xref: /linux/arch/riscv/mm/init.c (revision cee73b1e840c154f64ace682cb477c1ae2e29cc4)
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 #include <linux/kfence.h>
24 #include <linux/execmem.h>
25 
26 #include <asm/alternative.h>
27 #include <asm/fixmap.h>
28 #include <asm/io.h>
29 #include <asm/kasan.h>
30 #include <asm/module.h>
31 #include <asm/numa.h>
32 #include <asm/pgtable.h>
33 #include <asm/sections.h>
34 #include <asm/soc.h>
35 #include <asm/sparsemem.h>
36 #include <asm/tlbflush.h>
37 
38 #include "../kernel/head.h"
39 
40 u64 new_vmalloc[NR_CPUS / sizeof(u64) + 1];
41 
42 struct kernel_mapping kernel_map __ro_after_init;
43 EXPORT_SYMBOL(kernel_map);
44 #ifdef CONFIG_XIP_KERNEL
45 #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
46 #endif
47 
48 #ifdef CONFIG_64BIT
49 u64 satp_mode __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_57 : SATP_MODE_39;
50 #else
51 u64 satp_mode __ro_after_init = SATP_MODE_32;
52 #endif
53 EXPORT_SYMBOL(satp_mode);
54 
55 #ifdef CONFIG_64BIT
56 bool pgtable_l4_enabled __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL);
57 bool pgtable_l5_enabled __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL);
58 EXPORT_SYMBOL(pgtable_l4_enabled);
59 EXPORT_SYMBOL(pgtable_l5_enabled);
60 #endif
61 
62 phys_addr_t phys_ram_base __ro_after_init;
63 EXPORT_SYMBOL(phys_ram_base);
64 
65 #ifdef CONFIG_SPARSEMEM_VMEMMAP
66 #define VMEMMAP_ADDR_ALIGN	(1ULL << SECTION_SIZE_BITS)
67 
68 unsigned long vmemmap_start_pfn __ro_after_init;
69 EXPORT_SYMBOL(vmemmap_start_pfn);
70 #endif
71 
72 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
73 							__page_aligned_bss;
74 EXPORT_SYMBOL(empty_zero_page);
75 
76 extern char _start[];
77 void *_dtb_early_va __initdata;
78 uintptr_t _dtb_early_pa __initdata;
79 
80 phys_addr_t dma32_phys_limit __initdata;
81 
82 void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
83 {
84 #ifdef CONFIG_ZONE_DMA32
85 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
86 #endif
87 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
88 }
89 
90 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
91 
92 #define LOG2_SZ_1K  ilog2(SZ_1K)
93 #define LOG2_SZ_1M  ilog2(SZ_1M)
94 #define LOG2_SZ_1G  ilog2(SZ_1G)
95 #define LOG2_SZ_1T  ilog2(SZ_1T)
96 
97 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
98 {
99 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
100 		  (((t) - (b)) >> LOG2_SZ_1K));
101 }
102 
103 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
104 {
105 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
106 		  (((t) - (b)) >> LOG2_SZ_1M));
107 }
108 
109 static inline void print_mlg(char *name, unsigned long b, unsigned long t)
110 {
111 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld GB)\n", name, b, t,
112 		   (((t) - (b)) >> LOG2_SZ_1G));
113 }
114 
115 #ifdef CONFIG_64BIT
116 static inline void print_mlt(char *name, unsigned long b, unsigned long t)
117 {
118 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld TB)\n", name, b, t,
119 		   (((t) - (b)) >> LOG2_SZ_1T));
120 }
121 #else
122 #define print_mlt(n, b, t) do {} while (0)
123 #endif
124 
125 static inline void print_ml(char *name, unsigned long b, unsigned long t)
126 {
127 	unsigned long diff = t - b;
128 
129 	if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10)
130 		print_mlt(name, b, t);
131 	else if ((diff >> LOG2_SZ_1G) >= 10)
132 		print_mlg(name, b, t);
133 	else if ((diff >> LOG2_SZ_1M) >= 10)
134 		print_mlm(name, b, t);
135 	else
136 		print_mlk(name, b, t);
137 }
138 
139 static void __init print_vm_layout(void)
140 {
141 	pr_notice("Virtual kernel memory layout:\n");
142 	print_ml("fixmap", (unsigned long)FIXADDR_START,
143 		(unsigned long)FIXADDR_TOP);
144 	print_ml("pci io", (unsigned long)PCI_IO_START,
145 		(unsigned long)PCI_IO_END);
146 	print_ml("vmemmap", (unsigned long)VMEMMAP_START,
147 		(unsigned long)VMEMMAP_END);
148 	print_ml("vmalloc", (unsigned long)VMALLOC_START,
149 		(unsigned long)VMALLOC_END);
150 #ifdef CONFIG_64BIT
151 	print_ml("modules", (unsigned long)MODULES_VADDR,
152 		(unsigned long)MODULES_END);
153 #endif
154 	print_ml("lowmem", (unsigned long)PAGE_OFFSET,
155 		(unsigned long)high_memory);
156 	if (IS_ENABLED(CONFIG_64BIT)) {
157 #ifdef CONFIG_KASAN
158 		print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
159 #endif
160 
161 		print_ml("kernel", (unsigned long)kernel_map.virt_addr,
162 			 (unsigned long)ADDRESS_SPACE_END);
163 	}
164 }
165 #else
166 static void print_vm_layout(void) { }
167 #endif /* CONFIG_DEBUG_VM */
168 
169 void __init arch_mm_preinit(void)
170 {
171 	bool swiotlb = max_pfn > PFN_DOWN(dma32_phys_limit);
172 #ifdef CONFIG_FLATMEM
173 	BUG_ON(!mem_map);
174 #endif /* CONFIG_FLATMEM */
175 
176 	if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb &&
177 	    dma_cache_alignment != 1) {
178 		/*
179 		 * If no bouncing needed for ZONE_DMA, allocate 1MB swiotlb
180 		 * buffer per 1GB of RAM for kmalloc() bouncing on
181 		 * non-coherent platforms.
182 		 */
183 		unsigned long size =
184 			DIV_ROUND_UP(memblock_phys_mem_size(), 1024);
185 		swiotlb_adjust_size(min(swiotlb_size_or_default(), size));
186 		swiotlb = true;
187 	}
188 
189 	swiotlb_init(swiotlb, SWIOTLB_VERBOSE);
190 
191 	print_vm_layout();
192 }
193 
194 /* Limit the memory size via mem. */
195 static phys_addr_t memory_limit;
196 #ifdef CONFIG_XIP_KERNEL
197 #define memory_limit	(*(phys_addr_t *)XIP_FIXUP(&memory_limit))
198 #endif /* CONFIG_XIP_KERNEL */
199 
200 static int __init early_mem(char *p)
201 {
202 	u64 size;
203 
204 	if (!p)
205 		return 1;
206 
207 	size = memparse(p, &p) & PAGE_MASK;
208 	memory_limit = min_t(u64, size, memory_limit);
209 
210 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
211 
212 	return 0;
213 }
214 early_param("mem", early_mem);
215 
216 static void __init setup_bootmem(void)
217 {
218 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
219 	phys_addr_t max_mapped_addr;
220 	phys_addr_t phys_ram_end, vmlinux_start;
221 
222 	if (IS_ENABLED(CONFIG_XIP_KERNEL))
223 		vmlinux_start = __pa_symbol(&_sdata);
224 	else
225 		vmlinux_start = __pa_symbol(&_start);
226 
227 	memblock_enforce_memory_limit(memory_limit);
228 
229 	/*
230 	 * Make sure we align the reservation on PMD_SIZE since we will
231 	 * map the kernel in the linear mapping as read-only: we do not want
232 	 * any allocation to happen between _end and the next pmd aligned page.
