1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012 Regents of the University of California 4 * Copyright (C) 2019 Western Digital Corporation or its affiliates. 5 */ 6 7 #include <linux/init.h> 8 #include <linux/mm.h> 9 #include <linux/memblock.h> 10 #include <linux/initrd.h> 11 #include <linux/swap.h> 12 #include <linux/sizes.h> 13 #include <linux/of_fdt.h> 14 #include <linux/libfdt.h> 15 16 #include <asm/fixmap.h> 17 #include <asm/tlbflush.h> 18 #include <asm/sections.h> 19 #include <asm/pgtable.h> 20 #include <asm/io.h> 21 22 #include "../kernel/head.h" 23 24 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] 25 __page_aligned_bss; 26 EXPORT_SYMBOL(empty_zero_page); 27 28 extern char _start[]; 29 30 static void __init zone_sizes_init(void) 31 { 32 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; 33 34 #ifdef CONFIG_ZONE_DMA32 35 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, 36 (unsigned long) PFN_PHYS(max_low_pfn))); 37 #endif 38 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 39 40 free_area_init_nodes(max_zone_pfns); 41 } 42 43 void setup_zero_page(void) 44 { 45 memset((void *)empty_zero_page, 0, PAGE_SIZE); 46 } 47 48 void __init mem_init(void) 49 { 50 #ifdef CONFIG_FLATMEM 51 BUG_ON(!mem_map); 52 #endif /* CONFIG_FLATMEM */ 53 54 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn))); 55 memblock_free_all(); 56 57 mem_init_print_info(NULL); 58 } 59 60 #ifdef CONFIG_BLK_DEV_INITRD 61 static void __init setup_initrd(void) 62 { 63 unsigned long size; 64 65 if (initrd_start >= initrd_end) { 66 pr_info("initrd not found or empty"); 67 goto disable; 68 } 69 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { 70 pr_err("initrd extends beyond end of memory"); 71 goto disable; 72 } 73 74 size = initrd_end - initrd_start; 75 memblock_reserve(__pa(initrd_start), size); 76 initrd_below_start_ok = 1; 77 78 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 79 (void *)(initrd_start), size); 80 return; 81 disable: 82 pr_cont(" - disabling initrd\n"); 83 initrd_start = 0; 84 initrd_end = 0; 85 } 86 #endif /* CONFIG_BLK_DEV_INITRD */ 87 88 static phys_addr_t dtb_early_pa __initdata; 89 90 void __init setup_bootmem(void) 91 { 92 struct memblock_region *reg; 93 phys_addr_t mem_size = 0; 94 phys_addr_t vmlinux_end = __pa(&_end); 95 phys_addr_t vmlinux_start = __pa(&_start); 96 97 /* Find the memory region containing the kernel */ 98 for_each_memblock(memory, reg) { 99 phys_addr_t end = reg->base + reg->size; 100 101 if (reg->base <= vmlinux_end && vmlinux_end <= end) { 102 mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); 103 104 /* 105 * Remove memblock from the end of usable area to the 106 * end of region 107 */ 108 if (reg->base + mem_size < end) 109 memblock_remove(reg->base + mem_size, 110 end - reg->base - mem_size); 111 } 112 } 113 BUG_ON(mem_size == 0); 114 115 /* Reserve from the start of the kernel to the end of the kernel */ 116 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); 117 118 set_max_mapnr(PFN_DOWN(mem_size)); 119 max_low_pfn = PFN_DOWN(memblock_end_of_DRAM()); 120 121 #ifdef CONFIG_BLK_DEV_INITRD 122 setup_initrd(); 123 #endif /* CONFIG_BLK_DEV_INITRD */ 124 125 /* 126 * Avoid using early_init_fdt_reserve_self() since __pa() does 127 * not work for DTB pointers that are fixmap addresses 128 */ 129 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va)); 130 131 early_init_fdt_scan_reserved_mem(); 132 memblock_allow_resize(); 133 memblock_dump_all(); 134 135 for_each_memblock(memory, reg) { 136 unsigned long start_pfn = memblock_region_memory_base_pfn(reg); 137 unsigned long end_pfn = memblock_region_memory_end_pfn(reg); 138 139 memblock_set_node(PFN_PHYS(start_pfn), 140 PFN_PHYS(end_pfn - start_pfn), 141 &memblock.memory, 0); 142 } 143 } 144 145 unsigned long va_pa_offset; 146 EXPORT_SYMBOL(va_pa_offset); 147 unsigned long pfn_base; 148 EXPORT_SYMBOL(pfn_base); 149 150 void *dtb_early_va; 151 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 152 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 153 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; 154 static bool mmu_enabled; 155 156 #define MAX_EARLY_MAPPING_SIZE SZ_128M 157 158 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 159 160 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 161 { 162 unsigned long addr = __fix_to_virt(idx); 163 pte_t *ptep; 164 165 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 166 167 ptep = &fixmap_pte[pte_index(addr)]; 168 169 if (pgprot_val(prot)) { 170 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); 171 } else { 172 pte_clear(&init_mm, addr, ptep); 173 local_flush_tlb_page(addr); 174 } 175 } 176 177 static pte_t *__init get_pte_virt(phys_addr_t pa) 178 { 179 if (mmu_enabled) { 180 clear_fixmap(FIX_PTE); 181 return (pte_t *)set_fixmap_offset(FIX_PTE, pa); 182 } else { 183 return (pte_t *)((uintptr_t)pa); 184 } 185 } 186 187 static phys_addr_t __init alloc_pte(uintptr_t va) 188 { 189 /* 190 * We only create PMD or PGD early mappings so we 191 * should never reach here with MMU disabled. 