xref: /linux/arch/riscv/mm/init.c (revision a2a4ee550704901aa148b57a55cb73cc1e8ae9b1)
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  * Copyright (C) 2020 FORTH-ICS/CARV
6  *  Nick Kossifidis <mick@ics.forth.gr>
7  */
8 
9 #include <linux/init.h>
10 #include <linux/mm.h>
11 #include <linux/memblock.h>
12 #include <linux/initrd.h>
13 #include <linux/swap.h>
14 #include <linux/swiotlb.h>
15 #include <linux/sizes.h>
16 #include <linux/of_fdt.h>
17 #include <linux/of_reserved_mem.h>
18 #include <linux/libfdt.h>
19 #include <linux/set_memory.h>
20 #include <linux/dma-map-ops.h>
21 #include <linux/crash_dump.h>
22 #include <linux/hugetlb.h>
23 
24 #include <asm/fixmap.h>
25 #include <asm/tlbflush.h>
26 #include <asm/sections.h>
27 #include <asm/soc.h>
28 #include <asm/io.h>
29 #include <asm/ptdump.h>
30 #include <asm/numa.h>
31 
32 #include "../kernel/head.h"
33 
34 struct kernel_mapping kernel_map __ro_after_init;
35 EXPORT_SYMBOL(kernel_map);
36 #ifdef CONFIG_XIP_KERNEL
37 #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
38 #endif
39 
40 #ifdef CONFIG_64BIT
41 u64 satp_mode __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_57 : SATP_MODE_39;
42 #else
43 u64 satp_mode __ro_after_init = SATP_MODE_32;
44 #endif
45 EXPORT_SYMBOL(satp_mode);
46 
47 bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
48 bool pgtable_l5_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
49 EXPORT_SYMBOL(pgtable_l4_enabled);
50 EXPORT_SYMBOL(pgtable_l5_enabled);
51 
52 phys_addr_t phys_ram_base __ro_after_init;
53 EXPORT_SYMBOL(phys_ram_base);
54 
55 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
56 							__page_aligned_bss;
57 EXPORT_SYMBOL(empty_zero_page);
58 
59 extern char _start[];
60 #define DTB_EARLY_BASE_VA      PGDIR_SIZE
61 void *_dtb_early_va __initdata;
62 uintptr_t _dtb_early_pa __initdata;
63 
64 static phys_addr_t dma32_phys_limit __initdata;
65 
66 static void __init zone_sizes_init(void)
67 {
68 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
69 
70 #ifdef CONFIG_ZONE_DMA32
71 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
72 #endif
73 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
74 
75 	free_area_init(max_zone_pfns);
76 }
77 
78 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
79 
80 #define LOG2_SZ_1K  ilog2(SZ_1K)
81 #define LOG2_SZ_1M  ilog2(SZ_1M)
82 #define LOG2_SZ_1G  ilog2(SZ_1G)
83 #define LOG2_SZ_1T  ilog2(SZ_1T)
84 
85 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
86 {
87 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
88 		  (((t) - (b)) >> LOG2_SZ_1K));
89 }
90 
91 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
92 {
93 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
94 		  (((t) - (b)) >> LOG2_SZ_1M));
95 }
96 
97 static inline void print_mlg(char *name, unsigned long b, unsigned long t)
98 {
99 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld GB)\n", name, b, t,
100 		   (((t) - (b)) >> LOG2_SZ_1G));
101 }
102 
103 #ifdef CONFIG_64BIT
104 static inline void print_mlt(char *name, unsigned long b, unsigned long t)
105 {
106 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld TB)\n", name, b, t,
107 		   (((t) - (b)) >> LOG2_SZ_1T));
108 }
109 #else
110 #define print_mlt(n, b, t) do {} while (0)
111 #endif
112 
113 static inline void print_ml(char *name, unsigned long b, unsigned long t)
114 {
115 	unsigned long diff = t - b;
116 
117 	if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10)
118 		print_mlt(name, b, t);
119 	else if ((diff >> LOG2_SZ_1G) >= 10)
120 		print_mlg(name, b, t);
121 	else if ((diff >> LOG2_SZ_1M) >= 10)
122 		print_mlm(name, b, t);
123 	else
124 		print_mlk(name, b, t);
125 }
126 
127 static void __init print_vm_layout(void)
128 {
129 	pr_notice("Virtual kernel memory layout:\n");
130 	print_ml("fixmap", (unsigned long)FIXADDR_START,
131 		(unsigned long)FIXADDR_TOP);
132 	print_ml("pci io", (unsigned long)PCI_IO_START,
133 		(unsigned long)PCI_IO_END);
