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();
197 unsigned long va_pa_offset;
198 EXPORT_SYMBOL(va_pa_offset);
199 unsigned long pfn_base;
200 EXPORT_SYMBOL(pfn_base);
202 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
203 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
204 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
205 static bool mmu_enabled;
207 #define MAX_EARLY_MAPPING_SIZE SZ_128M
209 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
211 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
213 unsigned long addr = __fix_to_virt(idx);
216 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
218 ptep = &fixmap_pte[pte_index(addr)];
220 if (pgprot_val(prot))
221 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
223 pte_clear(&init_mm, addr, ptep);
224 local_flush_tlb_page(addr);
227 static pte_t *__init get_pte_virt(phys_addr_t pa)
230 clear_fixmap(FIX_PTE);
231 return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
233 return (pte_t *)((uintptr_t)pa);
237 static phys_addr_t __init alloc_pte(uintptr_t va)
240 * We only create PMD or PGD early mappings so we
241 * should never reach here with MMU disabled.
243 BUG_ON(!mmu_enabled);
245 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
248 static void __init create_pte_mapping(pte_t *ptep,
249 uintptr_t va, phys_addr_t pa,
250 phys_addr_t sz, pgprot_t prot)
252 uintptr_t pte_idx = pte_index(va);
254 BUG_ON(sz != PAGE_SIZE);
256 if (pte_none(ptep[pte_idx]))
257 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
260 #ifndef __PAGETABLE_PMD_FOLDED
262 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
263 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
265 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
266 #define NUM_EARLY_PMDS 1UL
268 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
270 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
272 static pmd_t *__init get_pmd_virt(phys_addr_t pa)
275 clear_fixmap(FIX_PMD);
276 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
278 return (pmd_t *)((uintptr_t)pa);
282 static phys_addr_t __init alloc_pmd(uintptr_t va)
287 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
289 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
290 BUG_ON(pmd_num >= NUM_EARLY_PMDS);
291 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
294 static void __init create_pmd_mapping(pmd_t *pmdp,
295 uintptr_t va, phys_addr_t pa,
296 phys_addr_t sz, pgprot_t prot)
299 phys_addr_t pte_phys;
300 uintptr_t pmd_idx = pmd_index(va);
302 if (sz == PMD_SIZE) {
303 if (pmd_none(pmdp[pmd_idx]))
304 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
308 if (pmd_none(pmdp[pmd_idx])) {
309 pte_phys = alloc_pte(va);
310 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
311 ptep = get_pte_virt(pte_phys);
312 memset(ptep, 0, PAGE_SIZE);
314 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
315 ptep = get_pte_virt(pte_phys);
318 create_pte_mapping(ptep, va, pa, sz, prot);
321 #define pgd_next_t pmd_t
322 #define alloc_pgd_next(__va) alloc_pmd(__va)
323 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa)
324 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
325 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
326 #define fixmap_pgd_next fixmap_pmd
328 #define pgd_next_t pte_t
329 #define alloc_pgd_next(__va) alloc_pte(__va)
330 #define get_pgd_next_virt(__pa) get_pte_virt(__pa)
331 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
332 create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
333 #define fixmap_pgd_next fixmap_pte
336 static void __init create_pgd_mapping(pgd_t *pgdp,
337 uintptr_t va, phys_addr_t pa,
338 phys_addr_t sz, pgprot_t prot)
341 phys_addr_t next_phys;
342 uintptr_t pgd_idx = pgd_index(va);
344 if (sz == PGDIR_SIZE) {
345 if (pgd_val(pgdp[pgd_idx]) == 0)
346 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
350 if (pgd_val(pgdp[pgd_idx]) == 0) {
351 next_phys = alloc_pgd_next(va);
352 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
353 nextp = get_pgd_next_virt(next_phys);
354 memset(nextp, 0, PAGE_SIZE);
356 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
357 nextp = get_pgd_next_virt(next_phys);
360 create_pgd_next_mapping(nextp, va, pa, sz, prot);
363 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
365 /* Upgrade to PMD_SIZE mappings whenever possible */
366 if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
373 * setup_vm() is called from head.S with MMU-off.
375 * Following requirements should be honoured for setup_vm() to work
377 * 1) It should use PC-relative addressing for accessing kernel symbols.
378 * To achieve this we always use GCC cmodel=medany.
379 * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
380 * so disable compiler instrumentation when FTRACE is enabled.
382 * Currently, the above requirements are honoured by using custom CFLAGS
383 * for init.o in mm/Makefile.