192 */ 193 BUG_ON(!mmu_enabled); 194 195 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 196 } 197 198 static void __init create_pte_mapping(pte_t *ptep, 199 uintptr_t va, phys_addr_t pa, 200 phys_addr_t sz, pgprot_t prot) 201 { 202 uintptr_t pte_index = pte_index(va); 203 204 BUG_ON(sz != PAGE_SIZE); 205 206 if (pte_none(ptep[pte_index])) 207 ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot); 208 } 209 210 #ifndef __PAGETABLE_PMD_FOLDED 211 212 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss; 213 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; 214 215 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE 216 #define NUM_EARLY_PMDS 1UL 217 #else 218 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE) 219 #endif 220 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE); 221 222 static pmd_t *__init get_pmd_virt(phys_addr_t pa) 223 { 224 if (mmu_enabled) { 225 clear_fixmap(FIX_PMD); 226 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); 227 } else { 228 return (pmd_t *)((uintptr_t)pa); 229 } 230 } 231 232 static phys_addr_t __init alloc_pmd(uintptr_t va) 233 { 234 uintptr_t pmd_num; 235 236 if (mmu_enabled) 237 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 238 239 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT; 240 BUG_ON(pmd_num >= NUM_EARLY_PMDS); 241 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD]; 242 } 243 244 static void __init create_pmd_mapping(pmd_t *pmdp, 245 uintptr_t va, phys_addr_t pa, 246 phys_addr_t sz, pgprot_t prot) 247 { 248 pte_t *ptep; 249 phys_addr_t pte_phys; 250 uintptr_t pmd_index = pmd_index(va); 251 252 if (sz == PMD_SIZE) { 253 if (pmd_none(pmdp[pmd_index])) 254 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot); 255 return; 256 } 257 258 if (pmd_none(pmdp[pmd_index])) { 259 pte_phys = alloc_pte(va); 260 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE); 261 ptep = get_pte_virt(pte_phys); 262 memset(ptep, 0, PAGE_SIZE); 263 } else { 264 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index])); 265 ptep = get_pte_virt(pte_phys); 266 } 267 268 create_pte_mapping(ptep, va, pa, sz, prot); 269 } 270 271 #define pgd_next_t pmd_t 272 #define alloc_pgd_next(__va) alloc_pmd(__va) 273 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa) 274 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 275 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot) 276 #define fixmap_pgd_next fixmap_pmd 277 #else 278 #define pgd_next_t pte_t 279 #define alloc_pgd_next(__va) alloc_pte(__va) 280 #define get_pgd_next_virt(__pa) get_pte_virt(__pa) 281 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 282 create_pte_mapping(__nextp, __va, __pa, __sz, __prot) 283 #define fixmap_pgd_next fixmap_pte 284 #endif 285 286 static void __init create_pgd_mapping(pgd_t *pgdp, 287 uintptr_t va, phys_addr_t pa, 288 phys_addr_t sz, pgprot_t prot) 289 { 290 pgd_next_t *nextp; 291 phys_addr_t next_phys; 292 uintptr_t pgd_index = pgd_index(va); 293 294 if (sz == PGDIR_SIZE) { 295 if (pgd_val(pgdp[pgd_index]) == 0) 296 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot); 297 return; 298 } 299 300 if (pgd_val(pgdp[pgd_index]) == 0) { 301 next_phys = alloc_pgd_next(va); 302 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE); 303 nextp = get_pgd_next_virt(next_phys); 304 memset(nextp, 0, PAGE_SIZE); 305 } else { 306 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index])); 307 nextp = get_pgd_next_virt(next_phys); 308 } 309 310 create_pgd_next_mapping(nextp, va, pa, sz, prot); 311 } 312 313 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) 314 { 315 /* Upgrade to PMD_SIZE mappings whenever possible */ 316 if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) 317 return PAGE_SIZE; 318 319 return PMD_SIZE; 320 } 321 322 /* 323 * setup_vm() is called from head.S with MMU-off. 324 * 325 * Following requirements should be honoured for setup_vm() to work 326 * correctly: 327 * 1) It should use PC-relative addressing for accessing kernel symbols. 