xref: /linux/arch/riscv/mm/init.c (revision 26e7aacb83dfd04330673c5c9ac336560da52bb3)
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 
27 #include <asm/fixmap.h>
28 #include <asm/tlbflush.h>
29 #include <asm/sections.h>
30 #include <asm/soc.h>
31 #include <asm/io.h>
32 #include <asm/ptdump.h>
33 #include <asm/numa.h>
34 
35 #include "../kernel/head.h"
36 
37 struct kernel_mapping kernel_map __ro_after_init;
38 EXPORT_SYMBOL(kernel_map);
39 #ifdef CONFIG_XIP_KERNEL
40 #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
41 #endif
42 
43 #ifdef CONFIG_64BIT
44 u64 satp_mode __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_57 : SATP_MODE_39;
45 #else
46 u64 satp_mode __ro_after_init = SATP_MODE_32;
47 #endif
48 EXPORT_SYMBOL(satp_mode);
49 
50 bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
51 bool pgtable_l5_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
52 EXPORT_SYMBOL(pgtable_l4_enabled);
53 EXPORT_SYMBOL(pgtable_l5_enabled);
54 
55 phys_addr_t phys_ram_base __ro_after_init;
56 EXPORT_SYMBOL(phys_ram_base);
57 
58 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
59 							__page_aligned_bss;
60 EXPORT_SYMBOL(empty_zero_page);
61 
62 extern char _start[];
63 #define DTB_EARLY_BASE_VA      (ADDRESS_SPACE_END - (PTRS_PER_PGD / 2 * PGDIR_SIZE) + 1)
64 void *_dtb_early_va __initdata;
65 uintptr_t _dtb_early_pa __initdata;
66 
67 static phys_addr_t dma32_phys_limit __initdata;
68 
69 static void __init zone_sizes_init(void)
70 {
71 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
72 
73 #ifdef CONFIG_ZONE_DMA32
74 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
75 #endif
76 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
77 
78 	free_area_init(max_zone_pfns);
79 }
80 
81 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
82 
83 #define LOG2_SZ_1K  ilog2(SZ_1K)
84 #define LOG2_SZ_1M  ilog2(SZ_1M)
85 #define LOG2_SZ_1G  ilog2(SZ_1G)
86 #define LOG2_SZ_1T  ilog2(SZ_1T)
87 
88 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
89 {
90 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
91 		  (((t) - (b)) >> LOG2_SZ_1K));
92 }
93 
94 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
95 {
96 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
97 		  (((t) - (b)) >> LOG2_SZ_1M));
98 }
99 
100 static inline void print_mlg(char *name, unsigned long b, unsigned long t)
101 {
102 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld GB)\n", name, b, t,
103 		   (((t) - (b)) >> LOG2_SZ_1G));
104 }
105 
106 #ifdef CONFIG_64BIT
107 static inline void print_mlt(char *name, unsigned long b, unsigned long t)
108 {
109 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld TB)\n", name, b, t,
110 		   (((t) - (b)) >> LOG2_SZ_1T));
111 }
112 #else
113 #define print_mlt(n, b, t) do {} while (0)
114 #endif
115 
116 static inline void print_ml(char *name, unsigned long b, unsigned long t)
117 {
118 	unsigned long diff = t - b;
119 
120 	if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10)
121 		print_mlt(name, b, t);
122 	else if ((diff >> LOG2_SZ_1G) >= 10)
123 		print_mlg(name, b, t);
124 	else if ((diff >> LOG2_SZ_1M) >= 10)
125 		print_mlm(name, b, t);
126 	else
127 		print_mlk(name, b, t);
128 }
129 
130 static void __init print_vm_layout(void)
131 {
132 	pr_notice("Virtual kernel memory layout:\n");
133 	print_ml("fixmap", (unsigned long)FIXADDR_START,
134 		(unsigned long)FIXADDR_TOP);
135 	print_ml("pci io", (unsigned long)PCI_IO_START,
136 		(unsigned long)PCI_IO_END);
137 	print_ml("vmemmap", (unsigned long)VMEMMAP_START,
138 		(unsigned long)VMEMMAP_END);
139 	print_ml("vmalloc", (unsigned long)VMALLOC_START,
140 		(unsigned long)VMALLOC_END);
141 #ifdef CONFIG_64BIT
142 	print_ml("modules", (unsigned long)MODULES_VADDR,
143 		(unsigned long)MODULES_END);
144 #endif
145 	print_ml("lowmem", (unsigned long)PAGE_OFFSET,
146 		(unsigned long)high_memory);
147 	if (IS_ENABLED(CONFIG_64BIT)) {
148 #ifdef CONFIG_KASAN
149 		print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
150 #endif
151 
152 		print_ml("kernel", (unsigned long)kernel_map.virt_addr,
153 			 (unsigned long)ADDRESS_SPACE_END);
154 	}
155 }
156 #else
157 static void print_vm_layout(void) { }
158 #endif /* CONFIG_DEBUG_VM */
159 
160 void __init mem_init(void)
161 {
162 #ifdef CONFIG_FLATMEM
163 	BUG_ON(!mem_map);
164 #endif /* CONFIG_FLATMEM */
165 
166 	swiotlb_init(max_pfn > PFN_DOWN(dma32_phys_limit), SWIOTLB_VERBOSE);
167 	memblock_free_all();
168 
169 	print_vm_layout();
170 }
171 
172 /* Limit the memory size via mem. */
173 static phys_addr_t memory_limit;
174 
175 static int __init early_mem(char *p)
176 {
177 	u64 size;
178 
179 	if (!p)
180 		return 1;
181 
182 	size = memparse(p, &p) & PAGE_MASK;
183 	memory_limit = min_t(u64, size, memory_limit);
184 
185 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
186 
187 	return 0;
188 }
189 early_param("mem", early_mem);
190 
191 static void __init setup_bootmem(void)
192 {
193 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
194 	phys_addr_t max_mapped_addr;
195 	phys_addr_t phys_ram_end, vmlinux_start;
196 
197 	if (IS_ENABLED(CONFIG_XIP_KERNEL))
198 		vmlinux_start = __pa_symbol(&_sdata);
199 	else
200 		vmlinux_start = __pa_symbol(&_start);
201 
202 	memblock_enforce_memory_limit(memory_limit);
203 
204 	/*
205 	 * Make sure we align the reservation on PMD_SIZE since we will
206 	 * map the kernel in the linear mapping as read-only: we do not want
207 	 * any allocation to happen between _end and the next pmd aligned page.
