xref: /linux/arch/riscv/mm/init.c (revision 4ac6d90867a4de2e12117e755dbd76e08d88697f)
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 
23 #include <asm/fixmap.h>
24 #include <asm/tlbflush.h>
25 #include <asm/sections.h>
26 #include <asm/soc.h>
27 #include <asm/io.h>
28 #include <asm/ptdump.h>
29 #include <asm/numa.h>
30 
31 #include "../kernel/head.h"
32 
33 struct kernel_mapping kernel_map __ro_after_init;
34 EXPORT_SYMBOL(kernel_map);
35 #ifdef CONFIG_XIP_KERNEL
36 #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
37 #endif
38 
39 phys_addr_t phys_ram_base __ro_after_init;
40 EXPORT_SYMBOL(phys_ram_base);
41 
42 #ifdef CONFIG_XIP_KERNEL
43 extern char _xiprom[], _exiprom[];
44 #endif
45 
46 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
47 							__page_aligned_bss;
48 EXPORT_SYMBOL(empty_zero_page);
49 
50 extern char _start[];
51 #define DTB_EARLY_BASE_VA      PGDIR_SIZE
52 void *_dtb_early_va __initdata;
53 uintptr_t _dtb_early_pa __initdata;
54 
55 struct pt_alloc_ops {
56 	pte_t *(*get_pte_virt)(phys_addr_t pa);
57 	phys_addr_t (*alloc_pte)(uintptr_t va);
58 #ifndef __PAGETABLE_PMD_FOLDED
59 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
60 	phys_addr_t (*alloc_pmd)(uintptr_t va);
61 #endif
62 };
63 
64 static phys_addr_t dma32_phys_limit __initdata;
65 
66 static void __init zone_sizes_init(void)
67 {
68 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
69 
70 #ifdef CONFIG_ZONE_DMA32
71 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
72 #endif
73 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
74 
75 	free_area_init(max_zone_pfns);
76 }
77 
78 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
79 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
80 {
81 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
82 		  (((t) - (b)) >> 10));
83 }
84 
85 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
86 {
87 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
88 		  (((t) - (b)) >> 20));
89 }
90 
91 static void __init print_vm_layout(void)
92 {
93 	pr_notice("Virtual kernel memory layout:\n");
94 	print_mlk("fixmap", (unsigned long)FIXADDR_START,
95 		  (unsigned long)FIXADDR_TOP);
96 	print_mlm("pci io", (unsigned long)PCI_IO_START,
97 		  (unsigned long)PCI_IO_END);
98 	print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
99 		  (unsigned long)VMEMMAP_END);
100 	print_mlm("vmalloc", (unsigned long)VMALLOC_START,
101 		  (unsigned long)VMALLOC_END);
102 	print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
103 		  (unsigned long)high_memory);
104 #ifdef CONFIG_64BIT
105 	print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR,
106 		  (unsigned long)ADDRESS_SPACE_END);
107 #endif
108 }
109 #else
110 static void print_vm_layout(void) { }
111 #endif /* CONFIG_DEBUG_VM */
112 
113 void __init mem_init(void)
114 {
115 #ifdef CONFIG_FLATMEM
116 	BUG_ON(!mem_map);
117 #endif /* CONFIG_FLATMEM */
118 
119 #ifdef CONFIG_SWIOTLB
120 	if (swiotlb_force == SWIOTLB_FORCE ||
121 	    max_pfn > PFN_DOWN(dma32_phys_limit))
122 		swiotlb_init(1);
123 	else
124 		swiotlb_force = SWIOTLB_NO_FORCE;
125 #endif
126 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
127 	memblock_free_all();
128 
129 	print_vm_layout();
130 }
131 
132 /*
133  * The default maximal physical memory size is -PAGE_OFFSET for 32-bit kernel,
134  * whereas for 64-bit kernel, the end of the virtual address space is occupied
135  * by the modules/BPF/kernel mappings which reduces the available size of the
136  * linear mapping.
