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