134 	print_ml("vmemmap", (unsigned long)VMEMMAP_START,
135 		(unsigned long)VMEMMAP_END);
136 	print_ml("vmalloc", (unsigned long)VMALLOC_START,
137 		(unsigned long)VMALLOC_END);
138 	print_ml("lowmem", (unsigned long)PAGE_OFFSET,
139 		(unsigned long)high_memory);
140 	if (IS_ENABLED(CONFIG_64BIT)) {
141 #ifdef CONFIG_KASAN
142 		print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
143 #endif
144 
145 		print_ml("kernel", (unsigned long)KERNEL_LINK_ADDR,
146 			 (unsigned long)ADDRESS_SPACE_END);
147 	}
148 }
149 #else
150 static void print_vm_layout(void) { }
151 #endif /* CONFIG_DEBUG_VM */
152 
153 void __init mem_init(void)
154 {
155 #ifdef CONFIG_FLATMEM
156 	BUG_ON(!mem_map);
157 #endif /* CONFIG_FLATMEM */
158 
159 	swiotlb_init(max_pfn > PFN_DOWN(dma32_phys_limit), SWIOTLB_VERBOSE);
160 	memblock_free_all();
161 
162 	print_vm_layout();
163 }
164 
165 /* Limit the memory size via mem. */
166 static phys_addr_t memory_limit;
167 
168 static int __init early_mem(char *p)
169 {
170 	u64 size;
171 
172 	if (!p)
173 		return 1;
174 
175 	size = memparse(p, &p) & PAGE_MASK;
176 	memory_limit = min_t(u64, size, memory_limit);
177 
178 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
179 
180 	return 0;
181 }
182 early_param("mem", early_mem);
183 
184 static void __init setup_bootmem(void)
185 {
186 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
187 	phys_addr_t max_mapped_addr;
188 	phys_addr_t phys_ram_end, vmlinux_start;
189 
190 	if (IS_ENABLED(CONFIG_XIP_KERNEL))
191 		vmlinux_start = __pa_symbol(&_sdata);
192 	else
193 		vmlinux_start = __pa_symbol(&_start);
194 
195 	memblock_enforce_memory_limit(memory_limit);
196 
197 	/*
198 	 * Make sure we align the reservation on PMD_SIZE since we will
199 	 * map the kernel in the linear mapping as read-only: we do not want
200 	 * any allocation to happen between _end and the next pmd aligned page.
201 	 */
202 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
203 		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
204 	/*
205 	 * Reserve from the start of the kernel to the end of the kernel
206 	 */
207 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
208 
209 	phys_ram_end = memblock_end_of_DRAM();
210 	if (!IS_ENABLED(CONFIG_XIP_KERNEL))
211 		phys_ram_base = memblock_start_of_DRAM();
212 	/*
213 	 * memblock allocator is not aware of the fact that last 4K bytes of
214 	 * the addressable memory can not be mapped because of IS_ERR_VALUE
215 	 * macro. Make sure that last 4k bytes are not usable by memblock
216 	 * if end of dram is equal to maximum addressable memory.  For 64-bit
217 	 * kernel, this problem can't happen here as the end of the virtual
218 	 * address space is occupied by the kernel mapping then this check must
219 	 * be done as soon as the kernel mapping base address is determined.
220 	 */
221 	if (!IS_ENABLED(CONFIG_64BIT)) {
222 		max_mapped_addr = __pa(~(ulong)0);
223 		if (max_mapped_addr == (phys_ram_end - 1))
224 			memblock_set_current_limit(max_mapped_addr - 4096);
225 	}
226 
227 	min_low_pfn = PFN_UP(phys_ram_base);
228 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
229 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
230 
231 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
232 	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
233 
234 	reserve_initrd_mem();
235 	/*
236 	 * If DTB is built in, no need to reserve its memblock.
237 	 * Otherwise, do reserve it but avoid using
238 	 * early_init_fdt_reserve_self() since __pa() does
239 	 * not work for DTB pointers that are fixmap addresses
240 	 */
241 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB)) {
242 		/*
243 		 * In case the DTB is not located in a memory region we won't
244 		 * be able to locate it later on via the linear mapping and
245 		 * get a segfault when accessing it via __va(dtb_early_pa).
246 		 * To avoid this situation copy DTB to a memory region.
247 		 * Note that memblock_phys_alloc will also reserve DTB region.
