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>
16 #include <asm/fixmap.h>
17 #include <asm/tlbflush.h>
18 #include <asm/sections.h>
19 #include <asm/pgtable.h>
22 #include "../kernel/head.h"
24 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
26 EXPORT_SYMBOL(empty_zero_page);
31 static void __init zone_sizes_init(void)
33 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
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)));
39 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
41 free_area_init_nodes(max_zone_pfns);
44 static void setup_zero_page(void)
46 memset((void *)empty_zero_page, 0, PAGE_SIZE);
49 void __init mem_init(void)
53 #endif /* CONFIG_FLATMEM */
55 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
58 mem_init_print_info(NULL);
61 #ifdef CONFIG_BLK_DEV_INITRD
62 static void __init setup_initrd(void)
66 if (initrd_start >= initrd_end) {
67 pr_info("initrd not found or empty");
70 if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
71 pr_err("initrd extends beyond end of memory");
75 size = initrd_end - initrd_start;
76 memblock_reserve(__pa(initrd_start), size);
77 initrd_below_start_ok = 1;
79 pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
80 (void *)(initrd_start), size);
83 pr_cont(" - disabling initrd\n");
87 #endif /* CONFIG_BLK_DEV_INITRD */
89 static phys_addr_t dtb_early_pa __initdata;
91 void __init setup_bootmem(void)
93 struct memblock_region *reg;
94 phys_addr_t mem_size = 0;
95 phys_addr_t vmlinux_end = __pa(&_end);
96 phys_addr_t vmlinux_start = __pa(&_start);
98 /* Find the memory region containing the kernel */
99 for_each_memblock(memory, reg) {
100 phys_addr_t end = reg->base + reg->size;
102 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
103 mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
106 * Remove memblock from the end of usable area to the
109 if (reg->base + mem_size < end)
110 memblock_remove(reg->base + mem_size,
111 end - reg->base - mem_size);
114 BUG_ON(mem_size == 0);
116 /* Reserve from the start of the kernel to the end of the kernel */
117 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
119 set_max_mapnr(PFN_DOWN(mem_size));
120 max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
122 #ifdef CONFIG_BLK_DEV_INITRD
124 #endif /* CONFIG_BLK_DEV_INITRD */
127 * Avoid using early_init_fdt_reserve_self() since __pa() does
128 * not work for DTB pointers that are fixmap addresses
130 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
132 early_init_fdt_scan_reserved_mem();
133 memblock_allow_resize();
136 for_each_memblock(memory, reg) {
137 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
138 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
140 memblock_set_node(PFN_PHYS(start_pfn),
141 PFN_PHYS(end_pfn - start_pfn),
142 &memblock.memory, 0);
147 unsigned long va_pa_offset;
148 EXPORT_SYMBOL(va_pa_offset);
149 unsigned long pfn_base;
150 EXPORT_SYMBOL(pfn_base);
152 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
153 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
154 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
155 static bool mmu_enabled;
157 #define MAX_EARLY_MAPPING_SIZE SZ_128M
159 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
161 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
163 unsigned long addr = __fix_to_virt(idx);
166 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
168 ptep = &fixmap_pte[pte_index(addr)];
170 if (pgprot_val(prot)) {
171 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
173 pte_clear(&init_mm, addr, ptep);
174 local_flush_tlb_page(addr);
178 static pte_t *__init get_pte_virt(phys_addr_t pa)
181 clear_fixmap(FIX_PTE);
182 return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
184 return (pte_t *)((uintptr_t)pa);
188 static phys_addr_t __init alloc_pte(uintptr_t va)
191 * We only create PMD or PGD early mappings so we
192 * should never reach here with MMU disabled.
194 BUG_ON(!mmu_enabled);
196 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
199 static void __init create_pte_mapping(pte_t *ptep,
200 uintptr_t va, phys_addr_t pa,
201 phys_addr_t sz, pgprot_t prot)
203 uintptr_t pte_index = pte_index(va);
205 BUG_ON(sz != PAGE_SIZE);
207 if (pte_none(ptep[pte_index]))
208 ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot);
211 #ifndef __PAGETABLE_PMD_FOLDED
213 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
214 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
216 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
217 #define NUM_EARLY_PMDS 1UL
219 #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
221 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
223 static pmd_t *__init get_pmd_virt(phys_addr_t pa)
226 clear_fixmap(FIX_PMD);
227 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
229 return (pmd_t *)((uintptr_t)pa);
233 static phys_addr_t __init alloc_pmd(uintptr_t va)
238 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
240 pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
241 BUG_ON(pmd_num >= NUM_EARLY_PMDS);
242 return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
245 static void __init create_pmd_mapping(pmd_t *pmdp,
246 uintptr_t va, phys_addr_t pa,
247 phys_addr_t sz, pgprot_t prot)
250 phys_addr_t pte_phys;
251 uintptr_t pmd_index = pmd_index(va);
253 if (sz == PMD_SIZE) {
254 if (pmd_none(pmdp[pmd_index]))
255 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot);
259 if (pmd_none(pmdp[pmd_index])) {
260 pte_phys = alloc_pte(va);
261 pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
262 ptep = get_pte_virt(pte_phys);
263 memset(ptep, 0, PAGE_SIZE);
265 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index]));
266 ptep = get_pte_virt(pte_phys);
269 create_pte_mapping(ptep, va, pa, sz, prot);
272 #define pgd_next_t pmd_t
273 #define alloc_pgd_next(__va) alloc_pmd(__va)
274 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa)
275 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
276 create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
277 #define fixmap_pgd_next fixmap_pmd
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 fixmap_pgd_next fixmap_pte
287 static void __init create_pgd_mapping(pgd_t *pgdp,
288 uintptr_t va, phys_addr_t pa,
289 phys_addr_t sz, pgprot_t prot)
292 phys_addr_t next_phys;
293 uintptr_t pgd_index = pgd_index(va);
295 if (sz == PGDIR_SIZE) {
296 if (pgd_val(pgdp[pgd_index]) == 0)
297 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot);
301 if (pgd_val(pgdp[pgd_index]) == 0) {
302 next_phys = alloc_pgd_next(va);
303 pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
304 nextp = get_pgd_next_virt(next_phys);
305 memset(nextp, 0, PAGE_SIZE);
307 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index]));
308 nextp = get_pgd_next_virt(next_phys);
311 create_pgd_next_mapping(nextp, va, pa, sz, prot);
314 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
316 /* Upgrade to PMD_SIZE mappings whenever possible */
317 if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
324 * setup_vm() is called from head.S with MMU-off.