233 	 */
234 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
235 		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
236 	/*
237 	 * Reserve from the start of the kernel to the end of the kernel
238 	 */
239 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
240 
241 	/*
242 	 * Make sure we align the start of the memory on a PMD boundary so that
243 	 * at worst, we map the linear mapping with PMD mappings.
244 	 */
245 	if (!IS_ENABLED(CONFIG_XIP_KERNEL)) {
246 		phys_ram_base = memblock_start_of_DRAM() & PMD_MASK;
247 #ifdef CONFIG_SPARSEMEM_VMEMMAP
248 		vmemmap_start_pfn = round_down(phys_ram_base, VMEMMAP_ADDR_ALIGN) >> PAGE_SHIFT;
249 #endif
250 	}
251 
252 	/*
253 	 * In 64-bit, any use of __va/__pa before this point is wrong as we
254 	 * did not know the start of DRAM before.
255 	 */
256 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU))
257 		kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
258 
259 	/*
260 	 * The size of the linear page mapping may restrict the amount of
261 	 * usable RAM.
262 	 */
263 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) {
264 		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
265 		if (memblock_end_of_DRAM() > max_mapped_addr) {
266 			memblock_cap_memory_range(phys_ram_base,
267 						  max_mapped_addr - phys_ram_base);
268 			pr_warn("Physical memory overflows the linear mapping size: region above %pa removed",
269 				&max_mapped_addr);
270 		}
271 	}
272 
273 	/*
274 	 * Reserve physical address space that would be mapped to virtual
275 	 * addresses greater than (void *)(-PAGE_SIZE) because:
276 	 *  - This memory would overlap with ERR_PTR
277 	 *  - This memory belongs to high memory, which is not supported
278 	 *
279 	 * This is not applicable to 64-bit kernel, because virtual addresses
280 	 * after (void *)(-PAGE_SIZE) are not linearly mapped: they are
281 	 * occupied by kernel mapping. Also it is unrealistic for high memory
282 	 * to exist on 64-bit platforms.
283 	 */
284 	if (!IS_ENABLED(CONFIG_64BIT)) {
285 		max_mapped_addr = __va_to_pa_nodebug(-PAGE_SIZE);
286 		memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr);
287 	}
288 
289 	phys_ram_end = memblock_end_of_DRAM();
290 	min_low_pfn = PFN_UP(phys_ram_base);
291 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
292 
293 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
294 
295 	reserve_initrd_mem();
296 
297 	/*
298 	 * No allocation should be done before reserving the memory as defined
299 	 * in the device tree, otherwise the allocation could end up in a
300 	 * reserved region.
301 	 */
302 	early_init_fdt_scan_reserved_mem();
303 
304 	/*
305 	 * If DTB is built in, no need to reserve its memblock.
306 	 * Otherwise, do reserve it but avoid using
307 	 * early_init_fdt_reserve_self() since __pa() does
308 	 * not work for DTB pointers that are fixmap addresses
309 	 */
310 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
311 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
312 
313 	dma_contiguous_reserve(dma32_phys_limit);
314 }
315 
316 #ifdef CONFIG_RELOCATABLE
317 extern unsigned long __rela_dyn_start, __rela_dyn_end;
318 
319 static void __init relocate_kernel(void)
320 {
321 	Elf_Rela *rela = (Elf_Rela *)&__rela_dyn_start;
322 	/*
323 	 * This holds the offset between the linked virtual address and the
324 	 * relocated virtual address.
325 	 */
326 	uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
327 	/*
328 	 * This holds the offset between kernel linked virtual address and
329 	 * physical address.
330 	 */
331 	uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
332 
333 	for ( ; rela < (Elf_Rela *)&__rela_dyn_end; rela++) {
334 		Elf_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
335 		Elf_Addr relocated_addr = rela->r_addend;
336 
337 		if (rela->r_info != R_RISCV_RELATIVE)
338 			continue;
339 
340 		/*
341 		 * Make sure to not relocate vdso symbols like rt_sigreturn
342 		 * which are linked from the address 0 in vmlinux since
343 		 * vdso symbol addresses are actually used as an offset from
344 		 * mm->context.vdso in VDSO_OFFSET macro.
345 		 */
346 		if (relocated_addr >= KERNEL_LINK_ADDR)
347 			relocated_addr += reloc_offset;
348 
349 		*(Elf_Addr *)addr = relocated_addr;
350 	}
351 }
352 #endif /* CONFIG_RELOCATABLE */
353 
354 #ifdef CONFIG_MMU
355 struct pt_alloc_ops pt_ops __meminitdata;
356 
357 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
358 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
359 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
360 
361 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
362 
363 #ifdef CONFIG_XIP_KERNEL
364 #define pt_ops			(*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
365 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
366 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
367 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
368 #endif /* CONFIG_XIP_KERNEL */
369 
370 static const pgprot_t protection_map[16] = {
371 	[VM_NONE]					= PAGE_NONE,
372 	[VM_READ]					= PAGE_READ,
373 	[VM_WRITE]					= PAGE_SHADOWSTACK,
374 	[VM_WRITE | VM_READ]				= PAGE_COPY,
375 	[VM_EXEC]					= PAGE_EXEC,
376 	[VM_EXEC | VM_READ]				= PAGE_READ_EXEC,
377 	[VM_EXEC | VM_WRITE]				= PAGE_COPY_EXEC,
378 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_COPY_EXEC,
379 	[VM_SHARED]					= PAGE_NONE,
380 	[VM_SHARED | VM_READ]				= PAGE_READ,
381 	[VM_SHARED | VM_WRITE]				= PAGE_SHARED,
382 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
383 	[VM_SHARED | VM_EXEC]				= PAGE_EXEC,
384 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ_EXEC,
385 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_SHARED_EXEC,
386 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED_EXEC
387 };
388 DECLARE_VM_GET_PAGE_PROT
389 
390 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
391 {
392 	unsigned long addr = __fix_to_virt(idx);
393 	pte_t *ptep;
394 
395 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
396 
397 	ptep = &fixmap_pte[pte_index(addr)];
398 
399 	if (pgprot_val(prot))
400 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
401 	else
402 		pte_clear(&init_mm, addr, ptep);
403 	local_flush_tlb_page(addr);
404 }
405 
406 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
407 {
408 	return (pte_t *)((uintptr_t)pa);
409 }
410 
411 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
412 {
413 	clear_fixmap(FIX_PTE);
414 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
415 }
416 
417 static inline pte_t *__meminit get_pte_virt_late(phys_addr_t pa)
418 {
419 	return (pte_t *) __va(pa);
420 }
421 
422 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
423 {
424 	/*
425 	 * We only create PMD or PGD early mappings so we
426 	 * should never reach here with MMU disabled.
427 	 */
428 	BUG();
429 }
430 
431 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
432 {
433 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
434 }
435 
436 static phys_addr_t __meminit alloc_pte_late(uintptr_t va)
437 {
438 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
439 
440 	/*
441 	 * We do not know which mm the PTE page is associated to at this point.
442 	 * Passing NULL to the ctor is the safe option, though it may result
443 	 * in unnecessary work (e.g. initialising the ptlock for init_mm).
