xref: /linux/arch/riscv/mm/init.c (revision a6d0dbba950880e269d433222ca6d516ebe8a6ae)
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 #ifdef CONFIG_RELOCATABLE
24 #include <linux/elf.h>
25 #endif
26 #include <linux/kfence.h>
27 #include <linux/execmem.h>
28 
29 #include <asm/fixmap.h>
30 #include <asm/io.h>
31 #include <asm/kasan.h>
32 #include <asm/numa.h>
33 #include <asm/pgtable.h>
34 #include <asm/sections.h>
35 #include <asm/soc.h>
36 #include <asm/sparsemem.h>
37 #include <asm/tlbflush.h>
38 
39 #include "../kernel/head.h"
40 
41 u64 new_vmalloc[NR_CPUS / sizeof(u64) + 1];
42 
43 struct kernel_mapping kernel_map __ro_after_init;
44 EXPORT_SYMBOL(kernel_map);
45 #ifdef CONFIG_XIP_KERNEL
46 #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
47 #endif
48 
49 #ifdef CONFIG_64BIT
50 u64 satp_mode __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_57 : SATP_MODE_39;
51 #else
52 u64 satp_mode __ro_after_init = SATP_MODE_32;
53 #endif
54 EXPORT_SYMBOL(satp_mode);
55 
56 #ifdef CONFIG_64BIT
57 bool pgtable_l4_enabled __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL);
58 bool pgtable_l5_enabled __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL);
59 EXPORT_SYMBOL(pgtable_l4_enabled);
60 EXPORT_SYMBOL(pgtable_l5_enabled);
61 #endif
62 
63 phys_addr_t phys_ram_base __ro_after_init;
64 EXPORT_SYMBOL(phys_ram_base);
65 
66 #ifdef CONFIG_SPARSEMEM_VMEMMAP
67 #define VMEMMAP_ADDR_ALIGN	(1ULL << SECTION_SIZE_BITS)
68 
69 unsigned long vmemmap_start_pfn __ro_after_init;
70 EXPORT_SYMBOL(vmemmap_start_pfn);
71 #endif
72 
73 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
74 							__page_aligned_bss;
75 EXPORT_SYMBOL(empty_zero_page);
76 
77 extern char _start[];
78 void *_dtb_early_va __initdata;
79 uintptr_t _dtb_early_pa __initdata;
80 
81 phys_addr_t dma32_phys_limit __initdata;
82 
83 static void __init zone_sizes_init(void)
84 {
85 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
86 
87 #ifdef CONFIG_ZONE_DMA32
88 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
89 #endif
90 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
91 
92 	free_area_init(max_zone_pfns);
93 }
94 
95 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
96 
97 #define LOG2_SZ_1K  ilog2(SZ_1K)
98 #define LOG2_SZ_1M  ilog2(SZ_1M)
99 #define LOG2_SZ_1G  ilog2(SZ_1G)
100 #define LOG2_SZ_1T  ilog2(SZ_1T)
101 
102 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
103 {
104 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
105 		  (((t) - (b)) >> LOG2_SZ_1K));
106 }
107 
108 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
109 {
110 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
111 		  (((t) - (b)) >> LOG2_SZ_1M));
112 }
113 
114 static inline void print_mlg(char *name, unsigned long b, unsigned long t)
115 {
116 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld GB)\n", name, b, t,
117 		   (((t) - (b)) >> LOG2_SZ_1G));
118 }
119 
120 #ifdef CONFIG_64BIT
121 static inline void print_mlt(char *name, unsigned long b, unsigned long t)
122 {
123 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld TB)\n", name, b, t,
124 		   (((t) - (b)) >> LOG2_SZ_1T));
125 }
126 #else
127 #define print_mlt(n, b, t) do {} while (0)
128 #endif
129 
130 static inline void print_ml(char *name, unsigned long b, unsigned long t)
131 {
132 	unsigned long diff = t - b;
133 
134 	if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10)
135 		print_mlt(name, b, t);
136 	else if ((diff >> LOG2_SZ_1G) >= 10)
137 		print_mlg(name, b, t);
138 	else if ((diff >> LOG2_SZ_1M) >= 10)
139 		print_mlm(name, b, t);
140 	else
141 		print_mlk(name, b, t);
142 }
143 
144 static void __init print_vm_layout(void)
145 {
146 	pr_notice("Virtual kernel memory layout:\n");
147 	print_ml("fixmap", (unsigned long)FIXADDR_START,
148 		(unsigned long)FIXADDR_TOP);
149 	print_ml("pci io", (unsigned long)PCI_IO_START,
150 		(unsigned long)PCI_IO_END);
151 	print_ml("vmemmap", (unsigned long)VMEMMAP_START,
152 		(unsigned long)VMEMMAP_END);
153 	print_ml("vmalloc", (unsigned long)VMALLOC_START,
154 		(unsigned long)VMALLOC_END);
155 #ifdef CONFIG_64BIT
156 	print_ml("modules", (unsigned long)MODULES_VADDR,
157 		(unsigned long)MODULES_END);
158 #endif
159 	print_ml("lowmem", (unsigned long)PAGE_OFFSET,
160 		(unsigned long)high_memory);
161 	if (IS_ENABLED(CONFIG_64BIT)) {
162 #ifdef CONFIG_KASAN
163 		print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
164 #endif
165 
166 		print_ml("kernel", (unsigned long)kernel_map.virt_addr,
167 			 (unsigned long)ADDRESS_SPACE_END);
168 	}
169 }
170 #else
171 static void print_vm_layout(void) { }
172 #endif /* CONFIG_DEBUG_VM */
173 
174 void __init arch_mm_preinit(void)
175 {
176 	bool swiotlb = max_pfn > PFN_DOWN(dma32_phys_limit);
177 #ifdef CONFIG_FLATMEM
178 	BUG_ON(!mem_map);
179 #endif /* CONFIG_FLATMEM */
180 
181 	if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb &&
182 	    dma_cache_alignment != 1) {
183 		/*
184 		 * If no bouncing needed for ZONE_DMA, allocate 1MB swiotlb
185 		 * buffer per 1GB of RAM for kmalloc() bouncing on
186 		 * non-coherent platforms.
187 		 */
188 		unsigned long size =
189 			DIV_ROUND_UP(memblock_phys_mem_size(), 1024);
190 		swiotlb_adjust_size(min(swiotlb_size_or_default(), size));
191 		swiotlb = true;
192 	}
193 
194 	swiotlb_init(swiotlb, SWIOTLB_VERBOSE);
195 
196 	print_vm_layout();
197 }
198 
199 /* Limit the memory size via mem. */
200 static phys_addr_t memory_limit;
201 #ifdef CONFIG_XIP_KERNEL
202 #define memory_limit	(*(phys_addr_t *)XIP_FIXUP(&memory_limit))
203 #endif /* CONFIG_XIP_KERNEL */
204 
205 static int __init early_mem(char *p)
206 {
207 	u64 size;
208 
209 	if (!p)
210 		return 1;
211 
212 	size = memparse(p, &p) & PAGE_MASK;
213 	memory_limit = min_t(u64, size, memory_limit);
214 
215 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
216 
217 	return 0;
218 }
219 early_param("mem", early_mem);
220 
221 static void __init setup_bootmem(void)
222 {
223 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
224 	phys_addr_t max_mapped_addr;
225 	phys_addr_t phys_ram_end, vmlinux_start;
226 
227 	if (IS_ENABLED(CONFIG_XIP_KERNEL))
228 		vmlinux_start = __pa_symbol(&_sdata);
229 	else
230 		vmlinux_start = __pa_symbol(&_start);
231 
232 	memblock_enforce_memory_limit(memory_limit);
233 
234 	/*
235 	 * Make sure we align the reservation on PMD_SIZE since we will
236 	 * map the kernel in the linear mapping as read-only: we do not want
237 	 * any allocation to happen between _end and the next pmd aligned page.
