xref: /linux/arch/riscv/mm/init.c (revision aec2f682d47c54ef434b2d440992626d80b1ebdc)
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	max(1ULL << SECTION_SIZE_BITS, \
67 				    MAX_FOLIO_VMEMMAP_ALIGN)
68 
69 unsigned long vmemmap_start_pfn __ro_after_init;
70 EXPORT_SYMBOL(vmemmap_start_pfn);
71 #endif
72 
73 extern char _start[];
74 void *_dtb_early_va __initdata;
75 uintptr_t _dtb_early_pa __initdata;
76 
77 phys_addr_t dma32_phys_limit __initdata;
78 
79 void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
80 {
81 #ifdef CONFIG_ZONE_DMA32
82 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
83 #endif
84 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
85 }
86 
87 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
88 
89 #define LOG2_SZ_1K  ilog2(SZ_1K)
90 #define LOG2_SZ_1M  ilog2(SZ_1M)
91 #define LOG2_SZ_1G  ilog2(SZ_1G)
92 #define LOG2_SZ_1T  ilog2(SZ_1T)
93 
94 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
95 {
96 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
97 		  (((t) - (b)) >> LOG2_SZ_1K));
98 }
99 
100 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
101 {
102 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
103 		  (((t) - (b)) >> LOG2_SZ_1M));
104 }
105 
106 static inline void print_mlg(char *name, unsigned long b, unsigned long t)
107 {
108 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld GB)\n", name, b, t,
109 		   (((t) - (b)) >> LOG2_SZ_1G));
110 }
111 
112 #ifdef CONFIG_64BIT
113 static inline void print_mlt(char *name, unsigned long b, unsigned long t)
114 {
115 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld TB)\n", name, b, t,
116 		   (((t) - (b)) >> LOG2_SZ_1T));
117 }
118 #else
119 #define print_mlt(n, b, t) do {} while (0)
120 #endif
121 
122 static inline void print_ml(char *name, unsigned long b, unsigned long t)
123 {
124 	unsigned long diff = t - b;
125 
126 	if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10)
127 		print_mlt(name, b, t);
128 	else if ((diff >> LOG2_SZ_1G) >= 10)
129 		print_mlg(name, b, t);
130 	else if ((diff >> LOG2_SZ_1M) >= 10)
131 		print_mlm(name, b, t);
132 	else
133 		print_mlk(name, b, t);
134 }
135 
136 static void __init print_vm_layout(void)
137 {
138 	pr_notice("Virtual kernel memory layout:\n");
139 	print_ml("fixmap", (unsigned long)FIXADDR_START,
140 		(unsigned long)FIXADDR_TOP);
141 	print_ml("pci io", (unsigned long)PCI_IO_START,
142 		(unsigned long)PCI_IO_END);
143 	print_ml("vmemmap", (unsigned long)VMEMMAP_START,
144 		(unsigned long)VMEMMAP_END);
145 	print_ml("vmalloc", (unsigned long)VMALLOC_START,
146 		(unsigned long)VMALLOC_END);
147 #ifdef CONFIG_64BIT
148 	print_ml("modules", (unsigned long)MODULES_VADDR,
149 		(unsigned long)MODULES_END);
150 #endif
151 	print_ml("lowmem", (unsigned long)PAGE_OFFSET,
152 		(unsigned long)high_memory);
153 	if (IS_ENABLED(CONFIG_64BIT)) {
154 #ifdef CONFIG_KASAN
155 		print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
156 #endif
157 
158 		print_ml("kernel", (unsigned long)kernel_map.virt_addr,
159 			 (unsigned long)ADDRESS_SPACE_END);
160 	}
161 }
162 #else
163 static void print_vm_layout(void) { }
164 #endif /* CONFIG_DEBUG_VM */
165 
166 void __init arch_mm_preinit(void)
167 {
168 	bool swiotlb = max_pfn > PFN_DOWN(dma32_phys_limit);
169 #ifdef CONFIG_FLATMEM
170 	BUG_ON(!mem_map);
171 #endif /* CONFIG_FLATMEM */
172 
173 	if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb &&
174 	    dma_cache_alignment != 1) {
175 		/*
176 		 * If no bouncing needed for ZONE_DMA, allocate 1MB swiotlb
177 		 * buffer per 1GB of RAM for kmalloc() bouncing on
178 		 * non-coherent platforms.
179 		 */
180 		unsigned long size =
181 			DIV_ROUND_UP(memblock_phys_mem_size(), 1024);
182 		swiotlb_adjust_size(min(swiotlb_size_or_default(), size));
183 		swiotlb = true;
184 	}
185 
186 	swiotlb_init(swiotlb, SWIOTLB_VERBOSE);
187 
188 	print_vm_layout();
189 }
190 
191 /* Limit the memory size via mem. */
192 static phys_addr_t memory_limit;
193 #ifdef CONFIG_XIP_KERNEL
194 #define memory_limit	(*(phys_addr_t *)XIP_FIXUP(&memory_limit))
195 #endif /* CONFIG_XIP_KERNEL */
196 
197 static int __init early_mem(char *p)
198 {
199 	u64 size;
200 
201 	if (!p)
202 		return 1;
203 
204 	size = memparse(p, &p) & PAGE_MASK;
205 	memory_limit = min_t(u64, size, memory_limit);
206 
207 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
208 
209 	return 0;
210 }
211 early_param("mem", early_mem);
212 
213 static void __init setup_bootmem(void)
214 {
215 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
216 	phys_addr_t max_mapped_addr;
217 	phys_addr_t phys_ram_end, vmlinux_start;
218 
219 	if (IS_ENABLED(CONFIG_XIP_KERNEL))
220 		vmlinux_start = __pa_symbol(&_sdata);
221 	else
222 		vmlinux_start = __pa_symbol(&_start);
223 
224 	memblock_enforce_memory_limit(memory_limit);
225 
226 	/*
227 	 * Make sure we align the reservation on PMD_SIZE since we will
228 	 * map the kernel in the linear mapping as read-only: we do not want
229 	 * any allocation to happen between _end and the next pmd aligned page.
230 	 */
231 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
232 		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
233 	/*
234 	 * Reserve from the start of the kernel to the end of the kernel
235 	 */
236 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
237 
238 	/*
239 	 * Make sure we align the start of the memory on a PMD boundary so that
240 	 * at worst, we map the linear mapping with PMD mappings.
241 	 */
242 	if (!IS_ENABLED(CONFIG_XIP_KERNEL)) {
243 		phys_ram_base = memblock_start_of_DRAM() & PMD_MASK;
244 #ifdef CONFIG_SPARSEMEM_VMEMMAP
245 		vmemmap_start_pfn = round_down(phys_ram_base, VMEMMAP_ADDR_ALIGN) >> PAGE_SHIFT;
246 #endif
247 	}
248 
249 	/*
250 	 * In 64-bit, any use of __va/__pa before this point is wrong as we
251 	 * did not know the start of DRAM before.
252 	 */
253 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU))
254 		kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
255 
256 	/*
257 	 * The size of the linear page mapping may restrict the amount of
258 	 * usable RAM.
