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 #include <linux/set_memory.h> 16 17 #include <asm/fixmap.h> 18 #include <asm/tlbflush.h> 19 #include <asm/sections.h> 20 #include <asm/soc.h> 21 #include <asm/io.h> 22 #include <asm/ptdump.h> 23 24 #include "../kernel/head.h" 25 26 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] 27 __page_aligned_bss; 28 EXPORT_SYMBOL(empty_zero_page); 29 30 extern char _start[]; 31 void *dtb_early_va; 32 33 static void __init zone_sizes_init(void) 34 { 35 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; 36 37 #ifdef CONFIG_ZONE_DMA32 38 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, 39 (unsigned long) PFN_PHYS(max_low_pfn))); 40 #endif 41 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 42 43 free_area_init(max_zone_pfns); 44 } 45 46 static void setup_zero_page(void) 47 { 48 memset((void *)empty_zero_page, 0, PAGE_SIZE); 49 } 50 51 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM) 52 static inline void print_mlk(char *name, unsigned long b, unsigned long t) 53 { 54 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld kB)\n", name, b, t, 55 (((t) - (b)) >> 10)); 56 } 57 58 static inline void print_mlm(char *name, unsigned long b, unsigned long t) 59 { 60 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld MB)\n", name, b, t, 61 (((t) - (b)) >> 20)); 62 } 63 64 static void print_vm_layout(void) 65 { 66 pr_notice("Virtual kernel memory layout:\n"); 67 print_mlk("fixmap", (unsigned long)FIXADDR_START, 68 (unsigned long)FIXADDR_TOP); 69 print_mlm("pci io", (unsigned long)PCI_IO_START, 70 (unsigned long)PCI_IO_END); 71 print_mlm("vmemmap", (unsigned long)VMEMMAP_START, 72 (unsigned long)VMEMMAP_END); 73 print_mlm("vmalloc", (unsigned long)VMALLOC_START, 74 (unsigned long)VMALLOC_END); 75 print_mlm("lowmem", (unsigned long)PAGE_OFFSET, 76 (unsigned long)high_memory); 77 } 78 #else 79 static void print_vm_layout(void) { } 80 #endif /* CONFIG_DEBUG_VM */ 81 82 void __init mem_init(void) 83 { 84 #ifdef CONFIG_FLATMEM 85 BUG_ON(!mem_map); 86 #endif /* CONFIG_FLATMEM */ 87 88 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn))); 89 memblock_free_all(); 90 91 mem_init_print_info(NULL); 92 print_vm_layout(); 93 } 94 95 #ifdef CONFIG_BLK_DEV_INITRD 96 static void __init setup_initrd(void) 97 { 98 phys_addr_t start; 99 unsigned long size; 100 101 /* Ignore the virtul address computed during device tree parsing */ 102 initrd_start = initrd_end = 0; 103 104 if (!phys_initrd_size) 105 return; 106 /* 107 * Round the memory region to page boundaries as per free_initrd_mem() 108 * This allows us to detect whether the pages overlapping the initrd 109 * are in use, but more importantly, reserves the entire set of pages 110 * as we don't want these pages allocated for other purposes. 111 */ 112 start = round_down(phys_initrd_start, PAGE_SIZE); 113 size = phys_initrd_size + (phys_initrd_start - start); 114 size = round_up(size, PAGE_SIZE); 115 116 if (!memblock_is_region_memory(start, size)) { 117 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region", 118 (u64)start, size); 119 goto disable; 120 } 121 122 if (memblock_is_region_reserved(start, size)) { 123 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n", 124 (u64)start, size); 125 goto disable; 126 } 127 128 memblock_reserve(start, size); 129 /* Now convert initrd to virtual addresses */ 130 initrd_start = (unsigned long)__va(phys_initrd_start); 131 initrd_end = initrd_start + phys_initrd_size; 132 initrd_below_start_ok = 1; 133 134 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", 135 (void *)(initrd_start), size); 136 return; 137 disable: 138 pr_cont(" - disabling initrd\n"); 139 initrd_start = 0; 140 initrd_end = 0; 141 } 142 #endif /* CONFIG_BLK_DEV_INITRD */ 143 144 static phys_addr_t dtb_early_pa __initdata; 145 146 void __init setup_bootmem(void) 147 { 148 struct memblock_region *reg; 149 phys_addr_t mem_size = 0; 150 phys_addr_t total_mem = 0; 151 phys_addr_t mem_start, end = 0; 152 phys_addr_t vmlinux_end = __pa_symbol(&_end); 153 phys_addr_t vmlinux_start = __pa_symbol(&_start); 154 155 /* Find the memory region containing the kernel */ 156 for_each_memblock(memory, reg) { 157 end = reg->base + reg->size; 158 if (!total_mem) 159 mem_start = reg->base; 160 if (reg->base <= vmlinux_start && vmlinux_end <= end) 161 BUG_ON(reg->size == 0); 162 total_mem = total_mem + reg->size; 163 } 164 165 /* 166 * Remove memblock from the end of usable area to the 167 * end of region 168 */ 169 mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET); 170 if (mem_start + mem_size < end) 171 memblock_remove(mem_start + mem_size, 172 end - mem_start - mem_size); 173 174 /* Reserve from the start of the kernel to the end of the kernel */ 175 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); 176 177 max_pfn = PFN_DOWN(memblock_end_of_DRAM()); 178 max_low_pfn = max_pfn; 179 set_max_mapnr(max_low_pfn); 180 181 #ifdef CONFIG_BLK_DEV_INITRD 182 setup_initrd(); 183 #endif /* CONFIG_BLK_DEV_INITRD */ 184 185 /* 186 * Avoid using early_init_fdt_reserve_self() since __pa() does 187 * not work for DTB pointers that are fixmap addresses 188 */ 189 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va)); 190 191 early_init_fdt_scan_reserved_mem(); 192 memblock_allow_resize(); 193 memblock_dump_all(); 194 195 for_each_memblock(memory, reg) { 196 unsigned long start_pfn = memblock_region_memory_base_pfn(reg); 197 unsigned long end_pfn = memblock_region_memory_end_pfn(reg); 198 199 memblock_set_node(PFN_PHYS(start_pfn), 200 PFN_PHYS(end_pfn - start_pfn), 201 &memblock.memory, 0); 202 } 203 } 204 205 #ifdef CONFIG_MMU 206 unsigned long va_pa_offset; 207 EXPORT_SYMBOL(va_pa_offset); 208 unsigned long pfn_base; 209 EXPORT_SYMBOL(pfn_base); 210 211 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 212 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 213 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; 214 static bool mmu_enabled; 215 216 #define MAX_EARLY_MAPPING_SIZE SZ_128M 217 218 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 219 220 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 221 { 222 unsigned long addr = __fix_to_virt(idx); 223 pte_t *ptep; 224 225 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 226 227 ptep = &fixmap_pte[pte_index(addr)]; 228 229 if (pgprot_val(prot)) { 230 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); 231 } else { 232 pte_clear(&init_mm, addr, ptep); 233 local_flush_tlb_page(addr); 234 } 235 } 236 237 static pte_t *__init get_pte_virt(phys_addr_t pa) 238 { 239 if (mmu_enabled) { 240 clear_fixmap(FIX_PTE); 241 return (pte_t *)set_fixmap_offset(FIX_PTE, pa); 242 } else { 243 return (pte_t *)((uintptr_t)pa); 244 } 245 } 246 247 static phys_addr_t __init alloc_pte(uintptr_t va) 248 { 249 /* 250 * We only create PMD or PGD early mappings so we 251 * should never reach here with MMU disabled. 252 */ 253 BUG_ON(!mmu_enabled); 254 255 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 256 } 257 258 static void __init create_pte_mapping(pte_t *ptep, 259 uintptr_t va, phys_addr_t pa, 260 phys_addr_t sz, pgprot_t prot) 261 { 262 uintptr_t pte_idx = pte_index(va); 263 264 BUG_ON(sz != PAGE_SIZE); 265 266 if (pte_none(ptep[pte_idx])) 267 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot); 268 } 269 270 #ifndef __PAGETABLE_PMD_FOLDED 271 272 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss; 273 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; 274 275 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE 276 #define NUM_EARLY_PMDS 1UL 277 #else 278 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE) 279 #endif 280 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE); 281 282 static pmd_t *__init get_pmd_virt(phys_addr_t pa) 283 { 284 if (mmu_enabled) { 285 clear_fixmap(FIX_PMD); 286 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); 287 } else { 288 return (pmd_t *)((uintptr_t)pa); 289 } 290 } 291 292 static phys_addr_t __init alloc_pmd(uintptr_t va) 293 { 294 uintptr_t pmd_num; 295 296 if (mmu_enabled) 297 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 298 299 