xref: /openbmc/linux/arch/riscv/mm/init.c (revision 9009b455811b0fa1f6b0adfa94db136984db5a38)
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 #include <linux/dma-map-ops.h>
17 
18 #include <asm/fixmap.h>
19 #include <asm/tlbflush.h>
20 #include <asm/sections.h>
21 #include <asm/soc.h>
22 #include <asm/io.h>
23 #include <asm/ptdump.h>
24 #include <asm/numa.h>
25 
26 #include "../kernel/head.h"
27 
28 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
29 							__page_aligned_bss;
30 EXPORT_SYMBOL(empty_zero_page);
31 
32 extern char _start[];
33 #define DTB_EARLY_BASE_VA      PGDIR_SIZE
34 void *dtb_early_va __initdata;
35 uintptr_t dtb_early_pa __initdata;
36 
37 struct pt_alloc_ops {
38 	pte_t *(*get_pte_virt)(phys_addr_t pa);
39 	phys_addr_t (*alloc_pte)(uintptr_t va);
40 #ifndef __PAGETABLE_PMD_FOLDED
41 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
42 	phys_addr_t (*alloc_pmd)(uintptr_t va);
43 #endif
44 };
45 
46 static phys_addr_t dma32_phys_limit __ro_after_init;
47 
48 static void __init zone_sizes_init(void)
49 {
50 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
51 
52 #ifdef CONFIG_ZONE_DMA32
53 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
54 #endif
55 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
56 
57 	free_area_init(max_zone_pfns);
58 }
59 
60 static void setup_zero_page(void)
61 {
62 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
63 }
64 
65 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
66 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
67 {
68 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
69 		  (((t) - (b)) >> 10));
70 }
71 
72 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
73 {
74 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
75 		  (((t) - (b)) >> 20));
76 }
77 
78 static void print_vm_layout(void)
79 {
80 	pr_notice("Virtual kernel memory layout:\n");
81 	print_mlk("fixmap", (unsigned long)FIXADDR_START,
82 		  (unsigned long)FIXADDR_TOP);
83 	print_mlm("pci io", (unsigned long)PCI_IO_START,
84 		  (unsigned long)PCI_IO_END);
85 	print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
86 		  (unsigned long)VMEMMAP_END);
87 	print_mlm("vmalloc", (unsigned long)VMALLOC_START,
88 		  (unsigned long)VMALLOC_END);
89 	print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
90 		  (unsigned long)high_memory);
91 }
92 #else
93 static void print_vm_layout(void) { }
94 #endif /* CONFIG_DEBUG_VM */
95 
96 void __init mem_init(void)
97 {
98 #ifdef CONFIG_FLATMEM
99 	BUG_ON(!mem_map);
100 #endif /* CONFIG_FLATMEM */
101 
102 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
103 	memblock_free_all();
104 
105 	print_vm_layout();
106 }
107 
108 void __init setup_bootmem(void)
109 {
110 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
111 	phys_addr_t vmlinux_start = __pa_symbol(&_start);
112 	phys_addr_t dram_end = memblock_end_of_DRAM();
113 	phys_addr_t max_mapped_addr = __pa(~(ulong)0);
114 
115 	/* The maximal physical memory size is -PAGE_OFFSET. */
116 	memblock_enforce_memory_limit(-PAGE_OFFSET);
117 
118 	/* Reserve from the start of the kernel to the end of the kernel */
119 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
120 
121 	/*
122 	 * memblock allocator is not aware of the fact that last 4K bytes of
123 	 * the addressable memory can not be mapped because of IS_ERR_VALUE
124 	 * macro. Make sure that last 4k bytes are not usable by memblock
125 	 * if end of dram is equal to maximum addressable memory.
126 	 */
127 	if (max_mapped_addr == (dram_end - 1))
128 		memblock_set_current_limit(max_mapped_addr - 4096);
129 
130 	max_pfn = PFN_DOWN(dram_end);
131 	max_low_pfn = max_pfn;
132 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
133 	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
134 
135 	reserve_initrd_mem();
136 	/*
137 	 * If DTB is built in, no need to reserve its memblock.
