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 phys_addr_t mem_size = 0; 149 phys_addr_t total_mem = 0; 150 phys_addr_t mem_start, start, end = 0; 151 phys_addr_t vmlinux_end = __pa_symbol(&_end); 152 phys_addr_t vmlinux_start = __pa_symbol(&_start); 153 u64 i; 154 155 /* Find the memory region containing the kernel */ 156 for_each_mem_range(i, &start, &end) { 157 phys_addr_t size = end - start; 158 if (!total_mem) 159 mem_start = start; 160 if (start <= vmlinux_start && vmlinux_end <= end) 161 BUG_ON(size == 0); 162 total_mem = total_mem + 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 } 195 196 #ifdef CONFIG_MMU 197 unsigned long va_pa_offset; 198 EXPORT_SYMBOL(va_pa_offset); 199 unsigned long pfn_base; 200 EXPORT_SYMBOL(pfn_base); 201 202 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 203 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 204 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; 205 static bool mmu_enabled; 206 207 #define MAX_EARLY_MAPPING_SIZE SZ_128M 208 209 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 210 211 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 212 { 213 unsigned long addr = __fix_to_virt(idx); 214 pte_t *ptep; 215 216 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 217 218 ptep = &fixmap_pte[pte_index(addr)]; 219 220 if (pgprot_val(prot)) 221 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); 222 else 223 pte_clear(&init_mm, addr, ptep); 224 local_flush_tlb_page(addr); 225 } 226 227 static pte_t *__init get_pte_virt(phys_addr_t pa) 228 { 229 if (mmu_enabled) { 230 clear_fixmap(FIX_PTE); 231 return (pte_t *)set_fixmap_offset(FIX_PTE, pa); 232 } else { 233 return (pte_t *)((uintptr_t)pa); 234 } 235 } 236 237 static phys_addr_t __init alloc_pte(uintptr_t va) 238 { 239 /* 240 * We only create PMD or PGD early mappings so we 241 * should never reach here with MMU disabled. 242 */ 243 BUG_ON(!mmu_enabled); 244 245 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 246 } 247 248 static void __init create_pte_mapping(pte_t *ptep, 249 uintptr_t va, phys_addr_t pa, 250 phys_addr_t sz, pgprot_t prot) 251 { 252 uintptr_t pte_idx = pte_index(va); 253 254 BUG_ON(sz != PAGE_SIZE); 255 256 if (pte_none(ptep[pte_idx])) 257 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot); 258 } 259 260 #ifndef __PAGETABLE_PMD_FOLDED 261 262 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss; 263 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; 264 265 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE 266 #define NUM_EARLY_PMDS 1UL 267 #else 268 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE) 269 #endif 270 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE); 271 272 static pmd_t *__init get_pmd_virt(phys_addr_t pa) 273 { 274 if (mmu_enabled) { 275 clear_fixmap(FIX_PMD); 276 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); 277 } else { 278 return (pmd_t *)((uintptr_t)pa); 279 } 280 } 281 282 static phys_addr_t __init alloc_pmd(uintptr_t va) 283 { 284 uintptr_t pmd_num; 285 286 if (mmu_enabled) 287 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 288 289 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT; 290 BUG_ON(pmd_num >= NUM_EARLY_PMDS); 291 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD]; 292 } 293 294 static void __init create_pmd_mapping(pmd_t *pmdp, 295 uintptr_t va, phys_addr_t pa, 296 phys_addr_t sz, pgprot_t prot) 297 { 298 pte_t *ptep; 299 phys_addr_t pte_phys; 300 uintptr_t pmd_idx = pmd_index(va); 301 302 if (sz == PMD_SIZE) { 303 if (pmd_none(pmdp[pmd_idx])) 304 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot); 305 return; 306 } 307 308 if (pmd_none(pmdp[pmd_idx])) { 309 pte_phys = alloc_pte(va); 310 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE); 311 ptep = get_pte_virt(pte_phys); 312 memset(ptep, 0, PAGE_SIZE); 313 } else { 314 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx])); 315 ptep = get_pte_virt(pte_phys); 316 } 317 318 