 last_addr = phys_addr + size - 1;
39 if (!size || last_addr < phys_addr)
40 return NULL;
41
42 /*
43 * Mappings have to be page-aligned
44 */
45 offset = phys_addr & ~PAGE_MASK;
46 phys_addr &= PAGE_MASK;
47 size = PAGE_ALIGN(last_addr+1) - phys_addr;
48
49 /*
50 * Ok, go for it..
51 */
52 area = get_vm_area(size, VM_IOREMAP);
53 if (!area)
54 return NULL;
55 addr = (void __iomem *)area->addr;
56 if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
57 phys_addr, prot)) {
58 vfree((void __force *)addr);
59 return NULL;
60 }
61 return (void __iomem *) (offset + (char __iomem *)addr);
62 }
63
__ioremap(unsigned long phys_addr,unsigned long size,unsigned long flags)64 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
65 {
66 return __ioremap_prot(phys_addr, size,
67 __pgprot(_PAGE_PRESENT | __READABLE |
68 __WRITEABLE | _PAGE_GLOBAL |
69 _PAGE_KERNEL | flags));
70 }
71
72 /**
73 * ioremap_nocache - map bus memory into CPU space
74 * @offset: bus address of the memory
75 * @size: size of the resource to map
76 *
77 * Must be freed with iounmap.
78 */
79
ioremap_nocache(unsigned long phys_addr,unsigned long size)80 void __iomem *ioremap_nocache(unsigned long phys_addr, unsigned long size)
81 {
82 return __ioremap(phys_addr | MEM_NON_CACHEABLE, size, 0);
83 }
84 EXPORT_SYMBOL(ioremap_nocache);
85
iounmap(volatile void __iomem * addr)86 void iounmap(volatile void __iomem *addr)
87 {
88 if (addr > high_memory)
89 return vfree((void *) (PAGE_MASK & (unsigned long) addr));
90 }
91