238 	 */
239 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
240 		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
241 	/*
242 	 * Reserve from the start of the kernel to the end of the kernel
243 	 */
244 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
245 
246 	/*
247 	 * Make sure we align the start of the memory on a PMD boundary so that
248 	 * at worst, we map the linear mapping with PMD mappings.
249 	 */
250 	if (!IS_ENABLED(CONFIG_XIP_KERNEL)) {
251 		phys_ram_base = memblock_start_of_DRAM() & PMD_MASK;
252 #ifdef CONFIG_SPARSEMEM_VMEMMAP
253 		vmemmap_start_pfn = round_down(phys_ram_base, VMEMMAP_ADDR_ALIGN) >> PAGE_SHIFT;
254 #endif
255 	}
256 
257 	/*
258 	 * In 64-bit, any use of __va/__pa before this point is wrong as we
259 	 * did not know the start of DRAM before.
260 	 */
261 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU))
262 		kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
263 
264 	/*
265 	 * The size of the linear page mapping may restrict the amount of
266 	 * usable RAM.
267 	 */
268 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) {
269 		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
270 		if (memblock_end_of_DRAM() > max_mapped_addr) {
271 			memblock_cap_memory_range(phys_ram_base,
272 						  max_mapped_addr - phys_ram_base);
273 			pr_warn("Physical memory overflows the linear mapping size: region above %pa removed",
274 				&max_mapped_addr);
275 		}
276 	}
277 
278 	/*
279 	 * Reserve physical address space that would be mapped to virtual
280 	 * addresses greater than (void *)(-PAGE_SIZE) because:
281 	 *  - This memory would overlap with ERR_PTR
282 	 *  - This memory belongs to high memory, which is not supported
283 	 *
284 	 * This is not applicable to 64-bit kernel, because virtual addresses
285 	 * after (void *)(-PAGE_SIZE) are not linearly mapped: they are
286 	 * occupied by kernel mapping. Also it is unrealistic for high memory
287 	 * to exist on 64-bit platforms.
288 	 */
289 	if (!IS_ENABLED(CONFIG_64BIT)) {
290 		max_mapped_addr = __va_to_pa_nodebug(-PAGE_SIZE);
291 		memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr);
292 	}
293 
294 	phys_ram_end = memblock_end_of_DRAM();
295 	min_low_pfn = PFN_UP(phys_ram_base);
296 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
297 
298 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
299 
300 	reserve_initrd_mem();
301 
302 	/*
303 	 * No allocation should be done before reserving the memory as defined
304 	 * in the device tree, otherwise the allocation could end up in a
305 	 * reserved region.
306 	 */
307 	early_init_fdt_scan_reserved_mem();
308 
309 	/*
310 	 * If DTB is built in, no need to reserve its memblock.
311 	 * Otherwise, do reserve it but avoid using
312 	 * early_init_fdt_reserve_self() since __pa() does
313 	 * not work for DTB pointers that are fixmap addresses
314 	 */
315 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
316 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
317 
318 	dma_contiguous_reserve(dma32_phys_limit);
319 	if (IS_ENABLED(CONFIG_64BIT))
320 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
321 }
322 
323 #ifdef CONFIG_MMU
324 struct pt_alloc_ops pt_ops __meminitdata;
325 
326 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
327 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
328 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
329 
330 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
331 
332 #ifdef CONFIG_XIP_KERNEL
333 #define pt_ops			(*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
334 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
335 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
336 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
337 #endif /* CONFIG_XIP_KERNEL */
338 
339 static const pgprot_t protection_map[16] = {
340 	[VM_NONE]					= PAGE_NONE,
341 	[VM_READ]					= PAGE_READ,
342 	[VM_WRITE]					= PAGE_COPY,
343 	[VM_WRITE | VM_READ]				= PAGE_COPY,
344 	[VM_EXEC]					= PAGE_EXEC,
345 	[VM_EXEC | VM_READ]				= PAGE_READ_EXEC,
346 	[VM_EXEC | VM_WRITE]				= PAGE_COPY_EXEC,
347 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_COPY_EXEC,
348 	[VM_SHARED]					= PAGE_NONE,
349 	[VM_SHARED | VM_READ]				= PAGE_READ,
350 	[VM_SHARED | VM_WRITE]				= PAGE_SHARED,
351 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
352 	[VM_SHARED | VM_EXEC]				= PAGE_EXEC,
353 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ_EXEC,
354 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_SHARED_EXEC,
355 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED_EXEC
356 };
357 DECLARE_VM_GET_PAGE_PROT
358 
359 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
360 {
361 	unsigned long addr = __fix_to_virt(idx);
362 	pte_t *ptep;
363 
364 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
365 
366 	ptep = &fixmap_pte[pte_index(addr)];
367 
368 	if (pgprot_val(prot))
369 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
370 	else
371 		pte_clear(&init_mm, addr, ptep);
372 	local_flush_tlb_page(addr);
373 }
374 
375 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
376 {
377 	return (pte_t *)((uintptr_t)pa);
378 }
379 
380 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
381 {
382 	clear_fixmap(FIX_PTE);
383 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
384 }
385 
386 static inline pte_t *__meminit get_pte_virt_late(phys_addr_t pa)
387 {
388 	return (pte_t *) __va(pa);
389 }
390 
391 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
392 {
393 	/*
394 	 * We only create PMD or PGD early mappings so we
395 	 * should never reach here with MMU disabled.
