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 static 34 void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags) 35 { 36 if (flags & EFI_MEMMAP_MEMBLOCK) { 37 if (slab_is_available()) 38 memblock_free_late(phys, size); 39 else 40 memblock_phys_free(phys, size); 41 } else if (flags & EFI_MEMMAP_SLAB) { 42 struct page *p = pfn_to_page(PHYS_PFN(phys)); 43 unsigned int order = get_order(size); 44 45 free_pages((unsigned long) page_address(p), order); 46 } 47 } 48 49 /** 50 * efi_memmap_alloc - Allocate memory for the EFI memory map 51 * @num_entries: Number of entries in the allocated map. 52 * @data: efi memmap installation parameters 53 * 54 * Depending on whether mm_init() has already been invoked or not, 55 * either memblock or "normal" page allocation is used. 56 * 57 * Returns zero on success, a negative error code on failure. 58 */ 59 int __init efi_memmap_alloc(unsigned int num_entries, 60 struct efi_memory_map_data *data) 61 { 62 /* Expect allocation parameters are zero initialized */ 63 WARN_ON(data->phys_map || data->size); 64 65 data->size = num_entries * efi.memmap.desc_size; 66 data->desc_version = efi.memmap.desc_version; 67 data->desc_size = efi.memmap.desc_size; 68 data->flags &= ~(EFI_MEMMAP_SLAB | EFI_MEMMAP_MEMBLOCK); 69 data->flags |= efi.memmap.flags & EFI_MEMMAP_LATE; 70 71 if (slab_is_available()) { 72 data->flags |= EFI_MEMMAP_SLAB; 73 data->phys_map = __efi_memmap_alloc_late(data->size); 74 } else { 75 data->flags |= EFI_MEMMAP_MEMBLOCK; 76 data->phys_map = __efi_memmap_alloc_early(data->size); 77 } 78 79 if (!data->phys_map) 80 return -ENOMEM; 81 return 0; 82 } 83 84 /** 85 * efi_memmap_install - Install a new EFI memory map in efi.memmap 86 * @data: efi memmap installation parameters 87 * 88 * Unlike efi_memmap_init_*(), this function does not allow the caller 89 * to switch from early to late mappings. It simply uses the existing 90 * mapping function and installs the new memmap. 91 * 92 * Returns zero on success, a negative error code on failure. 93 */ 94 int __init efi_memmap_install(struct efi_memory_map_data *data) 95 { 96 unsigned long size = efi.memmap.desc_size * efi.memmap.nr_map; 97 unsigned long flags = efi.memmap.flags; 98 u64 phys = efi.memmap.phys_map; 99 int ret; 100 101 efi_memmap_unmap(); 102 103 if (efi_enabled(EFI_PARAVIRT)) 104 return 0; 105 106 ret = __efi_memmap_init(data); 107 if (ret) 108 return ret; 109 110 __efi_memmap_free(phys, size, flags); 111 return 0; 112 } 113 114 /** 115 * efi_memmap_split_count - Count number of additional EFI memmap entries 116 * @md: EFI memory descriptor to split 117 * @range: Address range (start, end) to split around 118 * 119 * Returns the number of additional EFI memmap entries required to 120 * accommodate @range. 121 */ 122 int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range) 123 { 124 u64 m_start, m_end; 125 u64 start, end; 126 int count = 0; 127 128 start = md->phys_addr; 129 end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1; 130 131 /* modifying range */ 132 m_start = range->start; 133 m_end = range->end; 134 135 if (m_start <= start) { 136 /* split into 2 parts */ 137 if (start < m_end && m_end < end) 138 count++; 139 } 140 141 if (start < m_start && m_start < end) { 142 /* split into 3 parts */ 143 if (m_end < end) 144 count += 2; 145 /* split into 2 parts */ 146 if (end <= m_end) 147 count++; 148 } 149 150 return count; 151 } 152 153 /** 154 * efi_memmap_insert - Insert a memory region in an EFI memmap 155 * @old_memmap: The existing EFI memory map structure 156 * @buf: Address of buffer to store new map 157 * @mem: Memory map entry to insert 158 * 159 * It is suggested that you call efi_memmap_split_count() first 160 * to see how large @buf needs to be. 161 */ 162 void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf, 163 struct efi_mem_range *mem) 164 { 165 u64 m_start, m_end, m_attr; 166 efi_memory_desc_t *md; 167 u64 start, end; 168 void *old, *new; 169 170 /* modifying range */ 171 m_start = mem->range.start; 172 m_end = mem->range.end; 173 m_attr = mem->attribute; 174 175 /* 176 * The EFI memory map deals with regions in EFI_PAGE_SIZE 177 * units. Ensure that the region described by 'mem' is aligned 178 * correctly. 179 */ 180 if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) || 181 !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) { 182 WARN_ON(1); 183 return; 184 } 185 186 for (old = old_memmap->map, new = buf; 187 old < old_memmap->map_end; 188 old += old_memmap->desc_size, new += old_memmap->desc_size) { 189 190 /* copy original EFI memory descriptor */ 191 memcpy(new, old, old_memmap->desc_size); 192 md = new; 193 start = md->phys_addr; 194 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1; 195 196 if (m_start <= start && end <= m_end) 197 md->attribute |= m_attr; 198 199 if (m_start <= start && 200 (start < m_end && m_end < end)) { 201 /* first part */ 202 md->attribute |= m_attr; 203 md->num_pages = (m_end - md->phys_addr + 1) >> 204 EFI_PAGE_SHIFT; 205 /* latter part */ 206 new += old_memmap->desc_size; 207 memcpy(new, old, old_memmap->desc_size); 208 md = new; 209 md->phys_addr = m_end + 1; 210 md->num_pages = (end - md->phys_addr + 1) >> 211 EFI_PAGE_SHIFT; 212 } 213 214 if ((start < m_start && m_start < end) && m_end < end) { 215 /* first part */ 216 md->num_pages = (m_start - md->phys_addr) >> 217 EFI_PAGE_SHIFT; 218 /* middle part */ 219 new += old_memmap->desc_size; 220 memcpy(new, old, old_memmap->desc_size); 221 md = new; 222 md->attribute |= m_attr; 223 md->phys_addr = m_start; 224 md->num_pages = (m_end - m_start + 1) >> 225 EFI_PAGE_SHIFT; 226 /* last part */ 227 new += old_memmap->desc_size; 228 memcpy(new, old, old_memmap->desc_size); 229 md = new; 230 md->phys_addr = m_end + 1; 231 md->num_pages = (end - m_end) >> 232 EFI_PAGE_SHIFT; 233 } 234 235 if ((start < m_start && m_start < end) && 236 (end <= m_end)) { 237 /* first part */ 238 md->num_pages = (m_start - md->phys_addr) >> 239 EFI_PAGE_SHIFT; 240 /* latter part */ 241 new += old_memmap->desc_size; 242 memcpy(new, old, old_memmap->desc_size); 243 md = new; 244 md->phys_addr = m_start; 245 md->num_pages = (end - md->phys_addr + 1) >> 246 EFI_PAGE_SHIFT; 247 md->attribute |= m_attr; 248 } 249 } 250 } 251