1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2012 Regents of the University of California
4 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
7 #include <linux/init.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>
17 #include <asm/fixmap.h>
18 #include <asm/tlbflush.h>
19 #include <asm/sections.h>
22 #include <asm/ptdump.h>
24 #include "../kernel/head.h"
26 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
28 EXPORT_SYMBOL(empty_zero_page);
33 static void __init zone_sizes_init(void)
35 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
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)));
41 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
43 free_area_init(max_zone_pfns);
46 static void setup_zero_page(void)
48 memset((void *)empty_zero_page, 0, PAGE_SIZE);
51 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
52 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
54 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld kB)\n", name, b, t,
58 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
60 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld MB)\n", name, b, t,
64 static void print_vm_layout(void)
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);
79 static void print_vm_layout(void) { }
80 #endif /* CONFIG_DEBUG_VM */
82 void __init mem_init(void)
86 #endif /* CONFIG_FLATMEM */
88 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
91 mem_init_print_info(NULL);
95 #ifdef CONFIG_BLK_DEV_INITRD
96 static void __init setup_initrd(void)
101 /* Ignore the virtul address computed during device tree parsing */
102 initrd_start = initrd_end = 0;
104 if (!phys_initrd_size)
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.
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);
116 if (!memblock_is_region_memory(start, size)) {
117 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
122 if (memblock_is_region_reserved(start, size)) {
123 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
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;
134 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
135 (void *)(initrd_start), size);
138 pr_cont(" - disabling initrd\n");
142 #endif /* CONFIG_BLK_DEV_INITRD */
144 static phys_addr_t dtb_early_pa __initdata;
146 void __init setup_bootmem(void)
148 struct memblock_region *reg;
149 phys_addr_t mem_size = 0;
150 phys_addr_t total_mem = 0;
151 phys_addr_t mem_start, end = 0;
152 phys_addr_t vmlinux_end = __pa_symbol(&_end);
153 phys_addr_t vmlinux_start = __pa_symbol(&_start);
155 /* Find the memory region containing the kernel */
156 for_each_memblock(memory, reg) {
157 end = reg->base + reg->size;
159 mem_start = reg->base;
160 if (reg->base <= vmlinux_start && vmlinux_end <= end)
161 BUG_ON(reg->size == 0);
162 total_mem = total_mem + reg->size;
166 * Remove memblock from the end of usable area to the
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);
174 /* Reserve from the start of the kernel to the end of the kernel */
175 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
177 max_pfn = PFN_DOWN(memblock_end_of_DRAM());
178 max_low_pfn = max_pfn;
179 set_max_mapnr(max_low_pfn);
181 #ifdef CONFIG_BLK_DEV_INITRD
183 #endif /* CONFIG_BLK_DEV_INITRD */
186 * Avoid using early_init_fdt_reserve_self() since __pa() does
187 * not work for DTB pointers that are fixmap addresses
189 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
191 early_init_fdt_scan_reserved_mem();
192 memblock_allow_resize();
195 for_each_memblock(memory, reg) {
196 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
197 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
199 memblock_set_node(PFN_PHYS(start_pfn),
200 PFN_PHYS(end_pfn - start_pfn),
201 &memblock.memory, 0);
206 unsigned long va_pa_offset;
207 EXPORT_SYMBOL(va_pa_offset);
208 unsigned long pfn_base;
209 EXPORT_SYMBOL(pfn_base);
211 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
212 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
213 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
214 static bool mmu_enabled;
216 #define MAX_EARLY_MAPPING_SIZE SZ_128M
218 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
220 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
222 unsigned long addr = __fix_to_virt(idx);
225 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
227 ptep = &fixmap_pte[pte_index(addr)];
229 if (pgprot_val(prot))
230 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
232 pte_clear(&init_mm, addr, ptep);
233 local_flush_tlb_page(addr);
236 static pte_t *__init get_pte_virt(phys_addr_t pa)
239 clear_fixmap(FIX_PTE);
240 return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
242 return (pte_t *)((uintptr_t)pa);
246 static phys_addr_t __init alloc_pte(uintptr_t va)
249 * We only create PMD or PGD early mappings so we
250 * should never reach here with MMU disabled.
