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 unsigned long size = efi.memmap.desc_size * efi.memmap.nr_map; 96 unsigned long flags = efi.memmap.flags; 97 u64 phys = efi.memmap.phys_map; 98 int ret; 99 100 efi_memmap_unmap(); 101 102 if (efi_enabled(EFI_PARAVIRT)) 103 return 0; 104 105 ret = __efi_memmap_init(data); 106 if (ret) 107 return ret; 108 109 __efi_memmap_free(phys, size, flags); 110 return 0; 111 } 112 113 /** 114 * efi_memmap_split_count - Count number of additional EFI memmap entries 115 * @md: EFI memory descriptor to split 116 * @range: Address range (start, end) to split around 117 * 118 * Returns the number of additional EFI memmap entries required to 119 * accommodate @range. 120 */ 121 int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range) 122 { 123 u64 m_start, m_end; 124 u64 start, end; 125 int count = 0; 126 127 start = md->phys_addr; 128 end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1; 129 130 /* modifying range */ 131 m_start = range->start; 132 m_end = range->end; 133 134 if (m_start <= start) { 135 /* split into 2 parts */ 136 if (start < m_end && m_end < end) 137 count++; 138 } 139 140 if (start < m_start && m_start < end) { 141 /* split into 3 parts */ 142 if (m_end < end) 143 count += 2; 144 /* split into 2 parts */ 145 if (end <= m_end) 146 count++; 147 } 148 149 return count; 150 } 151 152 /** 153 * efi_memmap_insert - Insert a memory region in an EFI memmap 154 * @old_memmap: The existing EFI memory map structure 155 * @buf: Address of buffer to store new map 156 * @mem: Memory map entry to insert 157 * 158 * It is suggested that you call efi_memmap_split_count() first 159 * to see how large @buf needs to be. 160 */ 161 void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf, 162 struct efi_mem_range *mem) 163 { 164 u64 m_start, m_end, m_attr; 165 efi_memory_desc_t *md; 166 u64 start, end; 167 void *old, *new; 168 169 /* modifying range */ 170 m_start = mem->range.start; 171 m_end = mem->range.end; 172 m_attr = mem->attribute; 173 174 /* 175 * The EFI memory map deals with regions in EFI_PAGE_SIZE 176 * units. Ensure that the region described by 'mem' is aligned 177 * correctly. 178 */ 179 if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) || 180 !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) { 181 WARN_ON(1); 182 return; 183 } 184 185 for (old = old_memmap->map, new = buf; 186 old < old_memmap->map_end; 187 old += old_memmap->desc_size, new += old_memmap->desc_size) { 188 189 /* copy original EFI memory descriptor */ 190 memcpy(new, old, old_memmap->desc_size); 191 md = new; 192 start = md->phys_addr; 193 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1; 194 195 if (m_start <= start && end <= m_end) 196 md->attribute |= m_attr; 197 198 if (m_start <= start && 199 (start < m_end && m_end < end)) { 200 /* first part */ 201 md->attribute |= m_attr; 202 md->num_pages = (m_end - md->phys_addr + 1) >> 203 EFI_PAGE_SHIFT; 204 /* latter part */ 205 new += old_memmap->desc_size; 206 memcpy(new, old, old_memmap->desc_size); 207 md = new; 208 md->phys_addr = m_end + 1; 209 md->num_pages = (end - md->phys_addr + 1) >> 210 EFI_PAGE_SHIFT; 211 } 212 213 if ((start < m_start && m_start < end) && m_end < end) { 214 /* first part */ 215 md->num_pages = (m_start - md->phys_addr) >> 216 EFI_PAGE_SHIFT; 217 /* middle part */ 218 new += old_memmap->desc_size; 219 memcpy(new, old, old_memmap->desc_size); 220 md = new; 221 md->attribute |= m_attr; 222 md->phys_addr = m_start; 223 md->num_pages = (m_end - m_start + 1) >> 224 EFI_PAGE_SHIFT; 225 /* last part */ 226 new += old_memmap->desc_size; 227 memcpy(new, old, old_memmap->desc_size); 228 md = new; 229 md->phys_addr = m_end + 1; 230 md->num_pages = (end - m_end) >> 231 EFI_PAGE_SHIFT; 232 } 233 234 if ((start < m_start && m_start < end) && 235 (end <= m_end)) { 236 /* first part */ 237 md->num_pages = (m_start - md->phys_addr) >> 238 EFI_PAGE_SHIFT; 239 /* latter part */ 240 new += old_memmap->desc_size; 241 memcpy(new, old, old_memmap->desc_size); 242 md = new; 243 md->phys_addr = m_start; 244 md->num_pages = (end - md->phys_addr + 1) >> 245 EFI_PAGE_SHIFT; 246 md->attribute |= m_attr; 247 } 248 } 249 } 250