xref: /linux/arch/riscv/mm/init.c (revision 68550cbc6129159b7a6434796b721e8b66ee12f6)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  * Copyright (C) 2019 Western Digital Corporation or its affiliates.
5  * Copyright (C) 2020 FORTH-ICS/CARV
6  *  Nick Kossifidis <mick@ics.forth.gr>
7  */
8 
9 #include <linux/init.h>
10 #include <linux/mm.h>
11 #include <linux/memblock.h>
12 #include <linux/initrd.h>
13 #include <linux/swap.h>
14 #include <linux/swiotlb.h>
15 #include <linux/sizes.h>
16 #include <linux/of_fdt.h>
17 #include <linux/of_reserved_mem.h>
18 #include <linux/libfdt.h>
19 #include <linux/set_memory.h>
20 #include <linux/dma-map-ops.h>
21 #include <linux/crash_dump.h>
22 #include <linux/hugetlb.h>
23 
24 #include <asm/fixmap.h>
25 #include <asm/tlbflush.h>
26 #include <asm/sections.h>
27 #include <asm/soc.h>
28 #include <asm/io.h>
29 #include <asm/ptdump.h>
30 #include <asm/numa.h>
31 
32 #include "../kernel/head.h"
33 
34 struct kernel_mapping kernel_map __ro_after_init;
35 EXPORT_SYMBOL(kernel_map);
36 #ifdef CONFIG_XIP_KERNEL
37 #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
38 #endif
39 
40 phys_addr_t phys_ram_base __ro_after_init;
41 EXPORT_SYMBOL(phys_ram_base);
42 
43 #ifdef CONFIG_XIP_KERNEL
44 extern char _xiprom[], _exiprom[], __data_loc;
45 #endif
46 
47 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
48 							__page_aligned_bss;
49 EXPORT_SYMBOL(empty_zero_page);
50 
51 extern char _start[];
52 #define DTB_EARLY_BASE_VA      PGDIR_SIZE
53 void *_dtb_early_va __initdata;
54 uintptr_t _dtb_early_pa __initdata;
55 
56 struct pt_alloc_ops {
57 	pte_t *(*get_pte_virt)(phys_addr_t pa);
58 	phys_addr_t (*alloc_pte)(uintptr_t va);
59 #ifndef __PAGETABLE_PMD_FOLDED
60 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
61 	phys_addr_t (*alloc_pmd)(uintptr_t va);
62 #endif
63 };
64 
65 static phys_addr_t dma32_phys_limit __initdata;
66 
67 static void __init zone_sizes_init(void)
68 {
69 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
70 
71 #ifdef CONFIG_ZONE_DMA32
72 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
73 #endif
74 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
75 
76 	free_area_init(max_zone_pfns);
77 }
78 
79 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
80 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
81 {
82 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
83 		  (((t) - (b)) >> 10));
84 }
85 
86 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
87 {
88 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
89 		  (((t) - (b)) >> 20));
90 }
91 
92 static void __init print_vm_layout(void)
93 {
94 	pr_notice("Virtual kernel memory layout:\n");
95 	print_mlk("fixmap", (unsigned long)FIXADDR_START,
96 		  (unsigned long)FIXADDR_TOP);
97 	print_mlm("pci io", (unsigned long)PCI_IO_START,
98 		  (unsigned long)PCI_IO_END);
99 	print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
100 		  (unsigned long)VMEMMAP_END);
101 	print_mlm("vmalloc", (unsigned long)VMALLOC_START,
102 		  (unsigned long)VMALLOC_END);
103 	print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
104 		  (unsigned long)high_memory);
105 #ifdef CONFIG_64BIT
106 	print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR,
107 		  (unsigned long)ADDRESS_SPACE_END);
108 #endif
109 }
110 #else
111 static void print_vm_layout(void) { }
112 #endif /* CONFIG_DEBUG_VM */
113 
114 void __init mem_init(void)
115 {
116 #ifdef CONFIG_FLATMEM
117 	BUG_ON(!mem_map);
118 #endif /* CONFIG_FLATMEM */
119 
120 #ifdef CONFIG_SWIOTLB
121 	if (swiotlb_force == SWIOTLB_FORCE ||
122 	    max_pfn > PFN_DOWN(dma32_phys_limit))
123 		swiotlb_init(1);
124 	else
125 		swiotlb_force = SWIOTLB_NO_FORCE;
126 #endif
127 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
128 	memblock_free_all();
129 
130 	print_vm_layout();
131 }
132 
133 /*
134  * The default maximal physical memory size is -PAGE_OFFSET for 32-bit kernel,
135  * whereas for 64-bit kernel, the end of the virtual address space is occupied
136  * by the modules/BPF/kernel mappings which reduces the available size of the
137  * linear mapping.