396 	 */
397 	BUG();
398 }
399 
400 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
401 {
402 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
403 }
404 
405 static phys_addr_t __meminit alloc_pte_late(uintptr_t va)
406 {
407 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
408 
409 	BUG_ON(!ptdesc || !pagetable_pte_ctor(ptdesc));
410 	return __pa((pte_t *)ptdesc_address(ptdesc));
411 }
412 
413 static void __meminit create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
414 					 pgprot_t prot)
415 {
416 	uintptr_t pte_idx = pte_index(va);
417 
418 	BUG_ON(sz != PAGE_SIZE);
419 
420 	if (pte_none(ptep[pte_idx]))
421 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
422 }
423 
424 #ifndef __PAGETABLE_PMD_FOLDED
425 
426 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
427 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
428 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
429 
430 #ifdef CONFIG_XIP_KERNEL
431 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
432 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
433 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
434 #endif /* CONFIG_XIP_KERNEL */
435 
436 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss;
437 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss;
438 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
439 
440 #ifdef CONFIG_XIP_KERNEL
441 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d))
442 #define fixmap_p4d     ((p4d_t *)XIP_FIXUP(fixmap_p4d))
443 #define early_p4d      ((p4d_t *)XIP_FIXUP(early_p4d))
444 #endif /* CONFIG_XIP_KERNEL */
445 
446 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss;
447 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss;
448 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
449 
450 #ifdef CONFIG_XIP_KERNEL
451 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud))
452 #define fixmap_pud     ((pud_t *)XIP_FIXUP(fixmap_pud))
453 #define early_pud      ((pud_t *)XIP_FIXUP(early_pud))
454 #endif /* CONFIG_XIP_KERNEL */
455 
456 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
457 {
458 	/* Before MMU is enabled */
459 	return (pmd_t *)((uintptr_t)pa);
460 }
461 
462 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
463 {
464 	clear_fixmap(FIX_PMD);
465 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
466 }
467 
468 static pmd_t *__meminit get_pmd_virt_late(phys_addr_t pa)
469 {
470 	return (pmd_t *) __va(pa);
471 }
472 
473 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
474 {
475 	BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT);
476 
477 	return (uintptr_t)early_pmd;
478 }
479 
480 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
481 {
482 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
483 }
484 
485 static phys_addr_t __meminit alloc_pmd_late(uintptr_t va)
486 {
487 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
488 
489 	BUG_ON(!ptdesc || !pagetable_pmd_ctor(ptdesc));
490 	return __pa((pmd_t *)ptdesc_address(ptdesc));
491 }
492 
493 static void __meminit create_pmd_mapping(pmd_t *pmdp,
494 					 uintptr_t va, phys_addr_t pa,
495 					 phys_addr_t sz, pgprot_t prot)
496 {
497 	pte_t *ptep;
498 	phys_addr_t pte_phys;
499 	uintptr_t pmd_idx = pmd_index(va);
500 
501 	if (sz == PMD_SIZE) {
502 		if (pmd_none(pmdp[pmd_idx]))
503 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
504 		return;
505 	}
506 
507 	if (pmd_none(pmdp[pmd_idx])) {
508 		pte_phys = pt_ops.alloc_pte(va);
509 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
510 		ptep = pt_ops.get_pte_virt(pte_phys);
511 		memset(ptep, 0, PAGE_SIZE);
512 	} else {
513 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
514 		ptep = pt_ops.get_pte_virt(pte_phys);
515 	}
516 
517 	create_pte_mapping(ptep, va, pa, sz, prot);
518 }
519 
520 static pud_t *__init get_pud_virt_early(phys_addr_t pa)
521 {
522 	return (pud_t *)((uintptr_t)pa);
523 }
524 
525 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
526 {
527 	clear_fixmap(FIX_PUD);
528 	return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
529 }
530 
531 static pud_t *__meminit get_pud_virt_late(phys_addr_t pa)
532 {
533 	return (pud_t *)__va(pa);
534 }
535 
536 static phys_addr_t __init alloc_pud_early(uintptr_t va)
537 {
538 	/* Only one PUD is available for early mapping */
539 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
540 
541 	return (uintptr_t)early_pud;
542 }
543 
544 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
545 {
546 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
547 }
548 
549 static phys_addr_t __meminit alloc_pud_late(uintptr_t va)
550 {
551 	unsigned long vaddr;
552 
553 	vaddr = __get_free_page(GFP_KERNEL);
554 	BUG_ON(!vaddr);
555 	return __pa(vaddr);
556 }
557 
558 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa)
559 {
560 	return (p4d_t *)((uintptr_t)pa);
561 }
562 
563 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
564 {
565 	clear_fixmap(FIX_P4D);
566 	return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
567 }
568 
569 static p4d_t *__meminit get_p4d_virt_late(phys_addr_t pa)
570 {
571 	return (p4d_t *)__va(pa);
572 }
573 
574 static phys_addr_t __init alloc_p4d_early(uintptr_t va)
575 {
576 	/* Only one P4D is available for early mapping */
577 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
578 
579 	return (uintptr_t)early_p4d;
580 }
581 
582 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
583 {
584 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
585 }
586 
587 static phys_addr_t __meminit alloc_p4d_late(uintptr_t va)
588 {
589 	unsigned long vaddr;
590 
591 	vaddr = __get_free_page(GFP_KERNEL);
592 	BUG_ON(!vaddr);
593 	return __pa(vaddr);
594 }
595 
596 static void __meminit create_pud_mapping(pud_t *pudp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
597 					 pgprot_t prot)
598 {
599 	pmd_t *nextp;
600 	phys_addr_t next_phys;
601 	uintptr_t pud_index = pud_index(va);
602 
603 	if (sz == PUD_SIZE) {
604 		if (pud_val(pudp[pud_index]) == 0)
605 			pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot);
606 		return;
607 	}
608 
609 	if (pud_val(pudp[pud_index]) == 0) {
610 		next_phys = pt_ops.alloc_pmd(va);
611 		pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE);
612 		nextp = pt_ops.get_pmd_virt(next_phys);
613 		memset(nextp, 0, PAGE_SIZE);
614 	} else {
615 		next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index]));
616 		nextp = pt_ops.get_pmd_virt(next_phys);
617 	}
618 
619 	create_pmd_mapping(nextp, va, pa, sz, prot);
620 }
621 
622 static void __meminit create_p4d_mapping(p4d_t *p4dp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
623 					 pgprot_t prot)
624 {
625 	pud_t *nextp;
626 	phys_addr_t next_phys;
627 	uintptr_t p4d_index = p4d_index(va);
628 
629 	if (sz == P4D_SIZE) {
630 		if (p4d_val(p4dp[p4d_index]) == 0)
631 			p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot);
632 		return;
633 	}
634 
635 	if (p4d_val(p4dp[p4d_index]) == 0) {
636 		next_phys = pt_ops.alloc_pud(va);
637 		p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE);
638 		nextp = pt_ops.get_pud_virt(next_phys);
639 		memset(nextp, 0, PAGE_SIZE);
640 	} else {
641 		next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index]));
642 		nextp = pt_ops.get_pud_virt(next_phys);
643 	}
644 
645 	create_pud_mapping(nextp, va, pa, sz, prot);
646 }
647 
648 #define pgd_next_t		p4d_t
649 #define alloc_pgd_next(__va)	(pgtable_l5_enabled ?			\
650 		pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ?		\
651 		pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
652 #define get_pgd_next_virt(__pa)	(pgtable_l5_enabled ?			\
653 		pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ?	\
654 		pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
655 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
656 				(pgtable_l5_enabled ?			\
657 		create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
658 				(pgtable_l4_enabled ?			\
659 		create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) :	\
660 		create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
661 #define fixmap_pgd_next		(pgtable_l5_enabled ?			\
662 		(uintptr_t)fixmap_p4d : (pgtable_l4_enabled ?		\
663 		(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
664 #define trampoline_pgd_next	(pgtable_l5_enabled ?			\
665 		(uintptr_t)trampoline_p4d : (pgtable_l4_enabled ?	\
666 		(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
667 #else
668 #define pgd_next_t		pte_t
669 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
670 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
671 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
672 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
673 #define fixmap_pgd_next		((uintptr_t)fixmap_pte)
674 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
675 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
676 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
677 #endif /* __PAGETABLE_PMD_FOLDED */
678 
679 void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
680 				  pgprot_t prot)
681 {
682 	pgd_next_t *nextp;
683 	phys_addr_t next_phys;
684 	uintptr_t pgd_idx = pgd_index(va);
685 
686 	if (sz == PGDIR_SIZE) {
687 		if (pgd_val(pgdp[pgd_idx]) == 0)
688 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
689 		return;
690 	}
691 
692 	if (pgd_val(pgdp[pgd_idx]) == 0) {
693 		next_phys = alloc_pgd_next(va);
694 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
695 		nextp = get_pgd_next_virt(next_phys);
696 		memset(nextp, 0, PAGE_SIZE);
697 	} else {
698 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
699 		nextp = get_pgd_next_virt(next_phys);
700 	}
701 
702 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
703 }
704 
705 static uintptr_t __meminit best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size)
706 {
707 	if (debug_pagealloc_enabled())
708 		return PAGE_SIZE;
709 
710 	if (pgtable_l5_enabled &&
711 	    !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)
712 		return P4D_SIZE;
713 
714 	if (pgtable_l4_enabled &&
715 	    !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE)
716 		return PUD_SIZE;
717 
718 	if (IS_ENABLED(CONFIG_64BIT) &&
719 	    !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE)
720 		return PMD_SIZE;
721 
722 	return PAGE_SIZE;
723 }
724 
725 #ifdef CONFIG_XIP_KERNEL
726 #define phys_ram_base  (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base))
727 extern char _xiprom[], _exiprom[], __data_loc;
728 
729 /* called from head.S with MMU off */
730 asmlinkage void __init __copy_data(void)
731 {
732 	void *from = (void *)(&__data_loc);
733 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
734 	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
735 
736 	memcpy(to, from, sz);
737 }
738 #endif
739 
740 #ifdef CONFIG_STRICT_KERNEL_RWX
741 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
742 {
743 	if (is_va_kernel_text(va))
744 		return PAGE_KERNEL_READ_EXEC;
745 
746 	/*
747 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
748 	 * we must protect its linear mapping alias from being executed and
749 	 * written.
