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