1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Common EFI memory map functions. 4 */ 5 6 #define pr_fmt(fmt) "efi: " fmt 7 8 #include <linux/init.h> 9 #include <linux/kernel.h> 10 #include <linux/efi.h> 11 #include <linux/io.h> 12 #include <asm/early_ioremap.h> 13 #include <asm/efi.h> 14 #include <linux/memblock.h> 15 #include <linux/slab.h> 16 17 static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size) 18 { 19 return memblock_phys_alloc(size, SMP_CACHE_BYTES); 20 } 21 22 static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size) 23 { 24 unsigned int order = get_order(size); 25 struct page *p = alloc_pages(GFP_KERNEL, order); 26 27 if (!p) 28 return 0; 29 30 return PFN_PHYS(page_to_pfn(p)); 31 } 32 33 void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags) 34 { 35 if (flags & EFI_MEMMAP_MEMBLOCK) { 36 if (slab_is_available()) 37 memblock_free_late(phys, size); 38 else 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); 43 44 free_pages((unsigned long) page_address(p), order); 45 } 46 } 47 48 /** 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 52 * 53 * Depending on whether mm_init() has already been invoked or not, 54 * either memblock or "normal" page allocation is used. 55 * 56 * Returns zero on success, a negative error code on failure. 57 */ 58 int __init efi_memmap_alloc(unsigned int num_entries, 59 struct efi_memory_map_data *data) 60 { 61 /* Expect allocation parameters are zero initialized */ 62 WARN_ON(data->phys_map || data->size); 63 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; 69 70 if (slab_is_available()) { 71 data->flags |= EFI_MEMMAP_SLAB; 72 data->phys_map = __efi_memmap_alloc_late(data->size); 73 } else { 74 data->flags |= EFI_MEMMAP_MEMBLOCK; 75 data->phys_map = __efi_memmap_alloc_early(data->size); 76 } 77 78 if (!data->phys_map) 79 return -ENOMEM; 80 return 0; 81 } 82 83 /** 84 * efi_memmap_install - Install a new EFI memory map in efi.memmap 85 * @data: efi memmap installation parameters 86 * 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. 90 * 91 * Returns zero on success, a negative error code on failure. 92 */ 93 int __init efi_memmap_install(struct efi_memory_map_data *data) 94 { 95 efi_memmap_unmap(); 96 97 if (efi_enabled(EFI_PARAVIRT)) 98 return 0; 99 100 return __efi_memmap_init(data); 101 } 102 103 /** 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 107 * 108 * Returns the number of additional EFI memmap entries required to 109 * accommodate @range. 110 */ 111 int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range) 112 { 113 u64 m_start, m_end; 114 u64 start, end; 115 int count = 0; 116 117 start = md->phys_addr; 118 end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1; 119 120 /* modifying range */ 121 m_start = range->start; 122 m_end = range->end; 123 124 if (m_start <= start) { 125 /* split into 2 parts */ 126 if (start < m_end && m_end < end) 127 count++; 128 } 129 130 if (start < m_start && m_start < end) { 131 /* split into 3 parts */ 132 if (m_end < end) 133 count += 2; 134 /* split into 2 parts */ 135 if (end <= m_end) 136 count++; 137 } 138 139 return count; 140 } 141 142 /** 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 147 * 148 * It is suggested that you call efi_memmap_split_count() first 149 * to see how large @buf needs to be. 150 */ 151 void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf, 152 struct efi_mem_range *mem) 153 { 154 u64 m_start, m_end, m_attr; 155 efi_memory_desc_t *md; 156 u64 start, end; 157 void *old, *new; 158 159 /* modifying range */ 160 m_start = mem->range.start; 161 m_end = mem->range.end; 162 m_attr = mem->attribute; 163 164 /* 165 * The EFI memory map deals with regions in EFI_PAGE_SIZE 166 * units. Ensure that the region described by 'mem' is aligned 167 * correctly. 168 */ 169 if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) || 170 !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) { 171 WARN_ON(1); 172 return; 173 } 174 175 for (old = old_memmap->map, new = buf; 176 old < old_memmap->map_end; 177 old += old_memmap->desc_size, new += old_memmap->desc_size) { 178 179 /* copy original EFI memory descriptor */ 180 memcpy(new, old, old_memmap->desc_size); 181 md = new; 182 start = md->phys_addr; 183 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1; 184 185 if (m_start <= start && end <= m_end) 186 md->attribute |= m_attr; 187 188 if (m_start <= start && 189 (start < m_end && m_end < end)) { 190 /* first part */ 191 md->attribute |= m_attr; 192 md->num_pages = (m_end - md->phys_addr + 1) >> 193 EFI_PAGE_SHIFT; 194 /* latter part */ 195 new += old_memmap->desc_size; 196 memcpy(new, old, old_memmap->desc_size); 197 md = new; 198 md->phys_addr = m_end + 1; 199 md->num_pages = (end - md->phys_addr + 1) >> 200 EFI_PAGE_SHIFT; 201 } 202 203 if ((start < m_start && m_start < end) && m_end < end) { 204 /* first part */ 205 md->num_pages = (m_start - md->phys_addr) >> 206 EFI_PAGE_SHIFT; 207 /* middle part */ 208 new += old_memmap->desc_size; 209 memcpy(new, old, old_memmap->desc_size); 210 md = new; 211 md->attribute |= m_attr; 212 md->phys_addr = m_start; 213 md->num_pages = (m_end - m_start + 1) >> 214 EFI_PAGE_SHIFT; 215 /* last part */ 216 new += old_memmap->desc_size; 217 memcpy(new, old, old_memmap->desc_size); 218 md = new; 219 md->phys_addr = m_end + 1; 220 md->num_pages = (end - m_end) >> 221 EFI_PAGE_SHIFT; 222 } 223 224 if ((start < m_start && m_start < end) && 225 (end <= m_end)) { 226 /* first part */ 227 md->num_pages = (m_start - md->phys_addr) >> 228 EFI_PAGE_SHIFT; 229 /* latter part */ 230 new += old_memmap->desc_size; 231 memcpy(new, old, old_memmap->desc_size); 232 md = new; 233 md->phys_addr = m_start; 234 md->num_pages = (end - md->phys_addr + 1) >> 235 EFI_PAGE_SHIFT; 236 md->attribute |= m_attr; 237 } 238 } 239 } 240