444 	 */
445 	BUG_ON(!ptdesc || !pagetable_pte_ctor(NULL, ptdesc));
446 	return __pa((pte_t *)ptdesc_address(ptdesc));
447 }
448 
449 static void __meminit create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
450 					 pgprot_t prot)
451 {
452 	uintptr_t pte_idx = pte_index(va);
453 
454 	BUG_ON(sz != PAGE_SIZE);
455 
456 	if (pte_none(ptep[pte_idx]))
457 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
458 }
459 
460 #ifndef __PAGETABLE_PMD_FOLDED
461 
462 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
463 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
464 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
465 
466 #ifdef CONFIG_XIP_KERNEL
467 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
468 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
469 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
470 #endif /* CONFIG_XIP_KERNEL */
471 
472 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss;
473 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss;
474 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
475 
476 #ifdef CONFIG_XIP_KERNEL
477 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d))
478 #define fixmap_p4d     ((p4d_t *)XIP_FIXUP(fixmap_p4d))
479 #define early_p4d      ((p4d_t *)XIP_FIXUP(early_p4d))
480 #endif /* CONFIG_XIP_KERNEL */
481 
482 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss;
483 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss;
484 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
485 
486 #ifdef CONFIG_XIP_KERNEL
487 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud))
488 #define fixmap_pud     ((pud_t *)XIP_FIXUP(fixmap_pud))
489 #define early_pud      ((pud_t *)XIP_FIXUP(early_pud))
490 #endif /* CONFIG_XIP_KERNEL */
491 
492 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
493 {
494 	/* Before MMU is enabled */
495 	return (pmd_t *)((uintptr_t)pa);
496 }
497 
498 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
499 {
500 	clear_fixmap(FIX_PMD);
501 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
502 }
503 
504 static pmd_t *__meminit get_pmd_virt_late(phys_addr_t pa)
505 {
506 	return (pmd_t *) __va(pa);
507 }
508 
509 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
510 {
511 	BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT);
512 
513 	return (uintptr_t)early_pmd;
514 }
515 
516 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
517 {
518 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
519 }
520 
521 static phys_addr_t __meminit alloc_pmd_late(uintptr_t va)
522 {
523 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
524 
525 	/* See comment in alloc_pte_late() regarding NULL passed the ctor */
526 	BUG_ON(!ptdesc || !pagetable_pmd_ctor(NULL, ptdesc));
527 	return __pa((pmd_t *)ptdesc_address(ptdesc));
528 }
529 
530 static void __meminit create_pmd_mapping(pmd_t *pmdp,
531 					 uintptr_t va, phys_addr_t pa,
532 					 phys_addr_t sz, pgprot_t prot)
533 {
534 	pte_t *ptep;
535 	phys_addr_t pte_phys;
536 	uintptr_t pmd_idx = pmd_index(va);
537 
538 	if (sz == PMD_SIZE) {
539 		if (pmd_none(pmdp[pmd_idx]))
540 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
541 		return;
542 	}
543 
544 	if (pmd_none(pmdp[pmd_idx])) {
545 		pte_phys = pt_ops.alloc_pte(va);
546 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
547 		ptep = pt_ops.get_pte_virt(pte_phys);
548 		memset(ptep, 0, PAGE_SIZE);
549 	} else {
550 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
551 		ptep = pt_ops.get_pte_virt(pte_phys);
552 	}
553 
554 	create_pte_mapping(ptep, va, pa, sz, prot);
555 }
556 
557 static pud_t *__init get_pud_virt_early(phys_addr_t pa)
558 {
559 	return (pud_t *)((uintptr_t)pa);
560 }
561 
562 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
563 {
564 	clear_fixmap(FIX_PUD);
565 	return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
566 }
567 
568 static pud_t *__meminit get_pud_virt_late(phys_addr_t pa)
569 {
570 	return (pud_t *)__va(pa);
571 }
572 
573 static phys_addr_t __init alloc_pud_early(uintptr_t va)
574 {
575 	/* Only one PUD is available for early mapping */
576 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
577 
578 	return (uintptr_t)early_pud;
579 }
580 
581 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
582 {
583 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
584 }
585 
586 static phys_addr_t __meminit alloc_pud_late(uintptr_t va)
587 {
588 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
589 
590 	BUG_ON(!ptdesc);
591 	pagetable_pud_ctor(ptdesc);
592 	return __pa((pud_t *)ptdesc_address(ptdesc));
593 }
594 
595 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa)
596 {
597 	return (p4d_t *)((uintptr_t)pa);
598 }
599 
600 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
601 {
602 	clear_fixmap(FIX_P4D);
603 	return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
604 }
605 
606 static p4d_t *__meminit get_p4d_virt_late(phys_addr_t pa)
607 {
608 	return (p4d_t *)__va(pa);
609 }
610 
611 static phys_addr_t __init alloc_p4d_early(uintptr_t va)
612 {
613 	/* Only one P4D is available for early mapping */
614 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
615 
616 	return (uintptr_t)early_p4d;
617 }
618 
619 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
620 {
621 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
622 }
623 
624 static phys_addr_t __meminit alloc_p4d_late(uintptr_t va)
625 {
626 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
627 
628 	BUG_ON(!ptdesc);
629 	pagetable_p4d_ctor(ptdesc);
630 	return __pa((p4d_t *)ptdesc_address(ptdesc));
631 }
632 
633 static void __meminit create_pud_mapping(pud_t *pudp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
634 					 pgprot_t prot)
635 {
636 	pmd_t *nextp;
637 	phys_addr_t next_phys;
638 	uintptr_t pud_index = pud_index(va);
639 
640 	if (sz == PUD_SIZE) {
641 		if (pud_val(pudp[pud_index]) == 0)
642 			pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot);
643 		return;
644 	}
645 
646 	if (pud_val(pudp[pud_index]) == 0) {
647 		next_phys = pt_ops.alloc_pmd(va);
648 		pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE);
649 		nextp = pt_ops.get_pmd_virt(next_phys);
650 		memset(nextp, 0, PAGE_SIZE);
651 	} else {
652 		next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index]));
653 		nextp = pt_ops.get_pmd_virt(next_phys);
654 	}
655 
656 	create_pmd_mapping(nextp, va, pa, sz, prot);
657 }
658 
659 static void __meminit create_p4d_mapping(p4d_t *p4dp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
660 					 pgprot_t prot)
661 {
662 	pud_t *nextp;
663 	phys_addr_t next_phys;
664 	uintptr_t p4d_index = p4d_index(va);
665 
666 	if (sz == P4D_SIZE) {
667 		if (p4d_val(p4dp[p4d_index]) == 0)
668 			p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot);
669 		return;
670 	}
671 
672 	if (p4d_val(p4dp[p4d_index]) == 0) {
673 		next_phys = pt_ops.alloc_pud(va);
674 		p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE);
675 		nextp = pt_ops.get_pud_virt(next_phys);
676 		memset(nextp, 0, PAGE_SIZE);
677 	} else {
678 		next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index]));
679 		nextp = pt_ops.get_pud_virt(next_phys);
680 	}
681 
682 	create_pud_mapping(nextp, va, pa, sz, prot);
683 }
684 
685 #define pgd_next_t		p4d_t
686 #define alloc_pgd_next(__va)	(pgtable_l5_enabled ?			\
687 		pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ?		\
688 		pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
689 #define get_pgd_next_virt(__pa)	(pgtable_l5_enabled ?			\
690 		pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ?	\
691 		pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
692 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
693 				(pgtable_l5_enabled ?			\
694 		create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
695 				(pgtable_l4_enabled ?			\
696 		create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) :	\
697 		create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
698 #define fixmap_pgd_next		(pgtable_l5_enabled ?			\
699 		(uintptr_t)fixmap_p4d : (pgtable_l4_enabled ?		\
700 		(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
701 #define trampoline_pgd_next	(pgtable_l5_enabled ?			\
702 		(uintptr_t)trampoline_p4d : (pgtable_l4_enabled ?	\
703 		(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
704 #else
705 #define pgd_next_t		pte_t
706 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
707 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
708 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
709 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
710 #define fixmap_pgd_next		((uintptr_t)fixmap_pte)
711 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
712 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
713 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
714 #endif /* __PAGETABLE_PMD_FOLDED */
715 
716 void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
717 				  pgprot_t prot)
718 {
719 	pgd_next_t *nextp;
720 	phys_addr_t next_phys;
721 	uintptr_t pgd_idx = pgd_index(va);
722 
723 	if (sz == PGDIR_SIZE) {
724 		if (pgd_val(pgdp[pgd_idx]) == 0)
725 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
726 		return;
727 	}
728 
729 	if (pgd_val(pgdp[pgd_idx]) == 0) {
730 		next_phys = alloc_pgd_next(va);
731 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
732 		nextp = get_pgd_next_virt(next_phys);
733 		memset(nextp, 0, PAGE_SIZE);
734 	} else {
735 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
736 		nextp = get_pgd_next_virt(next_phys);
737 	}
738 
739 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
740 }
741 
742 static uintptr_t __meminit best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size)
743 {
744 	if (debug_pagealloc_enabled())
745 		return PAGE_SIZE;
746 
747 	if (pgtable_l5_enabled &&
748 	    !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)
749 		return P4D_SIZE;
750 
751 	if (pgtable_l4_enabled &&
752 	    !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE)
753 		return PUD_SIZE;
754 
755 	if (IS_ENABLED(CONFIG_64BIT) &&
756 	    !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE)
757 		return PMD_SIZE;
758 
759 	return PAGE_SIZE;
760 }
761 
762 #ifdef CONFIG_XIP_KERNEL
763 #define phys_ram_base  (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base))
764 extern char _xiprom[], _exiprom[], __data_loc;
765 
766 /* called from head.S with MMU off */
767 asmlinkage void __init __copy_data(void)
768 {
769 	void *from = (void *)(&__data_loc);
770 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
771 	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
772 
773 	memcpy(to, from, sz);
774 }
775 #endif
776 
777 #ifdef CONFIG_STRICT_KERNEL_RWX
778 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
779 {
780 	if (is_va_kernel_text(va))
781 		return PAGE_KERNEL_READ_EXEC;
782 
783 	/*
784 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
785 	 * we must protect its linear mapping alias from being executed and
786 	 * written.