137  * Limit the memory size via mem.
138  */
139 #ifdef CONFIG_64BIT
140 static phys_addr_t memory_limit = -PAGE_OFFSET - SZ_4G;
141 #else
142 static phys_addr_t memory_limit = -PAGE_OFFSET;
143 #endif
144 
145 static int __init early_mem(char *p)
146 {
147 	u64 size;
148 
149 	if (!p)
150 		return 1;
151 
152 	size = memparse(p, &p) & PAGE_MASK;
153 	memory_limit = min_t(u64, size, memory_limit);
154 
155 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
156 
157 	return 0;
158 }
159 early_param("mem", early_mem);
160 
161 static void __init setup_bootmem(void)
162 {
163 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
164 	phys_addr_t vmlinux_start = __pa_symbol(&_start);
165 	phys_addr_t __maybe_unused max_mapped_addr;
166 	phys_addr_t phys_ram_end;
167 
168 #ifdef CONFIG_XIP_KERNEL
169 	vmlinux_start = __pa_symbol(&_sdata);
170 #endif
171 
172 	memblock_enforce_memory_limit(memory_limit);
173 
174 	/*
175 	 * Reserve from the start of the kernel to the end of the kernel
176 	 */
177 #if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
178 	/*
179 	 * Make sure we align the reservation on PMD_SIZE since we will
180 	 * map the kernel in the linear mapping as read-only: we do not want
181 	 * any allocation to happen between _end and the next pmd aligned page.
182 	 */
183 	vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
184 #endif
185 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
186 
187 
188 	phys_ram_end = memblock_end_of_DRAM();
189 #ifndef CONFIG_64BIT
190 #ifndef CONFIG_XIP_KERNEL
191 	phys_ram_base = memblock_start_of_DRAM();
192 #endif
193 	/*
194 	 * memblock allocator is not aware of the fact that last 4K bytes of
195 	 * the addressable memory can not be mapped because of IS_ERR_VALUE
196 	 * macro. Make sure that last 4k bytes are not usable by memblock
197 	 * if end of dram is equal to maximum addressable memory.  For 64-bit
198 	 * kernel, this problem can't happen here as the end of the virtual
199 	 * address space is occupied by the kernel mapping then this check must
200 	 * be done as soon as the kernel mapping base address is determined.
201 	 */
202 	max_mapped_addr = __pa(~(ulong)0);
203 	if (max_mapped_addr == (phys_ram_end - 1))
204 		memblock_set_current_limit(max_mapped_addr - 4096);
205 #endif
206 
207 	min_low_pfn = PFN_UP(phys_ram_base);
208 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
209 
210 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
211 	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
212 
213 	reserve_initrd_mem();
214 	/*
215 	 * If DTB is built in, no need to reserve its memblock.
216 	 * Otherwise, do reserve it but avoid using
217 	 * early_init_fdt_reserve_self() since __pa() does
218 	 * not work for DTB pointers that are fixmap addresses
219 	 */
220 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
221 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
222 
223 	early_init_fdt_scan_reserved_mem();
224 	dma_contiguous_reserve(dma32_phys_limit);
225 	memblock_allow_resize();
226 }
227 
228 #ifdef CONFIG_MMU
229 static struct pt_alloc_ops _pt_ops __initdata;
230 
231 #ifdef CONFIG_XIP_KERNEL
232 #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&_pt_ops))
233 #else
234 #define pt_ops _pt_ops
235 #endif
236 
237 unsigned long pfn_base __ro_after_init;
238 EXPORT_SYMBOL(pfn_base);
239 
240 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
241 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
242 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
243 
244 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
245 
246 #ifdef CONFIG_XIP_KERNEL
247 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
248 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
249 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
250 #endif /* CONFIG_XIP_KERNEL */
251 
252 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
253 {
254 	unsigned long addr = __fix_to_virt(idx);
255 	pte_t *ptep;
256 
257 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
258 
259 	ptep = &fixmap_pte[pte_index(addr)];
260 
261 	if (pgprot_val(prot))
262 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
263 	else
264 		pte_clear(&init_mm, addr, ptep);
265 	local_flush_tlb_page(addr);
266 }
267 
268 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
269 {
270 	return (pte_t *)((uintptr_t)pa);
271 }
272 
273 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
274 {
275 	clear_fixmap(FIX_PTE);
276 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
277 }
278 
279 static inline pte_t *__init get_pte_virt_late(phys_addr_t pa)
280 {
281 	return (pte_t *) __va(pa);
282 }
283 
284 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
285 {
286 	/*
287 	 * We only create PMD or PGD early mappings so we
288 	 * should never reach here with MMU disabled.
