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 void *dtb_early_va; 30 31 static void __init zone_sizes_init(void) 32 { 33 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; 34 35 #ifdef CONFIG_ZONE_DMA32 36 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, 37 (unsigned long) PFN_PHYS(max_low_pfn))); 38 #endif 39 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 40 41 free_area_init_nodes(max_zone_pfns); 42 } 43 44 static void setup_zero_page(void) 45 { 46 memset((void *)empty_zero_page, 0, PAGE_SIZE); 47 } 48 49 void __init mem_init(void) 50 { 51 #ifdef CONFIG_FLATMEM 52 BUG_ON(!mem_map); 53 #endif /* CONFIG_FLATMEM */ 54 55 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn))); 56 memblock_free_all(); 57 58 mem_init_print_info(NULL); 59 } 60 61 #ifdef CONFIG_BLK_DEV_INITRD 62 static void __init setup_initrd(void) 63 { 64 unsigned long size; 65 66 if (initrd_start >= initrd_end) { 67 pr_info("initrd not found or empty"); 68 goto disable; 69 } 70 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { 71 pr_err("initrd extends beyond end of memory"); 72 goto disable; 73 } 74 75 size = initrd_end - initrd_start; 76 memblock_reserve(__pa(initrd_start), size); 77 initrd_below_start_ok = 1; 78 79 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 80 (void *)(initrd_start), size); 81 return; 82 disable: 83 pr_cont(" - disabling initrd\n"); 84 initrd_start = 0; 85 initrd_end = 0; 86 } 87 #endif /* CONFIG_BLK_DEV_INITRD */ 88 89 static phys_addr_t dtb_early_pa __initdata; 90 91 void __init setup_bootmem(void) 92 { 93 struct memblock_region *reg; 94 phys_addr_t mem_size = 0; 95 phys_addr_t vmlinux_end = __pa(&_end); 96 phys_addr_t vmlinux_start = __pa(&_start); 97 98 /* Find the memory region containing the kernel */ 99 for_each_memblock(memory, reg) { 100 phys_addr_t end = reg->base + reg->size; 101 102 if (reg->base <= vmlinux_end && vmlinux_end <= end) { 103 mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); 104 105 /* 106 * Remove memblock from the end of usable area to the 107 * end of region 108 */ 109 if (reg->base + mem_size < end) 110 memblock_remove(reg->base + mem_size, 111 end - reg->base - mem_size); 112 } 113 } 114 BUG_ON(mem_size == 0); 115 116 /* Reserve from the start of the kernel to the end of the kernel */ 117 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); 118 119 set_max_mapnr(PFN_DOWN(mem_size)); 120 max_low_pfn = PFN_DOWN(memblock_end_of_DRAM()); 121 122 #ifdef CONFIG_BLK_DEV_INITRD 123 setup_initrd(); 124 #endif /* CONFIG_BLK_DEV_INITRD */ 125 126 /* 127 * Avoid using early_init_fdt_reserve_self() since __pa() does 128 * not work for DTB pointers that are fixmap addresses 129 */ 130 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va)); 131 132 early_init_fdt_scan_reserved_mem(); 133 memblock_allow_resize(); 134 memblock_dump_all(); 135 136 for_each_memblock(memory, reg) { 137 unsigned long start_pfn = memblock_region_memory_base_pfn(reg); 138 unsigned long end_pfn = memblock_region_memory_end_pfn(reg); 139 140 memblock_set_node(PFN_PHYS(start_pfn), 141 PFN_PHYS(end_pfn - start_pfn), 142 &memblock.memory, 0); 143 } 144 } 145 146 #ifdef CONFIG_MMU 147 unsigned long va_pa_offset; 148 EXPORT_SYMBOL(va_pa_offset); 149 unsigned long pfn_base; 150 EXPORT_SYMBOL(pfn_base); 151 152 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 153 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 154 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; 155 static bool mmu_enabled; 156 157 #define MAX_EARLY_MAPPING_SIZE SZ_128M 158 159 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 160 161 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 162 { 163 unsigned long addr = __fix_to_virt(idx); 164 pte_t *ptep; 165 166 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 167 168 ptep = &fixmap_pte[pte_index(addr)]; 169 170 if (pgprot_val(prot)) { 171 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); 172 } else { 173 pte_clear(&init_mm, addr, ptep); 174 local_flush_tlb_page(addr); 175 } 176 } 177 178 static pte_t *__init get_pte_virt(phys_addr_t pa) 179 { 180 if (mmu_enabled) { 181 clear_fixmap(FIX_PTE); 182 return (pte_t *)set_fixmap_offset(FIX_PTE, pa); 183 } else { 184 return (pte_t *)((uintptr_t)pa); 185 } 186 } 187 188 static phys_addr_t __init alloc_pte(uintptr_t va) 189 { 190 /* 191 * We only create PMD or PGD early mappings so we 192 * should never reach here with MMU disabled. 