248 		 */
249 		if (!memblock_is_memory(dtb_early_pa)) {
250 			size_t fdt_size = fdt_totalsize(dtb_early_va);
251 			phys_addr_t new_dtb_early_pa = memblock_phys_alloc(fdt_size, PAGE_SIZE);
252 			void *new_dtb_early_va = early_memremap(new_dtb_early_pa, fdt_size);
253 
254 			memcpy(new_dtb_early_va, dtb_early_va, fdt_size);
255 			early_memunmap(new_dtb_early_va, fdt_size);
256 			_dtb_early_pa = new_dtb_early_pa;
257 		} else
258 			memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
259 	}
260 
261 	early_init_fdt_scan_reserved_mem();
262 	dma_contiguous_reserve(dma32_phys_limit);
263 	if (IS_ENABLED(CONFIG_64BIT))
264 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
265 	memblock_allow_resize();
266 }
267 
268 #ifdef CONFIG_MMU
269 struct pt_alloc_ops pt_ops __initdata;
270 
271 unsigned long riscv_pfn_base __ro_after_init;
272 EXPORT_SYMBOL(riscv_pfn_base);
273 
274 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
275 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
276 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
277 
278 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
279 static p4d_t __maybe_unused early_dtb_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
280 static pud_t __maybe_unused early_dtb_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
281 static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
282 
283 #ifdef CONFIG_XIP_KERNEL
284 #define pt_ops			(*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
285 #define riscv_pfn_base         (*(unsigned long  *)XIP_FIXUP(&riscv_pfn_base))
286 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
287 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
288 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
289 #endif /* CONFIG_XIP_KERNEL */
290 
291 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
292 {
293 	unsigned long addr = __fix_to_virt(idx);
294 	pte_t *ptep;
295 
296 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
297 
298 	ptep = &fixmap_pte[pte_index(addr)];
299 
300 	if (pgprot_val(prot))
301 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
302 	else
303 		pte_clear(&init_mm, addr, ptep);
304 	local_flush_tlb_page(addr);
305 }
306 
307 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
308 {
309 	return (pte_t *)((uintptr_t)pa);
310 }
311 
312 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
313 {
314 	clear_fixmap(FIX_PTE);
315 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
316 }
317 
318 static inline pte_t *__init get_pte_virt_late(phys_addr_t pa)
319 {
320 	return (pte_t *) __va(pa);
321 }
322 
323 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
324 {
325 	/*
326 	 * We only create PMD or PGD early mappings so we
327 	 * should never reach here with MMU disabled.
328 	 */
329 	BUG();
330 }
331 
332 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
333 {
334 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
335 }
336 
337 static phys_addr_t __init alloc_pte_late(uintptr_t va)
338 {
339 	unsigned long vaddr;
340 
341 	vaddr = __get_free_page(GFP_KERNEL);
342 	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)));
343 
344 	return __pa(vaddr);
345 }
346 
347 static void __init create_pte_mapping(pte_t *ptep,
348 				      uintptr_t va, phys_addr_t pa,
349 				      phys_addr_t sz, pgprot_t prot)
350 {
351 	uintptr_t pte_idx = pte_index(va);
352 
353 	BUG_ON(sz != PAGE_SIZE);
354 
355 	if (pte_none(ptep[pte_idx]))
356 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
357 }
358 
359 #ifndef __PAGETABLE_PMD_FOLDED
360 
361 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
362 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
363 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
364 
365 #ifdef CONFIG_XIP_KERNEL
366 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
367 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
368 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
369 #endif /* CONFIG_XIP_KERNEL */
370 
371 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss;
372 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss;
373 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
374 
375 #ifdef CONFIG_XIP_KERNEL
376 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d))
377 #define fixmap_p4d     ((p4d_t *)XIP_FIXUP(fixmap_p4d))
378 #define early_p4d      ((p4d_t *)XIP_FIXUP(early_p4d))
379 #endif /* CONFIG_XIP_KERNEL */
380 
381 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss;
382 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss;
383 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
384 
385 #ifdef CONFIG_XIP_KERNEL
386 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud))
387 #define fixmap_pud     ((pud_t *)XIP_FIXUP(fixmap_pud))
388 #define early_pud      ((pud_t *)XIP_FIXUP(early_pud))
389 #endif /* CONFIG_XIP_KERNEL */
390 
391 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
392 {
393 	/* Before MMU is enabled */
394 	return (pmd_t *)((uintptr_t)pa);
395 }
396 
397 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
398 {
399 	clear_fixmap(FIX_PMD);
400 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
401 }
402 
403 static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)
404 {
405 	return (pmd_t *) __va(pa);
406 }
407 
408 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
409 {
410 	BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT);
411 
412 	return (uintptr_t)early_pmd;
413 }
414 
415 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
416 {
417 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
418 }
419 
420 static phys_addr_t __init alloc_pmd_late(uintptr_t va)