208 	 */
209 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
210 		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
211 	/*
212 	 * Reserve from the start of the kernel to the end of the kernel
213 	 */
214 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
215 
216 	phys_ram_end = memblock_end_of_DRAM();
217 	if (!IS_ENABLED(CONFIG_XIP_KERNEL))
218 		phys_ram_base = memblock_start_of_DRAM();
219 
220 	/*
221 	 * In 64-bit, any use of __va/__pa before this point is wrong as we
222 	 * did not know the start of DRAM before.
223 	 */
224 	if (IS_ENABLED(CONFIG_64BIT))
225 		kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
226 
227 	/*
228 	 * memblock allocator is not aware of the fact that last 4K bytes of
229 	 * the addressable memory can not be mapped because of IS_ERR_VALUE
230 	 * macro. Make sure that last 4k bytes are not usable by memblock
231 	 * if end of dram is equal to maximum addressable memory.  For 64-bit
232 	 * kernel, this problem can't happen here as the end of the virtual
233 	 * address space is occupied by the kernel mapping then this check must
234 	 * be done as soon as the kernel mapping base address is determined.
235 	 */
236 	if (!IS_ENABLED(CONFIG_64BIT)) {
237 		max_mapped_addr = __pa(~(ulong)0);
238 		if (max_mapped_addr == (phys_ram_end - 1))
239 			memblock_set_current_limit(max_mapped_addr - 4096);
240 	}
241 
242 	min_low_pfn = PFN_UP(phys_ram_base);
243 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
244 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
245 
246 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
247 	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
248 
249 	reserve_initrd_mem();
250 	/*
251 	 * If DTB is built in, no need to reserve its memblock.
252 	 * Otherwise, do reserve it but avoid using
253 	 * early_init_fdt_reserve_self() since __pa() does
254 	 * not work for DTB pointers that are fixmap addresses
255 	 */
256 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB)) {
257 		/*
258 		 * In case the DTB is not located in a memory region we won't
259 		 * be able to locate it later on via the linear mapping and
260 		 * get a segfault when accessing it via __va(dtb_early_pa).
261 		 * To avoid this situation copy DTB to a memory region.
262 		 * Note that memblock_phys_alloc will also reserve DTB region.
263 		 */
264 		if (!memblock_is_memory(dtb_early_pa)) {
265 			size_t fdt_size = fdt_totalsize(dtb_early_va);
266 			phys_addr_t new_dtb_early_pa = memblock_phys_alloc(fdt_size, PAGE_SIZE);
267 			void *new_dtb_early_va = early_memremap(new_dtb_early_pa, fdt_size);
268 
269 			memcpy(new_dtb_early_va, dtb_early_va, fdt_size);
270 			early_memunmap(new_dtb_early_va, fdt_size);
271 			_dtb_early_pa = new_dtb_early_pa;
272 		} else
273 			memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
274 	}
275 
276 	dma_contiguous_reserve(dma32_phys_limit);
277 	if (IS_ENABLED(CONFIG_64BIT))
278 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
279 	memblock_allow_resize();
280 }
281 
282 #ifdef CONFIG_MMU
283 struct pt_alloc_ops pt_ops __initdata;
284 
285 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
286 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
287 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
288 
289 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
290 static p4d_t __maybe_unused early_dtb_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
291 static pud_t __maybe_unused early_dtb_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
292 static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
293 
294 #ifdef CONFIG_XIP_KERNEL
295 #define pt_ops			(*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
296 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
297 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
298 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
299 #endif /* CONFIG_XIP_KERNEL */
300 
301 static const pgprot_t protection_map[16] = {
302 	[VM_NONE]					= PAGE_NONE,
303 	[VM_READ]					= PAGE_READ,
304 	[VM_WRITE]					= PAGE_COPY,
305 	[VM_WRITE | VM_READ]				= PAGE_COPY,
306 	[VM_EXEC]					= PAGE_EXEC,
307 	[VM_EXEC | VM_READ]				= PAGE_READ_EXEC,
308 	[VM_EXEC | VM_WRITE]				= PAGE_COPY_EXEC,
309 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_COPY_READ_EXEC,
310 	[VM_SHARED]					= PAGE_NONE,
311 	[VM_SHARED | VM_READ]				= PAGE_READ,
312 	[VM_SHARED | VM_WRITE]				= PAGE_SHARED,
313 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
314 	[VM_SHARED | VM_EXEC]				= PAGE_EXEC,
315 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ_EXEC,
316 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_SHARED_EXEC,
317 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED_EXEC
318 };
319 DECLARE_VM_GET_PAGE_PROT
320 
321 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
322 {
323 	unsigned long addr = __fix_to_virt(idx);
324 	pte_t *ptep;
325 
326 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
327 
328 	ptep = &fixmap_pte[pte_index(addr)];
329 
330 	if (pgprot_val(prot))
331 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
332 	else
333 		pte_clear(&init_mm, addr, ptep);
334 	local_flush_tlb_page(addr);
335 }
336 
337 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
338 {
339 	return (pte_t *)((uintptr_t)pa);
340 }
341 
342 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
343 {
344 	clear_fixmap(FIX_PTE);
345 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
346 }
347 
348 static inline pte_t *__init get_pte_virt_late(phys_addr_t pa)
349 {
350 	return (pte_t *) __va(pa);
351 }
352 
353 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
354 {
355 	/*
356 	 * We only create PMD or PGD early mappings so we
357 	 * should never reach here with MMU disabled.
