xref: /linux/arch/riscv/mm/init.c (revision 42b16d3ac371a2fac9b6f08fd75f23f34ba3955a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  * Copyright (C) 2019 Western Digital Corporation or its affiliates.
5  * Copyright (C) 2020 FORTH-ICS/CARV
6  *  Nick Kossifidis <mick@ics.forth.gr>
7  */
8 
9 #include <linux/init.h>
10 #include <linux/mm.h>
11 #include <linux/memblock.h>
12 #include <linux/initrd.h>
13 #include <linux/swap.h>
14 #include <linux/swiotlb.h>
15 #include <linux/sizes.h>
16 #include <linux/of_fdt.h>
17 #include <linux/of_reserved_mem.h>
18 #include <linux/libfdt.h>
19 #include <linux/set_memory.h>
20 #include <linux/dma-map-ops.h>
21 #include <linux/crash_dump.h>
22 #include <linux/hugetlb.h>
23 #ifdef CONFIG_RELOCATABLE
24 #include <linux/elf.h>
25 #endif
26 #include <linux/kfence.h>
27 #include <linux/execmem.h>
28 
29 #include <asm/fixmap.h>
30 #include <asm/io.h>
31 #include <asm/kasan.h>
32 #include <asm/numa.h>
33 #include <asm/pgtable.h>
34 #include <asm/sections.h>
35 #include <asm/soc.h>
36 #include <asm/tlbflush.h>
37 
38 #include "../kernel/head.h"
39 
40 u64 new_vmalloc[NR_CPUS / sizeof(u64) + 1];
41 
42 struct kernel_mapping kernel_map __ro_after_init;
43 EXPORT_SYMBOL(kernel_map);
44 #ifdef CONFIG_XIP_KERNEL
45 #define kernel_map	(*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
46 #endif
47 
48 #ifdef CONFIG_64BIT
49 u64 satp_mode __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_57 : SATP_MODE_39;
50 #else
51 u64 satp_mode __ro_after_init = SATP_MODE_32;
52 #endif
53 EXPORT_SYMBOL(satp_mode);
54 
55 #ifdef CONFIG_64BIT
56 bool pgtable_l4_enabled __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL);
57 bool pgtable_l5_enabled __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL);
58 EXPORT_SYMBOL(pgtable_l4_enabled);
59 EXPORT_SYMBOL(pgtable_l5_enabled);
60 #endif
61 
62 phys_addr_t phys_ram_base __ro_after_init;
63 EXPORT_SYMBOL(phys_ram_base);
64 
65 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
66 							__page_aligned_bss;
67 EXPORT_SYMBOL(empty_zero_page);
68 
69 extern char _start[];
70 void *_dtb_early_va __initdata;
71 uintptr_t _dtb_early_pa __initdata;
72 
73 phys_addr_t dma32_phys_limit __initdata;
74 
zone_sizes_init(void)75 static void __init zone_sizes_init(void)
76 {
77 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
78 
79 #ifdef CONFIG_ZONE_DMA32
80 	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
81 #endif
82 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
83 
84 	free_area_init(max_zone_pfns);
85 }
86 
87 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
88 
89 #define LOG2_SZ_1K  ilog2(SZ_1K)
90 #define LOG2_SZ_1M  ilog2(SZ_1M)
91 #define LOG2_SZ_1G  ilog2(SZ_1G)
92 #define LOG2_SZ_1T  ilog2(SZ_1T)
93 
print_mlk(char * name,unsigned long b,unsigned long t)94 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
95 {
96 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
97 		  (((t) - (b)) >> LOG2_SZ_1K));
98 }
99 
print_mlm(char * name,unsigned long b,unsigned long t)100 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
101 {
102 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
103 		  (((t) - (b)) >> LOG2_SZ_1M));
104 }
105 
print_mlg(char * name,unsigned long b,unsigned long t)106 static inline void print_mlg(char *name, unsigned long b, unsigned long t)
107 {
108 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld GB)\n", name, b, t,
109 		   (((t) - (b)) >> LOG2_SZ_1G));
110 }
111 
112 #ifdef CONFIG_64BIT
print_mlt(char * name,unsigned long b,unsigned long t)113 static inline void print_mlt(char *name, unsigned long b, unsigned long t)
114 {
115 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld TB)\n", name, b, t,
116 		   (((t) - (b)) >> LOG2_SZ_1T));
117 }
118 #else
119 #define print_mlt(n, b, t) do {} while (0)
120 #endif
121 
print_ml(char * name,unsigned long b,unsigned long t)122 static inline void print_ml(char *name, unsigned long b, unsigned long t)
123 {
124 	unsigned long diff = t - b;
125 
126 	if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10)
127 		print_mlt(name, b, t);
128 	else if ((diff >> LOG2_SZ_1G) >= 10)
129 		print_mlg(name, b, t);
130 	else if ((diff >> LOG2_SZ_1M) >= 10)
131 		print_mlm(name, b, t);
132 	else
133 		print_mlk(name, b, t);
134 }
135 
print_vm_layout(void)136 static void __init print_vm_layout(void)
137 {
138 	pr_notice("Virtual kernel memory layout:\n");
139 	print_ml("fixmap", (unsigned long)FIXADDR_START,
140 		(unsigned long)FIXADDR_TOP);
141 	print_ml("pci io", (unsigned long)PCI_IO_START,
142 		(unsigned long)PCI_IO_END);
143 	print_ml("vmemmap", (unsigned long)VMEMMAP_START,
144 		(unsigned long)VMEMMAP_END);
145 	print_ml("vmalloc", (unsigned long)VMALLOC_START,
146 		(unsigned long)VMALLOC_END);
147 #ifdef CONFIG_64BIT
148 	print_ml("modules", (unsigned long)MODULES_VADDR,
149 		(unsigned long)MODULES_END);
150 #endif
151 	print_ml("lowmem", (unsigned long)PAGE_OFFSET,
152 		(unsigned long)high_memory);
153 	if (IS_ENABLED(CONFIG_64BIT)) {
154 #ifdef CONFIG_KASAN
155 		print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
156 #endif
157 
158 		print_ml("kernel", (unsigned long)kernel_map.virt_addr,
159 			 (unsigned long)ADDRESS_SPACE_END);
160 	}
161 }
162 #else
print_vm_layout(void)163 static void print_vm_layout(void) { }
164 #endif /* CONFIG_DEBUG_VM */
165 
mem_init(void)166 void __init mem_init(void)
167 {
168 	bool swiotlb = max_pfn > PFN_DOWN(dma32_phys_limit);
169 #ifdef CONFIG_FLATMEM
170 	BUG_ON(!mem_map);
171 #endif /* CONFIG_FLATMEM */
172 
173 	if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb &&
174 	    dma_cache_alignment != 1) {
175 		/*
176 		 * If no bouncing needed for ZONE_DMA, allocate 1MB swiotlb
177 		 * buffer per 1GB of RAM for kmalloc() bouncing on
178 		 * non-coherent platforms.
179 		 */
180 		unsigned long size =
181 			DIV_ROUND_UP(memblock_phys_mem_size(), 1024);
182 		swiotlb_adjust_size(min(swiotlb_size_or_default(), size));
183 		swiotlb = true;
184 	}
185 
186 	swiotlb_init(swiotlb, SWIOTLB_VERBOSE);
187 	memblock_free_all();
188 
189 	print_vm_layout();
190 }
191 
192 /* Limit the memory size via mem. */
193 static phys_addr_t memory_limit;
194 #ifdef CONFIG_XIP_KERNEL
195 #define memory_limit	(*(phys_addr_t *)XIP_FIXUP(&memory_limit))
196 #endif /* CONFIG_XIP_KERNEL */
197 
early_mem(char * p)198 static int __init early_mem(char *p)
199 {
200 	u64 size;
201 
202 	if (!p)
203 		return 1;
204 
205 	size = memparse(p, &p) & PAGE_MASK;
206 	memory_limit = min_t(u64, size, memory_limit);
207 
208 	pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
209 
210 	return 0;
211 }
212 early_param("mem", early_mem);
213 
setup_bootmem(void)214 static void __init setup_bootmem(void)
215 {
216 	phys_addr_t vmlinux_end = __pa_symbol(&_end);
217 	phys_addr_t max_mapped_addr;
218 	phys_addr_t phys_ram_end, vmlinux_start;
219 
220 	if (IS_ENABLED(CONFIG_XIP_KERNEL))
221 		vmlinux_start = __pa_symbol(&_sdata);
222 	else
223 		vmlinux_start = __pa_symbol(&_start);
224 
225 	memblock_enforce_memory_limit(memory_limit);
226 
227 	/*
228 	 * Make sure we align the reservation on PMD_SIZE since we will
229 	 * map the kernel in the linear mapping as read-only: we do not want
230 	 * any allocation to happen between _end and the next pmd aligned page.