750 	 * And rodata section is marked readonly in mark_rodata_ro.
751 	 */
752 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
753 		return PAGE_KERNEL_READ;
754 
755 	return PAGE_KERNEL;
756 }
757 
758 void mark_rodata_ro(void)
759 {
760 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
761 	if (IS_ENABLED(CONFIG_64BIT))
762 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
763 				  set_memory_ro);
764 }
765 #else
766 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
767 {
768 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
769 		return PAGE_KERNEL;
770 
771 	return PAGE_KERNEL_EXEC;
772 }
773 #endif /* CONFIG_STRICT_KERNEL_RWX */
774 
775 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
776 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa);
777 
778 static void __init disable_pgtable_l5(void)
779 {
780 	pgtable_l5_enabled = false;
781 	kernel_map.page_offset = PAGE_OFFSET_L4;
782 	satp_mode = SATP_MODE_48;
783 }
784 
785 static void __init disable_pgtable_l4(void)
786 {
787 	pgtable_l4_enabled = false;
788 	kernel_map.page_offset = PAGE_OFFSET_L3;
789 	satp_mode = SATP_MODE_39;
790 }
791 
792 static int __init print_no4lvl(char *p)
793 {
794 	pr_info("Disabled 4-level and 5-level paging");
795 	return 0;
796 }
797 early_param("no4lvl", print_no4lvl);
798 
799 static int __init print_no5lvl(char *p)
800 {
801 	pr_info("Disabled 5-level paging");
802 	return 0;
803 }
804 early_param("no5lvl", print_no5lvl);
805 
806 static void __init set_mmap_rnd_bits_max(void)
807 {
808 	mmap_rnd_bits_max = MMAP_VA_BITS - PAGE_SHIFT - 3;
809 }
810 
811 /*
812  * There is a simple way to determine if 4-level is supported by the
813  * underlying hardware: establish 1:1 mapping in 4-level page table mode
814  * then read SATP to see if the configuration was taken into account
815  * meaning sv48 is supported.
816  */
817 static __init void set_satp_mode(uintptr_t dtb_pa)
818 {
819 	u64 identity_satp, hw_satp;
820 	uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
821 	u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa);
822 
823 	if (satp_mode_cmdline == SATP_MODE_57) {
824 		disable_pgtable_l5();
825 	} else if (satp_mode_cmdline == SATP_MODE_48) {
826 		disable_pgtable_l5();
827 		disable_pgtable_l4();
828 		return;
829 	}
830 
831 	create_p4d_mapping(early_p4d,
832 			set_satp_mode_pmd, (uintptr_t)early_pud,
833 			P4D_SIZE, PAGE_TABLE);
834 	create_pud_mapping(early_pud,
835 			   set_satp_mode_pmd, (uintptr_t)early_pmd,
836 			   PUD_SIZE, PAGE_TABLE);
837 	/* Handle the case where set_satp_mode straddles 2 PMDs */
838 	create_pmd_mapping(early_pmd,
839 			   set_satp_mode_pmd, set_satp_mode_pmd,
840 			   PMD_SIZE, PAGE_KERNEL_EXEC);
841 	create_pmd_mapping(early_pmd,
842 			   set_satp_mode_pmd + PMD_SIZE,
843 			   set_satp_mode_pmd + PMD_SIZE,
844 			   PMD_SIZE, PAGE_KERNEL_EXEC);
845 retry:
846 	create_pgd_mapping(early_pg_dir,
847 			   set_satp_mode_pmd,
848 			   pgtable_l5_enabled ?
849 				(uintptr_t)early_p4d : (uintptr_t)early_pud,
850 			   PGDIR_SIZE, PAGE_TABLE);
851 
852 	identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
853 
854 	local_flush_tlb_all();
855 	csr_write(CSR_SATP, identity_satp);
856 	hw_satp = csr_swap(CSR_SATP, 0ULL);
857 	local_flush_tlb_all();
858 
859 	if (hw_satp != identity_satp) {
860 		if (pgtable_l5_enabled) {
861 			disable_pgtable_l5();
862 			memset(early_pg_dir, 0, PAGE_SIZE);
863 			goto retry;
864 		}
865 		disable_pgtable_l4();
866 	}
867 
868 	memset(early_pg_dir, 0, PAGE_SIZE);
869 	memset(early_p4d, 0, PAGE_SIZE);
870 	memset(early_pud, 0, PAGE_SIZE);
871 	memset(early_pmd, 0, PAGE_SIZE);
872 }
873 #endif
874 
875 /*
876  * setup_vm() is called from head.S with MMU-off.
877  *
878  * Following requirements should be honoured for setup_vm() to work
879  * correctly:
880  * 1) It should use PC-relative addressing for accessing kernel symbols.
881  *    To achieve this we always use GCC cmodel=medany.
882  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
883  *    so disable compiler instrumentation when FTRACE is enabled.
884  *
885  * Currently, the above requirements are honoured by using custom CFLAGS
886  * for init.o in mm/Makefile.
887  */
888 
889 #ifndef __riscv_cmodel_medany
890 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
891 #endif
892 
893 #ifdef CONFIG_RELOCATABLE
894 extern unsigned long __rela_dyn_start, __rela_dyn_end;
895 
896 static void __init relocate_kernel(void)
897 {
898 	Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start;
899 	/*
900 	 * This holds the offset between the linked virtual address and the
901 	 * relocated virtual address.
902 	 */
903 	uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
904 	/*
905 	 * This holds the offset between kernel linked virtual address and
906 	 * physical address.
907 	 */
908 	uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
909 
910 	for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) {
911 		Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
912 		Elf64_Addr relocated_addr = rela->r_addend;
913 
914 		if (rela->r_info != R_RISCV_RELATIVE)
915 			continue;
916 
917 		/*
918 		 * Make sure to not relocate vdso symbols like rt_sigreturn
919 		 * which are linked from the address 0 in vmlinux since
920 		 * vdso symbol addresses are actually used as an offset from
921 		 * mm->context.vdso in VDSO_OFFSET macro.
