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