xref: /linux/arch/riscv/mm/init.c (revision b91540d52a08b65eb6a2b09132e1bd54fa82754c)
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 #include <linux/set_memory.h>
16 
17 #include <asm/fixmap.h>
18 #include <asm/tlbflush.h>
19 #include <asm/sections.h>
20 #include <asm/soc.h>
21 #include <asm/io.h>
22 #include <asm/ptdump.h>
23 
24 #include "../kernel/head.h"
25 
26 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
27 							__page_aligned_bss;
28 EXPORT_SYMBOL(empty_zero_page);
29 
30 extern char _start[];
31 #define DTB_EARLY_BASE_VA      PGDIR_SIZE
32 void *dtb_early_va __initdata;
33 uintptr_t dtb_early_pa __initdata;
34 
35 struct pt_alloc_ops {
36 	pte_t *(*get_pte_virt)(phys_addr_t pa);
37 	phys_addr_t (*alloc_pte)(uintptr_t va);
38 #ifndef __PAGETABLE_PMD_FOLDED
39 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
40 	phys_addr_t (*alloc_pmd)(uintptr_t va);
41 #endif
42 };
43 
44 static void __init zone_sizes_init(void)
45 {
46 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
47 
48 #ifdef CONFIG_ZONE_DMA32
49 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
50 			(unsigned long) PFN_PHYS(max_low_pfn)));
51 #endif
52 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
53 
54 	free_area_init(max_zone_pfns);
55 }
56 
57 static void setup_zero_page(void)
58 {
59 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
60 }
61 
62 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
63 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
64 {
65 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
66 		  (((t) - (b)) >> 10));
67 }
68 
69 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
70 {
71 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
72 		  (((t) - (b)) >> 20));
73 }
74 
75 static void print_vm_layout(void)
76 {
77 	pr_notice("Virtual kernel memory layout:\n");
78 	print_mlk("fixmap", (unsigned long)FIXADDR_START,
79 		  (unsigned long)FIXADDR_TOP);
80 	print_mlm("pci io", (unsigned long)PCI_IO_START,
81 		  (unsigned long)PCI_IO_END);
82 	print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
83 		  (unsigned long)VMEMMAP_END);
84 	print_mlm("vmalloc", (unsigned long)VMALLOC_START,
85 		  (unsigned long)VMALLOC_END);
86 	print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
87 		  (unsigned long)high_memory);
88 }
89 #else
90 static void print_vm_layout(void) { }
91 #endif /* CONFIG_DEBUG_VM */
92 
93 void __init mem_init(void)
94 {
95 #ifdef CONFIG_FLATMEM
96 	BUG_ON(!mem_map);
97 #endif /* CONFIG_FLATMEM */
98 
99 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
100 	memblock_free_all();
101 
102 	mem_init_print_info(NULL);
103 	print_vm_layout();
104 }
105 
106 #ifdef CONFIG_BLK_DEV_INITRD
107 static void __init setup_initrd(void)
108 {
109 	phys_addr_t start;
110 	unsigned long size;
111 
112 	/* Ignore the virtul address computed during device tree parsing */
113 	initrd_start = initrd_end = 0;
114 
115 	if (!phys_initrd_size)
116 		return;
117 	/*
118 	 * Round the memory region to page boundaries as per free_initrd_mem()
119 	 * This allows us to detect whether the pages overlapping the initrd
120 	 * are in use, but more importantly, reserves the entire set of pages
121 	 * as we don't want these pages allocated for other purposes.
