1 // SPDX-License-Identifier: GPL-2.0
3 * Common EFI memory map functions.
6 #define pr_fmt(fmt) "efi: " fmt
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/efi.h>
12 #include <asm/early_ioremap.h>
14 #include <linux/memblock.h>
15 #include <linux/slab.h>
17 static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size)
19 return memblock_phys_alloc(size, SMP_CACHE_BYTES);
22 static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
24 unsigned int order = get_order(size);
25 struct page *p = alloc_pages(GFP_KERNEL, order);
30 return PFN_PHYS(page_to_pfn(p));
33 void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags)
35 if (flags & EFI_MEMMAP_MEMBLOCK) {
36 if (slab_is_available())
37 memblock_free_late(phys, size);
39 memblock_phys_free(phys, size);
40 } else if (flags & EFI_MEMMAP_SLAB) {
41 struct page *p = pfn_to_page(PHYS_PFN(phys));
42 unsigned int order = get_order(size);
44 free_pages((unsigned long) page_address(p), order);
49 * efi_memmap_alloc - Allocate memory for the EFI memory map
50 * @num_entries: Number of entries in the allocated map.
51 * @data: efi memmap installation parameters
53 * Depending on whether mm_init() has already been invoked or not,
54 * either memblock or "normal" page allocation is used.
56 * Returns zero on success, a negative error code on failure.
58 int __init efi_memmap_alloc(unsigned int num_entries,
59 struct efi_memory_map_data *data)
61 /* Expect allocation parameters are zero initialized */
62 WARN_ON(data->phys_map || data->size);
64 data->size = num_entries * efi.memmap.desc_size;
65 data->desc_version = efi.memmap.desc_version;
66 data->desc_size = efi.memmap.desc_size;
67 data->flags &= ~(EFI_MEMMAP_SLAB | EFI_MEMMAP_MEMBLOCK);
68 data->flags |= efi.memmap.flags & EFI_MEMMAP_LATE;
70 if (slab_is_available()) {
71 data->flags |= EFI_MEMMAP_SLAB;
72 data->phys_map = __efi_memmap_alloc_late(data->size);
74 data->flags |= EFI_MEMMAP_MEMBLOCK;
75 data->phys_map = __efi_memmap_alloc_early(data->size);
84 * efi_memmap_install - Install a new EFI memory map in efi.memmap
85 * @data: efi memmap installation parameters
87 * Unlike efi_memmap_init_*(), this function does not allow the caller
88 * to switch from early to late mappings. It simply uses the existing
89 * mapping function and installs the new memmap.
91 * Returns zero on success, a negative error code on failure.
93 int __init efi_memmap_install(struct efi_memory_map_data *data)
97 if (efi_enabled(EFI_PARAVIRT))
100 return __efi_memmap_init(data);
104 * efi_memmap_split_count - Count number of additional EFI memmap entries
105 * @md: EFI memory descriptor to split
106 * @range: Address range (start, end) to split around
108 * Returns the number of additional EFI memmap entries required to
109 * accommodate @range.
111 int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range)
117 start = md->phys_addr;
118 end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
120 /* modifying range */
121 m_start = range->start;
124 if (m_start <= start) {
125 /* split into 2 parts */
126 if (start < m_end && m_end < end)
130 if (start < m_start && m_start < end) {
131 /* split into 3 parts */
134 /* split into 2 parts */
143 * efi_memmap_insert - Insert a memory region in an EFI memmap
144 * @old_memmap: The existing EFI memory map structure
145 * @buf: Address of buffer to store new map
146 * @mem: Memory map entry to insert
148 * It is suggested that you call efi_memmap_split_count() first
149 * to see how large @buf needs to be.
151 void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
152 struct efi_mem_range *mem)
154 u64 m_start, m_end, m_attr;
155 efi_memory_desc_t *md;
159 /* modifying range */
160 m_start = mem->range.start;
161 m_end = mem->range.end;
162 m_attr = mem->attribute;
165 * The EFI memory map deals with regions in EFI_PAGE_SIZE
166 * units. Ensure that the region described by 'mem' is aligned
169 if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) ||
170 !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) {
175 for (old = old_memmap->map, new = buf;
176 old < old_memmap->map_end;
177 old += old_memmap->desc_size, new += old_memmap->desc_size) {
179 /* copy original EFI memory descriptor */
180 memcpy(new, old, old_memmap->desc_size);
182 start = md->phys_addr;
183 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
185 if (m_start <= start && end <= m_end)
186 md->attribute |= m_attr;
188 if (m_start <= start &&
189 (start < m_end && m_end < end)) {
191 md->attribute |= m_attr;
192 md->num_pages = (m_end - md->phys_addr + 1) >>
195 new += old_memmap->desc_size;
196 memcpy(new, old, old_memmap->desc_size);
198 md->phys_addr = m_end + 1;
199 md->num_pages = (end - md->phys_addr + 1) >>
203 if ((start < m_start && m_start < end) && m_end < end) {
205 md->num_pages = (m_start - md->phys_addr) >>
208 new += old_memmap->desc_size;
209 memcpy(new, old, old_memmap->desc_size);
211 md->attribute |= m_attr;
212 md->phys_addr = m_start;
213 md->num_pages = (m_end - m_start + 1) >>
216 new += old_memmap->desc_size;
217 memcpy(new, old, old_memmap->desc_size);
219 md->phys_addr = m_end + 1;
220 md->num_pages = (end - m_end) >>
224 if ((start < m_start && m_start < end) &&
227 md->num_pages = (m_start - md->phys_addr) >>
230 new += old_memmap->desc_size;
231 memcpy(new, old, old_memmap->desc_size);
233 md->phys_addr = m_start;
234 md->num_pages = (end - md->phys_addr + 1) >>
236 md->attribute |= m_attr;