231 	 */
232 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
233 		vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
234 	/*
235 	 * Reserve from the start of the kernel to the end of the kernel
236 	 */
237 	memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
238 
239 	/*
240 	 * Make sure we align the start of the memory on a PMD boundary so that
241 	 * at worst, we map the linear mapping with PMD mappings.
242 	 */
243 	if (!IS_ENABLED(CONFIG_XIP_KERNEL))
244 		phys_ram_base = memblock_start_of_DRAM() & PMD_MASK;
245 
246 	/*
247 	 * In 64-bit, any use of __va/__pa before this point is wrong as we
248 	 * did not know the start of DRAM before.
249 	 */
250 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU))
251 		kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
252 
253 	/*
254 	 * The size of the linear page mapping may restrict the amount of
255 	 * usable RAM.
256 	 */
257 	if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) {
258 		max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE;
259 		memblock_cap_memory_range(phys_ram_base,
260 					  max_mapped_addr - phys_ram_base);
261 	}
262 
263 	/*
264 	 * Reserve physical address space that would be mapped to virtual
265 	 * addresses greater than (void *)(-PAGE_SIZE) because:
266 	 *  - This memory would overlap with ERR_PTR
267 	 *  - This memory belongs to high memory, which is not supported
268 	 *
269 	 * This is not applicable to 64-bit kernel, because virtual addresses
270 	 * after (void *)(-PAGE_SIZE) are not linearly mapped: they are
271 	 * occupied by kernel mapping. Also it is unrealistic for high memory
272 	 * to exist on 64-bit platforms.
273 	 */
274 	if (!IS_ENABLED(CONFIG_64BIT)) {
275 		max_mapped_addr = __va_to_pa_nodebug(-PAGE_SIZE);
276 		memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr);
277 	}
278 
279 	phys_ram_end = memblock_end_of_DRAM();
280 	min_low_pfn = PFN_UP(phys_ram_base);
281 	max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
282 	high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
283 
284 	dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
285 	set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
286 
287 	reserve_initrd_mem();
288 
289 	/*
290 	 * No allocation should be done before reserving the memory as defined
291 	 * in the device tree, otherwise the allocation could end up in a
292 	 * reserved region.
293 	 */
294 	early_init_fdt_scan_reserved_mem();
295 
296 	/*
297 	 * If DTB is built in, no need to reserve its memblock.
298 	 * Otherwise, do reserve it but avoid using
299 	 * early_init_fdt_reserve_self() since __pa() does
300 	 * not work for DTB pointers that are fixmap addresses
301 	 */
302 	if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
303 		memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
304 
305 	dma_contiguous_reserve(dma32_phys_limit);
306 	if (IS_ENABLED(CONFIG_64BIT))
307 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
308 }
309 
310 #ifdef CONFIG_MMU
311 struct pt_alloc_ops pt_ops __meminitdata;
312 
313 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
314 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
315 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
316 
317 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
318 
319 #ifdef CONFIG_XIP_KERNEL
320 #define pt_ops			(*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
321 #define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
322 #define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
323 #define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
324 #endif /* CONFIG_XIP_KERNEL */
325 
326 static const pgprot_t protection_map[16] = {
327 	[VM_NONE]					= PAGE_NONE,
328 	[VM_READ]					= PAGE_READ,
329 	[VM_WRITE]					= PAGE_COPY,
330 	[VM_WRITE | VM_READ]				= PAGE_COPY,
331 	[VM_EXEC]					= PAGE_EXEC,
332 	[VM_EXEC | VM_READ]				= PAGE_READ_EXEC,
333 	[VM_EXEC | VM_WRITE]				= PAGE_COPY_EXEC,
334 	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_COPY_EXEC,
335 	[VM_SHARED]					= PAGE_NONE,
336 	[VM_SHARED | VM_READ]				= PAGE_READ,
337 	[VM_SHARED | VM_WRITE]				= PAGE_SHARED,
338 	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_SHARED,
339 	[VM_SHARED | VM_EXEC]				= PAGE_EXEC,
340 	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ_EXEC,
341 	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_SHARED_EXEC,
342 	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_SHARED_EXEC
343 };
344 DECLARE_VM_GET_PAGE_PROT
345 
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t prot)346 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
347 {
348 	unsigned long addr = __fix_to_virt(idx);
349 	pte_t *ptep;
350 
351 	BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
352 
353 	ptep = &fixmap_pte[pte_index(addr)];
354 
355 	if (pgprot_val(prot))
356 		set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
357 	else
358 		pte_clear(&init_mm, addr, ptep);
359 	local_flush_tlb_page(addr);
360 }
361 
get_pte_virt_early(phys_addr_t pa)362 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
363 {
364 	return (pte_t *)((uintptr_t)pa);
365 }
366 
get_pte_virt_fixmap(phys_addr_t pa)367 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
368 {
369 	clear_fixmap(FIX_PTE);
370 	return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
371 }
372 
get_pte_virt_late(phys_addr_t pa)373 static inline pte_t *__meminit get_pte_virt_late(phys_addr_t pa)
374 {
375 	return (pte_t *) __va(pa);
376 }
377 
alloc_pte_early(uintptr_t va)378 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
379 {
380 	/*
381 	 * We only create PMD or PGD early mappings so we
382 	 * should never reach here with MMU disabled.
383 	 */
384 	BUG();
385 }
386 
alloc_pte_fixmap(uintptr_t va)387 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
388 {
389 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
390 }
391 
alloc_pte_late(uintptr_t va)392 static phys_addr_t __meminit alloc_pte_late(uintptr_t va)
393 {
394 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
395 
396 	BUG_ON(!ptdesc || !pagetable_pte_ctor(ptdesc));
397 	return __pa((pte_t *)ptdesc_address(ptdesc));
398 }
399 
create_pte_mapping(pte_t * ptep,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)400 static void __meminit create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
401 					 pgprot_t prot)
402 {
403 	uintptr_t pte_idx = pte_index(va);
404 
405 	BUG_ON(sz != PAGE_SIZE);
406 
407 	if (pte_none(ptep[pte_idx]))
408 		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
409 }
410 
411 #ifndef __PAGETABLE_PMD_FOLDED
412 
413 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
414 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
415 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
416 
417 #ifdef CONFIG_XIP_KERNEL
418 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
419 #define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
420 #define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
421 #endif /* CONFIG_XIP_KERNEL */
422 
423 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss;
424 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss;
425 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
426 
427 #ifdef CONFIG_XIP_KERNEL
428 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d))
429 #define fixmap_p4d     ((p4d_t *)XIP_FIXUP(fixmap_p4d))
430 #define early_p4d      ((p4d_t *)XIP_FIXUP(early_p4d))
431 #endif /* CONFIG_XIP_KERNEL */
432 
433 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss;
434 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss;
435 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
436 
437 #ifdef CONFIG_XIP_KERNEL
438 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud))
439 #define fixmap_pud     ((pud_t *)XIP_FIXUP(fixmap_pud))
440 #define early_pud      ((pud_t *)XIP_FIXUP(early_pud))
441 #endif /* CONFIG_XIP_KERNEL */
442 
get_pmd_virt_early(phys_addr_t pa)443 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
444 {
445 	/* Before MMU is enabled */
446 	return (pmd_t *)((uintptr_t)pa);
447 }
448 
get_pmd_virt_fixmap(phys_addr_t pa)449 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
450 {
451 	clear_fixmap(FIX_PMD);
452 	return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
453 }
454 
get_pmd_virt_late(phys_addr_t pa)455 static pmd_t *__meminit get_pmd_virt_late(phys_addr_t pa)
456 {
457 	return (pmd_t *) __va(pa);
458 }
459 
alloc_pmd_early(uintptr_t va)460 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
461 {
462 	BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT);
463 
464 	return (uintptr_t)early_pmd;
465 }
466 
alloc_pmd_fixmap(uintptr_t va)467 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
468 {
469 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
470 }
471 
alloc_pmd_late(uintptr_t va)472 static phys_addr_t __meminit alloc_pmd_late(uintptr_t va)
473 {
474 	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
475 
476 	BUG_ON(!ptdesc || !pagetable_pmd_ctor(ptdesc));