138 	 * Otherwise, do reserve it but avoid using
139 	 * early_init_fdt_reserve_self() since __pa() does
140 	 * not work for DTB pointers that are fixmap addresses
141 	 */
142 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
143 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
144 
145 	early_init_fdt_scan_reserved_mem();
146 	dma_contiguous_reserve(dma32_phys_limit);
147 	memblock_allow_resize();
148 }
149 
150 #ifdef CONFIG_MMU
151 static struct pt_alloc_ops pt_ops;
152 
153 unsigned long va_pa_offset;
154 EXPORT_SYMBOL(va_pa_offset);
155 unsigned long pfn_base;
156 EXPORT_SYMBOL(pfn_base);
157 
158 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
159 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
160 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
161 
162 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
163 
164 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
165 {
166 	unsigned long addr = __fix_to_virt(idx);
167 	pte_t *ptep;
168 
169 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
170 
171 	ptep = &fixmap_pte[pte_index(addr)];
172 
173 	if (pgprot_val(prot))
174 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
175 	else
176 		pte_clear(&init_mm, addr, ptep);
177 	local_flush_tlb_page(addr);
178 }
179 
180 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
181 {
182 	return (pte_t *)((uintptr_t)pa);
183 }
184 
185 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
186 {
187 	clear_fixmap(FIX_PTE);
188 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
189 }
190 
191 static inline pte_t *get_pte_virt_late(phys_addr_t pa)
192 {
193 	return (pte_t *) __va(pa);
194 }
195 
196 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
197 {
198 	/*
199 	 * We only create PMD or PGD early mappings so we
200 	 * should never reach here with MMU disabled.
201 	 */
202 	BUG();
203 }
204 
205 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
206 {
207 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
208 }
209 
210 static phys_addr_t alloc_pte_late(uintptr_t va)
211 {
212 	unsigned long vaddr;
213 
214 	vaddr = __get_free_page(GFP_KERNEL);
215 	if (!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)))
216 		BUG();
217 	return __pa(vaddr);
218 }
219 
220 static void __init create_pte_mapping(pte_t *ptep,
221 				      uintptr_t va, phys_addr_t pa,
222 				      phys_addr_t sz, pgprot_t prot)
223 {
224 	uintptr_t pte_idx = pte_index(va);
225 
226 	BUG_ON(sz != PAGE_SIZE);
227 
228 	if (pte_none(ptep[pte_idx]))
229 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
230 }
231 
232 #ifndef __PAGETABLE_PMD_FOLDED
233 
234 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
235 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
236 pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
237 pmd_t early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
238 
239 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
240 {
241 	/* Before MMU is enabled */
242 	return (pmd_t *)((uintptr_t)pa);
243 }
244 
245 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
246 {
247 	clear_fixmap(FIX_PMD);
248 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
249 }
250 
251 static pmd_t *get_pmd_virt_late(phys_addr_t pa)
252 {
253 	return (pmd_t *) __va(pa);
254 }
255 
256 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
257 {
258 	BUG_ON((va - PAGE_OFFSET) >> PGDIR_SHIFT);
259 
260 	return (uintptr_t)early_pmd;
261 }
262 
263 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
264 {
265 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
266 }
267 
268 static phys_addr_t alloc_pmd_late(uintptr_t va)
269 {
270 	unsigned long vaddr;
271 
272 	vaddr = __get_free_page(GFP_KERNEL);
273 	BUG_ON(!vaddr);
274 	return __pa(vaddr);
275 }
276 
277 static void __init create_pmd_mapping(pmd_t *pmdp,
278 				      uintptr_t va, phys_addr_t pa,
279 				      phys_addr_t sz, pgprot_t prot)
280 {
281 	pte_t *ptep;
282 	phys_addr_t pte_phys;
283 	uintptr_t pmd_idx = pmd_index(va);
284 
285 	if (sz == PMD_SIZE) {
286 		if (pmd_none(pmdp[pmd_idx]))
287 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
288 		return;
289 	}
290 
291 	if (pmd_none(pmdp[pmd_idx])) {
292 		pte_phys = pt_ops.alloc_pte(va);
293 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
294 		ptep = pt_ops.get_pte_virt(pte_phys);
295 		memset(ptep, 0, PAGE_SIZE);
296 	} else {
297 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
298 		ptep = pt_ops.get_pte_virt(pte_phys);
299 	}
300 
301 	create_pte_mapping(ptep, va, pa, sz, prot);
302 }
303 
304 #define pgd_next_t		pmd_t
305 #define alloc_pgd_next(__va)	pt_ops.alloc_pmd(__va)
306 #define get_pgd_next_virt(__pa)	pt_ops.get_pmd_virt(__pa)
307 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
308 	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
309 #define fixmap_pgd_next		fixmap_pmd
310 #else
311 #define pgd_next_t		pte_t
312 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
313 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
314 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
315 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
316 #define fixmap_pgd_next		fixmap_pte
317 #endif
318 
319 void __init create_pgd_mapping(pgd_t *pgdp,
320 				      uintptr_t va, phys_addr_t pa,
321 				      phys_addr_t sz, pgprot_t prot)
322 {
323 	pgd_next_t *nextp;
324 	phys_addr_t next_phys;
325 	uintptr_t pgd_idx = pgd_index(va);
326 
327 	if (sz == PGDIR_SIZE) {
328 		if (pgd_val(pgdp[pgd_idx]) == 0)
329 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
330 		return;
331 	}
332 
333 	if (pgd_val(pgdp[pgd_idx]) == 0) {
334 		next_phys = alloc_pgd_next(va);
335 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
336 		nextp = get_pgd_next_virt(next_phys);
337 		memset(nextp, 0, PAGE_SIZE);
338 	} else {
339 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
340 		nextp = get_pgd_next_virt(next_phys);
341 	}
342 
343 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
344 }
345 
346 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
347 {
348 	/* Upgrade to PMD_SIZE mappings whenever possible */
349 	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
350 		return PAGE_SIZE;
351 
352 	return PMD_SIZE;
353 }
354 
355 /*
356  * setup_vm() is called from head.S with MMU-off.