289 	 */
290 	BUG();
291 }
292 
293 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
294 {
295 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
296 }
297 
298 static phys_addr_t __init alloc_pte_late(uintptr_t va)
299 {
300 	unsigned long vaddr;
301 
302 	vaddr = __get_free_page(GFP_KERNEL);
303 	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)));
304 
305 	return __pa(vaddr);
306 }
307 
308 static void __init create_pte_mapping(pte_t *ptep,
309 				      uintptr_t va, phys_addr_t pa,
310 				      phys_addr_t sz, pgprot_t prot)
311 {
312 	uintptr_t pte_idx = pte_index(va);
313 
314 	BUG_ON(sz != PAGE_SIZE);
315 
316 	if (pte_none(ptep[pte_idx]))
317 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
318 }
319 
320 #ifndef __PAGETABLE_PMD_FOLDED
321 
322 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
323 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
324 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
325 static pmd_t early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
326 
327 #ifdef CONFIG_XIP_KERNEL
328 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
329 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
330 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
331 #endif /* CONFIG_XIP_KERNEL */
332 
333 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
334 {
335 	/* Before MMU is enabled */
336 	return (pmd_t *)((uintptr_t)pa);
337 }
338 
339 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
340 {
341 	clear_fixmap(FIX_PMD);
342 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
343 }
344 
345 static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)
346 {
347 	return (pmd_t *) __va(pa);
348 }
349 
350 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
351 {
352 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
353 
354 	return (uintptr_t)early_pmd;
355 }
356 
357 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
358 {
359 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
360 }
361 
362 static phys_addr_t __init alloc_pmd_late(uintptr_t va)
363 {
364 	unsigned long vaddr;
365 
366 	vaddr = __get_free_page(GFP_KERNEL);
367 	BUG_ON(!vaddr);
368 	return __pa(vaddr);
369 }
370 
371 static void __init create_pmd_mapping(pmd_t *pmdp,
372 				      uintptr_t va, phys_addr_t pa,
373 				      phys_addr_t sz, pgprot_t prot)
374 {
375 	pte_t *ptep;
376 	phys_addr_t pte_phys;
377 	uintptr_t pmd_idx = pmd_index(va);
378 
379 	if (sz == PMD_SIZE) {
380 		if (pmd_none(pmdp[pmd_idx]))
381 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
382 		return;
383 	}
384 
385 	if (pmd_none(pmdp[pmd_idx])) {
386 		pte_phys = pt_ops.alloc_pte(va);
387 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
388 		ptep = pt_ops.get_pte_virt(pte_phys);
389 		memset(ptep, 0, PAGE_SIZE);
390 	} else {
391 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
392 		ptep = pt_ops.get_pte_virt(pte_phys);
393 	}
394 
395 	create_pte_mapping(ptep, va, pa, sz, prot);
396 }
397 
398 #define pgd_next_t		pmd_t
399 #define alloc_pgd_next(__va)	pt_ops.alloc_pmd(__va)
400 #define get_pgd_next_virt(__pa)	pt_ops.get_pmd_virt(__pa)
401 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
402 	create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
403 #define fixmap_pgd_next		fixmap_pmd
404 #else
405 #define pgd_next_t		pte_t
406 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
407 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
408 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
409 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
410 #define fixmap_pgd_next		fixmap_pte
411 #endif
412 
413 void __init create_pgd_mapping(pgd_t *pgdp,
414 				      uintptr_t va, phys_addr_t pa,
415 				      phys_addr_t sz, pgprot_t prot)
416 {
417 	pgd_next_t *nextp;
418 	phys_addr_t next_phys;
419 	uintptr_t pgd_idx = pgd_index(va);
420 
421 	if (sz == PGDIR_SIZE) {
422 		if (pgd_val(pgdp[pgd_idx]) == 0)