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT; 300 BUG_ON(pmd_num >= NUM_EARLY_PMDS); 301 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD]; 302 } 303 304 static void __init create_pmd_mapping(pmd_t *pmdp, 305 uintptr_t va, phys_addr_t pa, 306 phys_addr_t sz, pgprot_t prot) 307 { 308 pte_t *ptep; 309 phys_addr_t pte_phys; 310 uintptr_t pmd_idx = pmd_index(va); 311 312 if (sz == PMD_SIZE) { 313 if (pmd_none(pmdp[pmd_idx])) 314 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot); 315 return; 316 } 317 318 if (pmd_none(pmdp[pmd_idx])) { 319 pte_phys = alloc_pte(va); 320 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE); 321 ptep = get_pte_virt(pte_phys); 322 memset(ptep, 0, PAGE_SIZE); 323 } else { 324 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx])); 325 ptep = get_pte_virt(pte_phys); 326 } 327 328 create_pte_mapping(ptep, va, pa, sz, prot); 329 } 330 331 #define pgd_next_t pmd_t 332 #define alloc_pgd_next(__va) alloc_pmd(__va) 333 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa) 334 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 335 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot) 336 #define fixmap_pgd_next fixmap_pmd 337 #else 338 #define pgd_next_t pte_t 339 #define alloc_pgd_next(__va) alloc_pte(__va) 340 #define get_pgd_next_virt(__pa) get_pte_virt(__pa) 341 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 342 create_pte_mapping(__nextp, __va, __pa, __sz, __prot) 343 #define fixmap_pgd_next fixmap_pte 344 #endif 345 346 static void __init create_pgd_mapping(pgd_t *pgdp, 347 uintptr_t va, phys_addr_t pa, 348 phys_addr_t sz, pgprot_t prot) 349 { 350 pgd_next_t *nextp; 351 phys_addr_t next_phys; 352 uintptr_t pgd_idx = pgd_index(va); 353 354 if (sz == PGDIR_SIZE) { 355 if (pgd_val(pgdp[pgd_idx]) == 0) 356 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot); 357 return; 358 } 359 360 if (pgd_val(pgdp[pgd_idx]) == 0) { 361 next_phys = alloc_pgd_next(va); 362 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE); 363 nextp = get_pgd_next_virt(next_phys); 364 memset(nextp, 0, PAGE_SIZE); 365 } else { 366 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx])); 367 nextp = get_pgd_next_virt(next_phys); 368 } 369 370 create_pgd_next_mapping(nextp, va, pa, sz, prot); 371 } 372 373 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) 374 { 375 /* Upgrade to PMD_SIZE mappings whenever possible */ 376 if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) 377 return PAGE_SIZE; 378 379 return PMD_SIZE; 380 } 381 382 /* 383 * setup_vm() is called from head.S with MMU-off. 384 * 385 * Following requirements should be honoured for setup_vm() to work 386 * correctly: 387 * 1) It should use PC-relative addressing for accessing kernel symbols. 388 * To achieve this we always use GCC cmodel=medany. 389 * 2) The compiler instrumentation for FTRACE will not work for setup_vm() 390 * so disable compiler instrumentation when FTRACE is enabled. 391 * 392 * Currently, the above requirements are honoured by using custom CFLAGS 393 * for init.o in mm/Makefile. 394 */ 395 396 #ifndef __riscv_cmodel_medany 397 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." 398 #endif 399 400 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 401 { 402 uintptr_t va, end_va; 403 uintptr_t load_pa = (uintptr_t)(&_start); 404 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; 405 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); 406 407 va_pa_offset = PAGE_OFFSET - load_pa; 408 pfn_base = PFN_DOWN(load_pa); 409 410 /* 411 * Enforce boot alignment requirements of RV32 and 412 * RV64 by only allowing PMD or PGD mappings. 