787 	 * And rodata section is marked readonly in mark_rodata_ro.
788 	 */
789 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
790 		return PAGE_KERNEL_READ;
791 
792 	return PAGE_KERNEL;
793 }
794 
795 void mark_rodata_ro(void)
796 {
797 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
798 	if (IS_ENABLED(CONFIG_64BIT))
799 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
800 				  set_memory_ro);
801 }
802 #else
803 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
804 {
805 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
806 		return PAGE_KERNEL;
807 
808 	return PAGE_KERNEL_EXEC;
809 }
810 #endif /* CONFIG_STRICT_KERNEL_RWX */
811 
812 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
813 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa);
814 u64 __pi_set_satp_mode_from_fdt(uintptr_t dtb_pa);
815 
816 static void __init disable_pgtable_l5(void)
817 {
818 	pgtable_l5_enabled = false;
819 	kernel_map.page_offset = PAGE_OFFSET_L4;
820 	satp_mode = SATP_MODE_48;
821 }
822 
823 static void __init disable_pgtable_l4(void)
824 {
825 	pgtable_l4_enabled = false;
826 	kernel_map.page_offset = PAGE_OFFSET_L3;
827 	satp_mode = SATP_MODE_39;
828 }
829 
830 static int __init print_no4lvl(char *p)
831 {
832 	pr_info("Disabled 4-level and 5-level paging");
833 	return 0;
834 }
835 early_param("no4lvl", print_no4lvl);
836 
837 static int __init print_no5lvl(char *p)
838 {
839 	pr_info("Disabled 5-level paging");
840 	return 0;
841 }
842 early_param("no5lvl", print_no5lvl);
843 
844 static void __init set_mmap_rnd_bits_max(void)
845 {
846 	mmap_rnd_bits_max = MMAP_VA_BITS - PAGE_SHIFT - 3;
847 }
848 
849 /*
850  * There is a simple way to determine if 4-level is supported by the
851  * underlying hardware: establish 1:1 mapping in 4-level page table mode
852  * then read SATP to see if the configuration was taken into account
853  * meaning sv48 is supported.
854  * The maximum SATP mode is limited by both the command line and the "mmu-type"
855  * property in the device tree, since some platforms may hang if an unsupported
856  * SATP mode is attempted.
857  */
858 static __init void set_satp_mode(uintptr_t dtb_pa)
859 {
860 	u64 identity_satp, hw_satp;
861 	uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
862 	u64 satp_mode_limit = min_not_zero(__pi_set_satp_mode_from_cmdline(dtb_pa),
863 					   __pi_set_satp_mode_from_fdt(dtb_pa));
864 
865 	kernel_map.page_offset = PAGE_OFFSET_L5;
866 
867 	if (satp_mode_limit == SATP_MODE_48) {
868 		disable_pgtable_l5();
869 	} else if (satp_mode_limit == SATP_MODE_39) {
870 		disable_pgtable_l5();
871 		disable_pgtable_l4();
872 		return;
873 	}
874 
875 	create_p4d_mapping(early_p4d,
876 			set_satp_mode_pmd, (uintptr_t)early_pud,
877 			P4D_SIZE, PAGE_TABLE);
878 	create_pud_mapping(early_pud,
879 			   set_satp_mode_pmd, (uintptr_t)early_pmd,
880 			   PUD_SIZE, PAGE_TABLE);
881 	/* Handle the case where set_satp_mode straddles 2 PMDs */
882 	create_pmd_mapping(early_pmd,
883 			   set_satp_mode_pmd, set_satp_mode_pmd,
884 			   PMD_SIZE, PAGE_KERNEL_EXEC);
885 	create_pmd_mapping(early_pmd,
886 			   set_satp_mode_pmd + PMD_SIZE,
887 			   set_satp_mode_pmd + PMD_SIZE,
888 			   PMD_SIZE, PAGE_KERNEL_EXEC);
889 retry:
890 	create_pgd_mapping(early_pg_dir,
891 			   set_satp_mode_pmd,
892 			   pgtable_l5_enabled ?
893 				(uintptr_t)early_p4d : (uintptr_t)early_pud,
894 			   PGDIR_SIZE, PAGE_TABLE);
895 
896 	identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
897 
898 	local_flush_tlb_all();
899 	csr_write(CSR_SATP, identity_satp);
900 	hw_satp = csr_swap(CSR_SATP, 0ULL);
901 	local_flush_tlb_all();
902 
903 	if (hw_satp != identity_satp) {
904 		if (pgtable_l5_enabled) {
905 			disable_pgtable_l5();
906 			memset(early_pg_dir, 0, PAGE_SIZE);
907 			goto retry;
908 		}
909 		disable_pgtable_l4();
910 	}
911 
912 	memset(early_pg_dir, 0, PAGE_SIZE);
913 	memset(early_p4d, 0, PAGE_SIZE);
914 	memset(early_pud, 0, PAGE_SIZE);
915 	memset(early_pmd, 0, PAGE_SIZE);
916 }
917 #endif
918 
919 /*
920  * setup_vm() is called from head.S with MMU-off.
921  *
922  * Following requirements should be honoured for setup_vm() to work
923  * correctly:
924  * 1) It should use PC-relative addressing for accessing kernel symbols.
925  *    To achieve this we always use GCC cmodel=medany.
926  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
927  *    so disable compiler instrumentation when FTRACE is enabled.
928  *
929  * Currently, the above requirements are honoured by using custom CFLAGS
930  * for init.o in mm/Makefile.