122 	 */
123 	start = round_down(phys_initrd_start, PAGE_SIZE);
124 	size = phys_initrd_size + (phys_initrd_start - start);
125 	size = round_up(size, PAGE_SIZE);
126 
127 	if (!memblock_is_region_memory(start, size)) {
128 		pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
129 		       (u64)start, size);
130 		goto disable;
131 	}
132 
133 	if (memblock_is_region_reserved(start, size)) {
134 		pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
135 		       (u64)start, size);
136 		goto disable;
137 	}
138 
139 	memblock_reserve(start, size);
140 	/* Now convert initrd to virtual addresses */
141 	initrd_start = (unsigned long)__va(phys_initrd_start);
142 	initrd_end = initrd_start + phys_initrd_size;
143 	initrd_below_start_ok = 1;
144 
145 	pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
146 		(void *)(initrd_start), size);
147 	return;
148 disable:
149 	pr_cont(" - disabling initrd\n");
150 	initrd_start = 0;
151 	initrd_end = 0;
152 }
153 #endif /* CONFIG_BLK_DEV_INITRD */
154 
155 void __init setup_bootmem(void)
156 {
157 	struct memblock_region *reg;
158 	phys_addr_t mem_size = 0;
159 	phys_addr_t total_mem = 0;
160 	phys_addr_t mem_start, end = 0;
161 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
162 	phys_addr_t vmlinux_start = __pa_symbol(&_start);
163 
164 	/* Find the memory region containing the kernel */
165 	for_each_memblock(memory, reg) {
166 		end = reg->base + reg->size;
167 		if (!total_mem)
168 			mem_start = reg->base;
169 		if (reg->base <= vmlinux_start && vmlinux_end <= end)
170 			BUG_ON(reg->size == 0);
171 		total_mem = total_mem + reg->size;
172 	}
173 
174 	/*
175 	 * Remove memblock from the end of usable area to the
176 	 * end of region
177 	 */
178 	mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET);
179 	if (mem_start + mem_size < end)
180 		memblock_remove(mem_start + mem_size,
181 				end - mem_start - mem_size);
182 
183 	/* Reserve from the start of the kernel to the end of the kernel */
184 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
185 
186 	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
187 	max_low_pfn = max_pfn;
188 	set_max_mapnr(max_low_pfn);
189 
190 #ifdef CONFIG_BLK_DEV_INITRD
191 	setup_initrd();
192 #endif /* CONFIG_BLK_DEV_INITRD */
193 
194 	/*
195 	 * Avoid using early_init_fdt_reserve_self() since __pa() does
196 	 * not work for DTB pointers that are fixmap addresses
197 	 */
198 	memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
199 
200 	early_init_fdt_scan_reserved_mem();
201 	memblock_allow_resize();
202 	memblock_dump_all();
203 
204 	for_each_memblock(memory, reg) {
205 		unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
206 		unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
207 
208 		memblock_set_node(PFN_PHYS(start_pfn),
209 				  PFN_PHYS(end_pfn - start_pfn),
210 				  &memblock.memory, 0);
211 	}
212 }
213 
214 #ifdef CONFIG_MMU
215 static struct pt_alloc_ops pt_ops;
216 
217 unsigned long va_pa_offset;
218 EXPORT_SYMBOL(va_pa_offset);
219 unsigned long pfn_base;
220 EXPORT_SYMBOL(pfn_base);
221 
222 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
223 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
224 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
225 
226 #define MAX_EARLY_MAPPING_SIZE	SZ_128M
227 
228 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
229 
230 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
231 {
232 	unsigned long addr = __fix_to_virt(idx);
233 	pte_t *ptep;
234 
235 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
236 
237 	ptep = &fixmap_pte[pte_index(addr)];
238 
239 	if (pgprot_val(prot)) {
240 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
241 	} else {
242 		pte_clear(&init_mm, addr, ptep);
243 		local_flush_tlb_page(addr);
244 	}
245 }
246 
247 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
248 {
249 	return (pte_t *)((uintptr_t)pa);
250 }
251 
252 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
253 {
254 	clear_fixmap(FIX_PTE);
255 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
256 }
257 
258 static inline pte_t *get_pte_virt_late(phys_addr_t pa)
259 {
260 	return (pte_t *) __va(pa);
261 }
262 
263 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
264 {
265 	/*
266 	 * We only create PMD or PGD early mappings so we
267 	 * should never reach here with MMU disabled.
