xref: /openbmc/linux/arch/riscv/mm/init.c (revision 0bf49ffb)
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 	mem_init_print_info(NULL);
106 	print_vm_layout();
107 }
108 
109 void __init setup_bootmem(void)
110 {
111 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
112 	phys_addr_t vmlinux_start = __pa_symbol(&_start);
113 	phys_addr_t dram_end = memblock_end_of_DRAM();
114 	phys_addr_t max_mapped_addr = __pa(~(ulong)0);
115 
116 	/* The maximal physical memory size is -PAGE_OFFSET. */
117 	memblock_enforce_memory_limit(-PAGE_OFFSET);
118 
119 	/* Reserve from the start of the kernel to the end of the kernel */
120 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
121 
122 	/*
123 	 * memblock allocator is not aware of the fact that last 4K bytes of
124 	 * the addressable memory can not be mapped because of IS_ERR_VALUE
125 	 * macro. Make sure that last 4k bytes are not usable by memblock
126 	 * if end of dram is equal to maximum addressable memory.
127 	 */
128 	if (max_mapped_addr == (dram_end - 1))
129 		memblock_set_current_limit(max_mapped_addr - 4096);
130 
131 	max_pfn = PFN_DOWN(dram_end);
132 	max_low_pfn = max_pfn;
133 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
134 	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
135 
136 	reserve_initrd_mem();
137 	/*
138 	 * If DTB is built in, no need to reserve its memblock.
139 	 * Otherwise, do reserve it but avoid using
140 	 * early_init_fdt_reserve_self() since __pa() does
141 	 * not work for DTB pointers that are fixmap addresses
142 	 */
143 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
144 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
145 
146 	early_init_fdt_scan_reserved_mem();
147 	dma_contiguous_reserve(dma32_phys_limit);
148 	memblock_allow_resize();
149 }
150 
151 #ifdef CONFIG_MMU
152 static struct pt_alloc_ops pt_ops;
153 
154 unsigned long va_pa_offset;
155 EXPORT_SYMBOL(va_pa_offset);
156 unsigned long pfn_base;
157 EXPORT_SYMBOL(pfn_base);
158 
159 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
160 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
161 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
162 
163 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
164 
165 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
166 {
167 	unsigned long addr = __fix_to_virt(idx);
168 	pte_t *ptep;
169 
170 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
171 
172 	ptep = &fixmap_pte[pte_index(addr)];
173 
174 	if (pgprot_val(prot))
175 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
176 	else
177 		pte_clear(&init_mm, addr, ptep);
178 	local_flush_tlb_page(addr);
179 }
180 
181 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
182 {
183 	return (pte_t *)((uintptr_t)pa);
184 }
185 
186 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
187 {
188 	clear_fixmap(FIX_PTE);
189 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
190 }
191 
192 static inline pte_t *get_pte_virt_late(phys_addr_t pa)
193 {
194 	return (pte_t *) __va(pa);
195 }
196 
197 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
198 {
199 	/*
200 	 * We only create PMD or PGD early mappings so we
201 	 * should never reach here with MMU disabled.