259 	 */
260 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) {
261 		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
262 		if (memblock_end_of_DRAM() > max_mapped_addr) {
263 			memblock_cap_memory_range(phys_ram_base,
264 						  max_mapped_addr - phys_ram_base);
265 			pr_warn("Physical memory overflows the linear mapping size: region above %pa removed",
266 				&max_mapped_addr);
267 		}
268 	}
269 
270 	/*
271 	 * Reserve physical address space that would be mapped to virtual
272 	 * addresses greater than (void *)(-PAGE_SIZE) because:
273 	 *  - This memory would overlap with ERR_PTR
274 	 *  - This memory belongs to high memory, which is not supported
275 	 *
276 	 * This is not applicable to 64-bit kernel, because virtual addresses
277 	 * after (void *)(-PAGE_SIZE) are not linearly mapped: they are
278 	 * occupied by kernel mapping. Also it is unrealistic for high memory
279 	 * to exist on 64-bit platforms.
280 	 */
281 	if (!IS_ENABLED(CONFIG_64BIT)) {
282 		max_mapped_addr = __va_to_pa_nodebug(-PAGE_SIZE);
283 		memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr);
284 	}
285 
286 	phys_ram_end = memblock_end_of_DRAM();
287 	min_low_pfn = PFN_UP(phys_ram_base);
288 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
289 
290 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
291 
292 	reserve_initrd_mem();
293 
294 	/*
295 	 * No allocation should be done before reserving the memory as defined
296 	 * in the device tree, otherwise the allocation could end up in a
297 	 * reserved region.
298 	 */
299 	early_init_fdt_scan_reserved_mem();
300 
301 	/*
302 	 * If DTB is built in, no need to reserve its memblock.
303 	 * Otherwise, do reserve it but avoid using
304 	 * early_init_fdt_reserve_self() since __pa() does
305 	 * not work for DTB pointers that are fixmap addresses
306 	 */
307 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
308 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
309 
310 	dma_contiguous_reserve(dma32_phys_limit);
311 }
312 
313 #ifdef CONFIG_RELOCATABLE
314 extern unsigned long __rela_dyn_start, __rela_dyn_end;
315 
316 static void __init relocate_kernel(void)
317 {
318 	Elf_Rela *rela = (Elf_Rela *)&__rela_dyn_start;
319 	/*
320 	 * This holds the offset between the linked virtual address and the
321 	 * relocated virtual address.
322 	 */
323 	uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
324 	/*
325 	 * This holds the offset between kernel linked virtual address and
326 	 * physical address.
327 	 */
328 	uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
329 
330 	for ( ; rela < (Elf_Rela *)&__rela_dyn_end; rela++) {
331 		Elf_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
332 		Elf_Addr relocated_addr = rela->r_addend;
333 
334 		if (rela->r_info != R_RISCV_RELATIVE)
335 			continue;
336 
337 		/*
338 		 * Make sure to not relocate vdso symbols like rt_sigreturn
339 		 * which are linked from the address 0 in vmlinux since
340 		 * vdso symbol addresses are actually used as an offset from
341 		 * mm->context.vdso in VDSO_OFFSET macro.
342 		 */
343 		if (relocated_addr >= KERNEL_LINK_ADDR)
344 			relocated_addr += reloc_offset;
345 
346 		*(Elf_Addr *)addr = relocated_addr;
347 	}
348 }
349 #endif /* CONFIG_RELOCATABLE */
350 
351 #ifdef CONFIG_MMU
352 struct pt_alloc_ops pt_ops __meminitdata;
353 
354 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
355 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
356 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
357 
358 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
359 
360 #ifdef CONFIG_XIP_KERNEL
361 #define pt_ops			(*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
362 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
363 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
364 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
365 #endif /* CONFIG_XIP_KERNEL */
366 
367 static const pgprot_t protection_map[16] = {
368 	[VM_NONE]					= PAGE_NONE,
369 	[VM_READ]					= PAGE_READ,
370 	[VM_WRITE]					= PAGE_SHADOWSTACK,
371 	[VM_WRITE | VM_READ]				= PAGE_COPY,
372 	[VM_EXEC]					= PAGE_EXEC,
373 	[VM_EXEC | VM_READ]				= PAGE_READ_EXEC,
374 	[VM_EXEC | VM_WRITE]				= PAGE_COPY_EXEC,
375 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_COPY_EXEC,
376 	[VM_SHARED]					= PAGE_NONE,
377 	[VM_SHARED | VM_READ]				= PAGE_READ,
378 	[VM_SHARED | VM_WRITE]				= PAGE_SHARED,
379 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
380 	[VM_SHARED | VM_EXEC]				= PAGE_EXEC,
381 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ_EXEC,
382 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_SHARED_EXEC,
383 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED_EXEC
384 };
385 DECLARE_VM_GET_PAGE_PROT
386 
387 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
388 {
389 	unsigned long addr = __fix_to_virt(idx);
390 	pte_t *ptep;
391 
392 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
393 
394 	ptep = &fixmap_pte[pte_index(addr)];
395 
396 	if (pgprot_val(prot))
397 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
398 	else
399 		pte_clear(&init_mm, addr, ptep);
400 	local_flush_tlb_page(addr);
401 }
402 
403 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
404 {
405 	return (pte_t *)((uintptr_t)pa);
406 }
407 
408 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
409 {
410 	clear_fixmap(FIX_PTE);
411 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
412 }
413 
414 static inline pte_t *__meminit get_pte_virt_late(phys_addr_t pa)
415 {
416 	return (pte_t *) __va(pa);
417 }
418 
419 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
420 {
421 	/*
422 	 * We only create PMD or PGD early mappings so we
423 	 * should never reach here with MMU disabled.
424 	 */
425 	BUG();
426 }
427 
428 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
429 {
430 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
431 }
432 
433 static phys_addr_t __meminit alloc_pte_late(uintptr_t va)
434 {
435 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
436 
437 	/*
438 	 * We do not know which mm the PTE page is associated to at this point.
439 	 * Passing NULL to the ctor is the safe option, though it may result
440 	 * in unnecessary work (e.g. initialising the ptlock for init_mm).