386 #ifndef __riscv_cmodel_medany
387 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
390 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
392 uintptr_t va, end_va;
393 uintptr_t load_pa = (uintptr_t)(&_start);
394 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
395 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
397 va_pa_offset = PAGE_OFFSET - load_pa;
398 pfn_base = PFN_DOWN(load_pa);
401 * Enforce boot alignment requirements of RV32 and
402 * RV64 by only allowing PMD or PGD mappings.
404 BUG_ON(map_size == PAGE_SIZE);
406 /* Sanity check alignment and size */
407 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
408 BUG_ON((load_pa % map_size) != 0);
409 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
411 /* Setup early PGD for fixmap */
412 create_pgd_mapping(early_pg_dir, FIXADDR_START,
413 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
415 #ifndef __PAGETABLE_PMD_FOLDED
416 /* Setup fixmap PMD */
417 create_pmd_mapping(fixmap_pmd, FIXADDR_START,
418 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
419 /* Setup trampoline PGD and PMD */
420 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
421 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
422 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
423 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
425 /* Setup trampoline PGD */
426 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
427 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
431 * Setup early PGD covering entire kernel which will allows
432 * us to reach paging_init(). We map all memory banks later
433 * in setup_vm_final() below.
435 end_va = PAGE_OFFSET + load_sz;
436 for (va = PAGE_OFFSET; va < end_va; va += map_size)
437 create_pgd_mapping(early_pg_dir, va,
438 load_pa + (va - PAGE_OFFSET),
439 map_size, PAGE_KERNEL_EXEC);
441 /* Create fixed mapping for early FDT parsing */
442 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
443 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
444 create_pte_mapping(fixmap_pte, va,
445 dtb_pa + (va - __fix_to_virt(FIX_FDT)),
446 PAGE_SIZE, PAGE_KERNEL);
448 /* Save pointer to DTB for early FDT parsing */
449 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
450 /* Save physical address for memblock reservation */
451 dtb_early_pa = dtb_pa;
454 static void __init setup_vm_final(void)
456 uintptr_t va, map_size;
457 phys_addr_t pa, start, end;
458 struct memblock_region *reg;
460 /* Set mmu_enabled flag */
463 /* Setup swapper PGD for fixmap */
464 create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
465 __pa_symbol(fixmap_pgd_next),
466 PGDIR_SIZE, PAGE_TABLE);
468 /* Map all memory banks */
469 for_each_memblock(memory, reg) {
471 end = start + reg->size;
475 if (memblock_is_nomap(reg))
477 if (start <= __pa(PAGE_OFFSET) &&
478 __pa(PAGE_OFFSET) < end)
479 start = __pa(PAGE_OFFSET);
481 map_size = best_map_size(start, end - start);
482 for (pa = start; pa < end; pa += map_size) {
483 va = (uintptr_t)__va(pa);
484 create_pgd_mapping(swapper_pg_dir, va, pa,
485 map_size, PAGE_KERNEL_EXEC);
489 /* Clear fixmap PTE and PMD mappings */
490 clear_fixmap(FIX_PTE);
491 clear_fixmap(FIX_PMD);
493 /* Move to swapper page table */
494 csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
495 local_flush_tlb_all();
498 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
500 #ifdef CONFIG_BUILTIN_DTB
501 dtb_early_va = soc_lookup_builtin_dtb();
503 /* Fallback to first available DTS */
504 dtb_early_va = (void *) __dtb_start;
507 dtb_early_va = (void *)dtb_pa;
509 dtb_early_pa = dtb_pa;
512 static inline void setup_vm_final(void)
515 #endif /* CONFIG_MMU */
517 #ifdef CONFIG_STRICT_KERNEL_RWX
518 void mark_rodata_ro(void)
520 unsigned long text_start = (unsigned long)_text;
521 unsigned long text_end = (unsigned long)_etext;
522 unsigned long rodata_start = (unsigned long)__start_rodata;
523 unsigned long data_start = (unsigned long)_data;
524 unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
526 set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
527 set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
528 set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
529 set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
535 static void __init resource_init(void)
537 struct memblock_region *region;
539 for_each_memblock(memory, region) {
540 struct resource *res;
542 res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
544 panic("%s: Failed to allocate %zu bytes\n", __func__,
545 sizeof(struct resource));
547 if (memblock_is_nomap(region)) {
548 res->name = "reserved";
549 res->flags = IORESOURCE_MEM;
551 res->name = "System RAM";
552 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
554 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
555 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
557 request_resource(&iomem_resource, res);
561 void __init paging_init(void)
570 #ifdef CONFIG_SPARSEMEM_VMEMMAP
571 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
572 struct vmem_altmap *altmap)
574 return vmemmap_populate_basepages(start, end, node, NULL);