358 	 */
359 	BUG();
360 }
361 
362 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
363 {
364 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
365 }
366 
367 static phys_addr_t __init alloc_pte_late(uintptr_t va)
368 {
369 	unsigned long vaddr;
370 
371 	vaddr = __get_free_page(GFP_KERNEL);
372 	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)));
373 
374 	return __pa(vaddr);
375 }
376 
377 static void __init create_pte_mapping(pte_t *ptep,
378 				      uintptr_t va, phys_addr_t pa,
379 				      phys_addr_t sz, pgprot_t prot)
380 {
381 	uintptr_t pte_idx = pte_index(va);
382 
383 	BUG_ON(sz != PAGE_SIZE);
384 
385 	if (pte_none(ptep[pte_idx]))
386 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
387 }
388 
389 #ifndef __PAGETABLE_PMD_FOLDED
390 
391 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
392 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
393 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
394 
395 #ifdef CONFIG_XIP_KERNEL
396 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
397 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
398 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
399 #endif /* CONFIG_XIP_KERNEL */
400 
401 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss;
402 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss;
403 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
404 
405 #ifdef CONFIG_XIP_KERNEL
406 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d))
407 #define fixmap_p4d     ((p4d_t *)XIP_FIXUP(fixmap_p4d))
408 #define early_p4d      ((p4d_t *)XIP_FIXUP(early_p4d))
409 #endif /* CONFIG_XIP_KERNEL */
410 
411 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss;
412 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss;
413 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
414 
415 #ifdef CONFIG_XIP_KERNEL
416 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud))
417 #define fixmap_pud     ((pud_t *)XIP_FIXUP(fixmap_pud))
418 #define early_pud      ((pud_t *)XIP_FIXUP(early_pud))
419 #endif /* CONFIG_XIP_KERNEL */
420 
421 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
422 {
423 	/* Before MMU is enabled */
424 	return (pmd_t *)((uintptr_t)pa);
425 }
426 
427 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
428 {
429 	clear_fixmap(FIX_PMD);
430 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
431 }
432 
433 static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)
434 {
435 	return (pmd_t *) __va(pa);
436 }
437 
438 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
439 {
440 	BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT);
441 
442 	return (uintptr_t)early_pmd;
443 }
444 
445 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
446 {
447 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
448 }
449 
450 static phys_addr_t __init alloc_pmd_late(uintptr_t va)
451 {
452 	unsigned long vaddr;
453 
454 	vaddr = __get_free_page(GFP_KERNEL);
455 	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page(vaddr)));
456 
457 	return __pa(vaddr);
458 }
459 
460 static void __init create_pmd_mapping(pmd_t *pmdp,
461 				      uintptr_t va, phys_addr_t pa,
462 				      phys_addr_t sz, pgprot_t prot)
463 {
464 	pte_t *ptep;
465 	phys_addr_t pte_phys;
466 	uintptr_t pmd_idx = pmd_index(va);
467 
468 	if (sz == PMD_SIZE) {
469 		if (pmd_none(pmdp[pmd_idx]))
470 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
471 		return;
472 	}
473 
474 	if (pmd_none(pmdp[pmd_idx])) {
475 		pte_phys = pt_ops.alloc_pte(va);
476 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
477 		ptep = pt_ops.get_pte_virt(pte_phys);
478 		memset(ptep, 0, PAGE_SIZE);
479 	} else {
480 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
481 		ptep = pt_ops.get_pte_virt(pte_phys);
482 	}
483 
484 	create_pte_mapping(ptep, va, pa, sz, prot);
485 }
486 
487 static pud_t *__init get_pud_virt_early(phys_addr_t pa)
488 {
489 	return (pud_t *)((uintptr_t)pa);
490 }
491 
492 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
493 {
494 	clear_fixmap(FIX_PUD);
495 	return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
496 }
497 
498 static pud_t *__init get_pud_virt_late(phys_addr_t pa)
499 {
500 	return (pud_t *)__va(pa);
501 }
502 
503 static phys_addr_t __init alloc_pud_early(uintptr_t va)
504 {
505 	/* Only one PUD is available for early mapping */
506 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
507 
508 	return (uintptr_t)early_pud;
509 }
510 
511 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
512 {
513 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
514 }
515 
516 static phys_addr_t alloc_pud_late(uintptr_t va)
517 {
518 	unsigned long vaddr;
519 
520 	vaddr = __get_free_page(GFP_KERNEL);
521 	BUG_ON(!vaddr);
522 	return __pa(vaddr);
523 }
524 
525 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa)
526 {
527 	return (p4d_t *)((uintptr_t)pa);
528 }
529 
530 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
531 {
532 	clear_fixmap(FIX_P4D);
533 	return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
534 }
535 
536 static p4d_t *__init get_p4d_virt_late(phys_addr_t pa)
537 {
538 	return (p4d_t *)__va(pa);
539 }
540 
541 static phys_addr_t __init alloc_p4d_early(uintptr_t va)
542 {
543 	/* Only one P4D is available for early mapping */
544 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
545 
546 	return (uintptr_t)early_p4d;
547 }
548 
549 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
550 {
551 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
552 }
553 
554 static phys_addr_t alloc_p4d_late(uintptr_t va)
555 {
556 	unsigned long vaddr;
557 
558 	vaddr = __get_free_page(GFP_KERNEL);