create_pte_mapping(ptep, va, pa, sz, prot); 319 } 320 321 #define pgd_next_t pmd_t 322 #define alloc_pgd_next(__va) alloc_pmd(__va) 323 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa) 324 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 325 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot) 326 #define fixmap_pgd_next fixmap_pmd 327 #else 328 #define pgd_next_t pte_t 329 #define alloc_pgd_next(__va) alloc_pte(__va) 330 #define get_pgd_next_virt(__pa) get_pte_virt(__pa) 331 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 332 create_pte_mapping(__nextp, __va, __pa, __sz, __prot) 333 #define fixmap_pgd_next fixmap_pte 334 #endif 335 336 static void __init create_pgd_mapping(pgd_t *pgdp, 337 uintptr_t va, phys_addr_t pa, 338 phys_addr_t sz, pgprot_t prot) 339 { 340 pgd_next_t *nextp; 341 phys_addr_t next_phys; 342 uintptr_t pgd_idx = pgd_index(va); 343 344 if (sz == PGDIR_SIZE) { 345 if (pgd_val(pgdp[pgd_idx]) == 0) 346 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot); 347 return; 348 } 349 350 if (pgd_val(pgdp[pgd_idx]) == 0) { 351 next_phys = alloc_pgd_next(va); 352 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE); 353 nextp = get_pgd_next_virt(next_phys); 354 memset(nextp, 0, PAGE_SIZE); 355 } else { 356 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx])); 357 nextp = get_pgd_next_virt(next_phys); 358 } 359 360 create_pgd_next_mapping(nextp, va, pa, sz, prot); 361 } 362 363 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size) 364 { 365 /* Upgrade to PMD_SIZE mappings whenever possible */ 366 if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1))) 367 return PAGE_SIZE; 368 369 return PMD_SIZE; 370 } 371 372 /* 373 * setup_vm() is called from head.S with MMU-off. 374 * 375 * Following requirements should be honoured for setup_vm() to work 376 * correctly: 377 * 1) It should use PC-relative addressing for accessing kernel symbols. 378 * To achieve this we always use GCC cmodel=medany. 379 * 2) The compiler instrumentation for FTRACE will not work for setup_vm() 380 * so disable compiler instrumentation when FTRACE is enabled. 381 * 382 * Currently, the above requirements are honoured by using custom CFLAGS 383 * for init.o in mm/Makefile. 384 */ 385 386 #ifndef __riscv_cmodel_medany 387 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." 388 #endif 389 390 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 391 { 392 uintptr_t va, end_va; 393 uintptr_t load_pa = (uintptr_t)(&_start); 394 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa; 395 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE); 396 397 va_pa_offset = PAGE_OFFSET - load_pa; 398 pfn_base = PFN_DOWN(load_pa); 399 400 /* 401 * Enforce boot alignment requirements of RV32 and 402 * RV64 by only allowing PMD or PGD mappings. 403 */ 404 BUG_ON(map_size == PAGE_SIZE); 405 406 /* Sanity check alignment and size */ 407 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); 408 BUG_ON((load_pa % map_size) != 0); 409 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE); 410 411 /* Setup early PGD for fixmap */ 412 create_pgd_mapping(early_pg_dir, FIXADDR_START, 413 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); 414 415 #ifndef __PAGETABLE_PMD_FOLDED 416 /* Setup fixmap PMD */ 417 create_pmd_mapping(fixmap_pmd, FIXADDR_START, 418 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); 419 /* Setup trampoline PGD and PMD */ 420 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 421 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); 422 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET, 423 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC); 424 #else 425 /* Setup trampoline PGD */ 426 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET, 427 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC); 428 #endif 429 430 /* 431 * Setup early PGD covering entire kernel which will allows 432 * us to reach paging_init(). We map all memory banks later 433 * in setup_vm_final() below. 