138  * Limit the memory size via mem.
139  */
140 #ifdef CONFIG_64BIT
141 static phys_addr_t memory_limit = -PAGE_OFFSET - SZ_4G;
142 #else
143 static phys_addr_t memory_limit = -PAGE_OFFSET;
144 #endif
145 
146 static int __init early_mem(char *p)
147 {
148 	u64 size;
149 
150 	if (!p)
151 		return 1;
152 
153 	size = memparse(p, &p) & PAGE_MASK;
154 	memory_limit = min_t(u64, size, memory_limit);
155 
156 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
157 
158 	return 0;
159 }
160 early_param("mem", early_mem);
161 
162 static void __init setup_bootmem(void)
163 {
164 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
165 	phys_addr_t vmlinux_start = __pa_symbol(&_start);
166 	phys_addr_t __maybe_unused max_mapped_addr;
167 	phys_addr_t phys_ram_end;
168 
169 #ifdef CONFIG_XIP_KERNEL
170 	vmlinux_start = __pa_symbol(&_sdata);
171 #endif
172 
173 	memblock_enforce_memory_limit(memory_limit);
174 
175 	/*
176 	 * Reserve from the start of the kernel to the end of the kernel
177 	 */
178 #if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
179 	/*
180 	 * Make sure we align the reservation on PMD_SIZE since we will
181 	 * map the kernel in the linear mapping as read-only: we do not want
182 	 * any allocation to happen between _end and the next pmd aligned page.
183 	 */
184 	vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
185 #endif
186 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
187 
188 
189 	phys_ram_end = memblock_end_of_DRAM();
190 #ifndef CONFIG_64BIT
191 #ifndef CONFIG_XIP_KERNEL
192 	phys_ram_base = memblock_start_of_DRAM();
193 #endif
194 	/*
195 	 * memblock allocator is not aware of the fact that last 4K bytes of
196 	 * the addressable memory can not be mapped because of IS_ERR_VALUE
197 	 * macro. Make sure that last 4k bytes are not usable by memblock
198 	 * if end of dram is equal to maximum addressable memory.  For 64-bit
199 	 * kernel, this problem can't happen here as the end of the virtual
200 	 * address space is occupied by the kernel mapping then this check must
201 	 * be done as soon as the kernel mapping base address is determined.
202 	 */
203 	max_mapped_addr = __pa(~(ulong)0);
204 	if (max_mapped_addr == (phys_ram_end - 1))
205 		memblock_set_current_limit(max_mapped_addr - 4096);
206 #endif
207 
208 	min_low_pfn = PFN_UP(phys_ram_base);
209 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
210 
211 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
212 	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
213 
214 	reserve_initrd_mem();
215 	/*
216 	 * If DTB is built in, no need to reserve its memblock.
217 	 * Otherwise, do reserve it but avoid using
218 	 * early_init_fdt_reserve_self() since __pa() does
219 	 * not work for DTB pointers that are fixmap addresses
220 	 */
221 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
222 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
223 
224 	early_init_fdt_scan_reserved_mem();
225 	dma_contiguous_reserve(dma32_phys_limit);
226 	if (IS_ENABLED(CONFIG_64BIT))
227 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
228 	memblock_allow_resize();
229 }
230 
231 #ifdef CONFIG_MMU
232 static struct pt_alloc_ops _pt_ops __initdata;
233 
234 #ifdef CONFIG_XIP_KERNEL
235 #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&_pt_ops))
236 #else
237 #define pt_ops _pt_ops
238 #endif
239 
240 unsigned long riscv_pfn_base __ro_after_init;
241 EXPORT_SYMBOL(riscv_pfn_base);
242 
243 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
244 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
245 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
246 
247 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
248 static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
249 
250 #ifdef CONFIG_XIP_KERNEL
251 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
252 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
253 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
254 #endif /* CONFIG_XIP_KERNEL */
255 
256 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
257 {
258 	unsigned long addr = __fix_to_virt(idx);
259 	pte_t *ptep;
260 
261 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
262 
263 	ptep = &fixmap_pte[pte_index(addr)];
264 
265 	if (pgprot_val(prot))
266 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
267 	else
268 		pte_clear(&init_mm, addr, ptep);
269 	local_flush_tlb_page(addr);
270 }
271 
272 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
273 {
274 	return (pte_t *)((uintptr_t)pa);
275 }
276 
277 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
278 {
279 	clear_fixmap(FIX_PTE);
280 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
281 }
282 
283 static inline pte_t *__init get_pte_virt_late(phys_addr_t pa)
284 {
285 	return (pte_t *) __va(pa);
286 }
287 
288 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
289 {
290 	/*
291 	 * We only create PMD or PGD early mappings so we
292 	 * should never reach here with MMU disabled.