922 		 */
923 		if (relocated_addr >= KERNEL_LINK_ADDR)
924 			relocated_addr += reloc_offset;
925 
926 		*(Elf64_Addr *)addr = relocated_addr;
927 	}
928 }
929 #endif /* CONFIG_RELOCATABLE */
930 
931 #ifdef CONFIG_XIP_KERNEL
932 static void __init create_kernel_page_table(pgd_t *pgdir,
933 					    __always_unused bool early)
934 {
935 	uintptr_t va, start_va, end_va;
936 
937 	/* Map the flash resident part */
938 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
939 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
940 		create_pgd_mapping(pgdir, va,
941 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
942 				   PMD_SIZE, PAGE_KERNEL_EXEC);
943 
944 	/* Map the data in RAM */
945 	start_va = kernel_map.virt_addr + (uintptr_t)&_sdata - (uintptr_t)&_start;
946 	end_va = kernel_map.virt_addr + kernel_map.size;
947 	for (va = start_va; va < end_va; va += PMD_SIZE)
948 		create_pgd_mapping(pgdir, va,
949 				   kernel_map.phys_addr + (va - start_va),
950 				   PMD_SIZE, PAGE_KERNEL);
951 }
952 #else
953 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
954 {
955 	uintptr_t va, end_va;
956 
957 	end_va = kernel_map.virt_addr + kernel_map.size;
958 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
959 		create_pgd_mapping(pgdir, va,
960 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
961 				   PMD_SIZE,
962 				   early ?
963 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
964 }
965 #endif
966 
967 /*
968  * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
969  * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
970  * entry.
971  */
972 static void __init create_fdt_early_page_table(uintptr_t fix_fdt_va,
973 					       uintptr_t dtb_pa)
974 {
975 #ifndef CONFIG_BUILTIN_DTB
976 	uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
977 
978 	/* Make sure the fdt fixmap address is always aligned on PMD size */
979 	BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE));
980 
981 	/* In 32-bit only, the fdt lies in its own PGD */
982 	if (!IS_ENABLED(CONFIG_64BIT)) {
983 		create_pgd_mapping(early_pg_dir, fix_fdt_va,
984 				   pa, MAX_FDT_SIZE, PAGE_KERNEL);
985 	} else {
986 		create_pmd_mapping(fixmap_pmd, fix_fdt_va,
987 				   pa, PMD_SIZE, PAGE_KERNEL);
988 		create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE,
989 				   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
990 	}
991 
992 	dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1));
993 #else
994 	/*
995 	 * For 64-bit kernel, __va can't be used since it would return a linear
996 	 * mapping address whereas dtb_early_va will be used before
997 	 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
998 	 * kernel is mapped in the linear mapping, that makes no difference.
999 	 */
1000 	dtb_early_va = kernel_mapping_pa_to_va(dtb_pa);
1001 #endif
1002 
1003 	dtb_early_pa = dtb_pa;
1004 }
1005 
1006 /*
1007  * MMU is not enabled, the page tables are allocated directly using
1008  * early_pmd/pud/p4d and the address returned is the physical one.
1009  */
1010 static void __init pt_ops_set_early(void)
1011 {
1012 	pt_ops.alloc_pte = alloc_pte_early;
1013 	pt_ops.get_pte_virt = get_pte_virt_early;
1014 #ifndef __PAGETABLE_PMD_FOLDED
1015 	pt_ops.alloc_pmd = alloc_pmd_early;
1016 	pt_ops.get_pmd_virt = get_pmd_virt_early;
1017 	pt_ops.alloc_pud = alloc_pud_early;
1018 	pt_ops.get_pud_virt = get_pud_virt_early;
1019 	pt_ops.alloc_p4d = alloc_p4d_early;
1020 	pt_ops.get_p4d_virt = get_p4d_virt_early;
1021 #endif
1022 }
1023 
1024 /*
1025  * MMU is enabled but page table setup is not complete yet.
1026  * fixmap page table alloc functions must be used as a means to temporarily
1027  * map the allocated physical pages since the linear mapping does not exist yet.
1028  *
1029  * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va,
1030  * but it will be used as described above.
1031  */
1032 static void __init pt_ops_set_fixmap(void)
1033 {
1034 	pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap);
1035 	pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap);
1036 #ifndef __PAGETABLE_PMD_FOLDED
1037 	pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap);
1038 	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap);
1039 	pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap);
1040 	pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap);
1041 	pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap);
1042 	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap);
1043 #endif
1044 }
1045 
1046 /*
1047  * MMU is enabled and page table setup is complete, so from now, we can use
1048  * generic page allocation functions to setup page table.
1049  */
1050 static void __init pt_ops_set_late(void)
1051 {
1052 	pt_ops.alloc_pte = alloc_pte_late;
1053 	pt_ops.get_pte_virt = get_pte_virt_late;
1054 #ifndef __PAGETABLE_PMD_FOLDED
1055 	pt_ops.alloc_pmd = alloc_pmd_late;
1056 	pt_ops.get_pmd_virt = get_pmd_virt_late;
1057 	pt_ops.alloc_pud = alloc_pud_late;
1058 	pt_ops.get_pud_virt = get_pud_virt_late;
1059 	pt_ops.alloc_p4d = alloc_p4d_late;
1060 	pt_ops.get_p4d_virt = get_p4d_virt_late;
1061 #endif
1062 }
1063 
1064 #ifdef CONFIG_RANDOMIZE_BASE
1065 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa);
1066 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa);
1067 extern u64 __init __pi_get_kaslr_seed_zkr(const uintptr_t dtb_pa);
1068 
1069 static int __init print_nokaslr(char *p)
1070 {
1071 	pr_info("Disabled KASLR");
1072 	return 0;
1073 }
1074 early_param("nokaslr", print_nokaslr);
1075 
1076 unsigned long kaslr_offset(void)
1077 {
1078 	return kernel_map.virt_offset;
1079 }
1080 #endif
1081 
1082 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1083 {
1084 	pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
1085 
1086 #ifdef CONFIG_RANDOMIZE_BASE
1087 	if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) {
1088 		u64 kaslr_seed = __pi_get_kaslr_seed_zkr(dtb_pa);
1089 		u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1090 		u32 nr_pos;
1091 
1092 		if (kaslr_seed == 0)
1093 			kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
1094 		/*
1095 		 * Compute the number of positions available: we are limited
1096 		 * by the early page table that only has one PUD and we must
1097 		 * be aligned on PMD_SIZE.