423 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
424 		return;
425 	}
426 
427 	if (pgd_val(pgdp[pgd_idx]) == 0) {
428 		next_phys = alloc_pgd_next(va);
429 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
430 		nextp = get_pgd_next_virt(next_phys);
431 		memset(nextp, 0, PAGE_SIZE);
432 	} else {
433 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
434 		nextp = get_pgd_next_virt(next_phys);
435 	}
436 
437 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
438 }
439 
440 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
441 {
442 	/* Upgrade to PMD_SIZE mappings whenever possible */
443 	if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
444 		return PAGE_SIZE;
445 
446 	return PMD_SIZE;
447 }
448 
449 #ifdef CONFIG_XIP_KERNEL
450 /* called from head.S with MMU off */
451 asmlinkage void __init __copy_data(void)
452 {
453 	void *from = (void *)(&_sdata);
454 	void *end = (void *)(&_end);
455 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
456 	size_t sz = (size_t)(end - from + 1);
457 
458 	memcpy(to, from, sz);
459 }
460 #endif
461 
462 #ifdef CONFIG_STRICT_KERNEL_RWX
463 static __init pgprot_t pgprot_from_va(uintptr_t va)
464 {
465 	if (is_va_kernel_text(va))
466 		return PAGE_KERNEL_READ_EXEC;
467 
468 	/*
469 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
470 	 * we must protect its linear mapping alias from being executed and
471 	 * written.
472 	 * And rodata section is marked readonly in mark_rodata_ro.
473 	 */
474 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
475 		return PAGE_KERNEL_READ;
476 
477 	return PAGE_KERNEL;
478 }
479 
480 void mark_rodata_ro(void)
481 {
482 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
483 	if (IS_ENABLED(CONFIG_64BIT))
484 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
485 				  set_memory_ro);
486 
487 	debug_checkwx();
488 }
489 #else
490 static __init pgprot_t pgprot_from_va(uintptr_t va)
491 {
492 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
493 		return PAGE_KERNEL;
494 
495 	return PAGE_KERNEL_EXEC;
496 }
497 #endif /* CONFIG_STRICT_KERNEL_RWX */
498 
499 /*
500  * setup_vm() is called from head.S with MMU-off.
501  *
502  * Following requirements should be honoured for setup_vm() to work
503  * correctly:
504  * 1) It should use PC-relative addressing for accessing kernel symbols.
505  *    To achieve this we always use GCC cmodel=medany.
506  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
507  *    so disable compiler instrumentation when FTRACE is enabled.
508  *
509  * Currently, the above requirements are honoured by using custom CFLAGS
510  * for init.o in mm/Makefile.
511  */
512 
513 #ifndef __riscv_cmodel_medany
514 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
515 #endif
516 
517 #ifdef CONFIG_XIP_KERNEL
518 static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size,
519 					    __always_unused bool early)
520 {
521 	uintptr_t va, end_va;
522 
523 	/* Map the flash resident part */
524 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
525 	for (va = kernel_map.virt_addr; va < end_va; va += map_size)
526 		create_pgd_mapping(pgdir, va,
527 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
528 				   map_size, PAGE_KERNEL_EXEC);
529 
530 	/* Map the data in RAM */
531 	end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size;
532 	for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += map_size)
533 		create_pgd_mapping(pgdir, va,
534 				   kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
535 				   map_size, PAGE_KERNEL);
536 }
537 #else
538 static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size,
539 					    bool early)
540 {
541 	uintptr_t va, end_va;
542 
543 	end_va = kernel_map.virt_addr + kernel_map.size;
544 	for (va = kernel_map.virt_addr; va < end_va; va += map_size)
545 		create_pgd_mapping(pgdir, va,
546 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
547 				   map_size,
548 				   early ?