441 	 */
442 	BUG_ON(!ptdesc || !pagetable_pte_ctor(NULL, ptdesc));
443 	return __pa((pte_t *)ptdesc_address(ptdesc));
444 }
445 
446 static void __meminit create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
447 					 pgprot_t prot)
448 {
449 	uintptr_t pte_idx = pte_index(va);
450 
451 	BUG_ON(sz != PAGE_SIZE);
452 
453 	if (pte_none(ptep[pte_idx]))
454 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
455 }
456 
457 #ifndef __PAGETABLE_PMD_FOLDED
458 
459 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
460 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
461 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
462 
463 #ifdef CONFIG_XIP_KERNEL
464 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
465 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
466 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
467 #endif /* CONFIG_XIP_KERNEL */
468 
469 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss;
470 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss;
471 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
472 
473 #ifdef CONFIG_XIP_KERNEL
474 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d))
475 #define fixmap_p4d     ((p4d_t *)XIP_FIXUP(fixmap_p4d))
476 #define early_p4d      ((p4d_t *)XIP_FIXUP(early_p4d))
477 #endif /* CONFIG_XIP_KERNEL */
478 
479 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss;
480 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss;
481 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
482 
483 #ifdef CONFIG_XIP_KERNEL
484 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud))
485 #define fixmap_pud     ((pud_t *)XIP_FIXUP(fixmap_pud))
486 #define early_pud      ((pud_t *)XIP_FIXUP(early_pud))
487 #endif /* CONFIG_XIP_KERNEL */
488 
489 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
490 {
491 	/* Before MMU is enabled */
492 	return (pmd_t *)((uintptr_t)pa);
493 }
494 
495 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
496 {
497 	clear_fixmap(FIX_PMD);
498 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
499 }
500 
501 static pmd_t *__meminit get_pmd_virt_late(phys_addr_t pa)
502 {
503 	return (pmd_t *) __va(pa);
504 }
505 
506 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
507 {
508 	BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT);
509 
510 	return (uintptr_t)early_pmd;
511 }
512 
513 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
514 {
515 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
516 }
517 
518 static phys_addr_t __meminit alloc_pmd_late(uintptr_t va)
519 {
520 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
521 
522 	/* See comment in alloc_pte_late() regarding NULL passed the ctor */
523 	BUG_ON(!ptdesc || !pagetable_pmd_ctor(NULL, ptdesc));
524 	return __pa((pmd_t *)ptdesc_address(ptdesc));
525 }
526 
527 static void __meminit create_pmd_mapping(pmd_t *pmdp,
528 					 uintptr_t va, phys_addr_t pa,
529 					 phys_addr_t sz, pgprot_t prot)
530 {
531 	pte_t *ptep;
532 	phys_addr_t pte_phys;
533 	uintptr_t pmd_idx = pmd_index(va);
534 
535 	if (sz == PMD_SIZE) {
536 		if (pmd_none(pmdp[pmd_idx]))
537 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
538 		return;
539 	}
540 
541 	if (pmd_none(pmdp[pmd_idx])) {
542 		pte_phys = pt_ops.alloc_pte(va);
543 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
544 		ptep = pt_ops.get_pte_virt(pte_phys);
545 		memset(ptep, 0, PAGE_SIZE);
546 	} else {
547 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
548 		ptep = pt_ops.get_pte_virt(pte_phys);
549 	}
550 
551 	create_pte_mapping(ptep, va, pa, sz, prot);
552 }
553 
554 static pud_t *__init get_pud_virt_early(phys_addr_t pa)
555 {
556 	return (pud_t *)((uintptr_t)pa);
557 }
558 
559 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
560 {
561 	clear_fixmap(FIX_PUD);
562 	return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
563 }
564 
565 static pud_t *__meminit get_pud_virt_late(phys_addr_t pa)
566 {
567 	return (pud_t *)__va(pa);
568 }
569 
570 static phys_addr_t __init alloc_pud_early(uintptr_t va)
571 {
572 	/* Only one PUD is available for early mapping */
573 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
574 
575 	return (uintptr_t)early_pud;
576 }
577 
578 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
579 {
580 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
581 }
582 
583 static phys_addr_t __meminit alloc_pud_late(uintptr_t va)
584 {
585 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
586 
587 	BUG_ON(!ptdesc);
588 	pagetable_pud_ctor(ptdesc);
589 	return __pa((pud_t *)ptdesc_address(ptdesc));
590 }
591 
592 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa)
593 {
594 	return (p4d_t *)((uintptr_t)pa);
595 }
596 
597 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
598 {
599 	clear_fixmap(FIX_P4D);
600 	return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
601 }
602 
603 static p4d_t *__meminit get_p4d_virt_late(phys_addr_t pa)
604 {
605 	return (p4d_t *)__va(pa);
606 }
607 
608 static phys_addr_t __init alloc_p4d_early(uintptr_t va)
609 {
610 	/* Only one P4D is available for early mapping */
611 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
612 
613 	return (uintptr_t)early_p4d;
614 }
615 
616 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
617 {
618 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
619 }
620 
621 static phys_addr_t __meminit alloc_p4d_late(uintptr_t va)
622 {
623 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0);
624 
625 	BUG_ON(!ptdesc);
626 	pagetable_p4d_ctor(ptdesc);
627 	return __pa((p4d_t *)ptdesc_address(ptdesc));
628 }
629 
630 static void __meminit create_pud_mapping(pud_t *pudp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
631 					 pgprot_t prot)
632 {
633 	pmd_t *nextp;
634 	phys_addr_t next_phys;
635 	uintptr_t pud_index = pud_index(va);
636 
637 	if (sz == PUD_SIZE) {
638 		if (pud_val(pudp[pud_index]) == 0)
639 			pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot);
640 		return;
641 	}
642 
643 	if (pud_val(pudp[pud_index]) == 0) {
644 		next_phys = pt_ops.alloc_pmd(va);
645 		pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE);
646 		nextp = pt_ops.get_pmd_virt(next_phys);
647 		memset(nextp, 0, PAGE_SIZE);
648 	} else {
649 		next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index]));
650 		nextp = pt_ops.get_pmd_virt(next_phys);
651 	}
652 
653 	create_pmd_mapping(nextp, va, pa, sz, prot);
654 }
655 
656 static void __meminit create_p4d_mapping(p4d_t *p4dp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
657 					 pgprot_t prot)
658 {
659 	pud_t *nextp;
660 	phys_addr_t next_phys;
661 	uintptr_t p4d_index = p4d_index(va);
662 
663 	if (sz == P4D_SIZE) {
664 		if (p4d_val(p4dp[p4d_index]) == 0)
665 			p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot);
666 		return;
667 	}
668 
669 	if (p4d_val(p4dp[p4d_index]) == 0) {
670 		next_phys = pt_ops.alloc_pud(va);
671 		p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE);
672 		nextp = pt_ops.get_pud_virt(next_phys);
673 		memset(nextp, 0, PAGE_SIZE);
674 	} else {
675 		next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index]));
676 		nextp = pt_ops.get_pud_virt(next_phys);
677 	}
678 
679 	create_pud_mapping(nextp, va, pa, sz, prot);
680 }
681 
682 #define pgd_next_t		p4d_t
683 #define alloc_pgd_next(__va)	(pgtable_l5_enabled ?			\
684 		pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ?		\
685 		pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
686 #define get_pgd_next_virt(__pa)	(pgtable_l5_enabled ?			\
687 		pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ?	\
688 		pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
689 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
690 				(pgtable_l5_enabled ?			\
691 		create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
692 				(pgtable_l4_enabled ?			\
693 		create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) :	\
694 		create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
695 #define fixmap_pgd_next		(pgtable_l5_enabled ?			\
696 		(uintptr_t)fixmap_p4d : (pgtable_l4_enabled ?		\
697 		(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
698 #define trampoline_pgd_next	(pgtable_l5_enabled ?			\
699 		(uintptr_t)trampoline_p4d : (pgtable_l4_enabled ?	\
700 		(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
701 #else
702 #define pgd_next_t		pte_t
703 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
704 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
705 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
706 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
707 #define fixmap_pgd_next		((uintptr_t)fixmap_pte)
708 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
709 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
710 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
711 #endif /* __PAGETABLE_PMD_FOLDED */
712 
713 void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
714 				  pgprot_t prot)
715 {
716 	pgd_next_t *nextp;
717 	phys_addr_t next_phys;
718 	uintptr_t pgd_idx = pgd_index(va);
719 
720 	if (sz == PGDIR_SIZE) {
721 		if (pgd_val(pgdp[pgd_idx]) == 0)
722 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
723 		return;
724 	}
725 
726 	if (pgd_val(pgdp[pgd_idx]) == 0) {
727 		next_phys = alloc_pgd_next(va);
728 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
729 		nextp = get_pgd_next_virt(next_phys);
730 		memset(nextp, 0, PAGE_SIZE);
731 	} else {
732 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
733 		nextp = get_pgd_next_virt(next_phys);
734 	}
735 
736 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
737 }
738 
739 static uintptr_t __meminit best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size)
740 {
741 	if (debug_pagealloc_enabled())
742 		return PAGE_SIZE;
743 
744 	if (pgtable_l5_enabled &&
745 	    !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)
746 		return P4D_SIZE;
747 
748 	if (pgtable_l4_enabled &&
749 	    !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE)
750 		return PUD_SIZE;
751 
752 	if (IS_ENABLED(CONFIG_64BIT) &&
753 	    !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE)
754 		return PMD_SIZE;
755 
756 	return PAGE_SIZE;
757 }
758 
759 #ifdef CONFIG_XIP_KERNEL
760 #define phys_ram_base  (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base))
761 extern char _xiprom[], _exiprom[], __data_loc;
762 
763 /* called from head.S with MMU off */
764 asmlinkage void __init __copy_data(void)
765 {
766 	void *from = (void *)(&__data_loc);
767 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
768 	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
769 
770 	memcpy(to, from, sz);
771 }
772 #endif
773 
774 #ifdef CONFIG_STRICT_KERNEL_RWX
775 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
776 {
777 	if (is_va_kernel_text(va))
778 		return PAGE_KERNEL_READ_EXEC;
779 
780 	/*
781 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
782 	 * we must protect its linear mapping alias from being executed and
783 	 * written.
