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
9 void __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 }
15 EXPORT_SYMBOL(ioremap_wt);
16
17 void __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
81 void 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 }
92 EXPORT_SYMBOL(iounmap);
93
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