477 	return __pa((pmd_t *)ptdesc_address(ptdesc));
478 }
479 
create_pmd_mapping(pmd_t * pmdp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)480 static void __meminit create_pmd_mapping(pmd_t *pmdp,
481 					 uintptr_t va, phys_addr_t pa,
482 					 phys_addr_t sz, pgprot_t prot)
483 {
484 	pte_t *ptep;
485 	phys_addr_t pte_phys;
486 	uintptr_t pmd_idx = pmd_index(va);
487 
488 	if (sz == PMD_SIZE) {
489 		if (pmd_none(pmdp[pmd_idx]))
490 			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
491 		return;
492 	}
493 
494 	if (pmd_none(pmdp[pmd_idx])) {
495 		pte_phys = pt_ops.alloc_pte(va);
496 		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
497 		ptep = pt_ops.get_pte_virt(pte_phys);
498 		memset(ptep, 0, PAGE_SIZE);
499 	} else {
500 		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
501 		ptep = pt_ops.get_pte_virt(pte_phys);
502 	}
503 
504 	create_pte_mapping(ptep, va, pa, sz, prot);
505 }
506 
get_pud_virt_early(phys_addr_t pa)507 static pud_t *__init get_pud_virt_early(phys_addr_t pa)
508 {
509 	return (pud_t *)((uintptr_t)pa);
510 }
511 
get_pud_virt_fixmap(phys_addr_t pa)512 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
513 {
514 	clear_fixmap(FIX_PUD);
515 	return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
516 }
517 
get_pud_virt_late(phys_addr_t pa)518 static pud_t *__meminit get_pud_virt_late(phys_addr_t pa)
519 {
520 	return (pud_t *)__va(pa);
521 }
522 
alloc_pud_early(uintptr_t va)523 static phys_addr_t __init alloc_pud_early(uintptr_t va)
524 {
525 	/* Only one PUD is available for early mapping */
526 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
527 
528 	return (uintptr_t)early_pud;
529 }
530 
alloc_pud_fixmap(uintptr_t va)531 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
532 {
533 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
534 }
535 
alloc_pud_late(uintptr_t va)536 static phys_addr_t __meminit alloc_pud_late(uintptr_t va)
537 {
538 	unsigned long vaddr;
539 
540 	vaddr = __get_free_page(GFP_KERNEL);
541 	BUG_ON(!vaddr);
542 	return __pa(vaddr);
543 }
544 
get_p4d_virt_early(phys_addr_t pa)545 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa)
546 {
547 	return (p4d_t *)((uintptr_t)pa);
548 }
549 
get_p4d_virt_fixmap(phys_addr_t pa)550 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
551 {
552 	clear_fixmap(FIX_P4D);
553 	return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
554 }
555 
get_p4d_virt_late(phys_addr_t pa)556 static p4d_t *__meminit get_p4d_virt_late(phys_addr_t pa)
557 {
558 	return (p4d_t *)__va(pa);
559 }
560 
alloc_p4d_early(uintptr_t va)561 static phys_addr_t __init alloc_p4d_early(uintptr_t va)
562 {
563 	/* Only one P4D is available for early mapping */
564 	BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
565 
566 	return (uintptr_t)early_p4d;
567 }
568 
alloc_p4d_fixmap(uintptr_t va)569 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
570 {
571 	return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
572 }
573 
alloc_p4d_late(uintptr_t va)574 static phys_addr_t __meminit alloc_p4d_late(uintptr_t va)
575 {
576 	unsigned long vaddr;
577 
578 	vaddr = __get_free_page(GFP_KERNEL);
579 	BUG_ON(!vaddr);
580 	return __pa(vaddr);
581 }
582 
create_pud_mapping(pud_t * pudp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)583 static void __meminit create_pud_mapping(pud_t *pudp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
584 					 pgprot_t prot)
585 {
586 	pmd_t *nextp;
587 	phys_addr_t next_phys;
588 	uintptr_t pud_index = pud_index(va);
589 
590 	if (sz == PUD_SIZE) {
591 		if (pud_val(pudp[pud_index]) == 0)
592 			pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot);
593 		return;
594 	}
595 
596 	if (pud_val(pudp[pud_index]) == 0) {
597 		next_phys = pt_ops.alloc_pmd(va);
598 		pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE);
599 		nextp = pt_ops.get_pmd_virt(next_phys);
600 		memset(nextp, 0, PAGE_SIZE);
601 	} else {
602 		next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index]));
603 		nextp = pt_ops.get_pmd_virt(next_phys);
604 	}
605 
606 	create_pmd_mapping(nextp, va, pa, sz, prot);
607 }
608 
create_p4d_mapping(p4d_t * p4dp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)609 static void __meminit create_p4d_mapping(p4d_t *p4dp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
610 					 pgprot_t prot)
611 {
612 	pud_t *nextp;
613 	phys_addr_t next_phys;
614 	uintptr_t p4d_index = p4d_index(va);
615 
616 	if (sz == P4D_SIZE) {
617 		if (p4d_val(p4dp[p4d_index]) == 0)
618 			p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot);
619 		return;
620 	}
621 
622 	if (p4d_val(p4dp[p4d_index]) == 0) {
623 		next_phys = pt_ops.alloc_pud(va);
624 		p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE);
625 		nextp = pt_ops.get_pud_virt(next_phys);
626 		memset(nextp, 0, PAGE_SIZE);
627 	} else {
628 		next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index]));
629 		nextp = pt_ops.get_pud_virt(next_phys);
630 	}
631 
632 	create_pud_mapping(nextp, va, pa, sz, prot);
633 }
634 
635 #define pgd_next_t		p4d_t
636 #define alloc_pgd_next(__va)	(pgtable_l5_enabled ?			\
637 		pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ?		\
638 		pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
639 #define get_pgd_next_virt(__pa)	(pgtable_l5_enabled ?			\
640 		pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ?	\
641 		pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
642 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
643 				(pgtable_l5_enabled ?			\
644 		create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
645 				(pgtable_l4_enabled ?			\
646 		create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) :	\
647 		create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
648 #define fixmap_pgd_next		(pgtable_l5_enabled ?			\
649 		(uintptr_t)fixmap_p4d : (pgtable_l4_enabled ?		\
650 		(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
651 #define trampoline_pgd_next	(pgtable_l5_enabled ?			\
652 		(uintptr_t)trampoline_p4d : (pgtable_l4_enabled ?	\
653 		(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
654 #else
655 #define pgd_next_t		pte_t
656 #define alloc_pgd_next(__va)	pt_ops.alloc_pte(__va)
657 #define get_pgd_next_virt(__pa)	pt_ops.get_pte_virt(__pa)
658 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)	\
659 	create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
660 #define fixmap_pgd_next		((uintptr_t)fixmap_pte)
661 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
662 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
663 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
664 #endif /* __PAGETABLE_PMD_FOLDED */
665 
create_pgd_mapping(pgd_t * pgdp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)666 void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz,
667 				  pgprot_t prot)
668 {
669 	pgd_next_t *nextp;
670 	phys_addr_t next_phys;
671 	uintptr_t pgd_idx = pgd_index(va);
672 
673 	if (sz == PGDIR_SIZE) {
674 		if (pgd_val(pgdp[pgd_idx]) == 0)
675 			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
676 		return;
677 	}
678 
679 	if (pgd_val(pgdp[pgd_idx]) == 0) {
680 		next_phys = alloc_pgd_next(va);
681 		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
682 		nextp = get_pgd_next_virt(next_phys);
683 		memset(nextp, 0, PAGE_SIZE);
684 	} else {
685 		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
686 		nextp = get_pgd_next_virt(next_phys);
687 	}
688 
689 	create_pgd_next_mapping(nextp, va, pa, sz, prot);
690 }
691 
best_map_size(phys_addr_t pa,uintptr_t va,phys_addr_t size)692 static uintptr_t __meminit best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size)
693 {
694 	if (debug_pagealloc_enabled())
695 		return PAGE_SIZE;
696 
697 	if (pgtable_l5_enabled &&
698 	    !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)
699 		return P4D_SIZE;
700 
701 	if (pgtable_l4_enabled &&
702 	    !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE)
703 		return PUD_SIZE;
704 
705 	if (IS_ENABLED(CONFIG_64BIT) &&
706 	    !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE)
707 		return PMD_SIZE;
708 
709 	return PAGE_SIZE;
710 }
711 
712 #ifdef CONFIG_XIP_KERNEL
713 #define phys_ram_base  (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base))
714 extern char _xiprom[], _exiprom[], __data_loc;
715 
716 /* called from head.S with MMU off */
__copy_data(void)717 asmlinkage void __init __copy_data(void)
718 {
719 	void *from = (void *)(&__data_loc);
720 	void *to = (void *)CONFIG_PHYS_RAM_BASE;
721 	size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
722 
723 	memcpy(to, from, sz);
724 }
725 #endif
726 
727 #ifdef CONFIG_STRICT_KERNEL_RWX
pgprot_from_va(uintptr_t va)728 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
729 {
730 	if (is_va_kernel_text(va))
731 		return PAGE_KERNEL_READ_EXEC;
732 
733 	/*
734 	 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
735 	 * we must protect its linear mapping alias from being executed and
736 	 * written.