784 	 * And rodata section is marked readonly in mark_rodata_ro.
785 	 */
786 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
787 		return PAGE_KERNEL_READ;
788 
789 	return PAGE_KERNEL;
790 }
791 
792 void mark_rodata_ro(void)
793 {
794 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
795 	if (IS_ENABLED(CONFIG_64BIT))
796 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
797 				  set_memory_ro);
798 }
799 #else
800 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
801 {
802 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
803 		return PAGE_KERNEL;
804 
805 	return PAGE_KERNEL_EXEC;
806 }
807 #endif /* CONFIG_STRICT_KERNEL_RWX */
808 
809 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
810 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa);
811 u64 __pi_set_satp_mode_from_fdt(uintptr_t dtb_pa);
812 
813 static void __init disable_pgtable_l5(void)
814 {
815 	pgtable_l5_enabled = false;
816 	kernel_map.page_offset = PAGE_OFFSET_L4;
817 	satp_mode = SATP_MODE_48;
818 }
819 
820 static void __init disable_pgtable_l4(void)
821 {
822 	pgtable_l4_enabled = false;
823 	kernel_map.page_offset = PAGE_OFFSET_L3;
824 	satp_mode = SATP_MODE_39;
825 }
826 
827 static int __init print_no4lvl(char *p)
828 {
829 	pr_info("Disabled 4-level and 5-level paging");
830 	return 0;
831 }
832 early_param("no4lvl", print_no4lvl);
833 
834 static int __init print_no5lvl(char *p)
835 {
836 	pr_info("Disabled 5-level paging");
837 	return 0;
838 }
839 early_param("no5lvl", print_no5lvl);
840 
841 static void __init set_mmap_rnd_bits_max(void)
842 {
843 	mmap_rnd_bits_max = MMAP_VA_BITS - PAGE_SHIFT - 3;
844 }
845 
846 /*
847  * There is a simple way to determine if 4-level is supported by the
848  * underlying hardware: establish 1:1 mapping in 4-level page table mode
849  * then read SATP to see if the configuration was taken into account
850  * meaning sv48 is supported.
851  * The maximum SATP mode is limited by both the command line and the "mmu-type"
852  * property in the device tree, since some platforms may hang if an unsupported
853  * SATP mode is attempted.
854  */
855 static __init void set_satp_mode(uintptr_t dtb_pa)
856 {
857 	u64 identity_satp, hw_satp;
858 	uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
859 	u64 satp_mode_limit = min_not_zero(__pi_set_satp_mode_from_cmdline(dtb_pa),
860 					   __pi_set_satp_mode_from_fdt(dtb_pa));
861 
862 	kernel_map.page_offset = PAGE_OFFSET_L5;
863 
864 	if (satp_mode_limit == SATP_MODE_48) {
865 		disable_pgtable_l5();
866 	} else if (satp_mode_limit == SATP_MODE_39) {
867 		disable_pgtable_l5();
868 		disable_pgtable_l4();
869 		return;
870 	}
871 
872 	create_p4d_mapping(early_p4d,
873 			set_satp_mode_pmd, (uintptr_t)early_pud,
874 			P4D_SIZE, PAGE_TABLE);
875 	create_pud_mapping(early_pud,
876 			   set_satp_mode_pmd, (uintptr_t)early_pmd,
877 			   PUD_SIZE, PAGE_TABLE);
878 	/* Handle the case where set_satp_mode straddles 2 PMDs */
879 	create_pmd_mapping(early_pmd,
880 			   set_satp_mode_pmd, set_satp_mode_pmd,
881 			   PMD_SIZE, PAGE_KERNEL_EXEC);
882 	create_pmd_mapping(early_pmd,
883 			   set_satp_mode_pmd + PMD_SIZE,
884 			   set_satp_mode_pmd + PMD_SIZE,
885 			   PMD_SIZE, PAGE_KERNEL_EXEC);
886 retry:
887 	create_pgd_mapping(early_pg_dir,
888 			   set_satp_mode_pmd,
889 			   pgtable_l5_enabled ?
890 				(uintptr_t)early_p4d : (uintptr_t)early_pud,
891 			   PGDIR_SIZE, PAGE_TABLE);
892 
893 	identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
894 
895 	local_flush_tlb_all();
896 	csr_write(CSR_SATP, identity_satp);
897 	hw_satp = csr_swap(CSR_SATP, 0ULL);
898 	local_flush_tlb_all();
899 
900 	if (hw_satp != identity_satp) {
901 		if (pgtable_l5_enabled) {
902 			disable_pgtable_l5();
903 			memset(early_pg_dir, 0, PAGE_SIZE);
904 			goto retry;
905 		}
906 		disable_pgtable_l4();
907 	}
908 
909 	memset(early_pg_dir, 0, PAGE_SIZE);
910 	memset(early_p4d, 0, PAGE_SIZE);
911 	memset(early_pud, 0, PAGE_SIZE);
912 	memset(early_pmd, 0, PAGE_SIZE);
913 }
914 #endif
915 
916 /*
917  * setup_vm() is called from head.S with MMU-off.
918  *
919  * Following requirements should be honoured for setup_vm() to work
920  * correctly:
921  * 1) It should use PC-relative addressing for accessing kernel symbols.
922  *    To achieve this we always use GCC cmodel=medany.
923  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
924  *    so disable compiler instrumentation when FTRACE is enabled.
925  *
926  * Currently, the above requirements are honoured by using custom CFLAGS
927  * for init.o in mm/Makefile.
928  */
929 
930 #ifndef __riscv_cmodel_medany
931 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
932 #endif
933 
934 #ifdef CONFIG_XIP_KERNEL
935 static void __init create_kernel_page_table(pgd_t *pgdir,
936 					    __always_unused bool early)
937 {
938 	uintptr_t va, start_va, end_va;
939 
940 	/* Map the flash resident part */
941 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
942 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
943 		create_pgd_mapping(pgdir, va,
944 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
945 				   PMD_SIZE, PAGE_KERNEL_EXEC);
946 
947 	/* Map the data in RAM */
948 	start_va = kernel_map.virt_addr + (uintptr_t)&_sdata - (uintptr_t)&_start;
949 	end_va = kernel_map.virt_addr + kernel_map.size;
950 	for (va = start_va; va < end_va; va += PMD_SIZE)
951 		create_pgd_mapping(pgdir, va,
952 				   kernel_map.phys_addr + (va - start_va),
953 				   PMD_SIZE, PAGE_KERNEL);
954 }
955 #else
956 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
957 {
958 	uintptr_t va, end_va;
959 
960 	end_va = kernel_map.virt_addr + kernel_map.size;
961 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
962 		create_pgd_mapping(pgdir, va,
963 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
964 				   PMD_SIZE,
965 				   early ?