421 {
422 	unsigned long vaddr;
423 
424 	vaddr = __get_free_page(GFP_KERNEL);
425 	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page(vaddr)));
426 
427 	return __pa(vaddr);
428 }
429 
430 static void __init create_pmd_mapping(pmd_t *pmdp,
431 				      uintptr_t va, phys_addr_t pa,
432 				      phys_addr_t sz, pgprot_t prot)
433 {
434 	pte_t *ptep;
435 	phys_addr_t pte_phys;
436 	uintptr_t pmd_idx = pmd_index(va);
437 
438 	if (sz == PMD_SIZE) {
439 		if (pmd_none(pmdp[pmd_idx]))
440 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
441 		return;
442 	}
443 
444 	if (pmd_none(pmdp[pmd_idx])) {
445 		pte_phys = pt_ops.alloc_pte(va);
446 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
447 		ptep = pt_ops.get_pte_virt(pte_phys);
448 		memset(ptep, 0, PAGE_SIZE);
449 	} else {
450 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
451 		ptep = pt_ops.get_pte_virt(pte_phys);
452 	}
453 
454 	create_pte_mapping(ptep, va, pa, sz, prot);
455 }
456 
457 static pud_t *__init get_pud_virt_early(phys_addr_t pa)
458 {
459 	return (pud_t *)((uintptr_t)pa);
460 }
461 
462 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
463 {
464 	clear_fixmap(FIX_PUD);
465 	return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
466 }
467 
468 static pud_t *__init get_pud_virt_late(phys_addr_t pa)
469 {
470 	return (pud_t *)__va(pa);
471 }
472 
473 static phys_addr_t __init alloc_pud_early(uintptr_t va)
474 {
475 	/* Only one PUD is available for early mapping */
476 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
477 
478 	return (uintptr_t)early_pud;
479 }
480 
481 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
482 {
483 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
484 }
485 
486 static phys_addr_t alloc_pud_late(uintptr_t va)
487 {
488 	unsigned long vaddr;
489 
490 	vaddr = __get_free_page(GFP_KERNEL);
491 	BUG_ON(!vaddr);
492 	return __pa(vaddr);
493 }
494 
495 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa)
496 {
497 	return (p4d_t *)((uintptr_t)pa);
498 }
499 
500 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
501 {
502 	clear_fixmap(FIX_P4D);
503 	return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
504 }
505 
506 static p4d_t *__init get_p4d_virt_late(phys_addr_t pa)
507 {
508 	return (p4d_t *)__va(pa);
509 }
510 
511 static phys_addr_t __init alloc_p4d_early(uintptr_t va)
512 {
513 	/* Only one P4D is available for early mapping */
514 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
515 
516 	return (uintptr_t)early_p4d;
517 }
518 
519 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
520 {
521 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
522 }
523 
524 static phys_addr_t alloc_p4d_late(uintptr_t va)
525 {
526 	unsigned long vaddr;
527 
528 	vaddr = __get_free_page(GFP_KERNEL);
529 	BUG_ON(!vaddr);
530 	return __pa(vaddr);
531 }
532 
533 static void __init create_pud_mapping(pud_t *pudp,
534 				      uintptr_t va, phys_addr_t pa,
535 				      phys_addr_t sz, pgprot_t prot)
536 {
537 	pmd_t *nextp;
538 	phys_addr_t next_phys;
539 	uintptr_t pud_index = pud_index(va);
540 
541 	if (sz == PUD_SIZE) {
542 		if (pud_val(pudp[pud_index]) == 0)
543 			pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot);
544 		return;
545 	}
546 
547 	if (pud_val(pudp[pud_index]) == 0) {
548 		next_phys = pt_ops.alloc_pmd(va);
549 		pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE);
550 		nextp = pt_ops.get_pmd_virt(next_phys);
551 		memset(nextp, 0, PAGE_SIZE);
552 	} else {
553 		next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index]));
554 		nextp = pt_ops.get_pmd_virt(next_phys);
555 	}
556 
557 	create_pmd_mapping(nextp, va, pa, sz, prot);
558 }
559 
560 static void __init create_p4d_mapping(p4d_t *p4dp,
561 				      uintptr_t va, phys_addr_t pa,
562 				      phys_addr_t sz, pgprot_t prot)
563 {
564 	pud_t *nextp;
565 	phys_addr_t next_phys;
566 	uintptr_t p4d_index = p4d_index(va);
567 
568 	if (sz == P4D_SIZE) {
569 		if (p4d_val(p4dp[p4d_index]) == 0)
570 			p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot);
571 		return;
572 	}
573 
574 	if (p4d_val(p4dp[p4d_index]) == 0) {
575 		next_phys = pt_ops.alloc_pud(va);
576 		p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE);
577 		nextp = pt_ops.get_pud_virt(next_phys);
578 		memset(nextp, 0, PAGE_SIZE);
579 	} else {
580 		next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index]));
581 		nextp = pt_ops.get_pud_virt(next_phys);
582 	}
583 
584 	create_pud_mapping(nextp, va, pa, sz, prot);
585 }
586 
587 #define pgd_next_t		p4d_t
588 #define alloc_pgd_next(__va)	(pgtable_l5_enabled ?			\
589 		pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ?		\
590 		pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
591 #define get_pgd_next_virt(__pa)	(pgtable_l5_enabled ?			\
592 		pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ?	\
593 		pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
594 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
595 				(pgtable_l5_enabled ?			\
596 		create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
597 				(pgtable_l4_enabled ?			\
598 		create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) :	\
599 		create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
600 #define fixmap_pgd_next		(pgtable_l5_enabled ?			\
601 		(uintptr_t)fixmap_p4d : (pgtable_l4_enabled ?		\
602 		(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
603 #define trampoline_pgd_next	(pgtable_l5_enabled ?			\
604 		(uintptr_t)trampoline_p4d : (pgtable_l4_enabled ?	\
605 		(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
