summaryrefslogtreecommitdiff
path: root/arch/x86/platform/efi/memmap.c
blob: 6ed1935504b96e8ac7d1acb1aa215a617125c768 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
// SPDX-License-Identifier: GPL-2.0
/*
 * Common EFI memory map functions.
 */

#define pr_fmt(fmt) "efi: " fmt

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/efi.h>
#include <linux/io.h>
#include <asm/early_ioremap.h>
#include <asm/efi.h>
#include <linux/memblock.h>
#include <linux/slab.h>

static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size)
{
	return memblock_phys_alloc(size, SMP_CACHE_BYTES);
}

static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
{
	unsigned int order = get_order(size);
	struct page *p = alloc_pages(GFP_KERNEL, order);

	if (!p)
		return 0;

	return PFN_PHYS(page_to_pfn(p));
}

void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags)
{
	if (flags & EFI_MEMMAP_MEMBLOCK) {
		if (slab_is_available())
			memblock_free_late(phys, size);
		else
			memblock_phys_free(phys, size);
	} else if (flags & EFI_MEMMAP_SLAB) {
		struct page *p = pfn_to_page(PHYS_PFN(phys));
		unsigned int order = get_order(size);

		free_pages((unsigned long) page_address(p), order);
	}
}

/**
 * efi_memmap_alloc - Allocate memory for the EFI memory map
 * @num_entries: Number of entries in the allocated map.
 * @data: efi memmap installation parameters
 *
 * Depending on whether mm_init() has already been invoked or not,
 * either memblock or "normal" page allocation is used.
 *
 * Returns zero on success, a negative error code on failure.
 */
int __init efi_memmap_alloc(unsigned int num_entries,
		struct efi_memory_map_data *data)
{
	/* Expect allocation parameters are zero initialized */
	WARN_ON(data->phys_map || data->size);

	data->size = num_entries * efi.memmap.desc_size;
	data->desc_version = efi.memmap.desc_version;
	data->desc_size = efi.memmap.desc_size;
	data->flags &= ~(EFI_MEMMAP_SLAB | EFI_MEMMAP_MEMBLOCK);
	data->flags |= efi.memmap.flags & EFI_MEMMAP_LATE;

	if (slab_is_available()) {
		data->flags |= EFI_MEMMAP_SLAB;
		data->phys_map = __efi_memmap_alloc_late(data->size);
	} else {
		data->flags |= EFI_MEMMAP_MEMBLOCK;
		data->phys_map = __efi_memmap_alloc_early(data->size);
	}

	if (!data->phys_map)
		return -ENOMEM;
	return 0;
}

/**
 * efi_memmap_install - Install a new EFI memory map in efi.memmap
 * @data: efi memmap installation parameters
 *
 * Unlike efi_memmap_init_*(), this function does not allow the caller
 * to switch from early to late mappings. It simply uses the existing
 * mapping function and installs the new memmap.
 *
 * Returns zero on success, a negative error code on failure.
 */
int __init efi_memmap_install(struct efi_memory_map_data *data)
{
	unsigned long size = efi.memmap.desc_size * efi.memmap.nr_map;
	unsigned long flags = efi.memmap.flags;
	u64 phys = efi.memmap.phys_map;
	int ret;

	efi_memmap_unmap();

	if (efi_enabled(EFI_PARAVIRT))
		return 0;

	ret = __efi_memmap_init(data);
	if (ret)
		return ret;

	__efi_memmap_free(phys, size, flags);
	return 0;
}

/**
 * efi_memmap_split_count - Count number of additional EFI memmap entries
 * @md: EFI memory descriptor to split
 * @range: Address range (start, end) to split around
 *
 * Returns the number of additional EFI memmap entries required to
 * accommodate @range.
 */
int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range)
{
	u64 m_start, m_end;
	u64 start, end;
	int count = 0;

	start = md->phys_addr;
	end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;

	/* modifying range */
	m_start = range->start;
	m_end = range->end;

	if (m_start <= start) {
		/* split into 2 parts */
		if (start < m_end && m_end < end)
			count++;
	}

	if (start < m_start && m_start < end) {
		/* split into 3 parts */
		if (m_end < end)
			count += 2;
		/* split into 2 parts */
		if (end <= m_end)
			count++;
	}

	return count;
}

/**
 * efi_memmap_insert - Insert a memory region in an EFI memmap
 * @old_memmap: The existing EFI memory map structure
 * @buf: Address of buffer to store new map
 * @mem: Memory map entry to insert
 *
 * It is suggested that you call efi_memmap_split_count() first
 * to see how large @buf needs to be.
 */
void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
			      struct efi_mem_range *mem)
{
	u64 m_start, m_end, m_attr;
	efi_memory_desc_t *md;
	u64 start, end;
	void *old, *new;

	/* modifying range */
	m_start = mem->range.start;
	m_end = mem->range.end;
	m_attr = mem->attribute;

	/*
	 * The EFI memory map deals with regions in EFI_PAGE_SIZE
	 * units. Ensure that the region described by 'mem' is aligned
	 * correctly.
	 */
	if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) ||
	    !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) {
		WARN_ON(1);
		return;
	}

	for (old = old_memmap->map, new = buf;
	     old < old_memmap->map_end;
	     old += old_memmap->desc_size, new += old_memmap->desc_size) {

		/* copy original EFI memory descriptor */
		memcpy(new, old, old_memmap->desc_size);
		md = new;
		start = md->phys_addr;
		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;

		if (m_start <= start && end <= m_end)
			md->attribute |= m_attr;

		if (m_start <= start &&
		    (start < m_end && m_end < end)) {
			/* first part */
			md->attribute |= m_attr;
			md->num_pages = (m_end - md->phys_addr + 1) >>
				EFI_PAGE_SHIFT;
			/* latter part */
			new += old_memmap->desc_size;
			memcpy(new, old, old_memmap->desc_size);
			md = new;
			md->phys_addr = m_end + 1;
			md->num_pages = (end - md->phys_addr + 1) >>
				EFI_PAGE_SHIFT;
		}

		if ((start < m_start && m_start < end) && m_end < end) {
			/* first part */
			md->num_pages = (m_start - md->phys_addr) >>
				EFI_PAGE_SHIFT;
			/* middle part */
			new += old_memmap->desc_size;
			memcpy(new, old, old_memmap->desc_size);
			md = new;
			md->attribute |= m_attr;
			md->phys_addr = m_start;
			md->num_pages = (m_end - m_start + 1) >>
				EFI_PAGE_SHIFT;
			/* last part */
			new += old_memmap->desc_size;
			memcpy(new, old, old_memmap->desc_size);
			md = new;
			md->phys_addr = m_end + 1;
			md->num_pages = (end - m_end) >>
				EFI_PAGE_SHIFT;
		}

		if ((start < m_start && m_start < end) &&
		    (end <= m_end)) {
			/* first part */
			md->num_pages = (m_start - md->phys_addr) >>
				EFI_PAGE_SHIFT;
			/* latter part */
			new += old_memmap->desc_size;
			memcpy(new, old, old_memmap->desc_size);
			md = new;
			md->phys_addr = m_start;
			md->num_pages = (end - md->phys_addr + 1) >>
				EFI_PAGE_SHIFT;
			md->attribute |= m_attr;
		}
	}
}