559 	BUG_ON(!vaddr);
560 	return __pa(vaddr);
561 }
562 
563 static void __init create_pud_mapping(pud_t *pudp,
564 				      uintptr_t va, phys_addr_t pa,
565 				      phys_addr_t sz, pgprot_t prot)
566 {
567 	pmd_t *nextp;
568 	phys_addr_t next_phys;
569 	uintptr_t pud_index = pud_index(va);
570 
571 	if (sz == PUD_SIZE) {
572 		if (pud_val(pudp[pud_index]) == 0)
573 			pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot);
574 		return;
575 	}
576 
577 	if (pud_val(pudp[pud_index]) == 0) {
578 		next_phys = pt_ops.alloc_pmd(va);
579 		pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE);
580 		nextp = pt_ops.get_pmd_virt(next_phys);
581 		memset(nextp, 0, PAGE_SIZE);
582 	} else {
583 		next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index]));
584 		nextp = pt_ops.get_pmd_virt(next_phys);
585 	}
586 
587 	create_pmd_mapping(nextp, va, pa, sz, prot);
588 }
589 
590 static void __init create_p4d_mapping(p4d_t *p4dp,
591 				      uintptr_t va, phys_addr_t pa,
592 				      phys_addr_t sz, pgprot_t prot)
593 {
594 	pud_t *nextp;
595 	phys_addr_t next_phys;
596 	uintptr_t p4d_index = p4d_index(va);
597 
598 	if (sz == P4D_SIZE) {
599 		if (p4d_val(p4dp[p4d_index]) == 0)
600 			p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot);
601 		return;
602 	}
603 
604 	if (p4d_val(p4dp[p4d_index]) == 0) {
605 		next_phys = pt_ops.alloc_pud(va);
606 		p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE);
607 		nextp = pt_ops.get_pud_virt(next_phys);
608 		memset(nextp, 0, PAGE_SIZE);
609 	} else {
610 		next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index]));
611 		nextp = pt_ops.get_pud_virt(next_phys);
612 	}
613 
614 	create_pud_mapping(nextp, va, pa, sz, prot);
615 }
616 
617 #define pgd_next_t		p4d_t
618 #define alloc_pgd_next(__va)	(pgtable_l5_enabled ?			\
619 		pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ?		\
620 		pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
621 #define get_pgd_next_virt(__pa)	(pgtable_l5_enabled ?			\
622 		pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ?	\
623 		pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
624 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
625 				(pgtable_l5_enabled ?			\
626 		create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
627 				(pgtable_l4_enabled ?			\
628 		create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) :	\
629 		create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
630 #define fixmap_pgd_next		(pgtable_l5_enabled ?			\
631 		(uintptr_t)fixmap_p4d : (pgtable_l4_enabled ?		\
632 		(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
633 #define trampoline_pgd_next	(pgtable_l5_enabled ?			\
634 		(uintptr_t)trampoline_p4d : (pgtable_l4_enabled ?	\
635 		(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
636 #define early_dtb_pgd_next	(pgtable_l5_enabled ?			\
637 		(uintptr_t)early_dtb_p4d : (pgtable_l4_enabled ?	\
638 		(uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd))
639 #else
640 #define pgd_next_t		pte_t
641 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
642 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
643 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
644 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
645 #define fixmap_pgd_next		((uintptr_t)fixmap_pte)
646 #define early_dtb_pgd_next	((uintptr_t)early_dtb_pmd)
647 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
648 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
649 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
650 #endif /* __PAGETABLE_PMD_FOLDED */
651 
652 void __init create_pgd_mapping(pgd_t *pgdp,
653 				      uintptr_t va, phys_addr_t pa,
654 				      phys_addr_t sz, pgprot_t prot)
655 {
656 	pgd_next_t *nextp;
657 	phys_addr_t next_phys;
658 	uintptr_t pgd_idx = pgd_index(va);
659 
660 	if (sz == PGDIR_SIZE) {
661 		if (pgd_val(pgdp[pgd_idx]) == 0)
662 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
663 		return;
664 	}
665 
666 	if (pgd_val(pgdp[pgd_idx]) == 0) {
667 		next_phys = alloc_pgd_next(va);
668 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
669 		nextp = get_pgd_next_virt(next_phys);
670 		memset(nextp, 0, PAGE_SIZE);
671 	} else {
672 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
673 		nextp = get_pgd_next_virt(next_phys);
674 	}
675 
676 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
677 }
678 
679 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
680 {
681 	if (!(base & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE)
682 		return PGDIR_SIZE;
683 
684 	if (!(base & (P4D_SIZE - 1)) && size >= P4D_SIZE)
685 		return P4D_SIZE;
686 
687 	if (!(base & (PUD_SIZE - 1)) && size >= PUD_SIZE)
688 		return PUD_SIZE;
689 
690 	if (!(base & (PMD_SIZE - 1)) && size >= PMD_SIZE)
691 		return PMD_SIZE;
692 
693 	return PAGE_SIZE;
694 }
695 
696 #ifdef CONFIG_XIP_KERNEL
697 #define phys_ram_base  (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base))
698 extern char _xiprom[], _exiprom[], __data_loc;
699 
700 /* called from head.S with MMU off */
701 asmlinkage void __init __copy_data(void)
702 {
703 	void *from = (void *)(&__data_loc);
704 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
705 	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
706 
707 	memcpy(to, from, sz);
708 }
709 #endif
710 
711 #ifdef CONFIG_STRICT_KERNEL_RWX
712 static __init pgprot_t pgprot_from_va(uintptr_t va)
713 {
714 	if (is_va_kernel_text(va))
715 		return PAGE_KERNEL_READ_EXEC;
716 
717 	/*
718 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
719 	 * we must protect its linear mapping alias from being executed and
720 	 * written.