252 BUG_ON(!mmu_enabled);
254 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
257 static void __init create_pte_mapping(pte_t *ptep,
258 uintptr_t va, phys_addr_t pa,
259 phys_addr_t sz, pgprot_t prot)
261 uintptr_t pte_idx = pte_index(va);
263 BUG_ON(sz != PAGE_SIZE);
265 if (pte_none(ptep[pte_idx]))
266 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
269 #ifndef __PAGETABLE_PMD_FOLDED
271 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
272 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
274 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
275 #define NUM_EARLY_PMDS 1UL
277 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
279 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
281 static pmd_t *__init get_pmd_virt(phys_addr_t pa)
284 clear_fixmap(FIX_PMD);
285 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
287 return (pmd_t *)((uintptr_t)pa);
291 static phys_addr_t __init alloc_pmd(uintptr_t va)
296 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
298 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
299 BUG_ON(pmd_num >= NUM_EARLY_PMDS);
300 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
303 static void __init create_pmd_mapping(pmd_t *pmdp,
304 uintptr_t va, phys_addr_t pa,
305 phys_addr_t sz, pgprot_t prot)
308 phys_addr_t pte_phys;
309 uintptr_t pmd_idx = pmd_index(va);
311 if (sz == PMD_SIZE) {
312 if (pmd_none(pmdp[pmd_idx]))
313 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
317 if (pmd_none(pmdp[pmd_idx])) {
318 pte_phys = alloc_pte(va);
319 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
320 ptep = get_pte_virt(pte_phys);
321 memset(ptep, 0, PAGE_SIZE);
323 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
324 ptep = get_pte_virt(pte_phys);
327 create_pte_mapping(ptep, va, pa, sz, prot);
330 #define pgd_next_t pmd_t
331 #define alloc_pgd_next(__va) alloc_pmd(__va)
332 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa)
333 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
334 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
335 #define fixmap_pgd_next fixmap_pmd
337 #define pgd_next_t pte_t
338 #define alloc_pgd_next(__va) alloc_pte(__va)
339 #define get_pgd_next_virt(__pa) get_pte_virt(__pa)
340 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
341 create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
342 #define fixmap_pgd_next fixmap_pte
345 static void __init create_pgd_mapping(pgd_t *pgdp,
346 uintptr_t va, phys_addr_t pa,
347 phys_addr_t sz, pgprot_t prot)
350 phys_addr_t next_phys;
351 uintptr_t pgd_idx = pgd_index(va);
353 if (sz == PGDIR_SIZE) {
354 if (pgd_val(pgdp[pgd_idx]) == 0)
355 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
359 if (pgd_val(pgdp[pgd_idx]) == 0) {
360 next_phys = alloc_pgd_next(va);
361 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
362 nextp = get_pgd_next_virt(next_phys);
363 memset(nextp, 0, PAGE_SIZE);
365 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
366 nextp = get_pgd_next_virt(next_phys);
369 create_pgd_next_mapping(nextp, va, pa, sz, prot);
372 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
374 /* Upgrade to PMD_SIZE mappings whenever possible */
375 if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
382 * setup_vm() is called from head.S with MMU-off.
384 * Following requirements should be honoured for setup_vm() to work
386 * 1) It should use PC-relative addressing for accessing kernel symbols.
387 * To achieve this we always use GCC cmodel=medany.
388 * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
389 * so disable compiler instrumentation when FTRACE is enabled.
391 * Currently, the above requirements are honoured by using custom CFLAGS
392 * for init.o in mm/Makefile.
395 #ifndef __riscv_cmodel_medany
396 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
399 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
401 uintptr_t va, end_va;
402 uintptr_t load_pa = (uintptr_t)(&_start);
403 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
404 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
406 va_pa_offset = PAGE_OFFSET - load_pa;
407 pfn_base = PFN_DOWN(load_pa);
410 * Enforce boot alignment requirements of RV32 and
411 * RV64 by only allowing PMD or PGD mappings.