1098 		 */
1099 		nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE;
1100 
1101 		kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE;
1102 	}
1103 #endif
1104 
1105 	kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset;
1106 
1107 #ifdef CONFIG_XIP_KERNEL
1108 #ifdef CONFIG_64BIT
1109 	kernel_map.page_offset = PAGE_OFFSET_L3;
1110 #else
1111 	kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
1112 #endif
1113 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
1114 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
1115 
1116 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
1117 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1118 	vmemmap_start_pfn = round_down(phys_ram_base, VMEMMAP_ADDR_ALIGN) >> PAGE_SHIFT;
1119 #endif
1120 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
1121 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1122 
1123 	kernel_map.va_kernel_xip_text_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
1124 	kernel_map.va_kernel_xip_data_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr
1125 						+ (uintptr_t)&_sdata - (uintptr_t)&_start;
1126 #else
1127 	kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
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 	BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size);
1175 	relocate_kernel();
1176 #endif
1177 
1178 	apply_early_boot_alternatives();
1179 	pt_ops_set_early();
1180 
1181 	/* Setup early PGD for fixmap */
1182 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
1183 			   fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1184 
1185 #ifndef __PAGETABLE_PMD_FOLDED
1186 	/* Setup fixmap P4D and PUD */
1187 	if (pgtable_l5_enabled)
1188 		create_p4d_mapping(fixmap_p4d, FIXADDR_START,
1189 				   (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
1190 	/* Setup fixmap PUD and PMD */
1191 	if (pgtable_l4_enabled)
1192 		create_pud_mapping(fixmap_pud, FIXADDR_START,
1193 				   (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
1194 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
1195 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
1196 	/* Setup trampoline PGD and PMD */
1197 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1198 			   trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1199 	if (pgtable_l5_enabled)
1200 		create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
1201 				   (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
1202 	if (pgtable_l4_enabled)
1203 		create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
1204 				   (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
1205 #ifdef CONFIG_XIP_KERNEL
1206 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1207 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
1208 #else
1209 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1210 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
1211 #endif
1212 #else
1213 	/* Setup trampoline PGD */
1214 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1215 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
1216 #endif
1217 
1218 	/*
1219 	 * Setup early PGD covering entire kernel which will allow
1220 	 * us to reach paging_init(). We map all memory banks later
1221 	 * in setup_vm_final() below.
1222 	 */
1223 	create_kernel_page_table(early_pg_dir, true);
1224 
1225 	/* Setup early mapping for FDT early scan */
1226 	create_fdt_early_page_table(__fix_to_virt(FIX_FDT), dtb_pa);
1227 
1228 	/*
1229 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
1230 	 * range can not span multiple pmds.
1231 	 */
1232 	BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1233 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1234 
1235 #ifndef __PAGETABLE_PMD_FOLDED
1236 	/*
1237 	 * Early ioremap fixmap is already created as it lies within first 2MB
1238 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
1239 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
1240 	 * the user if not.
1241 	 */
1242 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
1243 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
1244 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
1245 		WARN_ON(1);
1246 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
1247 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
1248 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1249 			fix_to_virt(FIX_BTMAP_BEGIN));
1250 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
1251 			fix_to_virt(FIX_BTMAP_END));
1252 
1253 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
1254 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
1255 	}
1256 #endif
1257 
1258 	pt_ops_set_fixmap();
1259 }
1260 
1261 static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end,
1262 						  uintptr_t fixed_map_size, const pgprot_t *pgprot)
1263 {
1264 	phys_addr_t pa;
1265 	uintptr_t va, map_size;
1266 
1267 	for (pa = start; pa < end; pa += map_size) {
1268 		va = (uintptr_t)__va(pa);
1269 		map_size = fixed_map_size ? fixed_map_size :
1270 					    best_map_size(pa, va, end - pa);
1271 
1272 		create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1273 				   pgprot ? *pgprot : pgprot_from_va(va));
1274 	}
1275 }
1276 
1277 static void __init create_linear_mapping_page_table(void)
1278 {
1279 	phys_addr_t start, end;
1280 	phys_addr_t kfence_pool __maybe_unused;
1281 	u64 i;
1282 
1283 #ifdef CONFIG_STRICT_KERNEL_RWX
1284 	phys_addr_t ktext_start = __pa_symbol(_start);
1285 	phys_addr_t ktext_size = __init_data_begin - _start;
1286 	phys_addr_t krodata_start = __pa_symbol(__start_rodata);
1287 	phys_addr_t krodata_size = _data - __start_rodata;
1288 
1289 	/* Isolate kernel text and rodata so they don't get mapped with a PUD */
1290 	memblock_mark_nomap(ktext_start,  ktext_size);
1291 	memblock_mark_nomap(krodata_start, krodata_size);
1292 #endif
1293 
1294 #ifdef CONFIG_KFENCE
1295 	/*
1296 	 *  kfence pool must be backed by PAGE_SIZE mappings, so allocate it
1297 	 *  before we setup the linear mapping so that we avoid using hugepages
1298 	 *  for this region.
1299 	 */
1300 	kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
1301 	BUG_ON(!kfence_pool);
1302 
1303 	memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE);
1304 	__kfence_pool = __va(kfence_pool);
1305 #endif
1306 
1307 	/* Map all memory banks in the linear mapping */
1308 	for_each_mem_range(i, &start, &end) {
1309 		if (start >= end)
1310 			break;
1311 		if (start <= __pa(PAGE_OFFSET) &&
1312 		    __pa(PAGE_OFFSET) < end)
1313 			start = __pa(PAGE_OFFSET);
1314 
1315 		create_linear_mapping_range(start, end, 0, NULL);
1316 	}
1317 
1318 #ifdef CONFIG_STRICT_KERNEL_RWX
1319 	create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0, NULL);
1320 	create_linear_mapping_range(krodata_start, krodata_start + krodata_size, 0, NULL);
1321 
1322 	memblock_clear_nomap(ktext_start,  ktext_size);
1323 	memblock_clear_nomap(krodata_start, krodata_size);
1324 #endif
1325 
1326 #ifdef CONFIG_KFENCE
1327 	create_linear_mapping_range(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, PAGE_SIZE, NULL);
1328 
1329 	memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
1330 #endif
1331 }
1332 
1333 static void __init setup_vm_final(void)
1334 {
1335 	/* Setup swapper PGD for fixmap */
1336 #if !defined(CONFIG_64BIT)
1337 	/*
1338 	 * In 32-bit, the device tree lies in a pgd entry, so it must be copied
1339 	 * directly in swapper_pg_dir in addition to the pgd entry that points
1340 	 * to fixmap_pte.
1341 	 */
1342 	unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT));
1343 
1344 	set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]);
1345 #endif
1346 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
1347 			   __pa_symbol(fixmap_pgd_next),
1348 			   PGDIR_SIZE, PAGE_TABLE);
1349 
1350 	/* Map the linear mapping */
1351 	create_linear_mapping_page_table();
1352 
1353 	/* Map the kernel */
1354 	if (IS_ENABLED(CONFIG_64BIT))
1355 		create_kernel_page_table(swapper_pg_dir, false);
1356 
1357 #ifdef CONFIG_KASAN
1358 	kasan_swapper_init();
1359 #endif
1360 
1361 	/* Clear fixmap PTE and PMD mappings */
1362 	clear_fixmap(FIX_PTE);
1363 	clear_fixmap(FIX_PMD);
1364 	clear_fixmap(FIX_PUD);
1365 	clear_fixmap(FIX_P4D);
1366 
1367 	/* Move to swapper page table */
1368 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode);
1369 	local_flush_tlb_all();
1370 
1371 	pt_ops_set_late();
1372 }
1373 #else
1374 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1375 {
1376 	dtb_early_va = (void *)dtb_pa;
1377 	dtb_early_pa = dtb_pa;
1378 }
1379 
1380 static inline void setup_vm_final(void)
1381 {
1382 }
1383 #endif /* CONFIG_MMU */
1384 
1385 /*
1386  * reserve_crashkernel() - reserves memory for crash kernel
1387  *
1388  * This function reserves memory area given in "crashkernel=" kernel command
1389  * line parameter. The memory reserved is used by dump capture kernel when
1390  * primary kernel is crashing.