268 	 */
269 	BUG();
270 }
271 
272 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
273 {
274 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
275 }
276 
277 static phys_addr_t alloc_pte_late(uintptr_t va)
278 {
279 	unsigned long vaddr;
280 
281 	vaddr = __get_free_page(GFP_KERNEL);
282 	if (!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)))
283 		BUG();
284 	return __pa(vaddr);
285 }
286 
287 static void __init create_pte_mapping(pte_t *ptep,
288 				      uintptr_t va, phys_addr_t pa,
289 				      phys_addr_t sz, pgprot_t prot)
290 {
291 	uintptr_t pte_idx = pte_index(va);
292 
293 	BUG_ON(sz != PAGE_SIZE);
294 
295 	if (pte_none(ptep[pte_idx]))
296 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
297 }
298 
299 #ifndef __PAGETABLE_PMD_FOLDED
300 
301 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
302 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
303 
304 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
305 #define NUM_EARLY_PMDS		1UL
306 #else
307 #define NUM_EARLY_PMDS		(1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
308 #endif
309 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
310 
311 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
312 {
313 	/* Before MMU is enabled */
314 	return (pmd_t *)((uintptr_t)pa);
315 }
316 
317 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
318 {
319 	clear_fixmap(FIX_PMD);
320 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
321 }
322 
323 static pmd_t *get_pmd_virt_late(phys_addr_t pa)
324 {
325 	return (pmd_t *) __va(pa);
326 }
327 
328 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
329 {
330 	uintptr_t pmd_num;
331 
332 	pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
333 	BUG_ON(pmd_num >= NUM_EARLY_PMDS);
334 	return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
335 }
336 
337 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
338 {
339 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
340 }
341 
342 static phys_addr_t alloc_pmd_late(uintptr_t va)
343 {
344 	unsigned long vaddr;
345 
346 	vaddr = __get_free_page(GFP_KERNEL);
347 	BUG_ON(!vaddr);
348 	return __pa(vaddr);
349 }
350 
351 static void __init create_pmd_mapping(pmd_t *pmdp,
352 				      uintptr_t va, phys_addr_t pa,
353 				      phys_addr_t sz, pgprot_t prot)
354 {
355 	pte_t *ptep;
356 	phys_addr_t pte_phys;
357 	uintptr_t pmd_idx = pmd_index(va);
358 
359 	if (sz == PMD_SIZE) {
360 		if (pmd_none(pmdp[pmd_idx]))
361 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
362 		return;
363 	}
364 
365 	if (pmd_none(pmdp[pmd_idx])) {
366 		pte_phys = pt_ops.alloc_pte(va);
367 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
368 		ptep = pt_ops.get_pte_virt(pte_phys);
369 		memset(ptep, 0, PAGE_SIZE);
370 	} else {
371 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
372 		ptep = pt_ops.get_pte_virt(pte_phys);
373 	}
374 
375 	create_pte_mapping(ptep, va, pa, sz, prot);
376 }
377 
378 #define pgd_next_t		pmd_t
379 #define alloc_pgd_next(__va)	pt_ops.alloc_pmd(__va)
380 #define get_pgd_next_virt(__pa)	pt_ops.get_pmd_virt(__pa)
381 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
382 	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
383 #define fixmap_pgd_next		fixmap_pmd
384 #else
385 #define pgd_next_t		pte_t
386 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
387 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
388 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
389 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
390 #define fixmap_pgd_next		fixmap_pte
391 #endif
392 
393 void __init create_pgd_mapping(pgd_t *pgdp,
394 				      uintptr_t va, phys_addr_t pa,
395 				      phys_addr_t sz, pgprot_t prot)
396 {
397 	pgd_next_t *nextp;
398 	phys_addr_t next_phys;
399 	uintptr_t pgd_idx = pgd_index(va);
400 
401 	if (sz == PGDIR_SIZE) {
402 		if (pgd_val(pgdp[pgd_idx]) == 0)
403 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
404 		return;
405 	}
406 
407 	if (pgd_val(pgdp[pgd_idx]) == 0) {
408 		next_phys = alloc_pgd_next(va);
409 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
410 		nextp = get_pgd_next_virt(next_phys);
411 		memset(nextp, 0, PAGE_SIZE);
412 	} else {
413 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
414 		nextp = get_pgd_next_virt(next_phys);
415 	}
416 
417 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
418 }
419 
420 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
421 {
422 	/* Upgrade to PMD_SIZE mappings whenever possible */
423 	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
424 		return PAGE_SIZE;
425 
426 	return PMD_SIZE;
427 }
428 
429 /*
430  * setup_vm() is called from head.S with MMU-off.