931  */
932 
933 #ifndef __riscv_cmodel_medany
934 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
935 #endif
936 
937 #ifdef CONFIG_XIP_KERNEL
938 static void __init create_kernel_page_table(pgd_t *pgdir,
939 					    __always_unused bool early)
940 {
941 	uintptr_t va, start_va, end_va;
942 
943 	/* Map the flash resident part */
944 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
945 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
946 		create_pgd_mapping(pgdir, va,
947 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
948 				   PMD_SIZE, PAGE_KERNEL_EXEC);
949 
950 	/* Map the data in RAM */
951 	start_va = kernel_map.virt_addr + (uintptr_t)&_sdata - (uintptr_t)&_start;
952 	end_va = kernel_map.virt_addr + kernel_map.size;
953 	for (va = start_va; va < end_va; va += PMD_SIZE)
954 		create_pgd_mapping(pgdir, va,
955 				   kernel_map.phys_addr + (va - start_va),
956 				   PMD_SIZE, PAGE_KERNEL);
957 }
958 #else
959 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
960 {
961 	uintptr_t va, end_va;
962 
963 	end_va = kernel_map.virt_addr + kernel_map.size;
964 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
965 		create_pgd_mapping(pgdir, va,
966 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
967 				   PMD_SIZE,
968 				   early ?
969 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
970 }
971 #endif
972 
973 /*
974  * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
975  * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
976  * entry.
977  */
978 static void __init create_fdt_early_page_table(uintptr_t fix_fdt_va,
979 					       uintptr_t dtb_pa)
980 {
981 #ifndef CONFIG_BUILTIN_DTB
982 	uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
983 
984 	/* Make sure the fdt fixmap address is always aligned on PMD size */
985 	BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE));
986 
987 	/* In 32-bit only, the fdt lies in its own PGD */
988 	if (!IS_ENABLED(CONFIG_64BIT)) {
989 		create_pgd_mapping(early_pg_dir, fix_fdt_va,
990 				   pa, MAX_FDT_SIZE, PAGE_KERNEL);
991 	} else {
992 		create_pmd_mapping(fixmap_pmd, fix_fdt_va,
993 				   pa, PMD_SIZE, PAGE_KERNEL);
994 		create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE,
995 				   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
996 	}
997 
998 	dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1));
999 #else
1000 	/*
1001 	 * For 64-bit kernel, __va can't be used since it would return a linear
1002 	 * mapping address whereas dtb_early_va will be used before
1003 	 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
1004 	 * kernel is mapped in the linear mapping, that makes no difference.
1005 	 */
1006 	dtb_early_va = kernel_mapping_pa_to_va(dtb_pa);
1007 #endif
1008 
1009 	dtb_early_pa = dtb_pa;
1010 }
1011 
1012 /*
1013  * MMU is not enabled, the page tables are allocated directly using
1014  * early_pmd/pud/p4d and the address returned is the physical one.
1015  */
1016 static void __init pt_ops_set_early(void)
1017 {
1018 	pt_ops.alloc_pte = alloc_pte_early;
1019 	pt_ops.get_pte_virt = get_pte_virt_early;
1020 #ifndef __PAGETABLE_PMD_FOLDED
1021 	pt_ops.alloc_pmd = alloc_pmd_early;
1022 	pt_ops.get_pmd_virt = get_pmd_virt_early;
1023 	pt_ops.alloc_pud = alloc_pud_early;
1024 	pt_ops.get_pud_virt = get_pud_virt_early;
1025 	pt_ops.alloc_p4d = alloc_p4d_early;
1026 	pt_ops.get_p4d_virt = get_p4d_virt_early;
1027 #endif
1028 }
1029 
1030 /*
1031  * MMU is enabled but page table setup is not complete yet.
1032  * fixmap page table alloc functions must be used as a means to temporarily
1033  * map the allocated physical pages since the linear mapping does not exist yet.
1034  *
1035  * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va,
1036  * but it will be used as described above.
1037  */
1038 static void __init pt_ops_set_fixmap(void)
1039 {
1040 	pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap);
1041 	pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap);
1042 #ifndef __PAGETABLE_PMD_FOLDED
1043 	pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap);
1044 	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap);
1045 	pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap);
1046 	pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap);
1047 	pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap);
1048 	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap);
1049 #endif
1050 }
1051 
1052 /*
1053  * MMU is enabled and page table setup is complete, so from now, we can use
1054  * generic page allocation functions to setup page table.
1055  */
1056 static void __init pt_ops_set_late(void)
1057 {
1058 	pt_ops.alloc_pte = alloc_pte_late;
1059 	pt_ops.get_pte_virt = get_pte_virt_late;
1060 #ifndef __PAGETABLE_PMD_FOLDED
1061 	pt_ops.alloc_pmd = alloc_pmd_late;
1062 	pt_ops.get_pmd_virt = get_pmd_virt_late;
1063 	pt_ops.alloc_pud = alloc_pud_late;
1064 	pt_ops.get_pud_virt = get_pud_virt_late;
1065 	pt_ops.alloc_p4d = alloc_p4d_late;
1066 	pt_ops.get_p4d_virt = get_p4d_virt_late;
1067 #endif
1068 }
1069 
1070 #ifdef CONFIG_RANDOMIZE_BASE
1071 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa);
1072 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa);
1073 extern u64 __init __pi_get_kaslr_seed_zkr(const uintptr_t dtb_pa);
1074 
1075 static int __init print_nokaslr(char *p)
1076 {
1077 	pr_info("Disabled KASLR");
1078 	return 0;
1079 }
1080 early_param("nokaslr", print_nokaslr);
1081 
1082 unsigned long kaslr_offset(void)
1083 {
1084 	return kernel_map.virt_offset;
1085 }
1086 #endif
1087 
1088 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1089 {
1090 	pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
1091 
1092 #ifdef CONFIG_RANDOMIZE_BASE
1093 	if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) {
1094 		u64 kaslr_seed = __pi_get_kaslr_seed_zkr(dtb_pa);
1095 		u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1096 		u32 nr_pos;
1097 
1098 		if (kaslr_seed == 0)
1099 			kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
1100 		/*
1101 		 * Compute the number of positions available: we are limited
1102 		 * by the early page table that only has one PUD and we must
1103 		 * be aligned on PMD_SIZE.
1104 		 */
1105 		nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE;
1106 
1107 		kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE;
1108 	}
1109 #endif
1110 
1111 	kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset;
1112 
1113 #ifdef CONFIG_XIP_KERNEL
1114 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
1115 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
1116 
1117 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
1118 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1119 	vmemmap_start_pfn = round_down(phys_ram_base, VMEMMAP_ADDR_ALIGN) >> PAGE_SHIFT;
1120 #endif
1121 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
1122 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1123 
1124 	kernel_map.va_kernel_xip_text_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
1125 	kernel_map.va_kernel_xip_data_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr
1126 						+ (uintptr_t)&_sdata - (uintptr_t)&_start;
1127 #else
1128 	kernel_map.phys_addr = (uintptr_t)(&_start);
1129 	kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
1130 	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
1131 #endif
1132 
1133 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
1134 	set_satp_mode(dtb_pa);
1135 	set_mmap_rnd_bits_max();
1136 #endif
1137 
1138 	/*
1139 	 * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem,
1140 	 * where we have the system memory layout: this allows us to align
1141 	 * the physical and virtual mappings and then make use of PUD/P4D/PGD
1142 	 * for the linear mapping. This is only possible because the kernel
1143 	 * mapping lies outside the linear mapping.
1144 	 * In 32-bit however, as the kernel resides in the linear mapping,
1145 	 * setup_vm_final can not change the mapping established here,
1146 	 * otherwise the same kernel addresses would get mapped to different
1147 	 * physical addresses (if the start of dram is different from the
1148 	 * kernel physical address start).
1149 	 */
1150 	kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ?