357  *
358  * Following requirements should be honoured for setup_vm() to work
359  * correctly:
360  * 1) It should use PC-relative addressing for accessing kernel symbols.
361  *    To achieve this we always use GCC cmodel=medany.
362  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
363  *    so disable compiler instrumentation when FTRACE is enabled.
364  *
365  * Currently, the above requirements are honoured by using custom CFLAGS
366  * for init.o in mm/Makefile.
367  */
368 
369 #ifndef __riscv_cmodel_medany
370 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
371 #endif
372 
373 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
374 {
375 	uintptr_t va, pa, end_va;
376 	uintptr_t load_pa = (uintptr_t)(&_start);
377 	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
378 	uintptr_t map_size;
379 #ifndef __PAGETABLE_PMD_FOLDED
380 	pmd_t fix_bmap_spmd, fix_bmap_epmd;
381 #endif
382 
383 	va_pa_offset = PAGE_OFFSET - load_pa;
384 	pfn_base = PFN_DOWN(load_pa);
385 
386 	/*
387 	 * Enforce boot alignment requirements of RV32 and
388 	 * RV64 by only allowing PMD or PGD mappings.
389 	 */
390 	map_size = PMD_SIZE;
391 
392 	/* Sanity check alignment and size */
393 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
394 	BUG_ON((load_pa % map_size) != 0);
395 
396 	pt_ops.alloc_pte = alloc_pte_early;
397 	pt_ops.get_pte_virt = get_pte_virt_early;
398 #ifndef __PAGETABLE_PMD_FOLDED
399 	pt_ops.alloc_pmd = alloc_pmd_early;
400 	pt_ops.get_pmd_virt = get_pmd_virt_early;
401 #endif
402 	/* Setup early PGD for fixmap */
403 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
404 			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
405 
406 #ifndef __PAGETABLE_PMD_FOLDED
407 	/* Setup fixmap PMD */
408 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
409 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
410 	/* Setup trampoline PGD and PMD */
411 	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
412 			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
413 	create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
414 			   load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
415 #else
416 	/* Setup trampoline PGD */
417 	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
418 			   load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
419 #endif
420 
421 	/*
422 	 * Setup early PGD covering entire kernel which will allows
423 	 * us to reach paging_init(). We map all memory banks later
424 	 * in setup_vm_final() below.
425 	 */
426 	end_va = PAGE_OFFSET + load_sz;
427 	for (va = PAGE_OFFSET; va < end_va; va += map_size)
428 		create_pgd_mapping(early_pg_dir, va,
429 				   load_pa + (va - PAGE_OFFSET),
430 				   map_size, PAGE_KERNEL_EXEC);
431 
432 #ifndef __PAGETABLE_PMD_FOLDED
433 	/* Setup early PMD for DTB */
434 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
435 			   (uintptr_t)early_dtb_pmd, PGDIR_SIZE, PAGE_TABLE);
436 #ifndef CONFIG_BUILTIN_DTB
437 	/* Create two consecutive PMD mappings for FDT early scan */
438 	pa = dtb_pa & ~(PMD_SIZE - 1);
439 	create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
440 			   pa, PMD_SIZE, PAGE_KERNEL);
441 	create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
442 			   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
443 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
444 #else /* CONFIG_BUILTIN_DTB */
445 	dtb_early_va = __va(dtb_pa);
446 #endif /* CONFIG_BUILTIN_DTB */
447 #else
448 #ifndef CONFIG_BUILTIN_DTB
449 	/* Create two consecutive PGD mappings for FDT early scan */
450 	pa = dtb_pa & ~(PGDIR_SIZE - 1);
451 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
452 			   pa, PGDIR_SIZE, PAGE_KERNEL);
453 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE,
454 			   pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
455 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
456 #else /* CONFIG_BUILTIN_DTB */
457 	dtb_early_va = __va(dtb_pa);
458 #endif /* CONFIG_BUILTIN_DTB */
459 #endif
460 	dtb_early_pa = dtb_pa;
461 
462 	/*
463 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
464 	 * range can not span multiple pmds.
