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
18static inline void __iomem *
19__ioremap_uc(unsigned long phys_addr)
20{
21	return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
22}
23
24void __iomem *
25early_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
34void __iomem *
35ioremap (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}
102EXPORT_SYMBOL(ioremap);
103
104void __iomem *
105ioremap_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}
112EXPORT_SYMBOL(ioremap_nocache);
113
114void
115early_iounmap (volatile void __iomem *addr, unsigned long size)
116{
117}
118
119void
120iounmap (volatile void __iomem *addr)
121{
122	if (REGION_NUMBER(addr) == RGN_GATE)
123		vunmap((void *) ((unsigned long) addr & PAGE_MASK));
124}
125EXPORT_SYMBOL(iounmap);
126