1151 				0UL : PAGE_OFFSET - kernel_map.phys_addr;
1152 
1153 	memory_limit = KERN_VIRT_SIZE;
1154 
1155 	/* Sanity check alignment and size */
1156 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
1157 	BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);
1158 
1159 #ifdef CONFIG_64BIT
1160 	/*
1161 	 * The last 4K bytes of the addressable memory can not be mapped because
1162 	 * of IS_ERR_VALUE macro.
1163 	 */
1164 	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
1165 #endif
1166 
1167 #ifdef CONFIG_RELOCATABLE
1168 	/*
1169 	 * Early page table uses only one PUD, which makes it possible
1170 	 * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset
1171 	 * makes the kernel cross over a PUD_SIZE boundary, raise a bug
1172 	 * since a part of the kernel would not get mapped.
1173 	 */
1174 	if (IS_ENABLED(CONFIG_64BIT))
1175 		BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size);
1176 	relocate_kernel();
1177 #endif
1178 
1179 	apply_early_boot_alternatives();
1180 	pt_ops_set_early();
1181 
1182 	/* Setup early PGD for fixmap */
1183 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
1184 			   fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1185 
1186 #ifndef __PAGETABLE_PMD_FOLDED
1187 	/* Setup fixmap P4D and PUD */
1188 	if (pgtable_l5_enabled)
1189 		create_p4d_mapping(fixmap_p4d, FIXADDR_START,
1190 				   (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
1191 	/* Setup fixmap PUD and PMD */
1192 	if (pgtable_l4_enabled)
1193 		create_pud_mapping(fixmap_pud, FIXADDR_START,
1194 				   (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
1195 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
1196 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
1197 	/* Setup trampoline PGD and PMD */
1198 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1199 			   trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1200 	if (pgtable_l5_enabled)
1201 		create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
1202 				   (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
1203 	if (pgtable_l4_enabled)
1204 		create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
1205 				   (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
1206 #ifdef CONFIG_XIP_KERNEL
1207 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1208 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
1209 #else
1210 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1211 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
1212 #endif
1213 #else
1214 	/* Setup trampoline PGD */
1215 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1216 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
1217 #endif
1218 
1219 	/*
1220 	 * Setup early PGD covering entire kernel which will allow
1221 	 * us to reach paging_init(). We map all memory banks later
1222 	 * in setup_vm_final() below.
1223 	 */
1224 	create_kernel_page_table(early_pg_dir, true);
1225 
1226 	/* Setup early mapping for FDT early scan */
1227 	create_fdt_early_page_table(__fix_to_virt(FIX_FDT), dtb_pa);
1228 
1229 	/*
1230 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
1231 	 * range can not span multiple pmds.
1232 	 */
1233 	BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1234 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1235 
1236 #ifndef __PAGETABLE_PMD_FOLDED
1237 	/*
1238 	 * Early ioremap fixmap is already created as it lies within first 2MB
1239 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
1240 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
1241 	 * the user if not.
1242 	 */
1243 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
1244 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
1245 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
1246 		WARN_ON(1);
1247 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
1248 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
1249 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1250 			fix_to_virt(FIX_BTMAP_BEGIN));
1251 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
1252 			fix_to_virt(FIX_BTMAP_END));
1253 
1254 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
1255 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
1256 	}
1257 #endif
1258 
1259 	pt_ops_set_fixmap();
1260 }
1261 
1262 static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end,
1263 						  uintptr_t fixed_map_size, const pgprot_t *pgprot)
1264 {
1265 	phys_addr_t pa;
1266 	uintptr_t va, map_size;
1267 
1268 	for (pa = start; pa < end; pa += map_size) {
1269 		va = (uintptr_t)__va(pa);
1270 		map_size = fixed_map_size ? fixed_map_size :
1271 					    best_map_size(pa, va, end - pa);
1272 
1273 		create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1274 				   pgprot ? *pgprot : pgprot_from_va(va));
1275 	}
1276 }
1277 
1278 static void __init create_linear_mapping_page_table(void)
1279 {
1280 	phys_addr_t start, end;
1281 	phys_addr_t kfence_pool __maybe_unused;
1282 	u64 i;
1283 
1284 #ifdef CONFIG_STRICT_KERNEL_RWX
1285 	phys_addr_t ktext_start = __pa_symbol(_start);
1286 	phys_addr_t ktext_size = __init_data_begin - _start;
1287 	phys_addr_t krodata_start = __pa_symbol(__start_rodata);
1288 	phys_addr_t krodata_size = _data - __start_rodata;
1289 
1290 	/* Isolate kernel text and rodata so they don't get mapped with a PUD */
1291 	memblock_mark_nomap(ktext_start,  ktext_size);
1292 	memblock_mark_nomap(krodata_start, krodata_size);
1293 #endif
1294 
1295 #ifdef CONFIG_KFENCE
1296 	/*
1297 	 *  kfence pool must be backed by PAGE_SIZE mappings, so allocate it
1298 	 *  before we setup the linear mapping so that we avoid using hugepages
1299 	 *  for this region.
1300 	 */
1301 	kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
1302 	BUG_ON(!kfence_pool);
1303 
1304 	memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE);
1305 	__kfence_pool = __va(kfence_pool);
1306 #endif
1307 
1308 	/* Map all memory banks in the linear mapping */
1309 	for_each_mem_range(i, &start, &end) {
1310 		if (start >= end)
1311 			break;
1312 		if (start <= __pa(PAGE_OFFSET) &&
1313 		    __pa(PAGE_OFFSET) < end)
1314 			start = __pa(PAGE_OFFSET);
1315 
1316 		create_linear_mapping_range(start, end, 0, NULL);
1317 	}
1318 
1319 #ifdef CONFIG_STRICT_KERNEL_RWX
1320 	create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0, NULL);
1321 	create_linear_mapping_range(krodata_start, krodata_start + krodata_size, 0, NULL);
1322 
1323 	memblock_clear_nomap(ktext_start,  ktext_size);
1324 	memblock_clear_nomap(krodata_start, krodata_size);
1325 #endif
1326 
1327 #ifdef CONFIG_KFENCE
1328 	create_linear_mapping_range(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, PAGE_SIZE, NULL);
1329 
1330 	memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
1331 #endif
1332 }
1333 
1334 static void __init setup_vm_final(void)
1335 {
1336 	/* Setup swapper PGD for fixmap */
1337 #if !defined(CONFIG_64BIT)
1338 	/*
1339 	 * In 32-bit, the device tree lies in a pgd entry, so it must be copied
1340 	 * directly in swapper_pg_dir in addition to the pgd entry that points
1341 	 * to fixmap_pte.
1342 	 */
1343 	unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT));
1344 
1345 	set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]);
1346 #endif
1347 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
1348 			   __pa_symbol(fixmap_pgd_next),
1349 			   PGDIR_SIZE, PAGE_TABLE);
1350 
1351 	/* Map the linear mapping */
1352 	create_linear_mapping_page_table();
1353 
1354 	/* Map the kernel */
1355 	if (IS_ENABLED(CONFIG_64BIT))
1356 		create_kernel_page_table(swapper_pg_dir, false);
1357 
1358 #ifdef CONFIG_KASAN
1359 	kasan_swapper_init();
1360 #endif
1361 
1362 	/* Clear fixmap PTE and PMD mappings */
1363 	clear_fixmap(FIX_PTE);
1364 	clear_fixmap(FIX_PMD);
1365 	clear_fixmap(FIX_PUD);
1366 	clear_fixmap(FIX_P4D);
1367 
1368 	/* Move to swapper page table */
1369 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode);
1370 	local_flush_tlb_all();
1371 
1372 	pt_ops_set_late();
1373 }
1374 #else
1375 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1376 {
1377 	dtb_early_va = (void *)dtb_pa;
1378 	dtb_early_pa = dtb_pa;
1379 
1380 #ifdef CONFIG_RELOCATABLE
1381 	kernel_map.virt_addr = (uintptr_t)_start;
1382 	kernel_map.phys_addr = (uintptr_t)_start;
1383 	relocate_kernel();
1384 #endif
1385 }
1386 
1387 static inline void setup_vm_final(void)
1388 {
1389 }
1390 #endif /* CONFIG_MMU */
1391 
1392 /*
1393  * reserve_crashkernel() - reserves memory for crash kernel
1394  *
1395  * This function reserves memory area given in "crashkernel=" kernel command
1396  * line parameter. The memory reserved is used by dump capture kernel when
1397  * primary kernel is crashing.
