1 /*
2 * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
3 * Bjorn Helgaas <bjorn.helgaas@hp.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10 #include <linux/compiler.h>
11 #include <linux/module.h>
12 #include <linux/efi.h>
13 #include <linux/io.h>
14 #include <linux/vmalloc.h>
15 #include <asm/io.h>
16 #include <asm/meminit.h>
17
18 static inline void __iomem *
__ioremap_uc(unsigned long phys_addr)19 __ioremap_uc(unsigned long phys_addr)
20 {
21 return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
22 }
23
24 void __iomem *
early_ioremap(unsigned long phys_addr,unsigned long size)25 early_ioremap (unsigned long phys_addr, unsigned long size)
26 {
27 u64 attr;
28 attr = kern_mem_attribute(phys_addr, size);
29 if (attr & EFI_MEMORY_WB)
30 return (void __iomem *) phys_to_virt(phys_addr);
31 return __ioremap_uc(phys_addr);
32 }
33
34 void __iomem *
ioremap(unsigned long phys_addr,unsigned long size)35 ioremap (unsigned long phys_addr, unsigned long size)
36 {
37 void __iomem *addr;
38 struct vm_struct *area;
39 unsigned long offset;
40 pgprot_t prot;
41 u64 attr;
42 unsigned long gran_base, gran_size;
43 unsigned long page_base;
44
45 /*
46 * For things in kern_memmap, we must use the same attribute
47 * as the rest of the kernel. For more details, see
48 * Documentation/ia64/aliasing.txt.
49 */
50 attr = kern_mem_attribute(phys_addr, size);
51 if (attr & EFI_MEMORY_WB)
52 return (void __iomem *) phys_to_virt(phys_addr);
53 else if (attr & EFI_MEMORY_UC)
54 return __ioremap_uc(phys_addr);
55
56 /*
57 * Some chipsets don't support UC access to memory. If
58 * WB is supported for the whole granule, we prefer that.
59 */
60 gran_base = GRANULEROUNDDOWN(phys_addr);
61 gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
62 if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
63 return (void __iomem *) phys_to_virt(phys_addr);
64
65 /*
66 * WB is not supported for the whole granule, so we can't use
67 * the region 7 identity mapping. If we can safely cover the
68 * area with kernel page table mappings, we can use those
69 * instead.
70 */
71 page_base = phys_addr & PAGE_MASK;
72 size = PAGE_ALIGN(phys_addr + size) - page_base;
73 if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
74 prot = PAGE_KERNEL;
75
76 /*
77 * Mappings have to be page-aligned
78 */
79 offset = phys_addr & ~PAGE_MASK;
80 phys_addr &= PAGE_MASK;
81
82 /*
83 * Ok, go for it..
84 */
85 area = get_vm_area(size, VM_IOREMAP);
86 if (!area)
87 return NULL;
88
89 area->phys_addr = phys_addr;
90 addr = (void __iomem *) area->addr;
91 if (ioremap_page_range((unsigned long) addr,
92 (unsigned long) addr + size, phys_addr, prot)) {
93 vunmap((void __force *) addr);
94 return NULL;
95 }
96
97 return (void __iomem *) (offset + (char __iomem *)addr);
98 }
99
100 return __ioremap_uc(phys_addr);
101 }
102 EXPORT_SYMBOL(ioremap);
103
104 void __iomem *
ioremap_nocache(unsigned long phys_addr,unsigned long size)105 ioremap_nocache (unsigned long phys_addr, unsigned long size)
106 {
107 if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
108 return NULL;
109
110 return __ioremap_uc(phys_addr);
111 }
112 EXPORT_SYMBOL(ioremap_nocache);
113
114 void
early_iounmap(volatile void __iomem * addr,unsigned long size)115 early_iounmap (volatile void __iomem *addr, unsigned long size)
116 {
117 }
118
119 void
iounmap(volatile void __iomem * addr)120 iounmap (volatile void __iomem *addr)
121 {
122 if (REGION_NUMBER(addr) == RGN_GATE)
123 vunmap((void *) ((unsigned long) addr & PAGE_MASK));
124 }
125 EXPORT_SYMBOL(iounmap);
126