413 */ 414 BUG_ON(map_size == PAGE_SIZE); 415 416 /* Sanity check alignment and size */ 417 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); 418 BUG_ON((load_pa % map_size) != 0); 419 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE); 420 421 /* Setup early PGD for fixmap */ 422 create_pgd_mapping(early_pg_dir, FIXADDR_START, 423 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); 424 425 #ifndef __PAGETABLE_PMD_FOLDED 426 /* Setup fixmap PMD */ 427 create_pmd_mapping(fixmap_pmd, FIXADDR_START, 428 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); 429 /* Setup trampoline PGD and PMD */ 430 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 431 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); 432 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET, 433 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC); 434 #else 435 /* Setup trampoline PGD */ 436 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 437 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); 438 #endif 439 440 /* 441 * Setup early PGD covering entire kernel which will allows 442 * us to reach paging_init(). We map all memory banks later 443 * in setup_vm_final() below. 444 */ 445 end_va = PAGE_OFFSET + load_sz; 446 for (va = PAGE_OFFSET; va < end_va; va += map_size) 447 create_pgd_mapping(early_pg_dir, va, 448 load_pa + (va - PAGE_OFFSET), 449 map_size, PAGE_KERNEL_EXEC); 450 451 /* Create fixed mapping for early FDT parsing */ 452 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; 453 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE) 454 create_pte_mapping(fixmap_pte, va, 455 dtb_pa + (va - __fix_to_virt(FIX_FDT)), 456 PAGE_SIZE, PAGE_KERNEL); 457 458 /* Save pointer to DTB for early FDT parsing */ 459 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK); 460 /* Save physical address for memblock reservation */ 461 dtb_early_pa = dtb_pa; 462 } 463 464 static void __init setup_vm_final(void) 465 { 466 uintptr_t va, map_size; 467 phys_addr_t pa, start, end; 468 struct memblock_region *reg; 469 470 /* Set mmu_enabled flag */ 471 mmu_enabled = true; 472 473 /* Setup swapper PGD for fixmap */ 474 create_pgd_mapping(swapper_pg_dir, FIXADDR_START, 475 __pa_symbol(fixmap_pgd_next), 476 PGDIR_SIZE, PAGE_TABLE); 477 478 /* Map all memory banks */ 479 for_each_memblock(memory, reg) { 480 start = reg->base; 481 end = start + reg->size; 482 483 if (start >= end) 484 break; 485 if (memblock_is_nomap(reg)) 486 continue; 487 if (start <= __pa(PAGE_OFFSET) && 488 __pa(PAGE_OFFSET) < end) 489 start = __pa(PAGE_OFFSET); 490 491 map_size = best_map_size(start, end - start); 492 for (pa = start; pa < end; pa += map_size) { 493 va = (uintptr_t)__va(pa); 494 create_pgd_mapping(swapper_pg_dir, va, pa, 495 map_size, PAGE_KERNEL_EXEC); 496 } 497 } 498 499 /* Clear fixmap PTE and PMD mappings */ 500 clear_fixmap(FIX_PTE); 501 clear_fixmap(FIX_PMD); 502 503 /* Move to swapper page table */ 504 csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE); 505 local_flush_tlb_all(); 506 } 507 #else 508 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 509 { 510 #ifdef CONFIG_BUILTIN_DTB 511 dtb_early_va = soc_lookup_builtin_dtb(); 512 if (!dtb_early_va) { 513 /* Fallback to first available DTS */ 514 dtb_early_va = (void *) __dtb_start; 515 } 516 #else 517 dtb_early_va = (void *)dtb_pa; 518 #endif 519 } 520 521 static inline void setup_vm_final(void) 522 { 523 } 524 #endif /* CONFIG_MMU */ 525 526 #ifdef CONFIG_STRICT_KERNEL_RWX 527 void mark_rodata_ro(void) 528 { 529 unsigned long text_start = (unsigned long)_text; 530 unsigned long text_end = (unsigned long)_etext; 531 unsigned long rodata_start = (unsigned long)__start_rodata; 532 unsigned long data_start = (unsigned long)_data; 533 unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn))); 534 535 set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT); 536 set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); 537 set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); 538 set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT); 539 540 debug_checkwx(); 541 } 542 #endif 543 544 void __init paging_init(void) 545 { 546 setup_vm_final(); 547 memblocks_present(); 548 sparse_init(); 549 setup_zero_page(); 550 zone_sizes_init(); 551 } 552 553 #ifdef CONFIG_SPARSEMEM_VMEMMAP 554 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 555 struct vmem_altmap *altmap) 556 { 557 return vmemmap_populate_basepages(start, end, node); 558 } 559 #endif 560