1391  */
1392 static void __init arch_reserve_crashkernel(void)
1393 {
1394 	unsigned long long low_size = 0;
1395 	unsigned long long crash_base, crash_size;
1396 	bool high = false;
1397 	int ret;
1398 
1399 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
1400 		return;
1401 
1402 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
1403 				&crash_size, &crash_base,
1404 				&low_size, &high);
1405 	if (ret)
1406 		return;
1407 
1408 	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
1409 }
1410 
1411 void __init paging_init(void)
1412 {
1413 	setup_bootmem();
1414 	setup_vm_final();
1415 
1416 	/* Depend on that Linear Mapping is ready */
1417 	memblock_allow_resize();
1418 }
1419 
1420 void __init misc_mem_init(void)
1421 {
1422 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
1423 	arch_numa_init();
1424 	sparse_init();
1425 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1426 	/* The entire VMEMMAP region has been populated. Flush TLB for this region */
1427 	local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END);
1428 #endif
1429 	zone_sizes_init();
1430 	arch_reserve_crashkernel();
1431 	memblock_dump_all();
1432 }
1433 
1434 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1435 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
1436 			       unsigned long addr, unsigned long next)
1437 {
1438 	pmd_set_huge(pmd, virt_to_phys(p), PAGE_KERNEL);
1439 }
1440 
1441 int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node,
1442 				unsigned long addr, unsigned long next)
1443 {
1444 	vmemmap_verify((pte_t *)pmdp, node, addr, next);
1445 	return 1;
1446 }
1447 
1448 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1449 			       struct vmem_altmap *altmap)
1450 {
1451 	/*
1452 	 * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we
1453 	 * can't use hugepage mappings for 2-level page table because in case of
1454 	 * memory hotplug, we are not able to update all the page tables with
1455 	 * the new PMDs.
1456 	 */
1457 	return vmemmap_populate_hugepages(start, end, node, altmap);
1458 }
1459 #endif
1460 
1461 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
1462 /*
1463  * Pre-allocates page-table pages for a specific area in the kernel
1464  * page-table. Only the level which needs to be synchronized between
1465  * all page-tables is allocated because the synchronization can be
1466  * expensive.
1467  */
1468 static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end,
1469 					       const char *area)
1470 {
1471 	unsigned long addr;
1472 	const char *lvl;
1473 
1474 	for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1475 		pgd_t *pgd = pgd_offset_k(addr);
1476 		p4d_t *p4d;
1477 		pud_t *pud;
1478 		pmd_t *pmd;
1479 
1480 		lvl = "p4d";
1481 		p4d = p4d_alloc(&init_mm, pgd, addr);
1482 		if (!p4d)
1483 			goto failed;
1484 
1485 		if (pgtable_l5_enabled)
1486 			continue;
1487 
1488 		lvl = "pud";
1489 		pud = pud_alloc(&init_mm, p4d, addr);
1490 		if (!pud)
1491 			goto failed;
1492 
1493 		if (pgtable_l4_enabled)
1494 			continue;
1495 
1496 		lvl = "pmd";
1497 		pmd = pmd_alloc(&init_mm, pud, addr);
1498 		if (!pmd)
1499 			goto failed;
1500 	}
1501 	return;
1502 
1503 failed:
1504 	/*
1505 	 * The pages have to be there now or they will be missing in
1506 	 * process page-tables later.
1507 	 */
1508 	panic("Failed to pre-allocate %s pages for %s area\n", lvl, area);
1509 }
1510 
1511 #define PAGE_END KASAN_SHADOW_START
1512 
1513 void __init pgtable_cache_init(void)
1514 {
1515 	preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc");
1516 	if (IS_ENABLED(CONFIG_MODULES))
1517 		preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules");
1518 	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) {
1519 		preallocate_pgd_pages_range(VMEMMAP_START, VMEMMAP_END, "vmemmap");
1520 		preallocate_pgd_pages_range(PAGE_OFFSET, PAGE_END, "direct map");
1521 		if (IS_ENABLED(CONFIG_KASAN))
1522 			preallocate_pgd_pages_range(KASAN_SHADOW_START, KASAN_SHADOW_END, "kasan");
1523 	}
1524 }
1525 #endif
1526 
1527 #ifdef CONFIG_EXECMEM
1528 #ifdef CONFIG_MMU
1529 static struct execmem_info execmem_info __ro_after_init;
1530 
1531 struct execmem_info __init *execmem_arch_setup(void)
1532 {
1533 	execmem_info = (struct execmem_info){
1534 		.ranges = {
1535 			[EXECMEM_DEFAULT] = {
1536 				.start	= MODULES_VADDR,
1537 				.end	= MODULES_END,
1538 				.pgprot	= PAGE_KERNEL,
1539 				.alignment = 1,
1540 			},
1541 			[EXECMEM_KPROBES] = {
1542 				.start	= VMALLOC_START,
1543 				.end	= VMALLOC_END,
1544 				.pgprot	= PAGE_KERNEL_READ_EXEC,
1545 				.alignment = 1,
1546 			},
1547 			[EXECMEM_BPF] = {
1548 				.start	= BPF_JIT_REGION_START,
1549 				.end	= BPF_JIT_REGION_END,
1550 				.pgprot	= PAGE_KERNEL,
1551 				.alignment = PAGE_SIZE,
1552 			},
1553 		},
1554 	};
1555 
1556 	return &execmem_info;
1557 }
1558 #endif /* CONFIG_MMU */
1559 #endif /* CONFIG_EXECMEM */
1560 
1561 #ifdef CONFIG_MEMORY_HOTPLUG
1562 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1563 {
1564 	struct page *page = pmd_page(*pmd);
1565 	struct ptdesc *ptdesc = page_ptdesc(page);
1566 	pte_t *pte;
1567 	int i;
1568 
1569 	for (i = 0; i < PTRS_PER_PTE; i++) {
1570 		pte = pte_start + i;
1571 		if (!pte_none(*pte))
1572 			return;
1573 	}
1574 
1575 	pagetable_dtor(ptdesc);
1576 	if (PageReserved(page))
1577 		free_reserved_page(page);
1578 	else
1579 		pagetable_free(ptdesc);
1580 	pmd_clear(pmd);
1581 }
1582 
1583 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud, bool is_vmemmap)
1584 {
1585 	struct page *page = pud_page(*pud);
1586 	struct ptdesc *ptdesc = page_ptdesc(page);
1587 	pmd_t *pmd;
1588 	int i;
1589 
1590 	for (i = 0; i < PTRS_PER_PMD; i++) {
1591 		pmd = pmd_start + i;
1592 		if (!pmd_none(*pmd))
1593 			return;
1594 	}
1595 
1596 	if (!is_vmemmap)
1597 		pagetable_dtor(ptdesc);
1598 	if (PageReserved(page))
1599 		free_reserved_page(page);
1600 	else
1601 		pagetable_free(ptdesc);
1602 	pud_clear(pud);
1603 }
1604 
1605 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1606 {