606 #define early_dtb_pgd_next	(pgtable_l5_enabled ?			\
607 		(uintptr_t)early_dtb_p4d : (pgtable_l4_enabled ?	\
608 		(uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd))
609 #else
610 #define pgd_next_t		pte_t
611 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
612 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
613 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
614 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
615 #define fixmap_pgd_next		((uintptr_t)fixmap_pte)
616 #define early_dtb_pgd_next	((uintptr_t)early_dtb_pmd)
617 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
618 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
619 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
620 #endif /* __PAGETABLE_PMD_FOLDED */
621 
622 void __init create_pgd_mapping(pgd_t *pgdp,
623 				      uintptr_t va, phys_addr_t pa,
624 				      phys_addr_t sz, pgprot_t prot)
625 {
626 	pgd_next_t *nextp;
627 	phys_addr_t next_phys;
628 	uintptr_t pgd_idx = pgd_index(va);
629 
630 	if (sz == PGDIR_SIZE) {
631 		if (pgd_val(pgdp[pgd_idx]) == 0)
632 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
633 		return;
634 	}
635 
636 	if (pgd_val(pgdp[pgd_idx]) == 0) {
637 		next_phys = alloc_pgd_next(va);
638 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
639 		nextp = get_pgd_next_virt(next_phys);
640 		memset(nextp, 0, PAGE_SIZE);
641 	} else {
642 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
643 		nextp = get_pgd_next_virt(next_phys);
644 	}
645 
646 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
647 }
648 
649 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
650 {
651 	/* Upgrade to PMD_SIZE mappings whenever possible */
652 	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
653 		return PAGE_SIZE;
654 
655 	return PMD_SIZE;
656 }
657 
658 #ifdef CONFIG_XIP_KERNEL
659 #define phys_ram_base  (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base))
660 extern char _xiprom[], _exiprom[], __data_loc;
661 
662 /* called from head.S with MMU off */
663 asmlinkage void __init __copy_data(void)
664 {
665 	void *from = (void *)(&__data_loc);
666 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
667 	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
668 
669 	memcpy(to, from, sz);
670 }
671 #endif
672 
673 #ifdef CONFIG_STRICT_KERNEL_RWX
674 static __init pgprot_t pgprot_from_va(uintptr_t va)
675 {
676 	if (is_va_kernel_text(va))
677 		return PAGE_KERNEL_READ_EXEC;
678 
679 	/*
680 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
681 	 * we must protect its linear mapping alias from being executed and
682 	 * written.
683 	 * And rodata section is marked readonly in mark_rodata_ro.
684 	 */
685 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
686 		return PAGE_KERNEL_READ;
687 
688 	return PAGE_KERNEL;
689 }
690 
691 void mark_rodata_ro(void)
692 {
693 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
694 	if (IS_ENABLED(CONFIG_64BIT))
695 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
696 				  set_memory_ro);
697 
698 	debug_checkwx();
699 }
700 #else
701 static __init pgprot_t pgprot_from_va(uintptr_t va)
702 {
703 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
704 		return PAGE_KERNEL;
705 
706 	return PAGE_KERNEL_EXEC;
707 }
708 #endif /* CONFIG_STRICT_KERNEL_RWX */
709 
710 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
711 static void __init disable_pgtable_l5(void)
712 {
713 	pgtable_l5_enabled = false;
714 	kernel_map.page_offset = PAGE_OFFSET_L4;
715 	satp_mode = SATP_MODE_48;
716 }
717 
718 static void __init disable_pgtable_l4(void)
719 {
720 	pgtable_l4_enabled = false;
721 	kernel_map.page_offset = PAGE_OFFSET_L3;
722 	satp_mode = SATP_MODE_39;
723 }
724 
725 /*
726  * There is a simple way to determine if 4-level is supported by the
727  * underlying hardware: establish 1:1 mapping in 4-level page table mode
728  * then read SATP to see if the configuration was taken into account
729  * meaning sv48 is supported.
730  */
731 static __init void set_satp_mode(void)
732 {
733 	u64 identity_satp, hw_satp;
734 	uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
735 	bool check_l4 = false;
736 
737 	create_p4d_mapping(early_p4d,
738 			set_satp_mode_pmd, (uintptr_t)early_pud,
739 			P4D_SIZE, PAGE_TABLE);
740 	create_pud_mapping(early_pud,
741 			   set_satp_mode_pmd, (uintptr_t)early_pmd,
742 			   PUD_SIZE, PAGE_TABLE);
743 	/* Handle the case where set_satp_mode straddles 2 PMDs */
744 	create_pmd_mapping(early_pmd,
745 			   set_satp_mode_pmd, set_satp_mode_pmd,
746 			   PMD_SIZE, PAGE_KERNEL_EXEC);
747 	create_pmd_mapping(early_pmd,
748 			   set_satp_mode_pmd + PMD_SIZE,
749 			   set_satp_mode_pmd + PMD_SIZE,
750 			   PMD_SIZE, PAGE_KERNEL_EXEC);
751 retry:
752 	create_pgd_mapping(early_pg_dir,
753 			   set_satp_mode_pmd,
754 			   check_l4 ? (uintptr_t)early_pud : (uintptr_t)early_p4d,
755 			   PGDIR_SIZE, PAGE_TABLE);
756 
757 	identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
758 
759 	local_flush_tlb_all();
760 	csr_write(CSR_SATP, identity_satp);
761 	hw_satp = csr_swap(CSR_SATP, 0ULL);
762 	local_flush_tlb_all();
763 
764 	if (hw_satp != identity_satp) {
765 		if (!check_l4) {
766 			disable_pgtable_l5();
767 			check_l4 = true;
768 			memset(early_pg_dir, 0, PAGE_SIZE);
769 			goto retry;
770 		}
771 		disable_pgtable_l4();
772 	}
773 
774 	memset(early_pg_dir, 0, PAGE_SIZE);
775 	memset(early_p4d, 0, PAGE_SIZE);
776 	memset(early_pud, 0, PAGE_SIZE);
777 	memset(early_pmd, 0, PAGE_SIZE);
778 }
779 #endif
780 
781 /*
782  * setup_vm() is called from head.S with MMU-off.