737 	 * And rodata section is marked readonly in mark_rodata_ro.
738 	 */
739 	if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
740 		return PAGE_KERNEL_READ;
741 
742 	return PAGE_KERNEL;
743 }
744 
mark_rodata_ro(void)745 void mark_rodata_ro(void)
746 {
747 	set_kernel_memory(__start_rodata, _data, set_memory_ro);
748 	if (IS_ENABLED(CONFIG_64BIT))
749 		set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
750 				  set_memory_ro);
751 }
752 #else
pgprot_from_va(uintptr_t va)753 static __meminit pgprot_t pgprot_from_va(uintptr_t va)
754 {
755 	if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
756 		return PAGE_KERNEL;
757 
758 	return PAGE_KERNEL_EXEC;
759 }
760 #endif /* CONFIG_STRICT_KERNEL_RWX */
761 
762 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
763 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa);
764 
disable_pgtable_l5(void)765 static void __init disable_pgtable_l5(void)
766 {
767 	pgtable_l5_enabled = false;
768 	kernel_map.page_offset = PAGE_OFFSET_L4;
769 	satp_mode = SATP_MODE_48;
770 }
771 
disable_pgtable_l4(void)772 static void __init disable_pgtable_l4(void)
773 {
774 	pgtable_l4_enabled = false;
775 	kernel_map.page_offset = PAGE_OFFSET_L3;
776 	satp_mode = SATP_MODE_39;
777 }
778 
print_no4lvl(char * p)779 static int __init print_no4lvl(char *p)
780 {
781 	pr_info("Disabled 4-level and 5-level paging");
782 	return 0;
783 }
784 early_param("no4lvl", print_no4lvl);
785 
print_no5lvl(char * p)786 static int __init print_no5lvl(char *p)
787 {
788 	pr_info("Disabled 5-level paging");
789 	return 0;
790 }
791 early_param("no5lvl", print_no5lvl);
792 
set_mmap_rnd_bits_max(void)793 static void __init set_mmap_rnd_bits_max(void)
794 {
795 	mmap_rnd_bits_max = MMAP_VA_BITS - PAGE_SHIFT - 3;
796 }
797 
798 /*
799  * There is a simple way to determine if 4-level is supported by the
800  * underlying hardware: establish 1:1 mapping in 4-level page table mode
801  * then read SATP to see if the configuration was taken into account
802  * meaning sv48 is supported.
803  */
set_satp_mode(uintptr_t dtb_pa)804 static __init void set_satp_mode(uintptr_t dtb_pa)
805 {
806 	u64 identity_satp, hw_satp;
807 	uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
808 	u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa);
809 
810 	if (satp_mode_cmdline == SATP_MODE_57) {
811 		disable_pgtable_l5();
812 	} else if (satp_mode_cmdline == SATP_MODE_48) {
813 		disable_pgtable_l5();
814 		disable_pgtable_l4();
815 		return;
816 	}
817 
818 	create_p4d_mapping(early_p4d,
819 			set_satp_mode_pmd, (uintptr_t)early_pud,
820 			P4D_SIZE, PAGE_TABLE);
821 	create_pud_mapping(early_pud,
822 			   set_satp_mode_pmd, (uintptr_t)early_pmd,
823 			   PUD_SIZE, PAGE_TABLE);
824 	/* Handle the case where set_satp_mode straddles 2 PMDs */
825 	create_pmd_mapping(early_pmd,
826 			   set_satp_mode_pmd, set_satp_mode_pmd,
827 			   PMD_SIZE, PAGE_KERNEL_EXEC);
828 	create_pmd_mapping(early_pmd,
829 			   set_satp_mode_pmd + PMD_SIZE,
830 			   set_satp_mode_pmd + PMD_SIZE,
831 			   PMD_SIZE, PAGE_KERNEL_EXEC);
832 retry:
833 	create_pgd_mapping(early_pg_dir,
834 			   set_satp_mode_pmd,
835 			   pgtable_l5_enabled ?
836 				(uintptr_t)early_p4d : (uintptr_t)early_pud,
837 			   PGDIR_SIZE, PAGE_TABLE);
838 
839 	identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
840 
841 	local_flush_tlb_all();
842 	csr_write(CSR_SATP, identity_satp);
843 	hw_satp = csr_swap(CSR_SATP, 0ULL);
844 	local_flush_tlb_all();
845 
846 	if (hw_satp != identity_satp) {
847 		if (pgtable_l5_enabled) {
848 			disable_pgtable_l5();
849 			memset(early_pg_dir, 0, PAGE_SIZE);
850 			goto retry;
851 		}
852 		disable_pgtable_l4();
853 	}
854 
855 	memset(early_pg_dir, 0, PAGE_SIZE);
856 	memset(early_p4d, 0, PAGE_SIZE);
857 	memset(early_pud, 0, PAGE_SIZE);
858 	memset(early_pmd, 0, PAGE_SIZE);
859 }
860 #endif
861 
862 /*
863  * setup_vm() is called from head.S with MMU-off.
864  *
865  * Following requirements should be honoured for setup_vm() to work
866  * correctly:
867  * 1) It should use PC-relative addressing for accessing kernel symbols.
868  *    To achieve this we always use GCC cmodel=medany.
869  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
870  *    so disable compiler instrumentation when FTRACE is enabled.
871  *
872  * Currently, the above requirements are honoured by using custom CFLAGS
873  * for init.o in mm/Makefile.
874  */
875 
876 #ifndef __riscv_cmodel_medany
877 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
878 #endif
879 
880 #ifdef CONFIG_RELOCATABLE
881 extern unsigned long __rela_dyn_start, __rela_dyn_end;
882 
relocate_kernel(void)883 static void __init relocate_kernel(void)
884 {
885 	Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start;
886 	/*
887 	 * This holds the offset between the linked virtual address and the
888 	 * relocated virtual address.
889 	 */
890 	uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
891 	/*
892 	 * This holds the offset between kernel linked virtual address and
893 	 * physical address.
894 	 */
895 	uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
896 
897 	for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) {
898 		Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
899 		Elf64_Addr relocated_addr = rela->r_addend;
900 
901 		if (rela->r_info != R_RISCV_RELATIVE)
902 			continue;
903 
904 		/*
905 		 * Make sure to not relocate vdso symbols like rt_sigreturn
906 		 * which are linked from the address 0 in vmlinux since
907 		 * vdso symbol addresses are actually used as an offset from
908 		 * mm->context.vdso in VDSO_OFFSET macro.
