1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * (C) Copyright 1995 1996 Linus Torvalds
7 * (C) Copyright 2001, 2002 Ralf Baechle
8 */
9#include <linux/export.h>
10#include <asm/addrspace.h>
11#include <asm/byteorder.h>
12#include <linux/ioport.h>
13#include <linux/sched.h>
14#include <linux/slab.h>
15#include <linux/vmalloc.h>
16#include <linux/mm_types.h>
17#include <linux/io.h>
18#include <asm/cacheflush.h>
19#include <asm/tlbflush.h>
20#include <ioremap.h>
21
22#define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
23#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
24
25static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
26			       void *arg)
27{
28	unsigned long i;
29
30	for (i = 0; i < nr_pages; i++) {
31		if (pfn_valid(start_pfn + i) &&
32		    !PageReserved(pfn_to_page(start_pfn + i)))
33			return 1;
34	}
35
36	return 0;
37}
38
39/*
40 * ioremap_prot     -   map bus memory into CPU space
41 * @phys_addr:    bus address of the memory
42 * @size:      size of the resource to map
43 *
44 * ioremap_prot gives the caller control over cache coherency attributes (CCA)
45 */
46void __iomem *ioremap_prot(phys_addr_t phys_addr, unsigned long size,
47		unsigned long prot_val)
48{
49	unsigned long flags = prot_val & _CACHE_MASK;
50	unsigned long offset, pfn, last_pfn;
51	struct vm_struct *area;
52	phys_addr_t last_addr;
53	unsigned long vaddr;
54	void __iomem *cpu_addr;
55
56	cpu_addr = plat_ioremap(phys_addr, size, flags);
57	if (cpu_addr)
58		return cpu_addr;
59
60	phys_addr = fixup_bigphys_addr(phys_addr, size);
61
62	/* Don't allow wraparound or zero size */
63	last_addr = phys_addr + size - 1;
64	if (!size || last_addr < phys_addr)
65		return NULL;
66
67	/*
68	 * Map uncached objects in the low 512mb of address space using KSEG1,
69	 * otherwise map using page tables.
70	 */
71	if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
72	    flags == _CACHE_UNCACHED)
73		return (void __iomem *) CKSEG1ADDR(phys_addr);
74
75	/* Early remaps should use the unmapped regions til' VM is available */
76	if (WARN_ON_ONCE(!slab_is_available()))
77		return NULL;
78
79	/*
80	 * Don't allow anybody to remap RAM that may be allocated by the page
81	 * allocator, since that could lead to races & data clobbering.
82	 */
83	pfn = PFN_DOWN(phys_addr);
84	last_pfn = PFN_DOWN(last_addr);
85	if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
86				  __ioremap_check_ram) == 1) {
87		WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
88			  &phys_addr, &last_addr);
89		return NULL;
90	}
91
92	/*
93	 * Mappings have to be page-aligned
94	 */
95	offset = phys_addr & ~PAGE_MASK;
96	phys_addr &= PAGE_MASK;
97	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
98
99	/*
100	 * Ok, go for it..
101	 */
102	area = get_vm_area(size, VM_IOREMAP);
103	if (!area)
104		return NULL;
105	vaddr = (unsigned long)area->addr;
106
107	flags |= _PAGE_GLOBAL | _PAGE_PRESENT | __READABLE | __WRITEABLE;
108	if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
109			__pgprot(flags))) {
110		free_vm_area(area);
111		return NULL;
112	}
113
114	return (void __iomem *)(vaddr + offset);
115}
116EXPORT_SYMBOL(ioremap_prot);
117
118void iounmap(const volatile void __iomem *addr)
119{
120	if (!plat_iounmap(addr) && !IS_KSEG1(addr))
121		vunmap((void *)((unsigned long)addr & PAGE_MASK));
122}
123EXPORT_SYMBOL(iounmap);
124