783  *
784  * Following requirements should be honoured for setup_vm() to work
785  * correctly:
786  * 1) It should use PC-relative addressing for accessing kernel symbols.
787  *    To achieve this we always use GCC cmodel=medany.
788  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
789  *    so disable compiler instrumentation when FTRACE is enabled.
790  *
791  * Currently, the above requirements are honoured by using custom CFLAGS
792  * for init.o in mm/Makefile.
793  */
794 
795 #ifndef __riscv_cmodel_medany
796 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
797 #endif
798 
799 #ifdef CONFIG_XIP_KERNEL
800 static void __init create_kernel_page_table(pgd_t *pgdir,
801 					    __always_unused bool early)
802 {
803 	uintptr_t va, end_va;
804 
805 	/* Map the flash resident part */
806 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
807 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
808 		create_pgd_mapping(pgdir, va,
809 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
810 				   PMD_SIZE, PAGE_KERNEL_EXEC);
811 
812 	/* Map the data in RAM */
813 	end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size;
814 	for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += PMD_SIZE)
815 		create_pgd_mapping(pgdir, va,
816 				   kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
817 				   PMD_SIZE, PAGE_KERNEL);
818 }
819 #else
820 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
821 {
822 	uintptr_t va, end_va;
823 
824 	end_va = kernel_map.virt_addr + kernel_map.size;
825 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
826 		create_pgd_mapping(pgdir, va,
827 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
828 				   PMD_SIZE,
829 				   early ?
830 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
831 }
832 #endif
833 
834 /*
835  * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
836  * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
837  * entry.
838  */
839 static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
840 {
841 #ifndef CONFIG_BUILTIN_DTB
842 	uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
843 
844 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
845 			   IS_ENABLED(CONFIG_64BIT) ? early_dtb_pgd_next : pa,
846 			   PGDIR_SIZE,
847 			   IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
848 
849 	if (pgtable_l5_enabled)
850 		create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
851 				   (uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
852 
853 	if (pgtable_l4_enabled)
854 		create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
855 				   (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
856 
857 	if (IS_ENABLED(CONFIG_64BIT)) {
858 		create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
859 				   pa, PMD_SIZE, PAGE_KERNEL);
860 		create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
861 				   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
862 	}
863 
864 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
865 #else
866 	/*
867 	 * For 64-bit kernel, __va can't be used since it would return a linear
868 	 * mapping address whereas dtb_early_va will be used before
869 	 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
870 	 * kernel is mapped in the linear mapping, that makes no difference.
871 	 */
872 	dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
873 #endif
874 
875 	dtb_early_pa = dtb_pa;
876 }
877 
878 /*
879  * MMU is not enabled, the page tables are allocated directly using
880  * early_pmd/pud/p4d and the address returned is the physical one.
881  */
882 static void __init pt_ops_set_early(void)
883 {
884 	pt_ops.alloc_pte = alloc_pte_early;
885 	pt_ops.get_pte_virt = get_pte_virt_early;
886 #ifndef __PAGETABLE_PMD_FOLDED
887 	pt_ops.alloc_pmd = alloc_pmd_early;
888 	pt_ops.get_pmd_virt = get_pmd_virt_early;
889 	pt_ops.alloc_pud = alloc_pud_early;
890 	pt_ops.get_pud_virt = get_pud_virt_early;
891 	pt_ops.alloc_p4d = alloc_p4d_early;
892 	pt_ops.get_p4d_virt = get_p4d_virt_early;
893 #endif
894 }
895 
896 /*
897  * MMU is enabled but page table setup is not complete yet.
898  * fixmap page table alloc functions must be used as a means to temporarily
899  * map the allocated physical pages since the linear mapping does not exist yet.
900  *
901  * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va,
902  * but it will be used as described above.
903  */
904 static void __init pt_ops_set_fixmap(void)
905 {
906 	pt_ops.alloc_pte = kernel_mapping_pa_to_va((uintptr_t)alloc_pte_fixmap);
907 	pt_ops.get_pte_virt = kernel_mapping_pa_to_va((uintptr_t)get_pte_virt_fixmap);
908 #ifndef __PAGETABLE_PMD_FOLDED
909 	pt_ops.alloc_pmd = kernel_mapping_pa_to_va((uintptr_t)alloc_pmd_fixmap);
910 	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va((uintptr_t)get_pmd_virt_fixmap);
911 	pt_ops.alloc_pud = kernel_mapping_pa_to_va((uintptr_t)alloc_pud_fixmap);
912 	pt_ops.get_pud_virt = kernel_mapping_pa_to_va((uintptr_t)get_pud_virt_fixmap);
913 	pt_ops.alloc_p4d = kernel_mapping_pa_to_va((uintptr_t)alloc_p4d_fixmap);
914 	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va((uintptr_t)get_p4d_virt_fixmap);
915 #endif
916 }
917 
918 /*
919  * MMU is enabled and page table setup is complete, so from now, we can use
920  * generic page allocation functions to setup page table.