293 	 */
294 	BUG();
295 }
296 
297 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
298 {
299 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
300 }
301 
302 static phys_addr_t __init alloc_pte_late(uintptr_t va)
303 {
304 	unsigned long vaddr;
305 
306 	vaddr = __get_free_page(GFP_KERNEL);
307 	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)));
308 
309 	return __pa(vaddr);
310 }
311 
312 static void __init create_pte_mapping(pte_t *ptep,
313 				      uintptr_t va, phys_addr_t pa,
314 				      phys_addr_t sz, pgprot_t prot)
315 {
316 	uintptr_t pte_idx = pte_index(va);
317 
318 	BUG_ON(sz != PAGE_SIZE);
319 
320 	if (pte_none(ptep[pte_idx]))
321 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
322 }
323 
324 #ifndef __PAGETABLE_PMD_FOLDED
325 
326 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
327 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
328 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
329 
330 #ifdef CONFIG_XIP_KERNEL
331 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
332 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
333 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
334 #endif /* CONFIG_XIP_KERNEL */
335 
336 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
337 {
338 	/* Before MMU is enabled */
339 	return (pmd_t *)((uintptr_t)pa);
340 }
341 
342 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
343 {
344 	clear_fixmap(FIX_PMD);
345 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
346 }
347 
348 static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)
349 {
350 	return (pmd_t *) __va(pa);
351 }
352 
353 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
354 {
355 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
356 
357 	return (uintptr_t)early_pmd;
358 }
359 
360 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
361 {
362 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
363 }
364 
365 static phys_addr_t __init alloc_pmd_late(uintptr_t va)
366 {
367 	unsigned long vaddr;
368 
369 	vaddr = __get_free_page(GFP_KERNEL);
370 	BUG_ON(!vaddr);
371 	return __pa(vaddr);
372 }
373 
374 static void __init create_pmd_mapping(pmd_t *pmdp,
375 				      uintptr_t va, phys_addr_t pa,
376 				      phys_addr_t sz, pgprot_t prot)
377 {
378 	pte_t *ptep;
379 	phys_addr_t pte_phys;
380 	uintptr_t pmd_idx = pmd_index(va);
381 
382 	if (sz == PMD_SIZE) {
383 		if (pmd_none(pmdp[pmd_idx]))
384 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
385 		return;
386 	}
387 
388 	if (pmd_none(pmdp[pmd_idx])) {
389 		pte_phys = pt_ops.alloc_pte(va);
390 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
391 		ptep = pt_ops.get_pte_virt(pte_phys);
392 		memset(ptep, 0, PAGE_SIZE);
393 	} else {
394 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
395 		ptep = pt_ops.get_pte_virt(pte_phys);
396 	}
397 
398 	create_pte_mapping(ptep, va, pa, sz, prot);
399 }
400 
401 #define pgd_next_t		pmd_t
402 #define alloc_pgd_next(__va)	pt_ops.alloc_pmd(__va)
403 #define get_pgd_next_virt(__pa)	pt_ops.get_pmd_virt(__pa)
404 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
405 	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
406 #define fixmap_pgd_next		fixmap_pmd
407 #else
408 #define pgd_next_t		pte_t
409 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
410 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
411 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
412 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
413 #define fixmap_pgd_next		fixmap_pte
414 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot)
415 #endif
416 
417 void __init create_pgd_mapping(pgd_t *pgdp,
418 				      uintptr_t va, phys_addr_t pa,
419 				      phys_addr_t sz, pgprot_t prot)
420 {
421 	pgd_next_t *nextp;
422 	phys_addr_t next_phys;
423 	uintptr_t pgd_idx = pgd_index(va);
424 
425 	if (sz == PGDIR_SIZE) {
426 		if (pgd_val(pgdp[pgd_idx]) == 0)
427 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
428 		return;
429 	}
430 
431 	if (pgd_val(pgdp[pgd_idx]) == 0) {
432 		next_phys = alloc_pgd_next(va);
433 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
434 		nextp = get_pgd_next_virt(next_phys);
435 		memset(nextp, 0, PAGE_SIZE);
436 	} else {
437 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
438 		nextp = get_pgd_next_virt(next_phys);
439 	}
440 
441 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
442 }
443 
444 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
445 {
446 	/* Upgrade to PMD_SIZE mappings whenever possible */