328 * To achieve this we always use GCC cmodel=medany. 329 * 2) The compiler instrumentation for FTRACE will not work for setup_vm() 330 * so disable compiler instrumentation when FTRACE is enabled. 331 * 332 * Currently, the above requirements are honoured by using custom CFLAGS 333 * for init.o in mm/Makefile. 334 */ 335 336 #ifndef __riscv_cmodel_medany 337 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." 338 #endif 339 340 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 341 { 342 uintptr_t va, end_va; 343 uintptr_t load_pa = (uintptr_t)(&_start); 344 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; 345 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); 346 347 va_pa_offset = PAGE_OFFSET - load_pa; 348 pfn_base = PFN_DOWN(load_pa); 349 350 /* 351 * Enforce boot alignment requirements of RV32 and 352 * RV64 by only allowing PMD or PGD mappings. 353 */ 354 BUG_ON(map_size == PAGE_SIZE); 355 356 /* Sanity check alignment and size */ 357 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); 358 BUG_ON((load_pa % map_size) != 0); 359 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE); 360 361 /* Setup early PGD for fixmap */ 362 create_pgd_mapping(early_pg_dir, FIXADDR_START, 363 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); 364 365 #ifndef __PAGETABLE_PMD_FOLDED 366 /* Setup fixmap PMD */ 367 create_pmd_mapping(fixmap_pmd, FIXADDR_START, 368 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); 369 /* Setup trampoline PGD and PMD */ 370 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 371 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); 372 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET, 373 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC); 374 #else 375 /* Setup trampoline PGD */ 376 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 377 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); 378 #endif 379 380 /* 381 * Setup early PGD covering entire kernel which will allows 382 * us to reach paging_init(). We map all memory banks later 383 * in setup_vm_final() below. 384 */ 385 end_va = PAGE_OFFSET + load_sz; 386 for (va = PAGE_OFFSET; va < end_va; va += map_size) 387 create_pgd_mapping(early_pg_dir, va, 388 load_pa + (va - PAGE_OFFSET), 389 map_size, PAGE_KERNEL_EXEC); 390 391 /* Create fixed mapping for early FDT parsing */ 392 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; 393 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE) 394 create_pte_mapping(fixmap_pte, va, 395 dtb_pa + (va - __fix_to_virt(FIX_FDT)), 396 PAGE_SIZE, PAGE_KERNEL); 397 398 /* Save pointer to DTB for early FDT parsing */ 399 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK); 400 /* Save physical address for memblock reservation */ 401 dtb_early_pa = dtb_pa; 402 } 403 404 static void __init setup_vm_final(void) 405 { 406 uintptr_t va, map_size; 407 phys_addr_t pa, start, end; 408 struct memblock_region *reg; 409 410 /* Set mmu_enabled flag */ 411 mmu_enabled = true; 412 413 /* Setup swapper PGD for fixmap */ 414 create_pgd_mapping(swapper_pg_dir, FIXADDR_START, 415 __pa(fixmap_pgd_next), 416 PGDIR_SIZE, PAGE_TABLE); 417 418 /* Map all memory banks */ 419 for_each_memblock(memory, reg) { 420 start = reg->base; 421 end = start + reg->size; 422 423 if (start >= end) 424 break; 425 if (memblock_is_nomap(reg)) 426 continue; 427 if (start <= __pa(PAGE_OFFSET) && 428 __pa(PAGE_OFFSET) < end) 429 start = __pa(PAGE_OFFSET); 430 431 map_size = best_map_size(start, end - start); 432 for (pa = start; pa < end; pa += map_size) { 433 va = (uintptr_t)__va(pa); 434 create_pgd_mapping(swapper_pg_dir, va, pa, 435 map_size, PAGE_KERNEL_EXEC); 436 } 437 } 438 439 /* Clear fixmap PTE and PMD mappings */ 440 clear_fixmap(FIX_PTE); 441 clear_fixmap(FIX_PMD); 442 443 /* Move to swapper page table */ 444 csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE); 445 local_flush_tlb_all(); 446 } 447 448 void __init paging_init(void) 449 { 450 setup_vm_final(); 451 memblocks_present(); 452 sparse_init(); 453 setup_zero_page(); 454 zone_sizes_init(); 455 } 456 457 #ifdef CONFIG_SPARSEMEM_VMEMMAP 458 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 459 struct vmem_altmap *altmap) 460 { 461 return vmemmap_populate_basepages(start, end, node); 462 } 463 #endif 464