921  */
922 static void __init pt_ops_set_late(void)
923 {
924 	pt_ops.alloc_pte = alloc_pte_late;
925 	pt_ops.get_pte_virt = get_pte_virt_late;
926 #ifndef __PAGETABLE_PMD_FOLDED
927 	pt_ops.alloc_pmd = alloc_pmd_late;
928 	pt_ops.get_pmd_virt = get_pmd_virt_late;
929 	pt_ops.alloc_pud = alloc_pud_late;
930 	pt_ops.get_pud_virt = get_pud_virt_late;
931 	pt_ops.alloc_p4d = alloc_p4d_late;
932 	pt_ops.get_p4d_virt = get_p4d_virt_late;
933 #endif
934 }
935 
936 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
937 {
938 	pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
939 
940 	kernel_map.virt_addr = KERNEL_LINK_ADDR;
941 	kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
942 
943 #ifdef CONFIG_XIP_KERNEL
944 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
945 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
946 
947 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
948 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
949 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
950 
951 	kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
952 #else
953 	kernel_map.phys_addr = (uintptr_t)(&_start);
954 	kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
955 #endif
956 
957 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
958 	set_satp_mode();
959 #endif
960 
961 	kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr;
962 	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
963 
964 	riscv_pfn_base = PFN_DOWN(kernel_map.phys_addr);
965 
966 	/*
967 	 * The default maximal physical memory size is KERN_VIRT_SIZE for 32-bit
968 	 * kernel, whereas for 64-bit kernel, the end of the virtual address
969 	 * space is occupied by the modules/BPF/kernel mappings which reduces
970 	 * the available size of the linear mapping.
971 	 */
972 	memory_limit = KERN_VIRT_SIZE - (IS_ENABLED(CONFIG_64BIT) ? SZ_4G : 0);
973 
974 	/* Sanity check alignment and size */
975 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
976 	BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);
977 
978 #ifdef CONFIG_64BIT
979 	/*
980 	 * The last 4K bytes of the addressable memory can not be mapped because
981 	 * of IS_ERR_VALUE macro.
982 	 */
983 	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
984 #endif
985 
986 	apply_early_boot_alternatives();
987 	pt_ops_set_early();
988 
989 	/* Setup early PGD for fixmap */
990 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
991 			   fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
992 
993 #ifndef __PAGETABLE_PMD_FOLDED
994 	/* Setup fixmap P4D and PUD */
995 	if (pgtable_l5_enabled)
996 		create_p4d_mapping(fixmap_p4d, FIXADDR_START,
997 				   (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
998 	/* Setup fixmap PUD and PMD */
999 	if (pgtable_l4_enabled)
1000 		create_pud_mapping(fixmap_pud, FIXADDR_START,
1001 				   (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
1002 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
1003 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
1004 	/* Setup trampoline PGD and PMD */
1005 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1006 			   trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1007 	if (pgtable_l5_enabled)
1008 		create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
1009 				   (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
1010 	if (pgtable_l4_enabled)
1011 		create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
1012 				   (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
1013 #ifdef CONFIG_XIP_KERNEL
1014 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1015 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
1016 #else
1017 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1018 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
1019 #endif
1020 #else
1021 	/* Setup trampoline PGD */
1022 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1023 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
1024 #endif
1025 
1026 	/*
1027 	 * Setup early PGD covering entire kernel which will allow
1028 	 * us to reach paging_init(). We map all memory banks later
1029 	 * in setup_vm_final() below.
1030 	 */
1031 	create_kernel_page_table(early_pg_dir, true);
1032 
1033 	/* Setup early mapping for FDT early scan */
1034 	create_fdt_early_page_table(early_pg_dir, dtb_pa);
1035 
1036 	/*
1037 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
1038 	 * range can not span multiple pmds.
1039 	 */
1040 	BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1041 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1042 
1043 #ifndef __PAGETABLE_PMD_FOLDED
1044 	/*
1045 	 * Early ioremap fixmap is already created as it lies within first 2MB
1046 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
1047 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
1048 	 * the user if not.