434 */ 435 end_va = PAGE_OFFSET + load_sz; 436 for (va = PAGE_OFFSET; va < end_va; va += map_size) 437 create_pgd_mapping(early_pg_dir, va, 438 load_pa + (va - PAGE_OFFSET), 439 map_size, PAGE_KERNEL_EXEC); 440 441 /* Create fixed mapping for early FDT parsing */ 442 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE; 443 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE) 444 create_pte_mapping(fixmap_pte, va, 445 dtb_pa + (va - __fix_to_virt(FIX_FDT)), 446 PAGE_SIZE, PAGE_KERNEL); 447 448 /* Save pointer to DTB for early FDT parsing */ 449 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK); 450 /* Save physical address for memblock reservation */ 451 dtb_early_pa = dtb_pa; 452 } 453 454 static void __init setup_vm_final(void) 455 { 456 uintptr_t va, map_size; 457 phys_addr_t pa, start, end; 458 u64 i; 459 460 /* Set mmu_enabled flag */ 461 mmu_enabled = true; 462 463 /* Setup swapper PGD for fixmap */ 464 create_pgd_mapping(swapper_pg_dir, FIXADDR_START, 465 __pa_symbol(fixmap_pgd_next), 466 PGDIR_SIZE, PAGE_TABLE); 467 468 /* Map all memory banks */ 469 for_each_mem_range(i, &start, &end) { 470 if (start >= end) 471 break; 472 if (start <= __pa(PAGE_OFFSET) && 473 __pa(PAGE_OFFSET) < end) 474 start = __pa(PAGE_OFFSET); 475 476 map_size = best_map_size(start, end - start); 477 for (pa = start; pa < end; pa += map_size) { 478 va = (uintptr_t)__va(pa); 479 create_pgd_mapping(swapper_pg_dir, va, pa, 480 map_size, PAGE_KERNEL_EXEC); 481 } 482 } 483 484 /* Clear fixmap PTE and PMD mappings */ 485 clear_fixmap(FIX_PTE); 486 clear_fixmap(FIX_PMD); 487 488 /* Move to swapper page table */ 489 csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE); 490 local_flush_tlb_all(); 491 } 492 #else 493 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 494 { 495 #ifdef CONFIG_BUILTIN_DTB 496 dtb_early_va = soc_lookup_builtin_dtb(); 497 if (!dtb_early_va) { 498 /* Fallback to first available DTS */ 499 dtb_early_va = (void *) __dtb_start; 500 } 501 #else 502 dtb_early_va = (void *)dtb_pa; 503 #endif 504 dtb_early_pa = dtb_pa; 505 } 506 507 static inline void setup_vm_final(void) 508 { 509 } 510 #endif /* CONFIG_MMU */ 511 512 #ifdef CONFIG_STRICT_KERNEL_RWX 513 void mark_rodata_ro(void) 514 { 515 unsigned long text_start = (unsigned long)_text; 516 unsigned long text_end = (unsigned long)_etext; 517 unsigned long rodata_start = (unsigned long)__start_rodata; 518 unsigned long data_start = (unsigned long)_data; 519 unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn))); 520 521 set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT); 522 set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); 523 set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT); 524 set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT); 525 526 debug_checkwx(); 527 } 528 #endif 529 530 static void __init resource_init(void) 531 { 532 struct memblock_region *region; 533 534 for_each_mem_region(region) { 535 struct resource *res; 536 537 res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES); 538 if (!res) 539 panic("%s: Failed to allocate %zu bytes\n", __func__, 540 sizeof(struct resource)); 541 542 if (memblock_is_nomap(region)) { 543 res->name = "reserved"; 544 res->flags = IORESOURCE_MEM; 545 } else { 546 res->name = "System RAM"; 547 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 548 } 549 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); 550 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1; 551 552 request_resource(&iomem_resource, res); 553 } 554 } 555 556 void __init paging_init(void) 557 { 558 setup_vm_final(); 559 sparse_init(); 560 setup_zero_page(); 561 zone_sizes_init(); 562 resource_init(); 563 } 564 565 #ifdef CONFIG_SPARSEMEM_VMEMMAP 566 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 567 struct vmem_altmap *altmap) 568 { 569 return vmemmap_populate_basepages(start, end, node, NULL); 570 } 571 #endif 572