909 		 */
910 		if (relocated_addr >= KERNEL_LINK_ADDR)
911 			relocated_addr += reloc_offset;
912 
913 		*(Elf64_Addr *)addr = relocated_addr;
914 	}
915 }
916 #endif /* CONFIG_RELOCATABLE */
917 
918 #ifdef CONFIG_XIP_KERNEL
create_kernel_page_table(pgd_t * pgdir,__always_unused bool early)919 static void __init create_kernel_page_table(pgd_t *pgdir,
920 					    __always_unused bool early)
921 {
922 	uintptr_t va, start_va, end_va;
923 
924 	/* Map the flash resident part */
925 	end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
926 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
927 		create_pgd_mapping(pgdir, va,
928 				   kernel_map.xiprom + (va - kernel_map.virt_addr),
929 				   PMD_SIZE, PAGE_KERNEL_EXEC);
930 
931 	/* Map the data in RAM */
932 	start_va = kernel_map.virt_addr + (uintptr_t)&_sdata - (uintptr_t)&_start;
933 	end_va = kernel_map.virt_addr + kernel_map.size;
934 	for (va = start_va; va < end_va; va += PMD_SIZE)
935 		create_pgd_mapping(pgdir, va,
936 				   kernel_map.phys_addr + (va - start_va),
937 				   PMD_SIZE, PAGE_KERNEL);
938 }
939 #else
create_kernel_page_table(pgd_t * pgdir,bool early)940 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
941 {
942 	uintptr_t va, end_va;
943 
944 	end_va = kernel_map.virt_addr + kernel_map.size;
945 	for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
946 		create_pgd_mapping(pgdir, va,
947 				   kernel_map.phys_addr + (va - kernel_map.virt_addr),
948 				   PMD_SIZE,
949 				   early ?
950 					PAGE_KERNEL_EXEC : pgprot_from_va(va));
951 }
952 #endif
953 
954 /*
955  * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
956  * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
957  * entry.
958  */
create_fdt_early_page_table(uintptr_t fix_fdt_va,uintptr_t dtb_pa)959 static void __init create_fdt_early_page_table(uintptr_t fix_fdt_va,
960 					       uintptr_t dtb_pa)
961 {
962 #ifndef CONFIG_BUILTIN_DTB
963 	uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
964 
965 	/* Make sure the fdt fixmap address is always aligned on PMD size */
966 	BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE));
967 
968 	/* In 32-bit only, the fdt lies in its own PGD */
969 	if (!IS_ENABLED(CONFIG_64BIT)) {
970 		create_pgd_mapping(early_pg_dir, fix_fdt_va,
971 				   pa, MAX_FDT_SIZE, PAGE_KERNEL);
972 	} else {
973 		create_pmd_mapping(fixmap_pmd, fix_fdt_va,
974 				   pa, PMD_SIZE, PAGE_KERNEL);
975 		create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE,
976 				   pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
977 	}
978 
979 	dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1));
980 #else
981 	/*
982 	 * For 64-bit kernel, __va can't be used since it would return a linear
983 	 * mapping address whereas dtb_early_va will be used before
984 	 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
985 	 * kernel is mapped in the linear mapping, that makes no difference.
986 	 */
987 	dtb_early_va = kernel_mapping_pa_to_va(dtb_pa);
988 #endif
989 
990 	dtb_early_pa = dtb_pa;
991 }
992 
993 /*
994  * MMU is not enabled, the page tables are allocated directly using
995  * early_pmd/pud/p4d and the address returned is the physical one.
996  */
pt_ops_set_early(void)997 static void __init pt_ops_set_early(void)
998 {
999 	pt_ops.alloc_pte = alloc_pte_early;
1000 	pt_ops.get_pte_virt = get_pte_virt_early;
1001 #ifndef __PAGETABLE_PMD_FOLDED
1002 	pt_ops.alloc_pmd = alloc_pmd_early;
1003 	pt_ops.get_pmd_virt = get_pmd_virt_early;
1004 	pt_ops.alloc_pud = alloc_pud_early;
1005 	pt_ops.get_pud_virt = get_pud_virt_early;
1006 	pt_ops.alloc_p4d = alloc_p4d_early;
1007 	pt_ops.get_p4d_virt = get_p4d_virt_early;
1008 #endif
1009 }
1010 
1011 /*
1012  * MMU is enabled but page table setup is not complete yet.
1013  * fixmap page table alloc functions must be used as a means to temporarily
1014  * map the allocated physical pages since the linear mapping does not exist yet.
1015  *
1016  * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va,
1017  * but it will be used as described above.
1018  */
pt_ops_set_fixmap(void)1019 static void __init pt_ops_set_fixmap(void)
1020 {
1021 	pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap);
1022 	pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap);
1023 #ifndef __PAGETABLE_PMD_FOLDED
1024 	pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap);
1025 	pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap);
1026 	pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap);
1027 	pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap);
1028 	pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap);
1029 	pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap);
1030 #endif
1031 }
1032 
1033 /*
1034  * MMU is enabled and page table setup is complete, so from now, we can use
1035  * generic page allocation functions to setup page table.
1036  */
pt_ops_set_late(void)1037 static void __init pt_ops_set_late(void)
1038 {
1039 	pt_ops.alloc_pte = alloc_pte_late;
1040 	pt_ops.get_pte_virt = get_pte_virt_late;
1041 #ifndef __PAGETABLE_PMD_FOLDED
1042 	pt_ops.alloc_pmd = alloc_pmd_late;
1043 	pt_ops.get_pmd_virt = get_pmd_virt_late;
1044 	pt_ops.alloc_pud = alloc_pud_late;
1045 	pt_ops.get_pud_virt = get_pud_virt_late;
1046 	pt_ops.alloc_p4d = alloc_p4d_late;
1047 	pt_ops.get_p4d_virt = get_p4d_virt_late;
1048 #endif
1049 }
1050 
1051 #ifdef CONFIG_RANDOMIZE_BASE
1052 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa);
1053 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa);
1054 extern u64 __init __pi_get_kaslr_seed_zkr(const uintptr_t dtb_pa);
1055 
print_nokaslr(char * p)1056 static int __init print_nokaslr(char *p)
1057 {
1058 	pr_info("Disabled KASLR");
1059 	return 0;
1060 }
1061 early_param("nokaslr", print_nokaslr);
1062 
kaslr_offset(void)1063 unsigned long kaslr_offset(void)
1064 {
1065 	return kernel_map.virt_offset;
1066 }
1067 #endif
1068 
setup_vm(uintptr_t dtb_pa)1069 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1070 {
1071 	pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
1072 
1073 #ifdef CONFIG_RANDOMIZE_BASE
1074 	if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) {
1075 		u64 kaslr_seed = __pi_get_kaslr_seed_zkr(dtb_pa);
1076 		u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1077 		u32 nr_pos;
1078 
1079 		if (kaslr_seed == 0)
1080 			kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
1081 		/*
1082 		 * Compute the number of positions available: we are limited
1083 		 * by the early page table that only has one PUD and we must
1084 		 * be aligned on PMD_SIZE.
1085 		 */
1086 		nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE;
1087 
1088 		kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE;
1089 	}
1090 #endif
1091 
1092 	kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset;
1093 
1094 #ifdef CONFIG_XIP_KERNEL
1095 #ifdef CONFIG_64BIT
1096 	kernel_map.page_offset = PAGE_OFFSET_L3;
1097 #else
1098 	kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
1099 #endif
1100 	kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
1101 	kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
1102 
1103 	phys_ram_base = CONFIG_PHYS_RAM_BASE;
1104 	kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
1105 	kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1106 
1107 	kernel_map.va_kernel_xip_text_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
1108 	kernel_map.va_kernel_xip_data_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr
1109 						+ (uintptr_t)&_sdata - (uintptr_t)&_start;
1110 #else
1111 	kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
1112 	kernel_map.phys_addr = (uintptr_t)(&_start);
1113 	kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
1114 	kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
1115 #endif
1116 
1117 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
1118 	set_satp_mode(dtb_pa);
1119 	set_mmap_rnd_bits_max();
1120 #endif
1121 
1122 	/*
1123 	 * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem,
1124 	 * where we have the system memory layout: this allows us to align
1125 	 * the physical and virtual mappings and then make use of PUD/P4D/PGD
1126 	 * for the linear mapping. This is only possible because the kernel
1127 	 * mapping lies outside the linear mapping.
1128 	 * In 32-bit however, as the kernel resides in the linear mapping,
1129 	 * setup_vm_final can not change the mapping established here,
1130 	 * otherwise the same kernel addresses would get mapped to different
1131 	 * physical addresses (if the start of dram is different from the
1132 	 * kernel physical address start).
1133 	 */
1134 	kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ?
1135 				0UL : PAGE_OFFSET - kernel_map.phys_addr;
1136 
1137 	memory_limit = KERN_VIRT_SIZE;
1138 
1139 	/* Sanity check alignment and size */
1140 	BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
1141 	BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);
1142 
1143 #ifdef CONFIG_64BIT
1144 	/*
1145 	 * The last 4K bytes of the addressable memory can not be mapped because
1146 	 * of IS_ERR_VALUE macro.