447 	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
448 		return PAGE_SIZE;
449 
450 	return PMD_SIZE;
451 }
452 
453 #ifdef CONFIG_XIP_KERNEL
454 /* called from head.S with MMU off */
455 asmlinkage void __init __copy_data(void)
456 {
457 	void *from = (void *)(&__data_loc);
458 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
459 	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
460 
461 	memcpy(to, from, sz);
462 }
463 #endif
464 
465 #ifdef CONFIG_STRICT_KERNEL_RWX
466 static __init pgprot_t pgprot_from_va(uintptr_t va)
467 {
468 	if (is_va_kernel_text(va))
469 		return PAGE_KERNEL_READ_EXEC;
470 
471 	/*
472 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
473 	 * we must protect its linear mapping alias from being executed and
474 	 * written.
475 	 * And rodata section is marked readonly in mark_rodata_ro.
476 	 */
477 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
478 		return PAGE_KERNEL_READ;
479 
480 	return PAGE_KERNEL;
481 }
482 
483 void mark_rodata_ro(void)
484 {
485 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
486 	if (IS_ENABLED(CONFIG_64BIT))
487 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
488 				  set_memory_ro);
489 
490 	debug_checkwx();
491 }
492 #else
493 static __init pgprot_t pgprot_from_va(uintptr_t va)
494 {
495 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
496 		return PAGE_KERNEL;
497 
498 	return PAGE_KERNEL_EXEC;
499 }
500 #endif /* CONFIG_STRICT_KERNEL_RWX */
501 
502 /*
503  * setup_vm() is called from head.S with MMU-off.
504  *
505  * Following requirements should be honoured for setup_vm() to work
506  * correctly:
507  * 1) It should use PC-relative addressing for accessing kernel symbols.
508  *    To achieve this we always use GCC cmodel=medany.
509  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
510  *    so disable compiler instrumentation when FTRACE is enabled.
511  *
512  * Currently, the above requirements are honoured by using custom CFLAGS
513  * for init.o in mm/Makefile.
514  */
515 
516 #ifndef __riscv_cmodel_medany
517 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
518 #endif
519 
520 #ifdef CONFIG_XIP_KERNEL
521 static void __init create_kernel_page_table(pgd_t *pgdir,
522 					    __always_unused bool early)
523 {
524 	uintptr_t va, end_va;
525 
526 	/* Map the flash resident part */
527 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
528 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
529 		create_pgd_mapping(pgdir, va,
530 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
531 				   PMD_SIZE, PAGE_KERNEL_EXEC);
532 
533 	/* Map the data in RAM */
534 	end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size;
535 	for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += PMD_SIZE)
536 		create_pgd_mapping(pgdir, va,
537 				   kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
538 				   PMD_SIZE, PAGE_KERNEL);
539 }
540 #else
541 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
542 {
543 	uintptr_t va, end_va;
544 
545 	end_va = kernel_map.virt_addr + kernel_map.size;
546 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
547 		create_pgd_mapping(pgdir, va,
548 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
549 				   PMD_SIZE,
550 				   early ?
551 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
552 }
553 #endif
554 
555 /*
556  * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
557  * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
558  * entry.
559  */
560 static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
561 {
562 #ifndef CONFIG_BUILTIN_DTB
563 	uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
564 
565 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
566 			   IS_ENABLED(CONFIG_64BIT) ? (uintptr_t)early_dtb_pmd : pa,
567 			   PGDIR_SIZE,
568 			   IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
569 
570 	if (IS_ENABLED(CONFIG_64BIT)) {
571 		create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
572 				   pa, PMD_SIZE, PAGE_KERNEL);
573 		create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
574 				   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
575 	}
576 
577 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
578 #else
579 	/*
580 	 * For 64-bit kernel, __va can't be used since it would return a linear
581 	 * mapping address whereas dtb_early_va will be used before
582 	 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
583 	 * kernel is mapped in the linear mapping, that makes no difference.