1607 	struct page *page = p4d_page(*p4d);
1608 	pud_t *pud;
1609 	int i;
1610 
1611 	for (i = 0; i < PTRS_PER_PUD; i++) {
1612 		pud = pud_start + i;
1613 		if (!pud_none(*pud))
1614 			return;
1615 	}
1616 
1617 	if (PageReserved(page))
1618 		free_reserved_page(page);
1619 	else
1620 		free_pages((unsigned long)page_address(page), 0);
1621 	p4d_clear(p4d);
1622 }
1623 
1624 static void __meminit free_vmemmap_storage(struct page *page, size_t size,
1625 					   struct vmem_altmap *altmap)
1626 {
1627 	int order = get_order(size);
1628 
1629 	if (altmap) {
1630 		vmem_altmap_free(altmap, size >> PAGE_SHIFT);
1631 		return;
1632 	}
1633 
1634 	if (PageReserved(page)) {
1635 		unsigned int nr_pages = 1 << order;
1636 
1637 		while (nr_pages--)
1638 			free_reserved_page(page++);
1639 		return;
1640 	}
1641 
1642 	free_pages((unsigned long)page_address(page), order);
1643 }
1644 
1645 static void __meminit remove_pte_mapping(pte_t *pte_base, unsigned long addr, unsigned long end,
1646 					 bool is_vmemmap, struct vmem_altmap *altmap)
1647 {
1648 	unsigned long next;
1649 	pte_t *ptep, pte;
1650 
1651 	for (; addr < end; addr = next) {
1652 		next = (addr + PAGE_SIZE) & PAGE_MASK;
1653 		if (next > end)
1654 			next = end;
1655 
1656 		ptep = pte_base + pte_index(addr);
1657 		pte = ptep_get(ptep);
1658 		if (!pte_present(*ptep))
1659 			continue;
1660 
1661 		pte_clear(&init_mm, addr, ptep);
1662 		if (is_vmemmap)
1663 			free_vmemmap_storage(pte_page(pte), PAGE_SIZE, altmap);
1664 	}
1665 }
1666 
1667 static void __meminit remove_pmd_mapping(pmd_t *pmd_base, unsigned long addr, unsigned long end,
1668 					 bool is_vmemmap, struct vmem_altmap *altmap)
1669 {
1670 	unsigned long next;
1671 	pte_t *pte_base;
1672 	pmd_t *pmdp, pmd;
1673 
1674 	for (; addr < end; addr = next) {
1675 		next = pmd_addr_end(addr, end);
1676 		pmdp = pmd_base + pmd_index(addr);
1677 		pmd = pmdp_get(pmdp);
1678 		if (!pmd_present(pmd))
1679 			continue;
1680 
1681 		if (pmd_leaf(pmd)) {
1682 			pmd_clear(pmdp);
1683 			if (is_vmemmap)
1684 				free_vmemmap_storage(pmd_page(pmd), PMD_SIZE, altmap);
1685 			continue;
1686 		}
1687 
1688 		pte_base = (pte_t *)pmd_page_vaddr(*pmdp);
1689 		remove_pte_mapping(pte_base, addr, next, is_vmemmap, altmap);
1690 		free_pte_table(pte_base, pmdp);
1691 	}
1692 }
1693 
1694 static void __meminit remove_pud_mapping(pud_t *pud_base, unsigned long addr, unsigned long end,
1695 					 bool is_vmemmap, struct vmem_altmap *altmap)
1696 {
1697 	unsigned long next;
1698 	pud_t *pudp, pud;
1699 	pmd_t *pmd_base;
1700 
1701 	for (; addr < end; addr = next) {
1702 		next = pud_addr_end(addr, end);
1703 		pudp = pud_base + pud_index(addr);
1704 		pud = pudp_get(pudp);
1705 		if (!pud_present(pud))
1706 			continue;
1707 
1708 		if (pud_leaf(pud)) {
1709 			if (pgtable_l4_enabled) {
1710 				pud_clear(pudp);
1711 				if (is_vmemmap)
1712 					free_vmemmap_storage(pud_page(pud), PUD_SIZE, altmap);
1713 			}
1714 			continue;
1715 		}
1716 
1717 		pmd_base = pmd_offset(pudp, 0);
1718 		remove_pmd_mapping(pmd_base, addr, next, is_vmemmap, altmap);
1719 
1720 		if (pgtable_l4_enabled)
1721 			free_pmd_table(pmd_base, pudp, is_vmemmap);
1722 	}
1723 }
1724 
1725 static void __meminit remove_p4d_mapping(p4d_t *p4d_base, unsigned long addr, unsigned long end,
1726 					 bool is_vmemmap, struct vmem_altmap *altmap)
1727 {
1728 	unsigned long next;
1729 	p4d_t *p4dp, p4d;
1730 	pud_t *pud_base;
1731 
1732 	for (; addr < end; addr = next) {
1733 		next = p4d_addr_end(addr, end);
1734 		p4dp = p4d_base + p4d_index(addr);
1735 		p4d = p4dp_get(p4dp);
1736 		if (!p4d_present(p4d))
1737 			continue;
1738 
1739 		if (p4d_leaf(p4d)) {
1740 			if (pgtable_l5_enabled) {
1741 				p4d_clear(p4dp);
1742 				if (is_vmemmap)
1743 					free_vmemmap_storage(p4d_page(p4d), P4D_SIZE, altmap);
1744 			}
1745 			continue;
1746 		}
1747 
1748 		pud_base = pud_offset(p4dp, 0);
1749 		remove_pud_mapping(pud_base, addr, next, is_vmemmap, altmap);
1750 
1751 		if (pgtable_l5_enabled)
1752 			free_pud_table(pud_base, p4dp);
1753 	}
1754 }
1755 
1756 static void __meminit remove_pgd_mapping(unsigned long va, unsigned long end, bool is_vmemmap,
1757 					 struct vmem_altmap *altmap)
1758 {
1759 	unsigned long addr, next;
1760 	p4d_t *p4d_base;
1761 	pgd_t *pgd;
1762 
1763 	for (addr = va; addr < end; addr = next) {
1764 		next = pgd_addr_end(addr, end);
1765 		pgd = pgd_offset_k(addr);
1766 
1767 		if (!pgd_present(*pgd))
1768 			continue;
1769 
1770 		if (pgd_leaf(*pgd))
1771 			continue;
1772 
1773 		p4d_base = p4d_offset(pgd, 0);
1774 		remove_p4d_mapping(p4d_base, addr, next, is_vmemmap, altmap);
1775 	}
1776 
1777 	flush_tlb_all();
1778 }
1779 
1780 static void __meminit remove_linear_mapping(phys_addr_t start, u64 size)
1781 {
1782 	unsigned long va = (unsigned long)__va(start);
1783 	unsigned long end = (unsigned long)__va(start + size);
1784 
1785 	remove_pgd_mapping(va, end, false, NULL);
1786 }
1787 
1788 struct range arch_get_mappable_range(void)
1789 {
1790 	struct range mhp_range;
1791 
1792 	mhp_range.start = __pa(PAGE_OFFSET);
1793 	mhp_range.end = __pa(PAGE_END - 1);
1794 	return mhp_range;
1795 }
1796 
1797 int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
1798 {
1799 	int ret = 0;
1800 
1801 	create_linear_mapping_range(start, start + size, 0, &params->pgprot);
1802 	ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, params);
1803 	if (ret) {
1804 		remove_linear_mapping(start, size);
1805 		goto out;
1806 	}
1807 
1808 	max_pfn = PFN_UP(start + size);
1809 	max_low_pfn = max_pfn;
1810 
1811  out:
1812 	flush_tlb_all();
1813 	return ret;
1814 }
1815 
1816 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1817 {
1818 	__remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap);
1819 	remove_linear_mapping(start, size);
1820 	flush_tlb_all();
1821 }
1822 
1823 void __ref vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
1824 {
1825 	remove_pgd_mapping(start, end, true, altmap);
1826 }
1827 #endif /* CONFIG_MEMORY_HOTPLUG */
1828