193 */ 194 BUG_ON(!mmu_enabled); 195 196 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 197 } 198 199 static void __init create_pte_mapping(pte_t *ptep, 200 uintptr_t va, phys_addr_t pa, 201 phys_addr_t sz, pgprot_t prot) 202 { 203 uintptr_t pte_index = pte_index(va); 204 205 BUG_ON(sz != PAGE_SIZE); 206 207 if (pte_none(ptep[pte_index])) 208 ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot); 209 } 210 211 #ifndef __PAGETABLE_PMD_FOLDED 212 213 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss; 214 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; 215 216 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE 217 #define NUM_EARLY_PMDS 1UL 218 #else 219 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE) 220 #endif 221 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE); 222 223 static pmd_t *__init get_pmd_virt(phys_addr_t pa) 224 { 225 if (mmu_enabled) { 226 clear_fixmap(FIX_PMD); 227 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); 228 } else { 229 return (pmd_t *)((uintptr_t)pa); 230 } 231 } 232 233 static phys_addr_t __init alloc_pmd(uintptr_t va) 234 { 235 uintptr_t pmd_num; 236 237 if (mmu_enabled) 238 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 239 240 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT; 241 BUG_ON(pmd_num >= NUM_EARLY_PMDS); 242 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD]; 243 } 244 245 static void __init create_pmd_mapping(pmd_t *pmdp, 246 uintptr_t va, phys_addr_t pa, 247 phys_addr_t sz, pgprot_t prot) 248 { 249 pte_t *ptep; 250 phys_addr_t pte_phys; 251 uintptr_t pmd_index = pmd_index(va); 252 253 if (sz == PMD_SIZE) { 254 if (pmd_none(pmdp[pmd_index])) 255 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot); 256 return; 257 } 258 259 if (pmd_none(pmdp[pmd_index])) { 260 pte_phys = alloc_pte(va); 261 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE); 262 ptep = get_pte_virt(pte_phys); 263 memset(ptep, 0, PAGE_SIZE); 264 } else { 265 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index])); 266 ptep = get_pte_virt(pte_phys); 267 } 268 269 create_pte_mapping(ptep, va, pa, sz, prot); 270 } 271 272 #define pgd_next_t pmd_t 273 #define alloc_pgd_next(__va) alloc_pmd(__va) 274 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa) 275 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 276 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot) 277 #define fixmap_pgd_next fixmap_pmd 278 #else 279 #define pgd_next_t pte_t 280 #define alloc_pgd_next(__va) alloc_pte(__va) 281 #define get_pgd_next_virt(__pa) get_pte_virt(__pa) 282 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 283 create_pte_mapping(__nextp, __va, __pa, __sz, __prot) 284 #define fixmap_pgd_next fixmap_pte 285 #endif 286 287 static void __init create_pgd_mapping(pgd_t *pgdp, 288 uintptr_t va, phys_addr_t pa, 289 phys_addr_t sz, pgprot_t prot) 290 { 291 pgd_next_t *nextp; 292 phys_addr_t next_phys; 293 uintptr_t pgd_index = pgd_index(va); 294 295 if (sz == PGDIR_SIZE) { 296 if (pgd_val(pgdp[pgd_index]) == 0) 297 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot); 298 return; 299 } 300 301 if (pgd_val(pgdp[pgd_index]) == 0) { 302 next_phys = alloc_pgd_next(va); 303 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE); 304 nextp = get_pgd_next_virt(next_phys); 305 memset(nextp, 0, PAGE_SIZE); 306 } else { 307 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index])); 308 nextp = get_pgd_next_virt(next_phys); 309 } 310 311 create_pgd_next_mapping(nextp, va, pa, sz, prot); 312 } 313 314 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) 315 { 316 /* Upgrade to PMD_SIZE mappings whenever possible */ 317 if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) 318 return PAGE_SIZE; 319 320 return PMD_SIZE; 321 } 322 323 /* 324 * setup_vm() is called from head.S with MMU-off. 325 * 326 * Following requirements should be honoured for setup_vm() to work 327 * correctly: 328 * 1) It should use PC-relative addressing for accessing kernel symbols. 329 * To achieve this we always use GCC cmodel=medany. 330 * 2) The compiler instrumentation for FTRACE will not work for setup_vm() 331 * so disable compiler instrumentation when FTRACE is enabled. 