584 	 */
585 	dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
586 #endif
587 
588 	dtb_early_pa = dtb_pa;
589 }
590 
591 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
592 {
593 	pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
594 
595 	kernel_map.virt_addr = KERNEL_LINK_ADDR;
596 
597 #ifdef CONFIG_XIP_KERNEL
598 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
599 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
600 
601 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
602 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
603 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
604 
605 	kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
606 #else
607 	kernel_map.phys_addr = (uintptr_t)(&_start);
608 	kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
609 #endif
610 	kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr;
611 	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
612 
613 	riscv_pfn_base = PFN_DOWN(kernel_map.phys_addr);
614 
615 	/* Sanity check alignment and size */
616 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
617 	BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);
618 
619 #ifdef CONFIG_64BIT
620 	/*
621 	 * The last 4K bytes of the addressable memory can not be mapped because
622 	 * of IS_ERR_VALUE macro.
623 	 */
624 	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
625 #endif
626 
627 	pt_ops.alloc_pte = alloc_pte_early;
628 	pt_ops.get_pte_virt = get_pte_virt_early;
629 #ifndef __PAGETABLE_PMD_FOLDED
630 	pt_ops.alloc_pmd = alloc_pmd_early;
631 	pt_ops.get_pmd_virt = get_pmd_virt_early;
632 #endif
633 	/* Setup early PGD for fixmap */
634 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
635 			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
636 
637 #ifndef __PAGETABLE_PMD_FOLDED
638 	/* Setup fixmap PMD */
639 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
640 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
641 	/* Setup trampoline PGD and PMD */
642 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
643 			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
644 #ifdef CONFIG_XIP_KERNEL
645 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
646 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
647 #else
648 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
649 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
650 #endif
651 #else
652 	/* Setup trampoline PGD */
653 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
654 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
655 #endif
656 
657 	/*
658 	 * Setup early PGD covering entire kernel which will allow
659 	 * us to reach paging_init(). We map all memory banks later
660 	 * in setup_vm_final() below.
661 	 */
662 	create_kernel_page_table(early_pg_dir, true);
663 
664 	/* Setup early mapping for FDT early scan */
665 	create_fdt_early_page_table(early_pg_dir, dtb_pa);
666 
667 	/*
668 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
669 	 * range can not span multiple pmds.
670 	 */
671 	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
672 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
673 
674 #ifndef __PAGETABLE_PMD_FOLDED
675 	/*
676 	 * Early ioremap fixmap is already created as it lies within first 2MB
677 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
678 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
679 	 * the user if not.
680 	 */
681 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
682 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
683 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
684 		WARN_ON(1);
685 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
686 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
687 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
688 			fix_to_virt(FIX_BTMAP_BEGIN));
689 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
690 			fix_to_virt(FIX_BTMAP_END));
691 
692 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
693 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
694 	}
695 #endif
696 }
697 
698 static void __init setup_vm_final(void)
699 {
700 	uintptr_t va, map_size;
701 	phys_addr_t pa, start, end;
702 	u64 i;
703 
704 	/**
705 	 * MMU is enabled at this point. But page table setup is not complete yet.