1049 	 */
1050 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
1051 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
1052 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
1053 		WARN_ON(1);
1054 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
1055 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
1056 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1057 			fix_to_virt(FIX_BTMAP_BEGIN));
1058 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
1059 			fix_to_virt(FIX_BTMAP_END));
1060 
1061 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
1062 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
1063 	}
1064 #endif
1065 
1066 	pt_ops_set_fixmap();
1067 }
1068 
1069 static void __init setup_vm_final(void)
1070 {
1071 	uintptr_t va, map_size;
1072 	phys_addr_t pa, start, end;
1073 	u64 i;
1074 
1075 	/* Setup swapper PGD for fixmap */
1076 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
1077 			   __pa_symbol(fixmap_pgd_next),
1078 			   PGDIR_SIZE, PAGE_TABLE);
1079 
1080 	/* Map all memory banks in the linear mapping */
1081 	for_each_mem_range(i, &start, &end) {
1082 		if (start >= end)
1083 			break;
1084 		if (start <= __pa(PAGE_OFFSET) &&
1085 		    __pa(PAGE_OFFSET) < end)
1086 			start = __pa(PAGE_OFFSET);
1087 		if (end >= __pa(PAGE_OFFSET) + memory_limit)
1088 			end = __pa(PAGE_OFFSET) + memory_limit;
1089 
1090 		map_size = best_map_size(start, end - start);
1091 		for (pa = start; pa < end; pa += map_size) {
1092 			va = (uintptr_t)__va(pa);
1093 
1094 			create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1095 					   pgprot_from_va(va));
1096 		}
1097 	}
1098 
1099 	/* Map the kernel */
1100 	if (IS_ENABLED(CONFIG_64BIT))
1101 		create_kernel_page_table(swapper_pg_dir, false);
1102 
1103 #ifdef CONFIG_KASAN
1104 	kasan_swapper_init();
1105 #endif
1106 
1107 	/* Clear fixmap PTE and PMD mappings */
1108 	clear_fixmap(FIX_PTE);
1109 	clear_fixmap(FIX_PMD);
1110 	clear_fixmap(FIX_PUD);
1111 	clear_fixmap(FIX_P4D);
1112 
1113 	/* Move to swapper page table */
1114 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode);
1115 	local_flush_tlb_all();
1116 
1117 	pt_ops_set_late();
1118 }
1119 #else
1120 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1121 {
1122 	dtb_early_va = (void *)dtb_pa;
1123 	dtb_early_pa = dtb_pa;
1124 }
1125 
1126 static inline void setup_vm_final(void)
1127 {
1128 }
1129 #endif /* CONFIG_MMU */
1130 
1131 /*
1132  * reserve_crashkernel() - reserves memory for crash kernel
1133  *
1134  * This function reserves memory area given in "crashkernel=" kernel command
1135  * line parameter. The memory reserved is used by dump capture kernel when
1136  * primary kernel is crashing.
1137  */
1138 static void __init reserve_crashkernel(void)
1139 {
1140 	unsigned long long crash_base = 0;
1141 	unsigned long long crash_size = 0;
1142 	unsigned long search_start = memblock_start_of_DRAM();
1143 	unsigned long search_end = memblock_end_of_DRAM();
1144 
1145 	int ret = 0;
1146 
1147 	if (!IS_ENABLED(CONFIG_KEXEC_CORE))
1148 		return;
1149 	/*
1150 	 * Don't reserve a region for a crash kernel on a crash kernel
1151 	 * since it doesn't make much sense and we have limited memory
1152 	 * resources.
1153 	 */
1154 	if (is_kdump_kernel()) {
1155 		pr_info("crashkernel: ignoring reservation request\n");
1156 		return;
1157 	}
1158 
1159 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
1160 				&crash_size, &crash_base);
1161 	if (ret || !crash_size)
1162 		return;
1163 
1164 	crash_size = PAGE_ALIGN(crash_size);
1165 
1166 	if (crash_base) {
1167 		search_start = crash_base;
1168 		search_end = crash_base + crash_size;
1169 	}
1170 
1171 	/*
1172 	 * Current riscv boot protocol requires 2MB alignment for
1173 	 * RV64 and 4MB alignment for RV32 (hugepage size)
1174 	 *
1175 	 * Try to alloc from 32bit addressible physical memory so that
1176 	 * swiotlb can work on the crash kernel.
1177 	 */
1178 	crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
1179 					       search_start,
1180 					       min(search_end, (unsigned long) SZ_4G));
1181 	if (crash_base == 0) {
1182 		/* Try again without restricting region to 32bit addressible memory */
1183 		crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
1184 						search_start, search_end);
1185 		if (crash_base == 0) {
1186 			pr_warn("crashkernel: couldn't allocate %lldKB\n",
1187 				crash_size >> 10);
1188 			return;
1189 		}
1190 	}
1191 
1192 	pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
1193 		crash_base, crash_base + crash_size, crash_size >> 20);
1194 
1195 	crashk_res.start = crash_base;
1196 	crashk_res.end = crash_base + crash_size - 1;
1197 }
1198 
1199 void __init paging_init(void)
1200 {
1201 	setup_bootmem();
1202 	setup_vm_final();
1203 }
1204 
1205 void __init misc_mem_init(void)
1206 {
1207 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
1208 	arch_numa_init();
1209 	sparse_init();
1210 	zone_sizes_init();
1211 	reserve_crashkernel();
1212 	memblock_dump_all();
1213 }
1214 
1215 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1216 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1217 			       struct vmem_altmap *altmap)
1218 {
1219 	return vmemmap_populate_basepages(start, end, node, NULL);
1220 }
1221 #endif
1222