549 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
550 }
551 #endif
552 
553 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
554 {
555 	uintptr_t __maybe_unused pa;
556 	uintptr_t map_size;
557 #ifndef __PAGETABLE_PMD_FOLDED
558 	pmd_t fix_bmap_spmd, fix_bmap_epmd;
559 #endif
560 
561 	kernel_map.virt_addr = KERNEL_LINK_ADDR;
562 
563 #ifdef CONFIG_XIP_KERNEL
564 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
565 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
566 
567 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
568 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
569 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
570 
571 	kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
572 #else
573 	kernel_map.phys_addr = (uintptr_t)(&_start);
574 	kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
575 #endif
576 
577 	kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr;
578 #ifdef CONFIG_64BIT
579 	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
580 #endif
581 
582 	pfn_base = PFN_DOWN(kernel_map.phys_addr);
583 
584 	/*
585 	 * Enforce boot alignment requirements of RV32 and
586 	 * RV64 by only allowing PMD or PGD mappings.
587 	 */
588 	map_size = PMD_SIZE;
589 
590 	/* Sanity check alignment and size */
591 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
592 	BUG_ON((kernel_map.phys_addr % map_size) != 0);
593 
594 #ifdef CONFIG_64BIT
595 	/*
596 	 * The last 4K bytes of the addressable memory can not be mapped because
597 	 * of IS_ERR_VALUE macro.
598 	 */
599 	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
600 #endif
601 
602 	pt_ops.alloc_pte = alloc_pte_early;
603 	pt_ops.get_pte_virt = get_pte_virt_early;
604 #ifndef __PAGETABLE_PMD_FOLDED
605 	pt_ops.alloc_pmd = alloc_pmd_early;
606 	pt_ops.get_pmd_virt = get_pmd_virt_early;
607 #endif
608 	/* Setup early PGD for fixmap */
609 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
610 			   (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
611 
612 #ifndef __PAGETABLE_PMD_FOLDED
613 	/* Setup fixmap PMD */
614 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
615 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
616 	/* Setup trampoline PGD and PMD */
617 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
618 			   (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
619 #ifdef CONFIG_XIP_KERNEL
620 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
621 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
622 #else
623 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
624 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
625 #endif
626 #else
627 	/* Setup trampoline PGD */
628 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
629 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
630 #endif
631 
632 	/*
633 	 * Setup early PGD covering entire kernel which will allow
634 	 * us to reach paging_init(). We map all memory banks later
635 	 * in setup_vm_final() below.
636 	 */
637 	create_kernel_page_table(early_pg_dir, map_size, true);
638 
639 #ifndef __PAGETABLE_PMD_FOLDED
640 	/* Setup early PMD for DTB */
641 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
642 			   (uintptr_t)early_dtb_pmd, PGDIR_SIZE, PAGE_TABLE);
643 #ifndef CONFIG_BUILTIN_DTB
644 	/* Create two consecutive PMD mappings for FDT early scan */
645 	pa = dtb_pa & ~(PMD_SIZE - 1);
646 	create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
647 			   pa, PMD_SIZE, PAGE_KERNEL);
648 	create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
649 			   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
650 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
651 #else /* CONFIG_BUILTIN_DTB */
652 #ifdef CONFIG_64BIT
653 	/*
654 	 * __va can't be used since it would return a linear mapping address
655 	 * whereas dtb_early_va will be used before setup_vm_final installs
656 	 * the linear mapping.