465 	 */
466 	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
467 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
468 
469 #ifndef __PAGETABLE_PMD_FOLDED
470 	/*
471 	 * Early ioremap fixmap is already created as it lies within first 2MB
472 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
473 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
474 	 * the user if not.
475 	 */
476 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
477 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
478 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
479 		WARN_ON(1);
480 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
481 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
482 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
483 			fix_to_virt(FIX_BTMAP_BEGIN));
484 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
485 			fix_to_virt(FIX_BTMAP_END));
486 
487 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
488 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
489 	}
490 #endif
491 }
492 
493 static void __init setup_vm_final(void)
494 {
495 	uintptr_t va, map_size;
496 	phys_addr_t pa, start, end;
497 	u64 i;
498 
499 	/**
500 	 * MMU is enabled at this point. But page table setup is not complete yet.
501 	 * fixmap page table alloc functions should be used at this point
502 	 */
503 	pt_ops.alloc_pte = alloc_pte_fixmap;
504 	pt_ops.get_pte_virt = get_pte_virt_fixmap;
505 #ifndef __PAGETABLE_PMD_FOLDED
506 	pt_ops.alloc_pmd = alloc_pmd_fixmap;
507 	pt_ops.get_pmd_virt = get_pmd_virt_fixmap;
508 #endif
509 	/* Setup swapper PGD for fixmap */
510 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
511 			   __pa_symbol(fixmap_pgd_next),
512 			   PGDIR_SIZE, PAGE_TABLE);
513 
514 	/* Map all memory banks */
515 	for_each_mem_range(i, &start, &end) {
516 		if (start >= end)
517 			break;
518 		if (start <= __pa(PAGE_OFFSET) &&
519 		    __pa(PAGE_OFFSET) < end)
520 			start = __pa(PAGE_OFFSET);
521 
522 		map_size = best_map_size(start, end - start);
523 		for (pa = start; pa < end; pa += map_size) {
524 			va = (uintptr_t)__va(pa);
525 			create_pgd_mapping(swapper_pg_dir, va, pa,
526 					   map_size, PAGE_KERNEL_EXEC);
527 		}
528 	}
529 
530 	/* Clear fixmap PTE and PMD mappings */
531 	clear_fixmap(FIX_PTE);
532 	clear_fixmap(FIX_PMD);
533 
534 	/* Move to swapper page table */
535 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
536 	local_flush_tlb_all();
537 
538 	/* generic page allocation functions must be used to setup page table */
539 	pt_ops.alloc_pte = alloc_pte_late;
540 	pt_ops.get_pte_virt = get_pte_virt_late;
541 #ifndef __PAGETABLE_PMD_FOLDED
542 	pt_ops.alloc_pmd = alloc_pmd_late;
543 	pt_ops.get_pmd_virt = get_pmd_virt_late;
544 #endif
545 }
546 #else
547 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
548 {
549 	dtb_early_va = (void *)dtb_pa;
550 	dtb_early_pa = dtb_pa;
551 }
552 
553 static inline void setup_vm_final(void)
554 {
555 }
556 #endif /* CONFIG_MMU */
557 
558 #ifdef CONFIG_STRICT_KERNEL_RWX
559 void protect_kernel_text_data(void)
560 {
561 	unsigned long text_start = (unsigned long)_start;
562 	unsigned long init_text_start = (unsigned long)__init_text_begin;
563 	unsigned long init_data_start = (unsigned long)__init_data_begin;
564 	unsigned long rodata_start = (unsigned long)__start_rodata;
565 	unsigned long data_start = (unsigned long)_data;
566 	unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
567 
568 	set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT);
569 	set_memory_ro(init_text_start, (init_data_start - init_text_start) >> PAGE_SHIFT);
570 	set_memory_nx(init_data_start, (rodata_start - init_data_start) >> PAGE_SHIFT);
571 	/* rodata section is marked readonly in mark_rodata_ro */
572 	set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
573 	set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
574 }
575 
576 void mark_rodata_ro(void)
577 {
578 	unsigned long rodata_start = (unsigned long)__start_rodata;
579 	unsigned long data_start = (unsigned long)_data;
580 
581 	set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
582 
583 	debug_checkwx();
584 }
585 #endif
586 
587 void __init paging_init(void)
588 {
589 	setup_vm_final();
590 	setup_zero_page();
591 }
592 
593 void __init misc_mem_init(void)
594 {
595 	arch_numa_init();
596 	sparse_init();
597 	zone_sizes_init();
598 	memblock_dump_all();
599 }
600 
601 #ifdef CONFIG_SPARSEMEM_VMEMMAP
602 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
603 			       struct vmem_altmap *altmap)
604 {
605 	return vmemmap_populate_basepages(start, end, node, NULL);
606 }
607 #endif
608