721 	 * And rodata section is marked readonly in mark_rodata_ro.
722 	 */
723 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
724 		return PAGE_KERNEL_READ;
725 
726 	return PAGE_KERNEL;
727 }
728 
729 void mark_rodata_ro(void)
730 {
731 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
732 	if (IS_ENABLED(CONFIG_64BIT))
733 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
734 				  set_memory_ro);
735 
736 	debug_checkwx();
737 }
738 #else
739 static __init pgprot_t pgprot_from_va(uintptr_t va)
740 {
741 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
742 		return PAGE_KERNEL;
743 
744 	return PAGE_KERNEL_EXEC;
745 }
746 #endif /* CONFIG_STRICT_KERNEL_RWX */
747 
748 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
749 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa);
750 
751 static void __init disable_pgtable_l5(void)
752 {
753 	pgtable_l5_enabled = false;
754 	kernel_map.page_offset = PAGE_OFFSET_L4;
755 	satp_mode = SATP_MODE_48;
756 }
757 
758 static void __init disable_pgtable_l4(void)
759 {
760 	pgtable_l4_enabled = false;
761 	kernel_map.page_offset = PAGE_OFFSET_L3;
762 	satp_mode = SATP_MODE_39;
763 }
764 
765 static int __init print_no4lvl(char *p)
766 {
767 	pr_info("Disabled 4-level and 5-level paging");
768 	return 0;
769 }
770 early_param("no4lvl", print_no4lvl);
771 
772 static int __init print_no5lvl(char *p)
773 {
774 	pr_info("Disabled 5-level paging");
775 	return 0;
776 }
777 early_param("no5lvl", print_no5lvl);
778 
779 /*
780  * There is a simple way to determine if 4-level is supported by the
781  * underlying hardware: establish 1:1 mapping in 4-level page table mode
782  * then read SATP to see if the configuration was taken into account
783  * meaning sv48 is supported.
784  */
785 static __init void set_satp_mode(uintptr_t dtb_pa)
786 {
787 	u64 identity_satp, hw_satp;
788 	uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
789 	u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa);
790 
791 	if (satp_mode_cmdline == SATP_MODE_57) {
792 		disable_pgtable_l5();
793 	} else if (satp_mode_cmdline == SATP_MODE_48) {
794 		disable_pgtable_l5();
795 		disable_pgtable_l4();
796 		return;
797 	}
798 
799 	create_p4d_mapping(early_p4d,
800 			set_satp_mode_pmd, (uintptr_t)early_pud,
801 			P4D_SIZE, PAGE_TABLE);
802 	create_pud_mapping(early_pud,
803 			   set_satp_mode_pmd, (uintptr_t)early_pmd,
804 			   PUD_SIZE, PAGE_TABLE);
805 	/* Handle the case where set_satp_mode straddles 2 PMDs */
806 	create_pmd_mapping(early_pmd,
807 			   set_satp_mode_pmd, set_satp_mode_pmd,
808 			   PMD_SIZE, PAGE_KERNEL_EXEC);
809 	create_pmd_mapping(early_pmd,
810 			   set_satp_mode_pmd + PMD_SIZE,
811 			   set_satp_mode_pmd + PMD_SIZE,
812 			   PMD_SIZE, PAGE_KERNEL_EXEC);
813 retry:
814 	create_pgd_mapping(early_pg_dir,
815 			   set_satp_mode_pmd,
816 			   pgtable_l5_enabled ?
817 				(uintptr_t)early_p4d : (uintptr_t)early_pud,
818 			   PGDIR_SIZE, PAGE_TABLE);
819 
820 	identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
821 
822 	local_flush_tlb_all();
823 	csr_write(CSR_SATP, identity_satp);
824 	hw_satp = csr_swap(CSR_SATP, 0ULL);
825 	local_flush_tlb_all();
826 
827 	if (hw_satp != identity_satp) {
828 		if (pgtable_l5_enabled) {
829 			disable_pgtable_l5();
830 			memset(early_pg_dir, 0, PAGE_SIZE);
831 			goto retry;
832 		}
833 		disable_pgtable_l4();
834 	}
835 
836 	memset(early_pg_dir, 0, PAGE_SIZE);
837 	memset(early_p4d, 0, PAGE_SIZE);
838 	memset(early_pud, 0, PAGE_SIZE);
839 	memset(early_pmd, 0, PAGE_SIZE);
840 }
841 #endif
842 
843 /*
844  * setup_vm() is called from head.S with MMU-off.
845  *
846  * Following requirements should be honoured for setup_vm() to work
847  * correctly:
848  * 1) It should use PC-relative addressing for accessing kernel symbols.
849  *    To achieve this we always use GCC cmodel=medany.
850  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
851  *    so disable compiler instrumentation when FTRACE is enabled.
852  *
853  * Currently, the above requirements are honoured by using custom CFLAGS
854  * for init.o in mm/Makefile.
855  */
856 
857 #ifndef __riscv_cmodel_medany
858 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
859 #endif
860 
861 #ifdef CONFIG_RELOCATABLE
862 extern unsigned long __rela_dyn_start, __rela_dyn_end;
863 
864 static void __init relocate_kernel(void)
865 {
866 	Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start;
867 	/*
868 	 * This holds the offset between the linked virtual address and the
869 	 * relocated virtual address.