202 	 */
203 	BUG();
204 }
205 
206 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
207 {
208 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
209 }
210 
211 static phys_addr_t alloc_pte_late(uintptr_t va)
212 {
213 	unsigned long vaddr;
214 
215 	vaddr = __get_free_page(GFP_KERNEL);
216 	if (!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)))
217 		BUG();
218 	return __pa(vaddr);
219 }
220 
221 static void __init create_pte_mapping(pte_t *ptep,
222 				      uintptr_t va, phys_addr_t pa,
223 				      phys_addr_t sz, pgprot_t prot)
224 {
225 	uintptr_t pte_idx = pte_index(va);
226 
227 	BUG_ON(sz != PAGE_SIZE);
228 
229 	if (pte_none(ptep[pte_idx]))
230 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
231 }
232 
233 #ifndef __PAGETABLE_PMD_FOLDED
234 
235 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
236 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
237 pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
238 pmd_t early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
239 
240 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
241 {
242 	/* Before MMU is enabled */
243 	return (pmd_t *)((uintptr_t)pa);
244 }
245 
246 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
247 {
248 	clear_fixmap(FIX_PMD);
249 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
250 }
251 
252 static pmd_t *get_pmd_virt_late(phys_addr_t pa)
253 {
254 	return (pmd_t *) __va(pa);
255 }
256 
257 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
258 {
259 	BUG_ON((va - PAGE_OFFSET) >> PGDIR_SHIFT);
260 
261 	return (uintptr_t)early_pmd;
262 }
263 
264 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
265 {
266 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
267 }
268 
269 static phys_addr_t alloc_pmd_late(uintptr_t va)
270 {
271 	unsigned long vaddr;
272 
273 	vaddr = __get_free_page(GFP_KERNEL);
274 	BUG_ON(!vaddr);
275 	return __pa(vaddr);
276 }
277 
278 static void __init create_pmd_mapping(pmd_t *pmdp,
279 				      uintptr_t va, phys_addr_t pa,
280 				      phys_addr_t sz, pgprot_t prot)
281 {
282 	pte_t *ptep;
283 	phys_addr_t pte_phys;
284 	uintptr_t pmd_idx = pmd_index(va);
285 
286 	if (sz == PMD_SIZE) {
287 		if (pmd_none(pmdp[pmd_idx]))
288 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
289 		return;
290 	}
291 
292 	if (pmd_none(pmdp[pmd_idx])) {
293 		pte_phys = pt_ops.alloc_pte(va);
294 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
295 		ptep = pt_ops.get_pte_virt(pte_phys);
296 		memset(ptep, 0, PAGE_SIZE);
297 	} else {
298 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
299 		ptep = pt_ops.get_pte_virt(pte_phys);
300 	}
301 
302 	create_pte_mapping(ptep, va, pa, sz, prot);
303 }
304 
305 #define pgd_next_t		pmd_t
306 #define alloc_pgd_next(__va)	pt_ops.alloc_pmd(__va)
307 #define get_pgd_next_virt(__pa)	pt_ops.get_pmd_virt(__pa)
308 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
309 	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
310 #define fixmap_pgd_next		fixmap_pmd
311 #else
312 #define pgd_next_t		pte_t
313 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
314 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
315 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
316 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
317 #define fixmap_pgd_next		fixmap_pte
318 #endif
319 
320 void __init create_pgd_mapping(pgd_t *pgdp,
321 				      uintptr_t va, phys_addr_t pa,
322 				      phys_addr_t sz, pgprot_t prot)
323 {
324 	pgd_next_t *nextp;
325 	phys_addr_t next_phys;
326 	uintptr_t pgd_idx = pgd_index(va);
327 
328 	if (sz == PGDIR_SIZE) {
329 		if (pgd_val(pgdp[pgd_idx]) == 0)
330 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
331 		return;
332 	}
333 
334 	if (pgd_val(pgdp[pgd_idx]) == 0) {
335 		next_phys = alloc_pgd_next(va);
336 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
337 		nextp = get_pgd_next_virt(next_phys);
338 		memset(nextp, 0, PAGE_SIZE);
339 	} else {
340 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
341 		nextp = get_pgd_next_virt(next_phys);
342 	}
343 
344 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
345 }
346 
347 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
348 {
349 	/* Upgrade to PMD_SIZE mappings whenever possible */
350 	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
351 		return PAGE_SIZE;
352 
353 	return PMD_SIZE;
354 }
355 
356 /*
357  * setup_vm() is called from head.S with MMU-off.
358  *
359  * Following requirements should be honoured for setup_vm() to work
360  * correctly:
361  * 1) It should use PC-relative addressing for accessing kernel symbols.
362  *    To achieve this we always use GCC cmodel=medany.
363  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
364  *    so disable compiler instrumentation when FTRACE is enabled.
365  *
366  * Currently, the above requirements are honoured by using custom CFLAGS
367  * for init.o in mm/Makefile.