332 * 333 * Currently, the above requirements are honoured by using custom CFLAGS 334 * for init.o in mm/Makefile. 335 */ 336 337 #ifndef __riscv_cmodel_medany 338 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." 339 #endif 340 341 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 342 { 343 uintptr_t va, end_va; 344 uintptr_t load_pa = (uintptr_t)(&_start); 345 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; 346 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); 347 348 va_pa_offset = PAGE_OFFSET - load_pa; 349 pfn_base = PFN_DOWN(load_pa); 350 351 /* 352 * Enforce boot alignment requirements of RV32 and 353 * RV64 by only allowing PMD or PGD mappings. 354 */ 355 BUG_ON(map_size == PAGE_SIZE); 356 357 /* Sanity check alignment and size */ 358 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); 359 BUG_ON((load_pa % map_size) != 0); 360 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE); 361 362 /* Setup early PGD for fixmap */ 363 create_pgd_mapping(early_pg_dir, FIXADDR_START, 364 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); 365 366 #ifndef __PAGETABLE_PMD_FOLDED 367 /* Setup fixmap PMD */ 368 create_pmd_mapping(fixmap_pmd, FIXADDR_START, 369 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); 370 /* Setup trampoline PGD and PMD */ 371 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 372 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); 373 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET, 374 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC); 375 #else 376 /* Setup trampoline PGD */ 377 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 378 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); 379 #endif 380 381 /* 382 * Setup early PGD covering entire kernel which will allows 383 * us to reach paging_init(). We map all memory banks later 384 * in setup_vm_final() below. 385 */ 386 end_va = PAGE_OFFSET + load_sz; 387 for (va = PAGE_OFFSET; va < end_va; va += map_size) 388 create_pgd_mapping(early_pg_dir, va, 389 load_pa + (va - PAGE_OFFSET), 390 map_size, PAGE_KERNEL_EXEC); 391 392 /* Create fixed mapping for early FDT parsing */ 393 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; 394 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE) 395 create_pte_mapping(fixmap_pte, va, 396 dtb_pa + (va - __fix_to_virt(FIX_FDT)), 397 PAGE_SIZE, PAGE_KERNEL); 398 399 /* Save pointer to DTB for early FDT parsing */ 400 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK); 401 /* Save physical address for memblock reservation */ 402 dtb_early_pa = dtb_pa; 403 } 404 405 static void __init setup_vm_final(void) 406 { 407 uintptr_t va, map_size; 408 phys_addr_t pa, start, end; 409 struct memblock_region *reg; 410 411 /* Set mmu_enabled flag */ 412 mmu_enabled = true; 413 414 /* Setup swapper PGD for fixmap */ 415 create_pgd_mapping(swapper_pg_dir, FIXADDR_START, 416 __pa(fixmap_pgd_next), 417 PGDIR_SIZE, PAGE_TABLE); 418 419 /* Map all memory banks */ 420 for_each_memblock(memory, reg) { 421 start = reg->base; 422 end = start + reg->size; 423 424 if (start >= end) 425 break; 426 if (memblock_is_nomap(reg)) 427 continue; 428 if (start <= __pa(PAGE_OFFSET) && 429 __pa(PAGE_OFFSET) < end) 430 start = __pa(PAGE_OFFSET); 431 432 map_size = best_map_size(start, end - start); 433 for (pa = start; pa < end; pa += map_size) { 434 va = (uintptr_t)__va(pa); 435 create_pgd_mapping(swapper_pg_dir, va, pa, 436 map_size, PAGE_KERNEL_EXEC); 437 } 438 } 439 440 /* Clear fixmap PTE and PMD mappings */ 441 clear_fixmap(FIX_PTE); 442 clear_fixmap(FIX_PMD); 443 444 /* Move to swapper page table */ 445 csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE); 446 local_flush_tlb_all(); 447 } 448 #else 449 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 450 { 451 dtb_early_va = (void *)dtb_pa; 452 } 453 454 static inline void setup_vm_final(void) 455 { 456 } 457 #endif /* CONFIG_MMU */ 458 459 void __init paging_init(void) 460 { 461 setup_vm_final(); 462 memblocks_present(); 463 sparse_init(); 464 setup_zero_page(); 465 zone_sizes_init(); 466 } 467 468 #ifdef CONFIG_SPARSEMEM_VMEMMAP 469 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 470 struct vmem_altmap *altmap) 471 { 472 return vmemmap_populate_basepages(start, end, node); 473 } 474 #endif 475