870 	 */
871 	uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
872 	/*
873 	 * This holds the offset between kernel linked virtual address and
874 	 * physical address.
875 	 */
876 	uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
877 
878 	for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) {
879 		Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
880 		Elf64_Addr relocated_addr = rela->r_addend;
881 
882 		if (rela->r_info != R_RISCV_RELATIVE)
883 			continue;
884 
885 		/*
886 		 * Make sure to not relocate vdso symbols like rt_sigreturn
887 		 * which are linked from the address 0 in vmlinux since
888 		 * vdso symbol addresses are actually used as an offset from
889 		 * mm->context.vdso in VDSO_OFFSET macro.
890 		 */
891 		if (relocated_addr >= KERNEL_LINK_ADDR)
892 			relocated_addr += reloc_offset;
893 
894 		*(Elf64_Addr *)addr = relocated_addr;
895 	}
896 }
897 #endif /* CONFIG_RELOCATABLE */
898 
899 #ifdef CONFIG_XIP_KERNEL
900 static void __init create_kernel_page_table(pgd_t *pgdir,
901 					    __always_unused bool early)
902 {
903 	uintptr_t va, end_va;
904 
905 	/* Map the flash resident part */
906 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
907 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
908 		create_pgd_mapping(pgdir, va,
909 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
910 				   PMD_SIZE, PAGE_KERNEL_EXEC);
911 
912 	/* Map the data in RAM */
913 	end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size;
914 	for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += PMD_SIZE)
915 		create_pgd_mapping(pgdir, va,
916 				   kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
917 				   PMD_SIZE, PAGE_KERNEL);
918 }
919 #else
920 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
921 {
922 	uintptr_t va, end_va;
923 
924 	end_va = kernel_map.virt_addr + kernel_map.size;
925 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
926 		create_pgd_mapping(pgdir, va,
927 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
928 				   PMD_SIZE,
929 				   early ?
930 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
931 }
932 #endif
933 
934 /*
935  * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
936  * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
937  * entry.
938  */
939 static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
940 {
941 #ifndef CONFIG_BUILTIN_DTB
942 	uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
943 
944 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
945 			   IS_ENABLED(CONFIG_64BIT) ? early_dtb_pgd_next : pa,
946 			   PGDIR_SIZE,
947 			   IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
948 
949 	if (pgtable_l5_enabled)
950 		create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
951 				   (uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
952 
953 	if (pgtable_l4_enabled)
954 		create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
955 				   (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
956 
957 	if (IS_ENABLED(CONFIG_64BIT)) {
958 		create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
959 				   pa, PMD_SIZE, PAGE_KERNEL);
960 		create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
961 				   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
962 	}
963 
964 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
965 #else
966 	/*
967 	 * For 64-bit kernel, __va can't be used since it would return a linear
968 	 * mapping address whereas dtb_early_va will be used before
969 	 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
970 	 * kernel is mapped in the linear mapping, that makes no difference.
971 	 */
972 	dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
973 #endif
974 
975 	dtb_early_pa = dtb_pa;
976 }
977 
978 /*
979  * MMU is not enabled, the page tables are allocated directly using
980  * early_pmd/pud/p4d and the address returned is the physical one.
981  */
982 static void __init pt_ops_set_early(void)
983 {
984 	pt_ops.alloc_pte = alloc_pte_early;
985 	pt_ops.get_pte_virt = get_pte_virt_early;
986 #ifndef __PAGETABLE_PMD_FOLDED
987 	pt_ops.alloc_pmd = alloc_pmd_early;
988 	pt_ops.get_pmd_virt = get_pmd_virt_early;
989 	pt_ops.alloc_pud = alloc_pud_early;
990 	pt_ops.get_pud_virt = get_pud_virt_early;
991 	pt_ops.alloc_p4d = alloc_p4d_early;
992 	pt_ops.get_p4d_virt = get_p4d_virt_early;
993 #endif
994 }
995 
996 /*
997  * MMU is enabled but page table setup is not complete yet.
998  * fixmap page table alloc functions must be used as a means to temporarily
999  * map the allocated physical pages since the linear mapping does not exist yet.
1000  *
1001  * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va,
1002  * but it will be used as described above.
1003  */
1004 static void __init pt_ops_set_fixmap(void)
1005 {
1006 	pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap);
1007 	pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap);
1008 #ifndef __PAGETABLE_PMD_FOLDED
1009 	pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap);
1010 	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap);
1011 	pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap);
1012 	pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap);
1013 	pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap);
1014 	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap);
1015 #endif
1016 }
1017 
1018 /*
1019  * MMU is enabled and page table setup is complete, so from now, we can use
1020  * generic page allocation functions to setup page table.
1021  */
1022 static void __init pt_ops_set_late(void)
1023 {
1024 	pt_ops.alloc_pte = alloc_pte_late;
1025 	pt_ops.get_pte_virt = get_pte_virt_late;
1026 #ifndef __PAGETABLE_PMD_FOLDED
1027 	pt_ops.alloc_pmd = alloc_pmd_late;
1028 	pt_ops.get_pmd_virt = get_pmd_virt_late;
1029 	pt_ops.alloc_pud = alloc_pud_late;
1030 	pt_ops.get_pud_virt = get_pud_virt_late;
1031 	pt_ops.alloc_p4d = alloc_p4d_late;
1032 	pt_ops.get_p4d_virt = get_p4d_virt_late;
1033 #endif
1034 }
1035 
1036 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1037 {
1038 	pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
1039 
1040 	kernel_map.virt_addr = KERNEL_LINK_ADDR;
1041 	kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
1042 
1043 #ifdef CONFIG_XIP_KERNEL
1044 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
1045 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
1046 
1047 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
1048 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
1049 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
1050 
1051 	kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
1052 #else
1053 	kernel_map.phys_addr = (uintptr_t)(&_start);
1054 	kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
1055 #endif
1056 
1057 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
1058 	set_satp_mode(dtb_pa);
1059 #endif
1060 
1061 	/*
1062 	 * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem,
1063 	 * where we have the system memory layout: this allows us to align
1064 	 * the physical and virtual mappings and then make use of PUD/P4D/PGD
1065 	 * for the linear mapping. This is only possible because the kernel
1066 	 * mapping lies outside the linear mapping.