1398  */
1399 static void __init arch_reserve_crashkernel(void)
1400 {
1401 	unsigned long long low_size = 0;
1402 	unsigned long long crash_base, crash_size;
1403 	bool high = false;
1404 	int ret;
1405 
1406 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
1407 		return;
1408 
1409 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
1410 				&crash_size, &crash_base,
1411 				&low_size, NULL, &high);
1412 	if (ret)
1413 		return;
1414 
1415 	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
1416 }
1417 
1418 void __init paging_init(void)
1419 {
1420 	setup_bootmem();
1421 	setup_vm_final();
1422 
1423 	/* Depend on that Linear Mapping is ready */
1424 	memblock_allow_resize();
1425 }
1426 
1427 void __init misc_mem_init(void)
1428 {
1429 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
1430 	arch_numa_init();
1431 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1432 	/* The entire VMEMMAP region has been populated. Flush TLB for this region */
1433 	local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END);
1434 #endif
1435 	arch_reserve_crashkernel();
1436 	memblock_dump_all();
1437 }
1438 
1439 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1440 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
1441 			       unsigned long addr, unsigned long next)
1442 {
1443 	pmd_set_huge(pmd, virt_to_phys(p), PAGE_KERNEL);
1444 }
1445 
1446 int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node,
1447 				unsigned long addr, unsigned long next)
1448 {
1449 	vmemmap_verify((pte_t *)pmdp, node, addr, next);
1450 	return 1;
1451 }
1452 
1453 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1454 			       struct vmem_altmap *altmap)
1455 {
1456 	/*
1457 	 * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we
1458 	 * can't use hugepage mappings for 2-level page table because in case of
1459 	 * memory hotplug, we are not able to update all the page tables with
1460 	 * the new PMDs.
1461 	 */
1462 	return vmemmap_populate_hugepages(start, end, node, altmap);
1463 }
1464 #endif
1465 
1466 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
1467 /*
1468  * Pre-allocates page-table pages for a specific area in the kernel
1469  * page-table. Only the level which needs to be synchronized between
1470  * all page-tables is allocated because the synchronization can be
1471  * expensive.
1472  */
1473 static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end,
1474 					       const char *area)
1475 {
1476 	unsigned long addr;
1477 	const char *lvl;
1478 
1479 	for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1480 		pgd_t *pgd = pgd_offset_k(addr);
1481 		p4d_t *p4d;
1482 		pud_t *pud;
1483 		pmd_t *pmd;
1484 
1485 		lvl = "p4d";
1486 		p4d = p4d_alloc(&init_mm, pgd, addr);
1487 		if (!p4d)
1488 			goto failed;
1489 
1490 		if (pgtable_l5_enabled)
1491 			continue;
1492 
1493 		lvl = "pud";
1494 		pud = pud_alloc(&init_mm, p4d, addr);
1495 		if (!pud)
1496 			goto failed;
1497 
1498 		if (pgtable_l4_enabled)
1499 			continue;
1500 
1501 		lvl = "pmd";
1502 		pmd = pmd_alloc(&init_mm, pud, addr);
1503 		if (!pmd)
1504 			goto failed;
1505 	}
1506 	return;
1507 
1508 failed:
1509 	/*
1510 	 * The pages have to be there now or they will be missing in
1511 	 * process page-tables later.
1512 	 */
1513 	panic("Failed to pre-allocate %s pages for %s area\n", lvl, area);
1514 }
1515 
1516 #define PAGE_END KASAN_SHADOW_START
1517 
1518 void __init pgtable_cache_init(void)
1519 {
1520 	preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc");
1521 	if (IS_ENABLED(CONFIG_MODULES))
1522 		preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules");
1523 	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) {
1524 		preallocate_pgd_pages_range(VMEMMAP_START, VMEMMAP_END, "vmemmap");
1525 		preallocate_pgd_pages_range(PAGE_OFFSET, PAGE_END, "direct map");
1526 		if (IS_ENABLED(CONFIG_KASAN))
1527 			preallocate_pgd_pages_range(KASAN_SHADOW_START, KASAN_SHADOW_END, "kasan");
1528 	}
1529 }
1530 #endif
1531 
1532 #ifdef CONFIG_EXECMEM
1533 #ifdef CONFIG_MMU
1534 static struct execmem_info execmem_info __ro_after_init;
1535 
1536 struct execmem_info __init *execmem_arch_setup(void)
1537 {
1538 	execmem_info = (struct execmem_info){
1539 		.ranges = {
1540 			[EXECMEM_DEFAULT] = {
1541 				.start	= MODULES_VADDR,
1542 				.end	= MODULES_END,
1543 				.pgprot	= PAGE_KERNEL,
1544 				.alignment = 1,
1545 			},
1546 			[EXECMEM_KPROBES] = {
1547 				.start	= VMALLOC_START,
1548 				.end	= VMALLOC_END,
1549 				.pgprot	= PAGE_KERNEL_READ_EXEC,
1550 				.alignment = 1,
1551 			},
1552 			[EXECMEM_BPF] = {
1553 				.start	= BPF_JIT_REGION_START,
1554 				.end	= BPF_JIT_REGION_END,
1555 				.pgprot	= PAGE_KERNEL,
1556 				.alignment = PAGE_SIZE,
1557 			},
1558 		},
1559 	};
1560 
1561 	return &execmem_info;
1562 }
1563 #endif /* CONFIG_MMU */
1564 #endif /* CONFIG_EXECMEM */
1565 
1566 #ifdef CONFIG_MEMORY_HOTPLUG
1567 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1568 {
1569 	struct page *page = pmd_page(*pmd);
1570 	struct ptdesc *ptdesc = page_ptdesc(page);
1571 	pte_t *pte;
1572 	int i;
1573 
1574 	for (i = 0; i < PTRS_PER_PTE; i++) {
1575 		pte = pte_start + i;
1576 		if (!pte_none(*pte))
1577 			return;
1578 	}
1579 
1580 	pagetable_dtor(ptdesc);
1581 	if (PageReserved(page))
1582 		free_reserved_page(page);
1583 	else
1584 		pagetable_free(ptdesc);
1585 	pmd_clear(pmd);
1586 }
1587 
1588 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud, bool is_vmemmap)
1589 {
1590 	struct page *page = pud_page(*pud);
1591 	struct ptdesc *ptdesc = page_ptdesc(page);
1592 	pmd_t *pmd;
1593 	int i;
1594 
1595 	for (i = 0; i < PTRS_PER_PMD; i++) {
1596 		pmd = pmd_start + i;
1597 		if (!pmd_none(*pmd))
1598 			return;
1599 	}
1600 
1601 	if (!is_vmemmap)
1602 		pagetable_dtor(ptdesc);
1603 	if (PageReserved(page))
1604 		free_reserved_page(page);
1605 	else
1606 		pagetable_free(ptdesc);
1607 	pud_clear(pud);
1608 }
1609 
1610 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1611 {