1147 	 */
1148 	BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
1149 #endif
1150 
1151 #ifdef CONFIG_RELOCATABLE
1152 	/*
1153 	 * Early page table uses only one PUD, which makes it possible
1154 	 * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset
1155 	 * makes the kernel cross over a PUD_SIZE boundary, raise a bug
1156 	 * since a part of the kernel would not get mapped.
1157 	 */
1158 	BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size);
1159 	relocate_kernel();
1160 #endif
1161 
1162 	apply_early_boot_alternatives();
1163 	pt_ops_set_early();
1164 
1165 	/* Setup early PGD for fixmap */
1166 	create_pgd_mapping(early_pg_dir, FIXADDR_START,
1167 			   fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1168 
1169 #ifndef __PAGETABLE_PMD_FOLDED
1170 	/* Setup fixmap P4D and PUD */
1171 	if (pgtable_l5_enabled)
1172 		create_p4d_mapping(fixmap_p4d, FIXADDR_START,
1173 				   (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
1174 	/* Setup fixmap PUD and PMD */
1175 	if (pgtable_l4_enabled)
1176 		create_pud_mapping(fixmap_pud, FIXADDR_START,
1177 				   (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
1178 	create_pmd_mapping(fixmap_pmd, FIXADDR_START,
1179 			   (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
1180 	/* Setup trampoline PGD and PMD */
1181 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1182 			   trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1183 	if (pgtable_l5_enabled)
1184 		create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
1185 				   (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
1186 	if (pgtable_l4_enabled)
1187 		create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
1188 				   (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
1189 #ifdef CONFIG_XIP_KERNEL
1190 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1191 			   kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
1192 #else
1193 	create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1194 			   kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
1195 #endif
1196 #else
1197 	/* Setup trampoline PGD */
1198 	create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1199 			   kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
1200 #endif
1201 
1202 	/*
1203 	 * Setup early PGD covering entire kernel which will allow
1204 	 * us to reach paging_init(). We map all memory banks later
1205 	 * in setup_vm_final() below.
1206 	 */
1207 	create_kernel_page_table(early_pg_dir, true);
1208 
1209 	/* Setup early mapping for FDT early scan */
1210 	create_fdt_early_page_table(__fix_to_virt(FIX_FDT), dtb_pa);
1211 
1212 	/*
1213 	 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
1214 	 * range can not span multiple pmds.
1215 	 */
1216 	BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1217 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1218 
1219 #ifndef __PAGETABLE_PMD_FOLDED
1220 	/*
1221 	 * Early ioremap fixmap is already created as it lies within first 2MB
1222 	 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
1223 	 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
1224 	 * the user if not.
1225 	 */
1226 	fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
1227 	fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
1228 	if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
1229 		WARN_ON(1);
1230 		pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
1231 			pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
1232 		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1233 			fix_to_virt(FIX_BTMAP_BEGIN));
1234 		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
1235 			fix_to_virt(FIX_BTMAP_END));
1236 
1237 		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
1238 		pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
1239 	}
1240 #endif
1241 
1242 	pt_ops_set_fixmap();
1243 }
1244 
create_linear_mapping_range(phys_addr_t start,phys_addr_t end,uintptr_t fixed_map_size,const pgprot_t * pgprot)1245 static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end,
1246 						  uintptr_t fixed_map_size, const pgprot_t *pgprot)
1247 {
1248 	phys_addr_t pa;
1249 	uintptr_t va, map_size;
1250 
1251 	for (pa = start; pa < end; pa += map_size) {
1252 		va = (uintptr_t)__va(pa);
1253 		map_size = fixed_map_size ? fixed_map_size :
1254 					    best_map_size(pa, va, end - pa);
1255 
1256 		create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1257 				   pgprot ? *pgprot : pgprot_from_va(va));
1258 	}
1259 }
1260 
create_linear_mapping_page_table(void)1261 static void __init create_linear_mapping_page_table(void)
1262 {
1263 	phys_addr_t start, end;
1264 	phys_addr_t kfence_pool __maybe_unused;
1265 	u64 i;
1266 
1267 #ifdef CONFIG_STRICT_KERNEL_RWX
1268 	phys_addr_t ktext_start = __pa_symbol(_start);
1269 	phys_addr_t ktext_size = __init_data_begin - _start;
1270 	phys_addr_t krodata_start = __pa_symbol(__start_rodata);
1271 	phys_addr_t krodata_size = _data - __start_rodata;
1272 
1273 	/* Isolate kernel text and rodata so they don't get mapped with a PUD */
1274 	memblock_mark_nomap(ktext_start,  ktext_size);
1275 	memblock_mark_nomap(krodata_start, krodata_size);
1276 #endif
1277 
1278 #ifdef CONFIG_KFENCE
1279 	/*
1280 	 *  kfence pool must be backed by PAGE_SIZE mappings, so allocate it
1281 	 *  before we setup the linear mapping so that we avoid using hugepages
1282 	 *  for this region.
1283 	 */
1284 	kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
1285 	BUG_ON(!kfence_pool);
1286 
1287 	memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE);
1288 	__kfence_pool = __va(kfence_pool);
1289 #endif
1290 
1291 	/* Map all memory banks in the linear mapping */
1292 	for_each_mem_range(i, &start, &end) {
1293 		if (start >= end)
1294 			break;
1295 		if (start <= __pa(PAGE_OFFSET) &&
1296 		    __pa(PAGE_OFFSET) < end)
1297 			start = __pa(PAGE_OFFSET);
1298 
1299 		create_linear_mapping_range(start, end, 0, NULL);
1300 	}
1301 
1302 #ifdef CONFIG_STRICT_KERNEL_RWX
1303 	create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0, NULL);
1304 	create_linear_mapping_range(krodata_start, krodata_start + krodata_size, 0, NULL);
1305 
1306 	memblock_clear_nomap(ktext_start,  ktext_size);
1307 	memblock_clear_nomap(krodata_start, krodata_size);
1308 #endif
1309 
1310 #ifdef CONFIG_KFENCE
1311 	create_linear_mapping_range(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, PAGE_SIZE, NULL);
1312 
1313 	memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
1314 #endif
1315 }
1316 
setup_vm_final(void)1317 static void __init setup_vm_final(void)
1318 {
1319 	/* Setup swapper PGD for fixmap */
1320 #if !defined(CONFIG_64BIT)
1321 	/*
1322 	 * In 32-bit, the device tree lies in a pgd entry, so it must be copied
1323 	 * directly in swapper_pg_dir in addition to the pgd entry that points
1324 	 * to fixmap_pte.
1325 	 */
1326 	unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT));
1327 
1328 	set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]);
1329 #endif
1330 	create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
1331 			   __pa_symbol(fixmap_pgd_next),
1332 			   PGDIR_SIZE, PAGE_TABLE);
1333 
1334 	/* Map the linear mapping */
1335 	create_linear_mapping_page_table();
1336 
1337 	/* Map the kernel */
1338 	if (IS_ENABLED(CONFIG_64BIT))
1339 		create_kernel_page_table(swapper_pg_dir, false);
1340 
1341 #ifdef CONFIG_KASAN
1342 	kasan_swapper_init();
1343 #endif
1344 
1345 	/* Clear fixmap PTE and PMD mappings */
1346 	clear_fixmap(FIX_PTE);
1347 	clear_fixmap(FIX_PMD);
1348 	clear_fixmap(FIX_PUD);
1349 	clear_fixmap(FIX_P4D);
1350 
1351 	/* Move to swapper page table */
1352 	csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode);
1353 	local_flush_tlb_all();
1354 
1355 	pt_ops_set_late();
1356 }
1357 #else
setup_vm(uintptr_t dtb_pa)1358 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1359 {
1360 	dtb_early_va = (void *)dtb_pa;
1361 	dtb_early_pa = dtb_pa;
1362 }
1363 
setup_vm_final(void)1364 static inline void setup_vm_final(void)
1365 {
1366 }
1367 #endif /* CONFIG_MMU */
1368 
1369 /*
1370  * reserve_crashkernel() - reserves memory for crash kernel
1371  *
1372  * This function reserves memory area given in "crashkernel=" kernel command
1373  * line parameter. The memory reserved is used by dump capture kernel when
1374  * primary kernel is crashing.