1067 	 * In 32-bit however, as the kernel resides in the linear mapping,
1068 	 * setup_vm_final can not change the mapping established here,
1069 	 * otherwise the same kernel addresses would get mapped to different
1070 	 * physical addresses (if the start of dram is different from the
1071 	 * kernel physical address start).
1072 	 */
1073 	kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ?
1074 				0UL : PAGE_OFFSET - kernel_map.phys_addr;
1075 	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
1076 
1077 	/*
1078 	 * The default maximal physical memory size is KERN_VIRT_SIZE for 32-bit
1079 	 * kernel, whereas for 64-bit kernel, the end of the virtual address
1080 	 * space is occupied by the modules/BPF/kernel mappings which reduces
1081 	 * the available size of the linear mapping.
1082 	 */
1083 	memory_limit = KERN_VIRT_SIZE - (IS_ENABLED(CONFIG_64BIT) ? SZ_4G : 0);
1084 
1085 	/* Sanity check alignment and size */
1086 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
1087 	BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);
1088 
1089 #ifdef CONFIG_64BIT
1090 	/*
1091 	 * The last 4K bytes of the addressable memory can not be mapped because
1092 	 * of IS_ERR_VALUE macro.
1093 	 */
1094 	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
1095 #endif
1096 
1097 #ifdef CONFIG_RELOCATABLE
1098 	/*
1099 	 * Early page table uses only one PUD, which makes it possible
1100 	 * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset
1101 	 * makes the kernel cross over a PUD_SIZE boundary, raise a bug
1102 	 * since a part of the kernel would not get mapped.
1103 	 */
1104 	BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size);
1105 	relocate_kernel();
1106 #endif
1107 
1108 	apply_early_boot_alternatives();
1109 	pt_ops_set_early();
1110 
1111 	/* Setup early PGD for fixmap */
1112 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
1113 			   fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1114 
1115 #ifndef __PAGETABLE_PMD_FOLDED
1116 	/* Setup fixmap P4D and PUD */
1117 	if (pgtable_l5_enabled)
1118 		create_p4d_mapping(fixmap_p4d, FIXADDR_START,
1119 				   (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
1120 	/* Setup fixmap PUD and PMD */
1121 	if (pgtable_l4_enabled)
1122 		create_pud_mapping(fixmap_pud, FIXADDR_START,
1123 				   (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
1124 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
1125 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
1126 	/* Setup trampoline PGD and PMD */
1127 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1128 			   trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1129 	if (pgtable_l5_enabled)
1130 		create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
1131 				   (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
1132 	if (pgtable_l4_enabled)
1133 		create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
1134 				   (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
1135 #ifdef CONFIG_XIP_KERNEL
1136 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1137 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
1138 #else
1139 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1140 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
1141 #endif
1142 #else
1143 	/* Setup trampoline PGD */
1144 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1145 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
1146 #endif
1147 
1148 	/*
1149 	 * Setup early PGD covering entire kernel which will allow
1150 	 * us to reach paging_init(). We map all memory banks later
1151 	 * in setup_vm_final() below.
1152 	 */
1153 	create_kernel_page_table(early_pg_dir, true);
1154 
1155 	/* Setup early mapping for FDT early scan */
1156 	create_fdt_early_page_table(early_pg_dir, dtb_pa);
1157 
1158 	/*
1159 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
1160 	 * range can not span multiple pmds.
1161 	 */
1162 	BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1163 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1164 
1165 #ifndef __PAGETABLE_PMD_FOLDED
1166 	/*
1167 	 * Early ioremap fixmap is already created as it lies within first 2MB
1168 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
1169 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
1170 	 * the user if not.