1612 	struct page *page = p4d_page(*p4d);
1613 	pud_t *pud;
1614 	int i;
1615 
1616 	for (i = 0; i < PTRS_PER_PUD; i++) {
1617 		pud = pud_start + i;
1618 		if (!pud_none(*pud))
1619 			return;
1620 	}
1621 
1622 	if (PageReserved(page))
1623 		free_reserved_page(page);
1624 	else
1625 		__free_pages(page, 0);
1626 	p4d_clear(p4d);
1627 }
1628 
1629 static void __meminit free_vmemmap_storage(struct page *page, size_t size,
1630 					   struct vmem_altmap *altmap)
1631 {
1632 	int order = get_order(size);
1633 
1634 	if (altmap) {
1635 		vmem_altmap_free(altmap, size >> PAGE_SHIFT);
1636 		return;
1637 	}
1638 
1639 	if (PageReserved(page)) {
1640 		unsigned int nr_pages = 1 << order;
1641 
1642 		while (nr_pages--)
1643 			free_reserved_page(page++);
1644 		return;
1645 	}
1646 
1647 	__free_pages(page, order);
1648 }
1649 
1650 static void __meminit remove_pte_mapping(pte_t *pte_base, unsigned long addr, unsigned long end,
1651 					 bool is_vmemmap, struct vmem_altmap *altmap)
1652 {
1653 	unsigned long next;
1654 	pte_t *ptep, pte;
1655 
1656 	for (; addr < end; addr = next) {
1657 		next = (addr + PAGE_SIZE) & PAGE_MASK;
1658 		if (next > end)
1659 			next = end;
1660 
1661 		ptep = pte_base + pte_index(addr);
1662 		pte = ptep_get(ptep);
1663 		if (!pte_present(*ptep))
1664 			continue;
1665 
1666 		pte_clear(&init_mm, addr, ptep);
1667 		if (is_vmemmap)
1668 			free_vmemmap_storage(pte_page(pte), PAGE_SIZE, altmap);
1669 	}
1670 }
1671 
1672 static void __meminit remove_pmd_mapping(pmd_t *pmd_base, unsigned long addr, unsigned long end,
1673 					 bool is_vmemmap, struct vmem_altmap *altmap)
1674 {
1675 	unsigned long next;
1676 	pte_t *pte_base;
1677 	pmd_t *pmdp, pmd;
1678 
1679 	for (; addr < end; addr = next) {
1680 		next = pmd_addr_end(addr, end);
1681 		pmdp = pmd_base + pmd_index(addr);
1682 		pmd = pmdp_get(pmdp);
1683 		if (!pmd_present(pmd))
1684 			continue;
1685 
1686 		if (pmd_leaf(pmd)) {
1687 			pmd_clear(pmdp);
1688 			if (is_vmemmap)
1689 				free_vmemmap_storage(pmd_page(pmd), PMD_SIZE, altmap);
1690 			continue;
1691 		}
1692 
1693 		pte_base = (pte_t *)pmd_page_vaddr(*pmdp);
1694 		remove_pte_mapping(pte_base, addr, next, is_vmemmap, altmap);
1695 		free_pte_table(pte_base, pmdp);
1696 	}
1697 }
1698 
1699 static void __meminit remove_pud_mapping(pud_t *pud_base, unsigned long addr, unsigned long end,
1700 					 bool is_vmemmap, struct vmem_altmap *altmap)
1701 {
1702 	unsigned long next;
1703 	pud_t *pudp, pud;
1704 	pmd_t *pmd_base;
1705 
1706 	for (; addr < end; addr = next) {
1707 		next = pud_addr_end(addr, end);
1708 		pudp = pud_base + pud_index(addr);
1709 		pud = pudp_get(pudp);
1710 		if (!pud_present(pud))
1711 			continue;
1712 
1713 		if (pud_leaf(pud)) {
1714 			if (pgtable_l4_enabled) {
1715 				pud_clear(pudp);
1716 				if (is_vmemmap)
1717 					free_vmemmap_storage(pud_page(pud), PUD_SIZE, altmap);
1718 			}
1719 			continue;
1720 		}
1721 
1722 		pmd_base = pmd_offset(pudp, 0);
1723 		remove_pmd_mapping(pmd_base, addr, next, is_vmemmap, altmap);
1724 
1725 		if (pgtable_l4_enabled)
1726 			free_pmd_table(pmd_base, pudp, is_vmemmap);
1727 	}
1728 }
1729 
1730 static void __meminit remove_p4d_mapping(p4d_t *p4d_base, unsigned long addr, unsigned long end,
1731 					 bool is_vmemmap, struct vmem_altmap *altmap)
1732 {
1733 	unsigned long next;
1734 	p4d_t *p4dp, p4d;
1735 	pud_t *pud_base;
1736 
1737 	for (; addr < end; addr = next) {
1738 		next = p4d_addr_end(addr, end);
1739 		p4dp = p4d_base + p4d_index(addr);
1740 		p4d = p4dp_get(p4dp);
1741 		if (!p4d_present(p4d))
1742 			continue;
1743 
1744 		if (p4d_leaf(p4d)) {
1745 			if (pgtable_l5_enabled) {
1746 				p4d_clear(p4dp);
1747 				if (is_vmemmap)
1748 					free_vmemmap_storage(p4d_page(p4d), P4D_SIZE, altmap);
1749 			}
1750 			continue;
1751 		}
1752 
1753 		pud_base = pud_offset(p4dp, 0);
1754 		remove_pud_mapping(pud_base, addr, next, is_vmemmap, altmap);
1755 
1756 		if (pgtable_l5_enabled)
1757 			free_pud_table(pud_base, p4dp);
1758 	}
1759 }
1760 
1761 static void __meminit remove_pgd_mapping(unsigned long va, unsigned long end, bool is_vmemmap,
1762 					 struct vmem_altmap *altmap)
1763 {
1764 	unsigned long addr, next;
1765 	p4d_t *p4d_base;
1766 	pgd_t *pgd;
1767 
1768 	for (addr = va; addr < end; addr = next) {
1769 		next = pgd_addr_end(addr, end);
1770 		pgd = pgd_offset_k(addr);
1771 
1772 		if (!pgd_present(*pgd))
1773 			continue;
1774 
1775 		if (pgd_leaf(*pgd))
1776 			continue;
1777 
1778 		p4d_base = p4d_offset(pgd, 0);
1779 		remove_p4d_mapping(p4d_base, addr, next, is_vmemmap, altmap);
1780 	}
1781 
1782 	flush_tlb_all();
1783 }
1784 
1785 static void __meminit remove_linear_mapping(phys_addr_t start, u64 size)
1786 {
1787 	unsigned long va = (unsigned long)__va(start);
1788 	unsigned long end = (unsigned long)__va(start + size);
1789 
1790 	remove_pgd_mapping(va, end, false, NULL);
1791 }
1792 
1793 struct range arch_get_mappable_range(void)
1794 {
1795 	struct range mhp_range;
1796 
1797 	mhp_range.start = __pa(PAGE_OFFSET);
1798 	mhp_range.end = __pa(PAGE_END - 1);
1799 	return mhp_range;
1800 }
1801 
1802 int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
1803 {
1804 	int ret = 0;
1805 
1806 	create_linear_mapping_range(start, start + size, 0, &params->pgprot);
1807 	ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, params);
1808 	if (ret) {
1809 		remove_linear_mapping(start, size);
1810 		goto out;
1811 	}
1812 
1813 	max_pfn = PFN_UP(start + size);
1814 	max_low_pfn = max_pfn;
1815 
1816  out:
1817 	flush_tlb_all();
1818 	return ret;
1819 }
1820 
1821 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1822 {
1823 	__remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap);
1824 	remove_linear_mapping(start, size);
1825 	flush_tlb_all();
1826 }
1827 
1828 void __ref vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
1829 {
1830 	remove_pgd_mapping(start, end, true, altmap);
1831 }
1832 #endif /* CONFIG_MEMORY_HOTPLUG */
1833