1375  */
arch_reserve_crashkernel(void)1376 static void __init arch_reserve_crashkernel(void)
1377 {
1378 	unsigned long long low_size = 0;
1379 	unsigned long long crash_base, crash_size;
1380 	char *cmdline = boot_command_line;
1381 	bool high = false;
1382 	int ret;
1383 
1384 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
1385 		return;
1386 
1387 	ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
1388 				&crash_size, &crash_base,
1389 				&low_size, &high);
1390 	if (ret)
1391 		return;
1392 
1393 	reserve_crashkernel_generic(cmdline, crash_size, crash_base,
1394 				    low_size, high);
1395 }
1396 
paging_init(void)1397 void __init paging_init(void)
1398 {
1399 	setup_bootmem();
1400 	setup_vm_final();
1401 
1402 	/* Depend on that Linear Mapping is ready */
1403 	memblock_allow_resize();
1404 }
1405 
misc_mem_init(void)1406 void __init misc_mem_init(void)
1407 {
1408 	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
1409 	arch_numa_init();
1410 	sparse_init();
1411 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1412 	/* The entire VMEMMAP region has been populated. Flush TLB for this region */
1413 	local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END);
1414 #endif
1415 	zone_sizes_init();
1416 	arch_reserve_crashkernel();
1417 	memblock_dump_all();
1418 }
1419 
1420 #ifdef CONFIG_SPARSEMEM_VMEMMAP
vmemmap_set_pmd(pmd_t * pmd,void * p,int node,unsigned long addr,unsigned long next)1421 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node,
1422 			       unsigned long addr, unsigned long next)
1423 {
1424 	pmd_set_huge(pmd, virt_to_phys(p), PAGE_KERNEL);
1425 }
1426 
vmemmap_check_pmd(pmd_t * pmdp,int node,unsigned long addr,unsigned long next)1427 int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node,
1428 				unsigned long addr, unsigned long next)
1429 {
1430 	vmemmap_verify((pte_t *)pmdp, node, addr, next);
1431 	return 1;
1432 }
1433 
vmemmap_populate(unsigned long start,unsigned long end,int node,struct vmem_altmap * altmap)1434 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1435 			       struct vmem_altmap *altmap)
1436 {
1437 	/*
1438 	 * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we
1439 	 * can't use hugepage mappings for 2-level page table because in case of
1440 	 * memory hotplug, we are not able to update all the page tables with
1441 	 * the new PMDs.
1442 	 */
1443 	return vmemmap_populate_hugepages(start, end, node, altmap);
1444 }
1445 #endif
1446 
1447 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
1448 /*
1449  * Pre-allocates page-table pages for a specific area in the kernel
1450  * page-table. Only the level which needs to be synchronized between
1451  * all page-tables is allocated because the synchronization can be
1452  * expensive.
1453  */
preallocate_pgd_pages_range(unsigned long start,unsigned long end,const char * area)1454 static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end,
1455 					       const char *area)
1456 {
1457 	unsigned long addr;
1458 	const char *lvl;
1459 
1460 	for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1461 		pgd_t *pgd = pgd_offset_k(addr);
1462 		p4d_t *p4d;
1463 		pud_t *pud;
1464 		pmd_t *pmd;
1465 
1466 		lvl = "p4d";
1467 		p4d = p4d_alloc(&init_mm, pgd, addr);
1468 		if (!p4d)
1469 			goto failed;
1470 
1471 		if (pgtable_l5_enabled)
1472 			continue;
1473 
1474 		lvl = "pud";
1475 		pud = pud_alloc(&init_mm, p4d, addr);
1476 		if (!pud)
1477 			goto failed;
1478 
1479 		if (pgtable_l4_enabled)
1480 			continue;
1481 
1482 		lvl = "pmd";
1483 		pmd = pmd_alloc(&init_mm, pud, addr);
1484 		if (!pmd)
1485 			goto failed;
1486 	}
1487 	return;
1488 
1489 failed:
1490 	/*
1491 	 * The pages have to be there now or they will be missing in
1492 	 * process page-tables later.
1493 	 */
1494 	panic("Failed to pre-allocate %s pages for %s area\n", lvl, area);
1495 }
1496 
1497 #define PAGE_END KASAN_SHADOW_START
1498 
pgtable_cache_init(void)1499 void __init pgtable_cache_init(void)
1500 {
1501 	preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc");
1502 	if (IS_ENABLED(CONFIG_MODULES))
1503 		preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules");
1504 	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) {
1505 		preallocate_pgd_pages_range(VMEMMAP_START, VMEMMAP_END, "vmemmap");
1506 		preallocate_pgd_pages_range(PAGE_OFFSET, PAGE_END, "direct map");
1507 		if (IS_ENABLED(CONFIG_KASAN))
1508 			preallocate_pgd_pages_range(KASAN_SHADOW_START, KASAN_SHADOW_END, "kasan");
1509 	}
1510 }
1511 #endif
1512 
1513 #ifdef CONFIG_EXECMEM
1514 #ifdef CONFIG_MMU
1515 static struct execmem_info execmem_info __ro_after_init;
1516 
execmem_arch_setup(void)1517 struct execmem_info __init *execmem_arch_setup(void)
1518 {
1519 	execmem_info = (struct execmem_info){
1520 		.ranges = {
1521 			[EXECMEM_DEFAULT] = {
1522 				.start	= MODULES_VADDR,
1523 				.end	= MODULES_END,
1524 				.pgprot	= PAGE_KERNEL,
1525 				.alignment = 1,
1526 			},
1527 			[EXECMEM_KPROBES] = {
1528 				.start	= VMALLOC_START,
1529 				.end	= VMALLOC_END,
1530 				.pgprot	= PAGE_KERNEL_READ_EXEC,
1531 				.alignment = 1,
1532 			},
1533 			[EXECMEM_BPF] = {
1534 				.start	= BPF_JIT_REGION_START,
1535 				.end	= BPF_JIT_REGION_END,
1536 				.pgprot	= PAGE_KERNEL,
1537 				.alignment = PAGE_SIZE,
1538 			},
1539 		},
1540 	};
1541 
1542 	return &execmem_info;
1543 }
1544 #endif /* CONFIG_MMU */
1545 #endif /* CONFIG_EXECMEM */
1546 
1547 #ifdef CONFIG_MEMORY_HOTPLUG
free_pte_table(pte_t * pte_start,pmd_t * pmd)1548 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)
1549 {
1550 	struct page *page = pmd_page(*pmd);
1551 	struct ptdesc *ptdesc = page_ptdesc(page);
1552 	pte_t *pte;
1553 	int i;
1554 
1555 	for (i = 0; i < PTRS_PER_PTE; i++) {
1556 		pte = pte_start + i;
1557 		if (!pte_none(*pte))
1558 			return;
1559 	}
1560 
1561 	pagetable_pte_dtor(ptdesc);
1562 	if (PageReserved(page))
1563 		free_reserved_page(page);
1564 	else
1565 		pagetable_free(ptdesc);
1566 	pmd_clear(pmd);
1567 }
1568 
free_pmd_table(pmd_t * pmd_start,pud_t * pud)1569 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud)
1570 {
1571 	struct page *page = pud_page(*pud);
1572 	struct ptdesc *ptdesc = page_ptdesc(page);
1573 	pmd_t *pmd;
1574 	int i;
1575 
1576 	for (i = 0; i < PTRS_PER_PMD; i++) {
1577 		pmd = pmd_start + i;
1578 		if (!pmd_none(*pmd))
1579 			return;
1580 	}
1581 
1582 	pagetable_pmd_dtor(ptdesc);
1583 	if (PageReserved(page))
1584 		free_reserved_page(page);
1585 	else
1586 		pagetable_free(ptdesc);
1587 	pud_clear(pud);
1588 }
1589 
free_pud_table(pud_t * pud_start,p4d_t * p4d)1590 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
1591 {
1592 	struct page *page = p4d_page(*p4d);
1593 	pud_t *pud;
1594 	int i;
1595 
1596 	for (i = 0; i < PTRS_PER_PUD; i++) {