413 BUG_ON(map_size == PAGE_SIZE);
415 /* Sanity check alignment and size */
416 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
417 BUG_ON((load_pa % map_size) != 0);
418 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
420 /* Setup early PGD for fixmap */
421 create_pgd_mapping(early_pg_dir, FIXADDR_START,
422 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
424 #ifndef __PAGETABLE_PMD_FOLDED
425 /* Setup fixmap PMD */
426 create_pmd_mapping(fixmap_pmd, FIXADDR_START,
427 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
428 /* Setup trampoline PGD and PMD */
429 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
430 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
431 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
432 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
434 /* Setup trampoline PGD */
435 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
436 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
440 * Setup early PGD covering entire kernel which will allows
441 * us to reach paging_init(). We map all memory banks later
442 * in setup_vm_final() below.
444 end_va = PAGE_OFFSET + load_sz;
445 for (va = PAGE_OFFSET; va < end_va; va += map_size)
446 create_pgd_mapping(early_pg_dir, va,
447 load_pa + (va - PAGE_OFFSET),
448 map_size, PAGE_KERNEL_EXEC);
450 /* Create fixed mapping for early FDT parsing */
451 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
452 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
453 create_pte_mapping(fixmap_pte, va,
454 dtb_pa + (va - __fix_to_virt(FIX_FDT)),
455 PAGE_SIZE, PAGE_KERNEL);
457 /* Save pointer to DTB for early FDT parsing */
458 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
459 /* Save physical address for memblock reservation */
460 dtb_early_pa = dtb_pa;
463 static void __init setup_vm_final(void)
465 uintptr_t va, map_size;
466 phys_addr_t pa, start, end;
467 struct memblock_region *reg;
469 /* Set mmu_enabled flag */
472 /* Setup swapper PGD for fixmap */
473 create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
474 __pa_symbol(fixmap_pgd_next),
475 PGDIR_SIZE, PAGE_TABLE);
477 /* Map all memory banks */
478 for_each_memblock(memory, reg) {
480 end = start + reg->size;
484 if (memblock_is_nomap(reg))
486 if (start <= __pa(PAGE_OFFSET) &&
487 __pa(PAGE_OFFSET) < end)
488 start = __pa(PAGE_OFFSET);
490 map_size = best_map_size(start, end - start);
491 for (pa = start; pa < end; pa += map_size) {
492 va = (uintptr_t)__va(pa);
493 create_pgd_mapping(swapper_pg_dir, va, pa,
494 map_size, PAGE_KERNEL_EXEC);
498 /* Clear fixmap PTE and PMD mappings */
499 clear_fixmap(FIX_PTE);
500 clear_fixmap(FIX_PMD);
502 /* Move to swapper page table */
503 csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
504 local_flush_tlb_all();
507 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
509 #ifdef CONFIG_BUILTIN_DTB
510 dtb_early_va = soc_lookup_builtin_dtb();
512 /* Fallback to first available DTS */
513 dtb_early_va = (void *) __dtb_start;
516 dtb_early_va = (void *)dtb_pa;
518 dtb_early_pa = dtb_pa;
521 static inline void setup_vm_final(void)
524 #endif /* CONFIG_MMU */
526 #ifdef CONFIG_STRICT_KERNEL_RWX
527 void mark_rodata_ro(void)
529 unsigned long text_start = (unsigned long)_text;
530 unsigned long text_end = (unsigned long)_etext;
531 unsigned long rodata_start = (unsigned long)__start_rodata;
532 unsigned long data_start = (unsigned long)_data;
533 unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
535 set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
536 set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
537 set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
538 set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
544 static void __init resource_init(void)
546 struct memblock_region *region;
548 for_each_memblock(memory, region) {
549 struct resource *res;
551 res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
553 panic("%s: Failed to allocate %zu bytes\n", __func__,
554 sizeof(struct resource));
556 if (memblock_is_nomap(region)) {
557 res->name = "reserved";
558 res->flags = IORESOURCE_MEM;
560 res->name = "System RAM";
561 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
563 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
564 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
566 request_resource(&iomem_resource, res);
570 void __init paging_init(void)
579 #ifdef CONFIG_SPARSEMEM_VMEMMAP
580 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
581 struct vmem_altmap *altmap)
583 return vmemmap_populate_basepages(start, end, node, NULL);