966 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
967 }
968 #endif
969 
970 /*
971  * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
972  * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
973  * entry.
974  */
975 static void __init create_fdt_early_page_table(uintptr_t fix_fdt_va,
976 					       uintptr_t dtb_pa)
977 {
978 #ifndef CONFIG_BUILTIN_DTB
979 	uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
980 
981 	/* Make sure the fdt fixmap address is always aligned on PMD size */
982 	BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE));
983 
984 	/* In 32-bit only, the fdt lies in its own PGD */
985 	if (!IS_ENABLED(CONFIG_64BIT)) {
986 		create_pgd_mapping(early_pg_dir, fix_fdt_va,
987 				   pa, MAX_FDT_SIZE, PAGE_KERNEL);
988 	} else {
989 		create_pmd_mapping(fixmap_pmd, fix_fdt_va,
990 				   pa, PMD_SIZE, PAGE_KERNEL);
991 		create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE,
992 				   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
993 	}
994 
995 	dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1));
996 #else
997 	/*
998 	 * For 64-bit kernel, __va can't be used since it would return a linear
999 	 * mapping address whereas dtb_early_va will be used before
1000 	 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
1001 	 * kernel is mapped in the linear mapping, that makes no difference.
1002 	 */
1003 	dtb_early_va = kernel_mapping_pa_to_va(dtb_pa);
1004 #endif
1005 
1006 	dtb_early_pa = dtb_pa;
1007 }
1008 
1009 /*
1010  * MMU is not enabled, the page tables are allocated directly using
1011  * early_pmd/pud/p4d and the address returned is the physical one.
1012  */
1013 static void __init pt_ops_set_early(void)
1014 {
1015 	pt_ops.alloc_pte = alloc_pte_early;
1016 	pt_ops.get_pte_virt = get_pte_virt_early;
1017 #ifndef __PAGETABLE_PMD_FOLDED
1018 	pt_ops.alloc_pmd = alloc_pmd_early;
1019 	pt_ops.get_pmd_virt = get_pmd_virt_early;
1020 	pt_ops.alloc_pud = alloc_pud_early;
1021 	pt_ops.get_pud_virt = get_pud_virt_early;
1022 	pt_ops.alloc_p4d = alloc_p4d_early;
1023 	pt_ops.get_p4d_virt = get_p4d_virt_early;
1024 #endif
1025 }
1026 
1027 /*
1028  * MMU is enabled but page table setup is not complete yet.
1029  * fixmap page table alloc functions must be used as a means to temporarily
1030  * map the allocated physical pages since the linear mapping does not exist yet.
1031  *
1032  * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va,
1033  * but it will be used as described above.
1034  */
1035 static void __init pt_ops_set_fixmap(void)
1036 {
1037 	pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap);
1038 	pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap);
1039 #ifndef __PAGETABLE_PMD_FOLDED
1040 	pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap);
1041 	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap);
1042 	pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap);
1043 	pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap);
1044 	pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap);
1045 	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap);
1046 #endif
1047 }
1048 
1049 /*
1050  * MMU is enabled and page table setup is complete, so from now, we can use
1051  * generic page allocation functions to setup page table.
1052  */
1053 static void __init pt_ops_set_late(void)
1054 {
1055 	pt_ops.alloc_pte = alloc_pte_late;
1056 	pt_ops.get_pte_virt = get_pte_virt_late;
1057 #ifndef __PAGETABLE_PMD_FOLDED
1058 	pt_ops.alloc_pmd = alloc_pmd_late;
1059 	pt_ops.get_pmd_virt = get_pmd_virt_late;
1060 	pt_ops.alloc_pud = alloc_pud_late;
1061 	pt_ops.get_pud_virt = get_pud_virt_late;
1062 	pt_ops.alloc_p4d = alloc_p4d_late;
1063 	pt_ops.get_p4d_virt = get_p4d_virt_late;
1064 #endif
1065 }
1066 
1067 #ifdef CONFIG_RANDOMIZE_BASE
1068 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa);
1069 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa);
1070 extern u64 __init __pi_get_kaslr_seed_zkr(const uintptr_t dtb_pa);
1071 
1072 static int __init print_nokaslr(char *p)
1073 {
1074 	pr_info("Disabled KASLR");
1075 	return 0;
1076 }
1077 early_param("nokaslr", print_nokaslr);
1078 
1079 unsigned long kaslr_offset(void)
1080 {
1081 	return kernel_map.virt_offset;
1082 }
1083 #endif
1084 
1085 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1086 {
1087 	pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
1088 
1089 #ifdef CONFIG_RANDOMIZE_BASE
1090 	if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) {
1091 		u64 kaslr_seed = __pi_get_kaslr_seed_zkr(dtb_pa);
1092 		u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1093 		u32 nr_pos;
1094 
1095 		if (kaslr_seed == 0)
1096 			kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
1097 		/*
1098 		 * Compute the number of positions available: we are limited
1099 		 * by the early page table that only has one PUD and we must
1100 		 * be aligned on PMD_SIZE.
1101 		 */
1102 		nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE;
1103 
1104 		kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE;
1105 	}
1106 #endif
1107 
1108 	kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset;
1109 
1110 #ifdef CONFIG_XIP_KERNEL
1111 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
1112 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
1113 
1114 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
1115 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1116 	vmemmap_start_pfn = round_down(phys_ram_base, VMEMMAP_ADDR_ALIGN) >> PAGE_SHIFT;
1117 #endif
1118 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
1119 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1120 
1121 	kernel_map.va_kernel_xip_text_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
1122 	kernel_map.va_kernel_xip_data_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr
1123 						+ (uintptr_t)&_sdata - (uintptr_t)&_start;
1124 #else
1125 	kernel_map.phys_addr = (uintptr_t)(&_start);
1126 	kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
1127 	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
1128 #endif
1129 
1130 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
1131 	set_satp_mode(dtb_pa);
1132 	set_mmap_rnd_bits_max();
1133 #endif
1134 
1135 	/*
1136 	 * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem,
1137 	 * where we have the system memory layout: this allows us to align
1138 	 * the physical and virtual mappings and then make use of PUD/P4D/PGD
1139 	 * for the linear mapping. This is only possible because the kernel
1140 	 * mapping lies outside the linear mapping.
1141 	 * In 32-bit however, as the kernel resides in the linear mapping,
1142 	 * setup_vm_final can not change the mapping established here,
1143 	 * otherwise the same kernel addresses would get mapped to different
1144 	 * physical addresses (if the start of dram is different from the
1145 	 * kernel physical address start).
1146 	 */
1147 	kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ?
1148 				0UL : PAGE_OFFSET - kernel_map.phys_addr;
1149 
1150 	memory_limit = KERN_VIRT_SIZE;
1151 
1152 	/* Sanity check alignment and size */
1153 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
1154 	BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);
1155 
1156 #ifdef CONFIG_64BIT
1157 	/*
1158 	 * The last 4K bytes of the addressable memory can not be mapped because
1159 	 * of IS_ERR_VALUE macro.
1160 	 */
1161 	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
1162 #endif
1163 
1164 #ifdef CONFIG_RELOCATABLE
1165 	/*
1166 	 * Early page table uses only one PUD, which makes it possible
1167 	 * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset
1168 	 * makes the kernel cross over a PUD_SIZE boundary, raise a bug
1169 	 * since a part of the kernel would not get mapped.
