1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include <linux/io.h>
4#include <linux/slab.h>
5#include <linux/vmalloc.h>
6
7#include <mm/mmu_decl.h>
8
9void __iomem *ioremap_wt(phys_addr_t addr, unsigned long size)
10{
11	pgprot_t prot = pgprot_cached_wthru(PAGE_KERNEL);
12
13	return __ioremap_caller(addr, size, prot, __builtin_return_address(0));
14}
15EXPORT_SYMBOL(ioremap_wt);
16
17void __iomem *
18__ioremap_caller(phys_addr_t addr, unsigned long size, pgprot_t prot, void *caller)
19{
20	unsigned long v;
21	phys_addr_t p, offset;
22	int err;
23
24	/*
25	 * If the address lies within the first 16 MB, assume it's in ISA
26	 * memory space
27	 */
28	if (addr < SZ_16M)
29		addr += _ISA_MEM_BASE;
30
31	/*
32	 * Choose an address to map it to.
33	 * Once the vmalloc system is running, we use it.
34	 * Before then, we use space going down from IOREMAP_TOP
35	 * (ioremap_bot records where we're up to).
36	 */
37	p = addr & PAGE_MASK;
38	offset = addr & ~PAGE_MASK;
39	size = PAGE_ALIGN(addr + size) - p;
40
41#ifndef CONFIG_CRASH_DUMP
42	/*
43	 * Don't allow anybody to remap normal RAM that we're using.
44	 * mem_init() sets high_memory so only do the check after that.
45	 */
46	if (slab_is_available() && p <= virt_to_phys(high_memory - 1) &&
47	    page_is_ram(__phys_to_pfn(p))) {
48		pr_warn("%s(): phys addr 0x%llx is RAM lr %ps\n", __func__,
49			(unsigned long long)p, __builtin_return_address(0));
50		return NULL;
51	}
52#endif
53
54	if (size == 0)
55		return NULL;
56
57	/*
58	 * Is it already mapped?  Perhaps overlapped by a previous
59	 * mapping.
60	 */
61	v = p_block_mapped(p);
62	if (v)
63		return (void __iomem *)v + offset;
64
65	if (slab_is_available())
66		return generic_ioremap_prot(addr, size, prot);
67
68	/*
69	 * Should check if it is a candidate for a BAT mapping
70	 */
71	pr_warn("ioremap() called early from %pS. Use early_ioremap() instead\n", caller);
72
73	err = early_ioremap_range(ioremap_bot - size - PAGE_SIZE, p, size, prot);
74	if (err)
75		return NULL;
76	ioremap_bot -= size + PAGE_SIZE;
77
78	return (void __iomem *)ioremap_bot + offset;
79}
80
81void iounmap(volatile void __iomem *addr)
82{
83	/*
84	 * If mapped by BATs then there is nothing to do.
85	 * Calling vfree() generates a benign warning.
86	 */
87	if (v_block_mapped((unsigned long)addr))
88		return;
89
90	generic_iounmap(addr);
91}
92EXPORT_SYMBOL(iounmap);
93