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1 | // SPDX-License-Identifier: GPL-2.0-only | |
2 | /* | |
3 | * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P. | |
4 | * Bjorn Helgaas <bjorn.helgaas@hp.com> | |
5 | */ | |
6 | ||
7 | #include <linux/compiler.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/efi.h> | |
10 | #include <linux/io.h> | |
11 | #include <linux/vmalloc.h> | |
12 | #include <asm/io.h> | |
13 | #include <asm/meminit.h> | |
14 | ||
15 | static inline void __iomem * | |
16 | __ioremap_uc(unsigned long phys_addr) | |
17 | { | |
18 | return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr); | |
19 | } | |
20 | ||
21 | void __iomem * | |
22 | early_ioremap (unsigned long phys_addr, unsigned long size) | |
23 | { | |
24 | u64 attr; | |
25 | attr = kern_mem_attribute(phys_addr, size); | |
26 | if (attr & EFI_MEMORY_WB) | |
27 | return (void __iomem *) phys_to_virt(phys_addr); | |
28 | return __ioremap_uc(phys_addr); | |
29 | } | |
30 | ||
31 | void __iomem * | |
32 | ioremap (unsigned long phys_addr, unsigned long size) | |
33 | { | |
34 | void __iomem *addr; | |
35 | struct vm_struct *area; | |
36 | unsigned long offset; | |
37 | pgprot_t prot; | |
38 | u64 attr; | |
39 | unsigned long gran_base, gran_size; | |
40 | unsigned long page_base; | |
41 | ||
42 | /* | |
43 | * For things in kern_memmap, we must use the same attribute | |
44 | * as the rest of the kernel. For more details, see | |
45 | * Documentation/ia64/aliasing.txt. | |
46 | */ | |
47 | attr = kern_mem_attribute(phys_addr, size); | |
48 | if (attr & EFI_MEMORY_WB) | |
49 | return (void __iomem *) phys_to_virt(phys_addr); | |
50 | else if (attr & EFI_MEMORY_UC) | |
51 | return __ioremap_uc(phys_addr); | |
52 | ||
53 | /* | |
54 | * Some chipsets don't support UC access to memory. If | |
55 | * WB is supported for the whole granule, we prefer that. | |
56 | */ | |
57 | gran_base = GRANULEROUNDDOWN(phys_addr); | |
58 | gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base; | |
59 | if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB) | |
60 | return (void __iomem *) phys_to_virt(phys_addr); | |
61 | ||
62 | /* | |
63 | * WB is not supported for the whole granule, so we can't use | |
64 | * the region 7 identity mapping. If we can safely cover the | |
65 | * area with kernel page table mappings, we can use those | |
66 | * instead. | |
67 | */ | |
68 | page_base = phys_addr & PAGE_MASK; | |
69 | size = PAGE_ALIGN(phys_addr + size) - page_base; | |
70 | if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) { | |
71 | prot = PAGE_KERNEL; | |
72 | ||
73 | /* | |
74 | * Mappings have to be page-aligned | |
75 | */ | |
76 | offset = phys_addr & ~PAGE_MASK; | |
77 | phys_addr &= PAGE_MASK; | |
78 | ||
79 | /* | |
80 | * Ok, go for it.. | |
81 | */ | |
82 | area = get_vm_area(size, VM_IOREMAP); | |
83 | if (!area) | |
84 | return NULL; | |
85 | ||
86 | area->phys_addr = phys_addr; | |
87 | addr = (void __iomem *) area->addr; | |
88 | if (ioremap_page_range((unsigned long) addr, | |
89 | (unsigned long) addr + size, phys_addr, prot)) { | |
90 | vunmap((void __force *) addr); | |
91 | return NULL; | |
92 | } | |
93 | ||
94 | return (void __iomem *) (offset + (char __iomem *)addr); | |
95 | } | |
96 | ||
97 | return __ioremap_uc(phys_addr); | |
98 | } | |
99 | EXPORT_SYMBOL(ioremap); | |
100 | ||
101 | void __iomem * | |
102 | ioremap_nocache (unsigned long phys_addr, unsigned long size) | |
103 | { | |
104 | if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB) | |
105 | return NULL; | |
106 | ||
107 | return __ioremap_uc(phys_addr); | |
108 | } | |
109 | EXPORT_SYMBOL(ioremap_nocache); | |
110 | ||
111 | void | |
112 | early_iounmap (volatile void __iomem *addr, unsigned long size) | |
113 | { | |
114 | } | |
115 | ||
116 | void | |
117 | iounmap (volatile void __iomem *addr) | |
118 | { | |
119 | if (REGION_NUMBER(addr) == RGN_GATE) | |
120 | vunmap((void *) ((unsigned long) addr & PAGE_MASK)); | |
121 | } | |
122 | EXPORT_SYMBOL(iounmap); |