1170 	 */
1171 	if (IS_ENABLED(CONFIG_64BIT))
1172 		BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size);
1173 	relocate_kernel();
1174 #endif
1175 
1176 	apply_early_boot_alternatives();
1177 	pt_ops_set_early();
1178 
1179 	/* Setup early PGD for fixmap */
1180 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
1181 			   fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1182 
1183 #ifndef __PAGETABLE_PMD_FOLDED
1184 	/* Setup fixmap P4D and PUD */
1185 	if (pgtable_l5_enabled)
1186 		create_p4d_mapping(fixmap_p4d, FIXADDR_START,
1187 				   (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
1188 	/* Setup fixmap PUD and PMD */
1189 	if (pgtable_l4_enabled)
1190 		create_pud_mapping(fixmap_pud, FIXADDR_START,
1191 				   (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
1192 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
1193 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
1194 	/* Setup trampoline PGD and PMD */
1195 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1196 			   trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1197 	if (pgtable_l5_enabled)
1198 		create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
1199 				   (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
1200 	if (pgtable_l4_enabled)
1201 		create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
1202 				   (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
1203 #ifdef CONFIG_XIP_KERNEL
1204 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1205 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
1206 #else
1207 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1208 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
1209 #endif
1210 #else
1211 	/* Setup trampoline PGD */
1212 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1213 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
1214 #endif
1215 
1216 	/*
1217 	 * Setup early PGD covering entire kernel which will allow
1218 	 * us to reach paging_init(). We map all memory banks later
1219 	 * in setup_vm_final() below.
1220 	 */
1221 	create_kernel_page_table(early_pg_dir, true);
1222 
1223 	/* Setup early mapping for FDT early scan */
1224 	create_fdt_early_page_table(__fix_to_virt(FIX_FDT), dtb_pa);
1225 
1226 	/*
1227 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
1228 	 * range can not span multiple pmds.
1229 	 */
1230 	BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1231 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1232 
1233 #ifndef __PAGETABLE_PMD_FOLDED
1234 	/*
1235 	 * Early ioremap fixmap is already created as it lies within first 2MB
1236 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
1237 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
1238 	 * the user if not.
1239 	 */
1240 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
1241 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
1242 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
1243 		WARN_ON(1);
1244 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
1245 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
1246 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1247 			fix_to_virt(FIX_BTMAP_BEGIN));
1248 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
1249 			fix_to_virt(FIX_BTMAP_END));
1250 
1251 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
1252 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
1253 	}
1254 #endif
1255 
1256 	pt_ops_set_fixmap();
1257 }
1258 
1259 static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end,
1260 						  uintptr_t fixed_map_size, const pgprot_t *pgprot)
1261 {
1262 	phys_addr_t pa;
1263 	uintptr_t va, map_size;
1264 
1265 	for (pa = start; pa < end; pa += map_size) {
1266 		va = (uintptr_t)__va(pa);
1267 		map_size = fixed_map_size ? fixed_map_size :
1268 					    best_map_size(pa, va, end - pa);
1269 
1270 		create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1271 				   pgprot ? *pgprot : pgprot_from_va(va));
1272 	}
1273 }
1274 
1275 static void __init create_linear_mapping_page_table(void)
1276 {
1277 	phys_addr_t start, end;
1278 	phys_addr_t kfence_pool __maybe_unused;
1279 	u64 i;
1280 
1281 #ifdef CONFIG_STRICT_KERNEL_RWX
1282 	phys_addr_t ktext_start = __pa_symbol(_start);
1283 	phys_addr_t ktext_size = __init_data_begin - _start;
1284 	phys_addr_t krodata_start = __pa_symbol(__start_rodata);
1285 	phys_addr_t krodata_size = _data - __start_rodata;
1286 
1287 	/* Isolate kernel text and rodata so they don't get mapped with a PUD */
1288 	memblock_mark_nomap(ktext_start,  ktext_size);
1289 	memblock_mark_nomap(krodata_start, krodata_size);
1290 #endif
1291 
1292 #ifdef CONFIG_KFENCE
1293 	/*
1294 	 *  kfence pool must be backed by PAGE_SIZE mappings, so allocate it
1295 	 *  before we setup the linear mapping so that we avoid using hugepages
1296 	 *  for this region.
1297 	 */
1298 	kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
1299 	BUG_ON(!kfence_pool);
1300 
1301 	memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE);
1302 	__kfence_pool = __va(kfence_pool);
1303 #endif
1304 
1305 	/* Map all memory banks in the linear mapping */
1306 	for_each_mem_range(i, &start, &end) {
1307 		if (start >= end)
1308 			break;
1309 		if (start <= __pa(PAGE_OFFSET) &&
1310 		    __pa(PAGE_OFFSET) < end)
1311 			start = __pa(PAGE_OFFSET);
1312 
1313 		create_linear_mapping_range(start, end, 0, NULL);
1314 	}
1315 
1316 #ifdef CONFIG_STRICT_KERNEL_RWX
1317 	create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0, NULL);
1318 	create_linear_mapping_range(krodata_start, krodata_start + krodata_size, 0, NULL);
1319 
1320 	memblock_clear_nomap(ktext_start,  ktext_size);
1321 	memblock_clear_nomap(krodata_start, krodata_size);
1322 #endif
1323 
1324 #ifdef CONFIG_KFENCE
1325 	create_linear_mapping_range(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, PAGE_SIZE, NULL);
1326 
1327 	memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
1328 #endif
1329 }
1330 
1331 static void __init setup_vm_final(void)
1332 {
1333 	/* Setup swapper PGD for fixmap */
1334 #if !defined(CONFIG_64BIT)
1335 	/*
1336 	 * In 32-bit, the device tree lies in a pgd entry, so it must be copied
1337 	 * directly in swapper_pg_dir in addition to the pgd entry that points
1338 	 * to fixmap_pte.
1339 	 */
1340 	unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT));
1341 
1342 	set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]);
1343 #endif
1344 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
1345 			   __pa_symbol(fixmap_pgd_next),
1346 			   PGDIR_SIZE, PAGE_TABLE);
1347 
1348 	/* Map the linear mapping */
1349 	create_linear_mapping_page_table();
1350 
1351 	/* Map the kernel */
1352 	if (IS_ENABLED(CONFIG_64BIT))
1353 		create_kernel_page_table(swapper_pg_dir, false);
1354 
1355 #ifdef CONFIG_KASAN
1356 	kasan_swapper_init();
1357 #endif
1358 
1359 	/* Clear fixmap PTE and PMD mappings */
1360 	clear_fixmap(FIX_PTE);
1361 	clear_fixmap(FIX_PMD);
1362 	clear_fixmap(FIX_PUD);
1363 	clear_fixmap(FIX_P4D);
1364 
1365 	/* Move to swapper page table */
1366 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode);
1367 	local_flush_tlb_all();
1368 
1369 	pt_ops_set_late();
1370 }
1371 #else
1372 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1373 {
1374 	dtb_early_va = (void *)dtb_pa;
1375 	dtb_early_pa = dtb_pa;
1376 
1377 #ifdef CONFIG_RELOCATABLE
1378 	kernel_map.virt_addr = (uintptr_t)_start;
1379 	kernel_map.phys_addr = (uintptr_t)_start;
1380 	relocate_kernel();
1381 #endif
1382 }
1383 
1384 static inline void setup_vm_final(void)
1385 {
1386 }
1387 #endif /* CONFIG_MMU */
1388 
1389 /*
1390  * reserve_crashkernel() - reserves memory for crash kernel
1391  *
1392  * This function reserves memory area given in "crashkernel=" kernel command
1393  * line parameter. The memory reserved is used by dump capture kernel when
1394  * primary kernel is crashing.