657 	 */
658 	dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
659 #else
660 	dtb_early_va = __va(dtb_pa);
661 #endif /* CONFIG_64BIT */
662 #endif /* CONFIG_BUILTIN_DTB */
663 #else
664 #ifndef CONFIG_BUILTIN_DTB
665 	/* Create two consecutive PGD mappings for FDT early scan */
666 	pa = dtb_pa & ~(PGDIR_SIZE - 1);
667 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
668 			   pa, PGDIR_SIZE, PAGE_KERNEL);
669 	create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE,
670 			   pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
671 	dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
672 #else /* CONFIG_BUILTIN_DTB */
673 #ifdef CONFIG_64BIT
674 	dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
675 #else
676 	dtb_early_va = __va(dtb_pa);
677 #endif /* CONFIG_64BIT */
678 #endif /* CONFIG_BUILTIN_DTB */
679 #endif
680 	dtb_early_pa = dtb_pa;
681 
682 	/*
683 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
684 	 * range can not span multiple pmds.
685 	 */
686 	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
687 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
688 
689 #ifndef __PAGETABLE_PMD_FOLDED
690 	/*
691 	 * Early ioremap fixmap is already created as it lies within first 2MB
692 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
693 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
694 	 * the user if not.
695 	 */
696 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
697 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
698 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
699 		WARN_ON(1);
700 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
701 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
702 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
703 			fix_to_virt(FIX_BTMAP_BEGIN));
704 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
705 			fix_to_virt(FIX_BTMAP_END));
706 
707 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
708 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
709 	}
710 #endif
711 }
712 
713 static void __init setup_vm_final(void)
714 {
715 	uintptr_t va, map_size;
716 	phys_addr_t pa, start, end;
717 	u64 i;
718 
719 	/**
720 	 * MMU is enabled at this point. But page table setup is not complete yet.
721 	 * fixmap page table alloc functions should be used at this point
722 	 */
723 	pt_ops.alloc_pte = alloc_pte_fixmap;
724 	pt_ops.get_pte_virt = get_pte_virt_fixmap;
725 #ifndef __PAGETABLE_PMD_FOLDED
726 	pt_ops.alloc_pmd = alloc_pmd_fixmap;
727 	pt_ops.get_pmd_virt = get_pmd_virt_fixmap;
728 #endif
729 	/* Setup swapper PGD for fixmap */
730 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
731 			   __pa_symbol(fixmap_pgd_next),
732 			   PGDIR_SIZE, PAGE_TABLE);
733 
734 	/* Map all memory banks in the linear mapping */
735 	for_each_mem_range(i, &start, &end) {
736 		if (start >= end)
737 			break;
738 		if (start <= __pa(PAGE_OFFSET) &&
739 		    __pa(PAGE_OFFSET) < end)
740 			start = __pa(PAGE_OFFSET);
741 		if (end >= __pa(PAGE_OFFSET) + memory_limit)
742 			end = __pa(PAGE_OFFSET) + memory_limit;
743 
744 		map_size = best_map_size(start, end - start);
745 		for (pa = start; pa < end; pa += map_size) {
746 			va = (uintptr_t)__va(pa);
747 
748 			create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
749 					   pgprot_from_va(va));
750 		}
751 	}
752 
753 #ifdef CONFIG_64BIT
754 	/* Map the kernel */
755 	create_kernel_page_table(swapper_pg_dir, PMD_SIZE, false);
756 #endif
757 
758 	/* Clear fixmap PTE and PMD mappings */
759 	clear_fixmap(FIX_PTE);
760 	clear_fixmap(FIX_PMD);
761 
762 	/* Move to swapper page table */
763 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
764 	local_flush_tlb_all();
765 
766 	/* generic page allocation functions must be used to setup page table */
767 	pt_ops.alloc_pte = alloc_pte_late;
768 	pt_ops.get_pte_virt = get_pte_virt_late;
769 #ifndef __PAGETABLE_PMD_FOLDED
770 	pt_ops.alloc_pmd = alloc_pmd_late;
771 	pt_ops.get_pmd_virt = get_pmd_virt_late;
772 #endif
773 }
774 #else
775 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
776 {
777 	dtb_early_va = (void *)dtb_pa;
778 	dtb_early_pa = dtb_pa;
779 }
780 
781 static inline void setup_vm_final(void)
782 {
783 }
784 #endif /* CONFIG_MMU */
785 
786 #ifdef CONFIG_KEXEC_CORE
787 /*
788  * reserve_crashkernel() - reserves memory for crash kernel
789  *
790  * This function reserves memory area given in "crashkernel=" kernel command
791  * line parameter. The memory reserved is used by dump capture kernel when
792  * primary kernel is crashing.