431  *
432  * Following requirements should be honoured for setup_vm() to work
433  * correctly:
434  * 1) It should use PC-relative addressing for accessing kernel symbols.
435  *    To achieve this we always use GCC cmodel=medany.
436  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
437  *    so disable compiler instrumentation when FTRACE is enabled.
438  *
439  * Currently, the above requirements are honoured by using custom CFLAGS
440  * for init.o in mm/Makefile.
441  */
442 
443 #ifndef __riscv_cmodel_medany
444 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
445 #endif
446 
447 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
448 {
449 	uintptr_t va, pa, end_va;
450 	uintptr_t load_pa = (uintptr_t)(&_start);
451 	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
452 	uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
453 #ifndef __PAGETABLE_PMD_FOLDED
454 	pmd_t fix_bmap_spmd, fix_bmap_epmd;
455 #endif
456 
457 	va_pa_offset = PAGE_OFFSET - load_pa;
458 	pfn_base = PFN_DOWN(load_pa);
459 
460 	/*
461 	 * Enforce boot alignment requirements of RV32 and
462 	 * RV64 by only allowing PMD or PGD mappings.
463 	 */
464 	BUG_ON(map_size == PAGE_SIZE);
465 
466 	/* Sanity check alignment and size */
467 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
468 	BUG_ON((load_pa % map_size) != 0);
469 	BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
470 
471 	pt_ops.alloc_pte = alloc_pte_early;
472 	pt_ops.get_pte_virt = get_pte_virt_early;
473 #ifndef __PAGETABLE_PMD_FOLDED
474 	pt_ops.alloc_pmd = alloc_pmd_early;
475 	pt_ops.get_pmd_virt = get_pmd_virt_early;
476 #endif
477 	/* Setup early PGD for fixmap */
478 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
479 			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
480 
481 #ifndef __PAGETABLE_PMD_FOLDED
482 	/* Setup fixmap PMD */
483 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
484 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
485 	/* Setup trampoline PGD and PMD */
486 	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
487 			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
488 	create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
489 			   load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
490 #else
491 	/* Setup trampoline PGD */
492 	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
493 			   load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
494 #endif
495 
496 	/*
497 	 * Setup early PGD covering entire kernel which will allows
498 	 * us to reach paging_init(). We map all memory banks later
499 	 * in setup_vm_final() below.
500 	 */
501 	end_va = PAGE_OFFSET + load_sz;
502 	for (va = PAGE_OFFSET; va < end_va; va += map_size)
503 		create_pgd_mapping(early_pg_dir, va,
504 				   load_pa + (va - PAGE_OFFSET),
505 				   map_size, PAGE_KERNEL_EXEC);
506 
507 	/* Create two consecutive PGD mappings for FDT early scan */
508 	pa = dtb_pa & ~(PGDIR_SIZE - 1);
509 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
510 			   pa, PGDIR_SIZE, PAGE_KERNEL);
511 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE,
512 			   pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
513 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
514 	dtb_early_pa = dtb_pa;
515 
516 	/*
517 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
518 	 * range can not span multiple pmds.
519 	 */
520 	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
521 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
522 
523 #ifndef __PAGETABLE_PMD_FOLDED
524 	/*
525 	 * Early ioremap fixmap is already created as it lies within first 2MB
526 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
527 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
528 	 * the user if not.
529 	 */
530 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
531 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
532 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
533 		WARN_ON(1);
534 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
535 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
536 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
537 			fix_to_virt(FIX_BTMAP_BEGIN));
538 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
539 			fix_to_virt(FIX_BTMAP_END));
540 
541 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
542 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
543 	}
544 #endif
545 }
546 
547 static void __init setup_vm_final(void)
548 {
549 	uintptr_t va, map_size;
550 	phys_addr_t pa, start, end;
551 	struct memblock_region *reg;
552 
553 	/**
554 	 * MMU is enabled at this point. But page table setup is not complete yet.
