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