368  */
369 
370 #ifndef __riscv_cmodel_medany
371 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
372 #endif
373 
374 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
375 {
376 	uintptr_t va, pa, end_va;
377 	uintptr_t load_pa = (uintptr_t)(&_start);
378 	uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
379 	uintptr_t map_size;
380 #ifndef __PAGETABLE_PMD_FOLDED
381 	pmd_t fix_bmap_spmd, fix_bmap_epmd;
382 #endif
383 
384 	va_pa_offset = PAGE_OFFSET - load_pa;
385 	pfn_base = PFN_DOWN(load_pa);
386 
387 	/*
388 	 * Enforce boot alignment requirements of RV32 and
389 	 * RV64 by only allowing PMD or PGD mappings.
390 	 */
391 	map_size = PMD_SIZE;
392 
393 	/* Sanity check alignment and size */
394 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
395 	BUG_ON((load_pa % map_size) != 0);
396 
397 	pt_ops.alloc_pte = alloc_pte_early;
398 	pt_ops.get_pte_virt = get_pte_virt_early;
399 #ifndef __PAGETABLE_PMD_FOLDED
400 	pt_ops.alloc_pmd = alloc_pmd_early;
401 	pt_ops.get_pmd_virt = get_pmd_virt_early;
402 #endif
403 	/* Setup early PGD for fixmap */
404 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
405 			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
406 
407 #ifndef __PAGETABLE_PMD_FOLDED
408 	/* Setup fixmap PMD */
409 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
410 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
411 	/* Setup trampoline PGD and PMD */
412 	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
413 			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
414 	create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
415 			   load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
416 #else
417 	/* Setup trampoline PGD */
418 	create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
419 			   load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
420 #endif
421 
422 	/*
423 	 * Setup early PGD covering entire kernel which will allows
424 	 * us to reach paging_init(). We map all memory banks later
425 	 * in setup_vm_final() below.
426 	 */
427 	end_va = PAGE_OFFSET + load_sz;
428 	for (va = PAGE_OFFSET; va < end_va; va += map_size)
429 		create_pgd_mapping(early_pg_dir, va,
430 				   load_pa + (va - PAGE_OFFSET),
431 				   map_size, PAGE_KERNEL_EXEC);
432 
433 #ifndef __PAGETABLE_PMD_FOLDED
434 	/* Setup early PMD for DTB */
435 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
436 			   (uintptr_t)early_dtb_pmd, PGDIR_SIZE, PAGE_TABLE);
437 #ifndef CONFIG_BUILTIN_DTB
438 	/* Create two consecutive PMD mappings for FDT early scan */
439 	pa = dtb_pa & ~(PMD_SIZE - 1);
440 	create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
441 			   pa, PMD_SIZE, PAGE_KERNEL);
442 	create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
443 			   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
444 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
445 #else /* CONFIG_BUILTIN_DTB */
446 	dtb_early_va = __va(dtb_pa);
447 #endif /* CONFIG_BUILTIN_DTB */
448 #else
449 #ifndef CONFIG_BUILTIN_DTB
450 	/* Create two consecutive PGD mappings for FDT early scan */
451 	pa = dtb_pa & ~(PGDIR_SIZE - 1);
452 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
453 			   pa, PGDIR_SIZE, PAGE_KERNEL);
454 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE,
455 			   pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
456 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
457 #else /* CONFIG_BUILTIN_DTB */
458 	dtb_early_va = __va(dtb_pa);
459 #endif /* CONFIG_BUILTIN_DTB */
460 #endif
461 	dtb_early_pa = dtb_pa;
462 
463 	/*
464 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
465 	 * range can not span multiple pmds.
466 	 */
467 	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
468 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
469 
470 #ifndef __PAGETABLE_PMD_FOLDED
471 	/*
472 	 * Early ioremap fixmap is already created as it lies within first 2MB
473 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
474 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
475 	 * the user if not.
476 	 */
477 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
478 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
479 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
480 		WARN_ON(1);
481 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
482 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
483 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
484 			fix_to_virt(FIX_BTMAP_BEGIN));
485 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
486 			fix_to_virt(FIX_BTMAP_END));
487 
488 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
489 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
490 	}
491 #endif
492 }
493 
494 static void __init setup_vm_final(void)
495 {
496 	uintptr_t va, map_size;
497 	phys_addr_t pa, start, end;
498 	u64 i;
499 
500 	/**
501 	 * MMU is enabled at this point. But page table setup is not complete yet.