326 * Following requirements should be honoured for setup_vm() to work
328 * 1) It should use PC-relative addressing for accessing kernel symbols.
329 * To achieve this we always use GCC cmodel=medany.
330 * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
331 * so disable compiler instrumentation when FTRACE is enabled.
333 * Currently, the above requirements are honoured by using custom CFLAGS
334 * for init.o in mm/Makefile.
337 #ifndef __riscv_cmodel_medany
338 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
341 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
343 uintptr_t va, end_va;
344 uintptr_t load_pa = (uintptr_t)(&_start);
345 uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
346 uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
348 va_pa_offset = PAGE_OFFSET - load_pa;
349 pfn_base = PFN_DOWN(load_pa);
352 * Enforce boot alignment requirements of RV32 and
353 * RV64 by only allowing PMD or PGD mappings.
355 BUG_ON(map_size == PAGE_SIZE);
357 /* Sanity check alignment and size */
358 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
359 BUG_ON((load_pa % map_size) != 0);
360 BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
362 /* Setup early PGD for fixmap */
363 create_pgd_mapping(early_pg_dir, FIXADDR_START,
364 (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
366 #ifndef __PAGETABLE_PMD_FOLDED
367 /* Setup fixmap PMD */
368 create_pmd_mapping(fixmap_pmd, FIXADDR_START,
369 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
370 /* Setup trampoline PGD and PMD */
371 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
372 (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
373 create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
374 load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
376 /* Setup trampoline PGD */
377 create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
378 load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
382 * Setup early PGD covering entire kernel which will allows
383 * us to reach paging_init(). We map all memory banks later
384 * in setup_vm_final() below.
386 end_va = PAGE_OFFSET + load_sz;
387 for (va = PAGE_OFFSET; va < end_va; va += map_size)
388 create_pgd_mapping(early_pg_dir, va,
389 load_pa + (va - PAGE_OFFSET),
390 map_size, PAGE_KERNEL_EXEC);
392 /* Create fixed mapping for early FDT parsing */
393 end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
394 for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
395 create_pte_mapping(fixmap_pte, va,
396 dtb_pa + (va - __fix_to_virt(FIX_FDT)),
397 PAGE_SIZE, PAGE_KERNEL);
399 /* Save pointer to DTB for early FDT parsing */
400 dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
401 /* Save physical address for memblock reservation */
402 dtb_early_pa = dtb_pa;
405 static void __init setup_vm_final(void)
407 uintptr_t va, map_size;
408 phys_addr_t pa, start, end;
409 struct memblock_region *reg;
411 /* Set mmu_enabled flag */
414 /* Setup swapper PGD for fixmap */
415 create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
416 __pa(fixmap_pgd_next),
417 PGDIR_SIZE, PAGE_TABLE);
419 /* Map all memory banks */
420 for_each_memblock(memory, reg) {
422 end = start + reg->size;
426 if (memblock_is_nomap(reg))
428 if (start <= __pa(PAGE_OFFSET) &&
429 __pa(PAGE_OFFSET) < end)
430 start = __pa(PAGE_OFFSET);
432 map_size = best_map_size(start, end - start);
433 for (pa = start; pa < end; pa += map_size) {
434 va = (uintptr_t)__va(pa);
435 create_pgd_mapping(swapper_pg_dir, va, pa,
436 map_size, PAGE_KERNEL_EXEC);
440 /* Clear fixmap PTE and PMD mappings */
441 clear_fixmap(FIX_PTE);
442 clear_fixmap(FIX_PMD);
444 /* Move to swapper page table */
445 csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | SATP_MODE);
446 local_flush_tlb_all();
449 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
451 dtb_early_va = (void *)dtb_pa;
454 static inline void setup_vm_final(void)
457 #endif /* CONFIG_MMU */
459 void __init paging_init(void)
468 #ifdef CONFIG_SPARSEMEM_VMEMMAP
469 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
470 struct vmem_altmap *altmap)
472 return vmemmap_populate_basepages(start, end, node);