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