502 	 * fixmap page table alloc functions should be used at this point
503 	 */
504 	pt_ops.alloc_pte = alloc_pte_fixmap;
505 	pt_ops.get_pte_virt = get_pte_virt_fixmap;
506 #ifndef __PAGETABLE_PMD_FOLDED
507 	pt_ops.alloc_pmd = alloc_pmd_fixmap;
508 	pt_ops.get_pmd_virt = get_pmd_virt_fixmap;
509 #endif
510 	/* Setup swapper PGD for fixmap */
511 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
512 			   __pa_symbol(fixmap_pgd_next),
513 			   PGDIR_SIZE, PAGE_TABLE);
514 
515 	/* Map all memory banks */
516 	for_each_mem_range(i, &start, &end) {
517 		if (start >= end)
518 			break;
519 		if (start <= __pa(PAGE_OFFSET) &&
520 		    __pa(PAGE_OFFSET) < end)
521 			start = __pa(PAGE_OFFSET);
522 
523 		map_size = best_map_size(start, end - start);
524 		for (pa = start; pa < end; pa += map_size) {
525 			va = (uintptr_t)__va(pa);
526 			create_pgd_mapping(swapper_pg_dir, va, pa,
527 					   map_size, PAGE_KERNEL_EXEC);
528 		}
529 	}
530 
531 	/* Clear fixmap PTE and PMD mappings */
532 	clear_fixmap(FIX_PTE);
533 	clear_fixmap(FIX_PMD);
534 
535 	/* Move to swapper page table */
536 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
537 	local_flush_tlb_all();
538 
539 	/* generic page allocation functions must be used to setup page table */
540 	pt_ops.alloc_pte = alloc_pte_late;
541 	pt_ops.get_pte_virt = get_pte_virt_late;
542 #ifndef __PAGETABLE_PMD_FOLDED
543 	pt_ops.alloc_pmd = alloc_pmd_late;
544 	pt_ops.get_pmd_virt = get_pmd_virt_late;
545 #endif
546 }
547 #else
548 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
549 {
550 	dtb_early_va = (void *)dtb_pa;
551 	dtb_early_pa = dtb_pa;
552 }
553 
554 static inline void setup_vm_final(void)
555 {
556 }
557 #endif /* CONFIG_MMU */
558 
559 #ifdef CONFIG_STRICT_KERNEL_RWX
560 void protect_kernel_text_data(void)
561 {
562 	unsigned long text_start = (unsigned long)_start;
563 	unsigned long init_text_start = (unsigned long)__init_text_begin;
564 	unsigned long init_data_start = (unsigned long)__init_data_begin;
565 	unsigned long rodata_start = (unsigned long)__start_rodata;
566 	unsigned long data_start = (unsigned long)_data;
567 	unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
568 
569 	set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT);
570 	set_memory_ro(init_text_start, (init_data_start - init_text_start) >> PAGE_SHIFT);
571 	set_memory_nx(init_data_start, (rodata_start - init_data_start) >> PAGE_SHIFT);
572 	/* rodata section is marked readonly in mark_rodata_ro */
573 	set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
574 	set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
575 }
576 
577 void mark_rodata_ro(void)
578 {
579 	unsigned long rodata_start = (unsigned long)__start_rodata;
580 	unsigned long data_start = (unsigned long)_data;
581 
582 	set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
583 
584 	debug_checkwx();
585 }
586 #endif
587 
588 void __init paging_init(void)
589 {
590 	setup_vm_final();
591 	setup_zero_page();
592 }
593 
594 void __init misc_mem_init(void)
595 {
596 	arch_numa_init();
597 	sparse_init();
598 	zone_sizes_init();
599 	memblock_dump_all();
600 }
601 
602 #ifdef CONFIG_SPARSEMEM_VMEMMAP
603 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
604 			       struct vmem_altmap *altmap)
605 {
606 	return vmemmap_populate_basepages(start, end, node, NULL);
607 }
608 #endif
609