1395  */
1396 static void __init arch_reserve_crashkernel(void)
1397 {
1398 	unsigned long long low_size = 0;
1399 	unsigned long long crash_base, crash_size;
1400 	bool high = false;
1401 	int ret;
1402 
1403 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
1404 		return;
1405 
1406 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
1407 				&crash_size, &crash_base,
1408 				&low_size, NULL, &high);
1409 	if (ret)
1410 		return;
1411 
1412 	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
1413 }
1414 
1415 void __init paging_init(void)
1416 {
1417 	setup_bootmem();
1418 	setup_vm_final();
1419 
1420 	/* Depend on that Linear Mapping is ready */
1421 	memblock_allow_resize();
1422 }
1423 
1424 void __init misc_mem_init(void)
1425 {
1426 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
1427 	arch_numa_init();
1428 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1429 	/* The entire VMEMMAP region has been populated. Flush TLB for this region */
1430 	local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END);
1431 #endif
1432 	arch_reserve_crashkernel();
1433 	memblock_dump_all();
1434 }
1435 
1436 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1437 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
1438 			       unsigned long addr, unsigned long next)
1439 {
1440 	pmd_set_huge(pmd, virt_to_phys(p), PAGE_KERNEL);
1441 }
1442 
1443 int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node,
1444 				unsigned long addr, unsigned long next)
1445 {
1446 	vmemmap_verify((pte_t *)pmdp, node, addr, next);
1447 	return 1;
1448 }
1449 
1450 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1451 			       struct vmem_altmap *altmap)
1452 {
1453 	/*
1454 	 * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we
1455 	 * can't use hugepage mappings for 2-level page table because in case of
1456 	 * memory hotplug, we are not able to update all the page tables with
1457 	 * the new PMDs.
1458 	 */
1459 	return vmemmap_populate_hugepages(start, end, node, altmap);
1460 }
1461 #endif
1462 
1463 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
1464 /*
1465  * Pre-allocates page-table pages for a specific area in the kernel
1466  * page-table. Only the level which needs to be synchronized between
1467  * all page-tables is allocated because the synchronization can be
1468  * expensive.
1469  */
1470 static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end,
1471 					       const char *area)
1472 {
1473 	unsigned long addr;
1474 	const char *lvl;
1475 
1476 	for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1477 		pgd_t *pgd = pgd_offset_k(addr);
1478 		p4d_t *p4d;
1479 		pud_t *pud;
1480 		pmd_t *pmd;
1481 
1482 		lvl = "p4d";
1483 		p4d = p4d_alloc(&init_mm, pgd, addr);
1484 		if (!p4d)
1485 			goto failed;
1486 
1487 		if (pgtable_l5_enabled)
1488 			continue;
1489 
1490 		lvl = "pud";
1491 		pud = pud_alloc(&init_mm, p4d, addr);
1492 		if (!pud)
1493 			goto failed;
1494 
1495 		if (pgtable_l4_enabled)
1496 			continue;
1497 
1498 		lvl = "pmd";
1499 		pmd = pmd_alloc(&init_mm, pud, addr);
1500 		if (!pmd)
1501 			goto failed;
1502 	}
1503 	return;
1504 
1505 failed:
1506 	/*
1507 	 * The pages have to be there now or they will be missing in
1508 	 * process page-tables later.
1509 	 */
1510 	panic("Failed to pre-allocate %s pages for %s area\n", lvl, area);
1511 }
1512 
1513 #define PAGE_END KASAN_SHADOW_START
1514 
1515 void __init pgtable_cache_init(void)
1516 {
1517 	preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc");
1518 	if (IS_ENABLED(CONFIG_MODULES))
1519 		preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules");
1520 	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) {
1521 		preallocate_pgd_pages_range(VMEMMAP_START, VMEMMAP_END, "vmemmap");
1522 		preallocate_pgd_pages_range(PAGE_OFFSET, PAGE_END, "direct map");
1523 		if (IS_ENABLED(CONFIG_KASAN))
1524 			preallocate_pgd_pages_range(KASAN_SHADOW_START, KASAN_SHADOW_END, "kasan");
1525 	}
1526 }
1527 #endif
1528 
1529 #ifdef CONFIG_EXECMEM
1530 #ifdef CONFIG_MMU
1531 static struct execmem_info execmem_info __ro_after_init;
1532 
1533 struct execmem_info __init *execmem_arch_setup(void)
1534 {
1535 	execmem_info = (struct execmem_info){
1536 		.ranges = {
1537 			[EXECMEM_DEFAULT] = {
1538 				.start	= MODULES_VADDR,
1539 				.end	= MODULES_END,
1540 				.pgprot	= PAGE_KERNEL,
1541 				.alignment = 1,
1542 			},
1543 			[EXECMEM_KPROBES] = {
1544 				.start	= VMALLOC_START,
1545 				.end	= VMALLOC_END,
1546 				.pgprot	= PAGE_KERNEL_READ_EXEC,
1547 				.alignment = 1,
1548 			},
1549 			[EXECMEM_BPF] = {
1550 				.start	= BPF_JIT_REGION_START,
1551 				.end	= BPF_JIT_REGION_END,
1552 				.pgprot	= PAGE_KERNEL,
1553 				.alignment = PAGE_SIZE,
1554 			},
1555 		},
1556 	};
1557 
1558 	return &execmem_info;
1559 }
1560 #endif /* CONFIG_MMU */
1561 #endif /* CONFIG_EXECMEM */
1562 
1563 #ifdef CONFIG_MEMORY_HOTPLUG
1564 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1565 {
1566 	struct page *page = pmd_page(*pmd);
1567 	struct ptdesc *ptdesc = page_ptdesc(page);
1568 	pte_t *pte;
1569 	int i;
1570 
1571 	for (i = 0; i < PTRS_PER_PTE; i++) {
1572 		pte = pte_start + i;
1573 		if (!pte_none(*pte))
1574 			return;
1575 	}
1576 
1577 	pagetable_dtor(ptdesc);
1578 	if (PageReserved(page))
1579 		free_reserved_page(page);
1580 	else
1581 		pagetable_free(ptdesc);
1582 	pmd_clear(pmd);
1583 }
1584 
1585 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud, bool is_vmemmap)
1586 {
1587 	struct page *page = pud_page(*pud);
1588 	struct ptdesc *ptdesc = page_ptdesc(page);
1589 	pmd_t *pmd;
1590 	int i;
1591 
1592 	for (i = 0; i < PTRS_PER_PMD; i++) {
1593 		pmd = pmd_start + i;
1594 		if (!pmd_none(*pmd))
1595 			return;
1596 	}
1597 
1598 	if (!is_vmemmap)
1599 		pagetable_dtor(ptdesc);
1600 	if (PageReserved(page))
1601 		free_reserved_page(page);
1602 	else
1603 		pagetable_free(ptdesc);
1604 	pud_clear(pud);
1605 }
1606 
1607 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1608 {