793  */
794 static void __init reserve_crashkernel(void)
795 {
796 	unsigned long long crash_base = 0;
797 	unsigned long long crash_size = 0;
798 	unsigned long search_start = memblock_start_of_DRAM();
799 	unsigned long search_end = memblock_end_of_DRAM();
800 
801 	int ret = 0;
802 
803 	/*
804 	 * Don't reserve a region for a crash kernel on a crash kernel
805 	 * since it doesn't make much sense and we have limited memory
806 	 * resources.
807 	 */
808 #ifdef CONFIG_CRASH_DUMP
809 	if (is_kdump_kernel()) {
810 		pr_info("crashkernel: ignoring reservation request\n");
811 		return;
812 	}
813 #endif
814 
815 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
816 				&crash_size, &crash_base);
817 	if (ret || !crash_size)
818 		return;
819 
820 	crash_size = PAGE_ALIGN(crash_size);
821 
822 	if (crash_base == 0) {
823 		/*
824 		 * Current riscv boot protocol requires 2MB alignment for
825 		 * RV64 and 4MB alignment for RV32 (hugepage size)
826 		 */
827 		crash_base = memblock_find_in_range(search_start, search_end,
828 						    crash_size, PMD_SIZE);
829 
830 		if (crash_base == 0) {
831 			pr_warn("crashkernel: couldn't allocate %lldKB\n",
832 				crash_size >> 10);
833 			return;
834 		}
835 	} else {
836 		/* User specifies base address explicitly. */
837 		if (!memblock_is_region_memory(crash_base, crash_size)) {
838 			pr_warn("crashkernel: requested region is not memory\n");
839 			return;
840 		}
841 
842 		if (memblock_is_region_reserved(crash_base, crash_size)) {
843 			pr_warn("crashkernel: requested region is reserved\n");
844 			return;
845 		}
846 
847 
848 		if (!IS_ALIGNED(crash_base, PMD_SIZE)) {
849 			pr_warn("crashkernel: requested region is misaligned\n");
850 			return;
851 		}
852 	}
853 	memblock_reserve(crash_base, crash_size);
854 
855 	pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
856 		crash_base, crash_base + crash_size, crash_size >> 20);
857 
858 	crashk_res.start = crash_base;
859 	crashk_res.end = crash_base + crash_size - 1;
860 }
861 #endif /* CONFIG_KEXEC_CORE */
862 
863 void __init paging_init(void)
864 {
865 	setup_bootmem();
866 	setup_vm_final();
867 }
868 
869 void __init misc_mem_init(void)
870 {
871 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
872 	arch_numa_init();
873 	sparse_init();
874 	zone_sizes_init();
875 #ifdef CONFIG_KEXEC_CORE
876 	reserve_crashkernel();
877 #endif
878 	memblock_dump_all();
879 }
880 
881 #ifdef CONFIG_SPARSEMEM_VMEMMAP
882 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
883 			       struct vmem_altmap *altmap)
884 {
885 	return vmemmap_populate_basepages(start, end, node, NULL);
886 }
887 #endif
888