1597 		pud = pud_start + i;
1598 		if (!pud_none(*pud))
1599 			return;
1600 	}
1601 
1602 	if (PageReserved(page))
1603 		free_reserved_page(page);
1604 	else
1605 		free_pages((unsigned long)page_address(page), 0);
1606 	p4d_clear(p4d);
1607 }
1608 
free_vmemmap_storage(struct page * page,size_t size,struct vmem_altmap * altmap)1609 static void __meminit free_vmemmap_storage(struct page *page, size_t size,
1610 					   struct vmem_altmap *altmap)
1611 {
1612 	int order = get_order(size);
1613 
1614 	if (altmap) {
1615 		vmem_altmap_free(altmap, size >> PAGE_SHIFT);
1616 		return;
1617 	}
1618 
1619 	if (PageReserved(page)) {
1620 		unsigned int nr_pages = 1 << order;
1621 
1622 		while (nr_pages--)
1623 			free_reserved_page(page++);
1624 		return;
1625 	}
1626 
1627 	free_pages((unsigned long)page_address(page), order);
1628 }
1629 
remove_pte_mapping(pte_t * pte_base,unsigned long addr,unsigned long end,bool is_vmemmap,struct vmem_altmap * altmap)1630 static void __meminit remove_pte_mapping(pte_t *pte_base, unsigned long addr, unsigned long end,
1631 					 bool is_vmemmap, struct vmem_altmap *altmap)
1632 {
1633 	unsigned long next;
1634 	pte_t *ptep, pte;
1635 
1636 	for (; addr < end; addr = next) {
1637 		next = (addr + PAGE_SIZE) & PAGE_MASK;
1638 		if (next > end)
1639 			next = end;
1640 
1641 		ptep = pte_base + pte_index(addr);
1642 		pte = ptep_get(ptep);
1643 		if (!pte_present(*ptep))
1644 			continue;
1645 
1646 		pte_clear(&init_mm, addr, ptep);
1647 		if (is_vmemmap)
1648 			free_vmemmap_storage(pte_page(pte), PAGE_SIZE, altmap);
1649 	}
1650 }
1651 
remove_pmd_mapping(pmd_t * pmd_base,unsigned long addr,unsigned long end,bool is_vmemmap,struct vmem_altmap * altmap)1652 static void __meminit remove_pmd_mapping(pmd_t *pmd_base, unsigned long addr, unsigned long end,
1653 					 bool is_vmemmap, struct vmem_altmap *altmap)
1654 {
1655 	unsigned long next;
1656 	pte_t *pte_base;
1657 	pmd_t *pmdp, pmd;
1658 
1659 	for (; addr < end; addr = next) {
1660 		next = pmd_addr_end(addr, end);
1661 		pmdp = pmd_base + pmd_index(addr);
1662 		pmd = pmdp_get(pmdp);
1663 		if (!pmd_present(pmd))
1664 			continue;
1665 
1666 		if (pmd_leaf(pmd)) {
1667 			pmd_clear(pmdp);
1668 			if (is_vmemmap)
1669 				free_vmemmap_storage(pmd_page(pmd), PMD_SIZE, altmap);
1670 			continue;
1671 		}
1672 
1673 		pte_base = (pte_t *)pmd_page_vaddr(*pmdp);
1674 		remove_pte_mapping(pte_base, addr, next, is_vmemmap, altmap);
1675 		free_pte_table(pte_base, pmdp);
1676 	}
1677 }
1678 
remove_pud_mapping(pud_t * pud_base,unsigned long addr,unsigned long end,bool is_vmemmap,struct vmem_altmap * altmap)1679 static void __meminit remove_pud_mapping(pud_t *pud_base, unsigned long addr, unsigned long end,
1680 					 bool is_vmemmap, struct vmem_altmap *altmap)
1681 {
1682 	unsigned long next;
1683 	pud_t *pudp, pud;
1684 	pmd_t *pmd_base;
1685 
1686 	for (; addr < end; addr = next) {
1687 		next = pud_addr_end(addr, end);
1688 		pudp = pud_base + pud_index(addr);
1689 		pud = pudp_get(pudp);
1690 		if (!pud_present(pud))
1691 			continue;
1692 
1693 		if (pud_leaf(pud)) {
1694 			if (pgtable_l4_enabled) {
1695 				pud_clear(pudp);
1696 				if (is_vmemmap)
1697 					free_vmemmap_storage(pud_page(pud), PUD_SIZE, altmap);
1698 			}
1699 			continue;
1700 		}
1701 
1702 		pmd_base = pmd_offset(pudp, 0);
1703 		remove_pmd_mapping(pmd_base, addr, next, is_vmemmap, altmap);
1704 
1705 		if (pgtable_l4_enabled)
1706 			free_pmd_table(pmd_base, pudp);
1707 	}
1708 }
1709 
remove_p4d_mapping(p4d_t * p4d_base,unsigned long addr,unsigned long end,bool is_vmemmap,struct vmem_altmap * altmap)1710 static void __meminit remove_p4d_mapping(p4d_t *p4d_base, unsigned long addr, unsigned long end,
1711 					 bool is_vmemmap, struct vmem_altmap *altmap)
1712 {
1713 	unsigned long next;
1714 	p4d_t *p4dp, p4d;
1715 	pud_t *pud_base;
1716 
1717 	for (; addr < end; addr = next) {
1718 		next = p4d_addr_end(addr, end);
1719 		p4dp = p4d_base + p4d_index(addr);
1720 		p4d = p4dp_get(p4dp);
1721 		if (!p4d_present(p4d))
1722 			continue;
1723 
1724 		if (p4d_leaf(p4d)) {
1725 			if (pgtable_l5_enabled) {
1726 				p4d_clear(p4dp);
1727 				if (is_vmemmap)
1728 					free_vmemmap_storage(p4d_page(p4d), P4D_SIZE, altmap);
1729 			}
1730 			continue;
1731 		}
1732 
1733 		pud_base = pud_offset(p4dp, 0);
1734 		remove_pud_mapping(pud_base, addr, next, is_vmemmap, altmap);
1735 
1736 		if (pgtable_l5_enabled)
1737 			free_pud_table(pud_base, p4dp);
1738 	}
1739 }
1740 
remove_pgd_mapping(unsigned long va,unsigned long end,bool is_vmemmap,struct vmem_altmap * altmap)1741 static void __meminit remove_pgd_mapping(unsigned long va, unsigned long end, bool is_vmemmap,
1742 					 struct vmem_altmap *altmap)
1743 {
1744 	unsigned long addr, next;
1745 	p4d_t *p4d_base;
1746 	pgd_t *pgd;
1747 
1748 	for (addr = va; addr < end; addr = next) {
1749 		next = pgd_addr_end(addr, end);
1750 		pgd = pgd_offset_k(addr);
1751 
1752 		if (!pgd_present(*pgd))
1753 			continue;
1754 
1755 		if (pgd_leaf(*pgd))
1756 			continue;
1757 
1758 		p4d_base = p4d_offset(pgd, 0);
1759 		remove_p4d_mapping(p4d_base, addr, next, is_vmemmap, altmap);
1760 	}
1761 
1762 	flush_tlb_all();
1763 }
1764 
remove_linear_mapping(phys_addr_t start,u64 size)1765 static void __meminit remove_linear_mapping(phys_addr_t start, u64 size)
1766 {
1767 	unsigned long va = (unsigned long)__va(start);
1768 	unsigned long end = (unsigned long)__va(start + size);
1769 
1770 	remove_pgd_mapping(va, end, false, NULL);
1771 }
1772 
arch_get_mappable_range(void)1773 struct range arch_get_mappable_range(void)
1774 {
1775 	struct range mhp_range;
1776 
1777 	mhp_range.start = __pa(PAGE_OFFSET);
1778 	mhp_range.end = __pa(PAGE_END - 1);
1779 	return mhp_range;
1780 }
1781 
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)1782 int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params)
1783 {
1784 	int ret = 0;
1785 
1786 	create_linear_mapping_range(start, start + size, 0, &params->pgprot);
1787 	ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, params);
1788 	if (ret) {
1789 		remove_linear_mapping(start, size);
1790 		goto out;
1791 	}
1792 
1793 	max_pfn = PFN_UP(start + size);
1794 	max_low_pfn = max_pfn;
1795 
1796  out:
1797 	flush_tlb_all();
1798 	return ret;
1799 }
1800 
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap)1801 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
1802 {
1803 	__remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap);
1804 	remove_linear_mapping(start, size);
1805 	flush_tlb_all();
1806 }
1807 
vmemmap_free(unsigned long start,unsigned long end,struct vmem_altmap * altmap)1808 void __ref vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap)
1809 {
1810 	remove_pgd_mapping(start, end, true, altmap);
1811 }
1812 #endif /* CONFIG_MEMORY_HOTPLUG */
1813