555 	 * fixmap page table alloc functions should be used at this point
556 	 */
557 	pt_ops.alloc_pte = alloc_pte_fixmap;
558 	pt_ops.get_pte_virt = get_pte_virt_fixmap;
559 #ifndef __PAGETABLE_PMD_FOLDED
560 	pt_ops.alloc_pmd = alloc_pmd_fixmap;
561 	pt_ops.get_pmd_virt = get_pmd_virt_fixmap;
562 #endif
563 	/* Setup swapper PGD for fixmap */
564 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
565 			   __pa_symbol(fixmap_pgd_next),
566 			   PGDIR_SIZE, PAGE_TABLE);
567 
568 	/* Map all memory banks */
569 	for_each_memblock(memory, reg) {
570 		start = reg->base;
571 		end = start + reg->size;
572 
573 		if (start >= end)
574 			break;
575 		if (memblock_is_nomap(reg))
576 			continue;
577 		if (start <= __pa(PAGE_OFFSET) &&
578 		    __pa(PAGE_OFFSET) < end)
579 			start = __pa(PAGE_OFFSET);
580 
581 		map_size = best_map_size(start, end - start);
582 		for (pa = start; pa < end; pa += map_size) {
583 			va = (uintptr_t)__va(pa);
584 			create_pgd_mapping(swapper_pg_dir, va, pa,
585 					   map_size, PAGE_KERNEL_EXEC);
586 		}
587 	}
588 
589 	/* Clear fixmap PTE and PMD mappings */
590 	clear_fixmap(FIX_PTE);
591 	clear_fixmap(FIX_PMD);
592 
593 	/* Move to swapper page table */
594 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
595 	local_flush_tlb_all();
596 
597 	/* generic page allocation functions must be used to setup page table */
598 	pt_ops.alloc_pte = alloc_pte_late;
599 	pt_ops.get_pte_virt = get_pte_virt_late;
600 #ifndef __PAGETABLE_PMD_FOLDED
601 	pt_ops.alloc_pmd = alloc_pmd_late;
602 	pt_ops.get_pmd_virt = get_pmd_virt_late;
603 #endif
604 }
605 #else
606 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
607 {
608 #ifdef CONFIG_BUILTIN_DTB
609 	dtb_early_va = soc_lookup_builtin_dtb();
610 	if (!dtb_early_va) {
611 		/* Fallback to first available DTS */
612 		dtb_early_va = (void *) __dtb_start;
613 	}
614 #else
615 	dtb_early_va = (void *)dtb_pa;
616 #endif
617 	dtb_early_pa = dtb_pa;
618 }
619 
620 static inline void setup_vm_final(void)
621 {
622 }
623 #endif /* CONFIG_MMU */
624 
625 #ifdef CONFIG_STRICT_KERNEL_RWX
626 void mark_rodata_ro(void)
627 {
628 	unsigned long text_start = (unsigned long)_text;
629 	unsigned long text_end = (unsigned long)_etext;
630 	unsigned long rodata_start = (unsigned long)__start_rodata;
631 	unsigned long data_start = (unsigned long)_data;
632 	unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
633 
634 	set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
635 	set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
636 	set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
637 	set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
638 
639 	debug_checkwx();
640 }
641 #endif
642 
643 static void __init resource_init(void)
644 {
645 	struct memblock_region *region;
646 
647 	for_each_memblock(memory, region) {
648 		struct resource *res;
649 
650 		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
651 		if (!res)
652 			panic("%s: Failed to allocate %zu bytes\n", __func__,
653 			      sizeof(struct resource));
654 
655 		if (memblock_is_nomap(region)) {
656 			res->name = "reserved";
657 			res->flags = IORESOURCE_MEM;
658 		} else {
659 			res->name = "System RAM";
660 			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
661 		}
662 		res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
663 		res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
664 
665 		request_resource(&iomem_resource, res);
666 	}
667 }
668 
669 void __init paging_init(void)
670 {
671 	setup_vm_final();
672 	sparse_init();
673 	setup_zero_page();
674 	zone_sizes_init();
675 	resource_init();
676 }
677 
678 #ifdef CONFIG_SPARSEMEM_VMEMMAP
679 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
680 			       struct vmem_altmap *altmap)
681 {
682 	return vmemmap_populate_basepages(start, end, node, NULL);
683 }
684 #endif
685