1171 	 */
1172 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
1173 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
1174 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
1175 		WARN_ON(1);
1176 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
1177 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
1178 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1179 			fix_to_virt(FIX_BTMAP_BEGIN));
1180 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
1181 			fix_to_virt(FIX_BTMAP_END));
1182 
1183 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
1184 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
1185 	}
1186 #endif
1187 
1188 	pt_ops_set_fixmap();
1189 }
1190 
1191 static void __init create_linear_mapping_range(phys_addr_t start,
1192 					       phys_addr_t end)
1193 {
1194 	phys_addr_t pa;
1195 	uintptr_t va, map_size;
1196 
1197 	for (pa = start; pa < end; pa += map_size) {
1198 		va = (uintptr_t)__va(pa);
1199 		map_size = best_map_size(pa, end - pa);
1200 
1201 		create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1202 				   pgprot_from_va(va));
1203 	}
1204 }
1205 
1206 static void __init create_linear_mapping_page_table(void)
1207 {
1208 	phys_addr_t start, end;
1209 	u64 i;
1210 
1211 #ifdef CONFIG_STRICT_KERNEL_RWX
1212 	phys_addr_t ktext_start = __pa_symbol(_start);
1213 	phys_addr_t ktext_size = __init_data_begin - _start;
1214 	phys_addr_t krodata_start = __pa_symbol(__start_rodata);
1215 	phys_addr_t krodata_size = _data - __start_rodata;
1216 
1217 	/* Isolate kernel text and rodata so they don't get mapped with a PUD */
1218 	memblock_mark_nomap(ktext_start,  ktext_size);
1219 	memblock_mark_nomap(krodata_start, krodata_size);
1220 #endif
1221 
1222 	/* Map all memory banks in the linear mapping */
1223 	for_each_mem_range(i, &start, &end) {
1224 		if (start >= end)
1225 			break;
1226 		if (start <= __pa(PAGE_OFFSET) &&
1227 		    __pa(PAGE_OFFSET) < end)
1228 			start = __pa(PAGE_OFFSET);
1229 		if (end >= __pa(PAGE_OFFSET) + memory_limit)
1230 			end = __pa(PAGE_OFFSET) + memory_limit;
1231 
1232 		create_linear_mapping_range(start, end);
1233 	}
1234 
1235 #ifdef CONFIG_STRICT_KERNEL_RWX
1236 	create_linear_mapping_range(ktext_start, ktext_start + ktext_size);
1237 	create_linear_mapping_range(krodata_start,
1238 				    krodata_start + krodata_size);
1239 
1240 	memblock_clear_nomap(ktext_start,  ktext_size);
1241 	memblock_clear_nomap(krodata_start, krodata_size);
1242 #endif
1243 }
1244 
1245 static void __init setup_vm_final(void)
1246 {
1247 	/* Setup swapper PGD for fixmap */
1248 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
1249 			   __pa_symbol(fixmap_pgd_next),
1250 			   PGDIR_SIZE, PAGE_TABLE);
1251 
1252 	/* Map the linear mapping */
1253 	create_linear_mapping_page_table();
1254 
1255 	/* Map the kernel */
1256 	if (IS_ENABLED(CONFIG_64BIT))
1257 		create_kernel_page_table(swapper_pg_dir, false);
1258 
1259 #ifdef CONFIG_KASAN
1260 	kasan_swapper_init();
1261 #endif
1262 
1263 	/* Clear fixmap PTE and PMD mappings */
1264 	clear_fixmap(FIX_PTE);
1265 	clear_fixmap(FIX_PMD);
1266 	clear_fixmap(FIX_PUD);
1267 	clear_fixmap(FIX_P4D);
1268 
1269 	/* Move to swapper page table */
1270 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode);
1271 	local_flush_tlb_all();
1272 
1273 	pt_ops_set_late();
1274 }
1275 #else
1276 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1277 {
1278 	dtb_early_va = (void *)dtb_pa;
1279 	dtb_early_pa = dtb_pa;
1280 }
1281 
1282 static inline void setup_vm_final(void)
1283 {
1284 }
1285 #endif /* CONFIG_MMU */
1286 
1287 /*
1288  * reserve_crashkernel() - reserves memory for crash kernel
1289  *
1290  * This function reserves memory area given in "crashkernel=" kernel command
1291  * line parameter. The memory reserved is used by dump capture kernel when
1292  * primary kernel is crashing.
1293  */
1294 static void __init reserve_crashkernel(void)
1295 {
1296 	unsigned long long crash_base = 0;
1297 	unsigned long long crash_size = 0;
1298 	unsigned long search_start = memblock_start_of_DRAM();
1299 	unsigned long search_end = memblock_end_of_DRAM();
1300 
1301 	int ret = 0;
1302 
1303 	if (!IS_ENABLED(CONFIG_KEXEC_CORE))
1304 		return;
1305 	/*
1306 	 * Don't reserve a region for a crash kernel on a crash kernel
1307 	 * since it doesn't make much sense and we have limited memory
1308 	 * resources.
1309 	 */
1310 	if (is_kdump_kernel()) {
1311 		pr_info("crashkernel: ignoring reservation request\n");
1312 		return;
1313 	}
1314 
1315 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
1316 				&crash_size, &crash_base);
1317 	if (ret || !crash_size)
1318 		return;
1319 
1320 	crash_size = PAGE_ALIGN(crash_size);
1321 
1322 	if (crash_base) {
1323 		search_start = crash_base;
1324 		search_end = crash_base + crash_size;
1325 	}
1326 
1327 	/*
1328 	 * Current riscv boot protocol requires 2MB alignment for
1329 	 * RV64 and 4MB alignment for RV32 (hugepage size)
1330 	 *
1331 	 * Try to alloc from 32bit addressible physical memory so that
1332 	 * swiotlb can work on the crash kernel.
1333 	 */
1334 	crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
1335 					       search_start,
1336 					       min(search_end, (unsigned long) SZ_4G));
1337 	if (crash_base == 0) {
1338 		/* Try again without restricting region to 32bit addressible memory */
1339 		crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
1340 						search_start, search_end);
1341 		if (crash_base == 0) {
1342 			pr_warn("crashkernel: couldn't allocate %lldKB\n",
1343 				crash_size >> 10);
1344 			return;
1345 		}
1346 	}
1347 
1348 	pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
1349 		crash_base, crash_base + crash_size, crash_size >> 20);
1350 
1351 	crashk_res.start = crash_base;
1352 	crashk_res.end = crash_base + crash_size - 1;
1353 }
1354 
1355 void __init paging_init(void)
1356 {
1357 	setup_bootmem();
1358 	setup_vm_final();
1359 }
1360 
1361 void __init misc_mem_init(void)
1362 {
1363 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
1364 	arch_numa_init();
1365 	sparse_init();
1366 	zone_sizes_init();
1367 	reserve_crashkernel();
1368 	memblock_dump_all();
1369 }
1370 
1371 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1372 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1373 			       struct vmem_altmap *altmap)
1374 {
1375 	return vmemmap_populate_basepages(start, end, node, NULL);
1376 }
1377 #endif
1378