706 	 * fixmap page table alloc functions should be used at this point
707 	 */
708 	pt_ops.alloc_pte = alloc_pte_fixmap;
709 	pt_ops.get_pte_virt = get_pte_virt_fixmap;
710 #ifndef __PAGETABLE_PMD_FOLDED
711 	pt_ops.alloc_pmd = alloc_pmd_fixmap;
712 	pt_ops.get_pmd_virt = get_pmd_virt_fixmap;
713 #endif
714 	/* Setup swapper PGD for fixmap */
715 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
716 			   __pa_symbol(fixmap_pgd_next),
717 			   PGDIR_SIZE, PAGE_TABLE);
718 
719 	/* Map all memory banks in the linear mapping */
720 	for_each_mem_range(i, &start, &end) {
721 		if (start >= end)
722 			break;
723 		if (start <= __pa(PAGE_OFFSET) &&
724 		    __pa(PAGE_OFFSET) < end)
725 			start = __pa(PAGE_OFFSET);
726 		if (end >= __pa(PAGE_OFFSET) + memory_limit)
727 			end = __pa(PAGE_OFFSET) + memory_limit;
728 
729 		map_size = best_map_size(start, end - start);
730 		for (pa = start; pa < end; pa += map_size) {
731 			va = (uintptr_t)__va(pa);
732 
733 			create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
734 					   pgprot_from_va(va));
735 		}
736 	}
737 
738 #ifdef CONFIG_64BIT
739 	/* Map the kernel */
740 	create_kernel_page_table(swapper_pg_dir, false);
741 #endif
742 
743 	/* Clear fixmap PTE and PMD mappings */
744 	clear_fixmap(FIX_PTE);
745 	clear_fixmap(FIX_PMD);
746 
747 	/* Move to swapper page table */
748 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
749 	local_flush_tlb_all();
750 
751 	/* generic page allocation functions must be used to setup page table */
752 	pt_ops.alloc_pte = alloc_pte_late;
753 	pt_ops.get_pte_virt = get_pte_virt_late;
754 #ifndef __PAGETABLE_PMD_FOLDED
755 	pt_ops.alloc_pmd = alloc_pmd_late;
756 	pt_ops.get_pmd_virt = get_pmd_virt_late;
757 #endif
758 }
759 #else
760 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
761 {
762 	dtb_early_va = (void *)dtb_pa;
763 	dtb_early_pa = dtb_pa;
764 }
765 
766 static inline void setup_vm_final(void)
767 {
768 }
769 #endif /* CONFIG_MMU */
770 
771 #ifdef CONFIG_KEXEC_CORE
772 /*
773  * reserve_crashkernel() - reserves memory for crash kernel
774  *
775  * This function reserves memory area given in "crashkernel=" kernel command
776  * line parameter. The memory reserved is used by dump capture kernel when
777  * primary kernel is crashing.
778  */
779 static void __init reserve_crashkernel(void)
780 {
781 	unsigned long long crash_base = 0;
782 	unsigned long long crash_size = 0;
783 	unsigned long search_start = memblock_start_of_DRAM();
784 	unsigned long search_end = memblock_end_of_DRAM();
785 
786 	int ret = 0;
787 
788 	/*
789 	 * Don't reserve a region for a crash kernel on a crash kernel
790 	 * since it doesn't make much sense and we have limited memory
791 	 * resources.
792 	 */
793 #ifdef CONFIG_CRASH_DUMP
794 	if (is_kdump_kernel()) {
795 		pr_info("crashkernel: ignoring reservation request\n");
796 		return;
797 	}
798 #endif
799 
800 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
801 				&crash_size, &crash_base);
802 	if (ret || !crash_size)
803 		return;
804 
805 	crash_size = PAGE_ALIGN(crash_size);
806 
807 	if (crash_base) {
808 		search_start = crash_base;
809 		search_end = crash_base + crash_size;
810 	}
811 
812 	/*
813 	 * Current riscv boot protocol requires 2MB alignment for
814 	 * RV64 and 4MB alignment for RV32 (hugepage size)
815 	 */
816 	crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
817 					       search_start, search_end);
818 	if (crash_base == 0) {
819 		pr_warn("crashkernel: couldn't allocate %lldKB\n",
820 			crash_size >> 10);
821 		return;
822 	}
823 
824 	pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
825 		crash_base, crash_base + crash_size, crash_size >> 20);
826 
827 	crashk_res.start = crash_base;
828 	crashk_res.end = crash_base + crash_size - 1;
829 }
830 #endif /* CONFIG_KEXEC_CORE */
831 
832 void __init paging_init(void)
833 {
834 	setup_bootmem();
835 	setup_vm_final();
836 }
837 
838 void __init misc_mem_init(void)
839 {
840 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
841 	arch_numa_init();
842 	sparse_init();
843 	zone_sizes_init();
844 #ifdef CONFIG_KEXEC_CORE
845 	reserve_crashkernel();
846 #endif
847 	memblock_dump_all();
848 }
849 
850 #ifdef CONFIG_SPARSEMEM_VMEMMAP
851 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
852 			       struct vmem_altmap *altmap)
853 {
854 	return vmemmap_populate_basepages(start, end, node, NULL);
855 }
856 #endif
857