1609 	struct page *page = p4d_page(*p4d);
1610 	pud_t *pud;
1611 	int i;
1612 
1613 	for (i = 0; i < PTRS_PER_PUD; i++) {
1614 		pud = pud_start + i;
1615 		if (!pud_none(*pud))
1616 			return;
1617 	}
1618 
1619 	if (PageReserved(page))
1620 		free_reserved_page(page);
1621 	else
1622 		__free_pages(page, 0);
1623 	p4d_clear(p4d);
1624 }
1625 
1626 static void __meminit free_vmemmap_storage(struct page *page, size_t size,
1627 					   struct vmem_altmap *altmap)
1628 {
1629 	int order = get_order(size);
1630 
1631 	if (altmap) {
1632 		vmem_altmap_free(altmap, size >> PAGE_SHIFT);
1633 		return;
1634 	}
1635 
1636 	if (PageReserved(page)) {
1637 		unsigned int nr_pages = 1 << order;
1638 
1639 		while (nr_pages--)
1640 			free_reserved_page(page++);
1641 		return;
1642 	}
1643 
1644 	__free_pages(page, order);
1645 }
1646 
1647 static void __meminit remove_pte_mapping(pte_t *pte_base, unsigned long addr, unsigned long end,
1648 					 bool is_vmemmap, struct vmem_altmap *altmap)
1649 {
1650 	unsigned long next;
1651 	pte_t *ptep, pte;
1652 
1653 	for (; addr < end; addr = next) {
1654 		next = (addr + PAGE_SIZE) & PAGE_MASK;
1655 		if (next > end)
1656 			next = end;
1657 
1658 		ptep = pte_base + pte_index(addr);
1659 		pte = ptep_get(ptep);
1660 		if (!pte_present(*ptep))
1661 			continue;
1662 
1663 		pte_clear(&init_mm, addr, ptep);
1664 		if (is_vmemmap)
1665 			free_vmemmap_storage(pte_page(pte), PAGE_SIZE, altmap);
1666 	}
1667 }
1668 
1669 static void __meminit remove_pmd_mapping(pmd_t *pmd_base, unsigned long addr, unsigned long end,
1670 					 bool is_vmemmap, struct vmem_altmap *altmap)
1671 {
1672 	unsigned long next;
1673 	pte_t *pte_base;
1674 	pmd_t *pmdp, pmd;
1675 
1676 	for (; addr < end; addr = next) {
1677 		next = pmd_addr_end(addr, end);
1678 		pmdp = pmd_base + pmd_index(addr);
1679 		pmd = pmdp_get(pmdp);
1680 		if (!pmd_present(pmd))
1681 			continue;
1682 
1683 		if (pmd_leaf(pmd)) {
1684 			pmd_clear(pmdp);
1685 			if (is_vmemmap)
1686 				free_vmemmap_storage(pmd_page(pmd), PMD_SIZE, altmap);
1687 			continue;
1688 		}
1689 
1690 		pte_base = (pte_t *)pmd_page_vaddr(*pmdp);
1691 		remove_pte_mapping(pte_base, addr, next, is_vmemmap, altmap);
1692 		free_pte_table(pte_base, pmdp);
1693 	}
1694 }
1695 
1696 static void __meminit remove_pud_mapping(pud_t *pud_base, unsigned long addr, unsigned long end,
1697 					 bool is_vmemmap, struct vmem_altmap *altmap)
1698 {
1699 	unsigned long next;
1700 	pud_t *pudp, pud;
1701 	pmd_t *pmd_base;
1702 
1703 	for (; addr < end; addr = next) {
1704 		next = pud_addr_end(addr, end);
1705 		pudp = pud_base + pud_index(addr);
1706 		pud = pudp_get(pudp);
1707 		if (!pud_present(pud))
1708 			continue;
1709 
1710 		if (pud_leaf(pud)) {
1711 			if (pgtable_l4_enabled) {
1712 				pud_clear(pudp);
1713 				if (is_vmemmap)
1714 					free_vmemmap_storage(pud_page(pud), PUD_SIZE, altmap);
1715 			}
1716 			continue;
1717 		}
1718 
1719 		pmd_base = pmd_offset(pudp, 0);
1720 		remove_pmd_mapping(pmd_base, addr, next, is_vmemmap, altmap);
1721 
1722 		if (pgtable_l4_enabled)
1723 			free_pmd_table(pmd_base, pudp, is_vmemmap);
1724 	}
1725 }
1726 
1727 static void __meminit remove_p4d_mapping(p4d_t *p4d_base, unsigned long addr, unsigned long end,
1728 					 bool is_vmemmap, struct vmem_altmap *altmap)
1729 {
1730 	unsigned long next;
1731 	p4d_t *p4dp, p4d;
1732 	pud_t *pud_base;
1733 
1734 	for (; addr < end; addr = next) {
1735 		next = p4d_addr_end(addr, end);
1736 		p4dp = p4d_base + p4d_index(addr);
1737 		p4d = p4dp_get(p4dp);
1738 		if (!p4d_present(p4d))
1739 			continue;
1740 
1741 		if (p4d_leaf(p4d)) {
1742 			if (pgtable_l5_enabled) {
1743 				p4d_clear(p4dp);
1744 				if (is_vmemmap)
1745 					free_vmemmap_storage(p4d_page(p4d), P4D_SIZE, altmap);
1746 			}
1747 			continue;
1748 		}
1749 
1750 		pud_base = pud_offset(p4dp, 0);
1751 		remove_pud_mapping(pud_base, addr, next, is_vmemmap, altmap);
1752 
1753 		if (pgtable_l5_enabled)
1754 			free_pud_table(pud_base, p4dp);
1755 	}
1756 }
1757 
1758 static void __meminit remove_pgd_mapping(unsigned long va, unsigned long end, bool is_vmemmap,
1759 					 struct vmem_altmap *altmap)
1760 {
1761 	unsigned long addr, next;
1762 	p4d_t *p4d_base;
1763 	pgd_t *pgd;
1764 
1765 	for (addr = va; addr < end; addr = next) {
1766 		next = pgd_addr_end(addr, end);
1767 		pgd = pgd_offset_k(addr);
1768 
1769 		if (!pgd_present(*pgd))
1770 			continue;
1771 
1772 		if (pgd_leaf(*pgd))
1773 			continue;
1774 
1775 		p4d_base = p4d_offset(pgd, 0);
1776 		remove_p4d_mapping(p4d_base, addr, next, is_vmemmap, altmap);
1777 	}
1778 
1779 	flush_tlb_all();
1780 }
1781 
1782 static void __meminit remove_linear_mapping(phys_addr_t start, u64 size)
1783 {
1784 	unsigned long va = (unsigned long)__va(start);
1785 	unsigned long end = (unsigned long)__va(start + size);
1786 
1787 	remove_pgd_mapping(va, end, false, NULL);
1788 }
1789 
1790 struct range arch_get_mappable_range(void)
1791 {
1792 	struct range mhp_range;
1793 
1794 	mhp_range.start = __pa(PAGE_OFFSET);
1795 	mhp_range.end = __pa(PAGE_END - 1);
1796 	return mhp_range;
1797 }
1798 
1799 int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
1800 {
1801 	int ret = 0;
1802 
1803 	create_linear_mapping_range(start, start + size, 0, &params->pgprot);
1804 	ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, params);
1805 	if (ret) {
1806 		remove_linear_mapping(start, size);
1807 		goto out;
1808 	}
1809 
1810 	max_pfn = PFN_UP(start + size);
1811 	max_low_pfn = max_pfn;
1812 
1813  out:
1814 	flush_tlb_all();
1815 	return ret;
1816 }
1817 
1818 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1819 {
1820 	__remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap);
1821 	remove_linear_mapping(start, size);
1822 	flush_tlb_all();
1823 }
1824 
1825 void __ref vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
1826 {
1827 	remove_pgd_mapping(start, end, true, altmap);
1828 }
1829 #endif /* CONFIG_MEMORY_HOTPLUG */
1830