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
28 #include <asm/fixmap.h>
29 #include <asm/io.h>
30 #include <asm/numa.h>
31 #include <asm/pgtable.h>
32 #include <asm/ptdump.h>
33 #include <asm/sections.h>
34 #include <asm/soc.h>
35 #include <asm/tlbflush.h>
36
37 #include "../kernel/head.h"
38
39 struct kernel_mapping kernel_map __ro_after_init;
40 EXPORT_SYMBOL(kernel_map);
41 #ifdef CONFIG_XIP_KERNEL
42 #define kernel_map (*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
43 #endif
44
45 #ifdef CONFIG_64BIT
46 u64 satp_mode __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_57 : SATP_MODE_39;
47 #else
48 u64 satp_mode __ro_after_init = SATP_MODE_32;
49 #endif
50 EXPORT_SYMBOL(satp_mode);
51
52 bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
53 bool pgtable_l5_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
54 EXPORT_SYMBOL(pgtable_l4_enabled);
55 EXPORT_SYMBOL(pgtable_l5_enabled);
56
57 phys_addr_t phys_ram_base __ro_after_init;
58 EXPORT_SYMBOL(phys_ram_base);
59
60 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
61 __page_aligned_bss;
62 EXPORT_SYMBOL(empty_zero_page);
63
64 extern char _start[];
65 void *_dtb_early_va __initdata;
66 uintptr_t _dtb_early_pa __initdata;
67
68 static phys_addr_t dma32_phys_limit __initdata;
69
zone_sizes_init(void)70 static void __init zone_sizes_init(void)
71 {
72 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
73
74 #ifdef CONFIG_ZONE_DMA32
75 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
76 #endif
77 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
78
79 free_area_init(max_zone_pfns);
80 }
81
82 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
83
84 #define LOG2_SZ_1K ilog2(SZ_1K)
85 #define LOG2_SZ_1M ilog2(SZ_1M)
86 #define LOG2_SZ_1G ilog2(SZ_1G)
87 #define LOG2_SZ_1T ilog2(SZ_1T)
88
print_mlk(char * name,unsigned long b,unsigned long t)89 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
90 {
91 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld kB)\n", name, b, t,
92 (((t) - (b)) >> LOG2_SZ_1K));
93 }
94
print_mlm(char * name,unsigned long b,unsigned long t)95 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
96 {
97 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld MB)\n", name, b, t,
98 (((t) - (b)) >> LOG2_SZ_1M));
99 }
100
print_mlg(char * name,unsigned long b,unsigned long t)101 static inline void print_mlg(char *name, unsigned long b, unsigned long t)
102 {
103 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld GB)\n", name, b, t,
104 (((t) - (b)) >> LOG2_SZ_1G));
105 }
106
107 #ifdef CONFIG_64BIT
print_mlt(char * name,unsigned long b,unsigned long t)108 static inline void print_mlt(char *name, unsigned long b, unsigned long t)
109 {
110 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld TB)\n", name, b, t,
111 (((t) - (b)) >> LOG2_SZ_1T));
112 }
113 #else
114 #define print_mlt(n, b, t) do {} while (0)
115 #endif
116
print_ml(char * name,unsigned long b,unsigned long t)117 static inline void print_ml(char *name, unsigned long b, unsigned long t)
118 {
119 unsigned long diff = t - b;
120
121 if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10)
122 print_mlt(name, b, t);
123 else if ((diff >> LOG2_SZ_1G) >= 10)
124 print_mlg(name, b, t);
125 else if ((diff >> LOG2_SZ_1M) >= 10)
126 print_mlm(name, b, t);
127 else
128 print_mlk(name, b, t);
129 }
130
print_vm_layout(void)131 static void __init print_vm_layout(void)
132 {
133 pr_notice("Virtual kernel memory layout:\n");
134 print_ml("fixmap", (unsigned long)FIXADDR_START,
135 (unsigned long)FIXADDR_TOP);
136 print_ml("pci io", (unsigned long)PCI_IO_START,
137 (unsigned long)PCI_IO_END);
138 print_ml("vmemmap", (unsigned long)VMEMMAP_START,
139 (unsigned long)VMEMMAP_END);
140 print_ml("vmalloc", (unsigned long)VMALLOC_START,
141 (unsigned long)VMALLOC_END);
142 #ifdef CONFIG_64BIT
143 print_ml("modules", (unsigned long)MODULES_VADDR,
144 (unsigned long)MODULES_END);
145 #endif
146 print_ml("lowmem", (unsigned long)PAGE_OFFSET,
147 (unsigned long)high_memory);
148 if (IS_ENABLED(CONFIG_64BIT)) {
149 #ifdef CONFIG_KASAN
150 print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END);
151 #endif
152
153 print_ml("kernel", (unsigned long)kernel_map.virt_addr,
154 (unsigned long)ADDRESS_SPACE_END);
155 }
156 }
157 #else
print_vm_layout(void)158 static void print_vm_layout(void) { }
159 #endif /* CONFIG_DEBUG_VM */
160
mem_init(void)161 void __init mem_init(void)
162 {
163 #ifdef CONFIG_FLATMEM
164 BUG_ON(!mem_map);
165 #endif /* CONFIG_FLATMEM */
166
167 swiotlb_init(max_pfn > PFN_DOWN(dma32_phys_limit), SWIOTLB_VERBOSE);
168 memblock_free_all();
169
170 print_vm_layout();
171 }
172
173 /* Limit the memory size via mem. */
174 static phys_addr_t memory_limit;
175 #ifdef CONFIG_XIP_KERNEL
176 #define memory_limit (*(phys_addr_t *)XIP_FIXUP(&memory_limit))
177 #endif /* CONFIG_XIP_KERNEL */
178
early_mem(char * p)179 static int __init early_mem(char *p)
180 {
181 u64 size;
182
183 if (!p)
184 return 1;
185
186 size = memparse(p, &p) & PAGE_MASK;
187 memory_limit = min_t(u64, size, memory_limit);
188
189 pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
190
191 return 0;
192 }
193 early_param("mem", early_mem);
194
setup_bootmem(void)195 static void __init setup_bootmem(void)
196 {
197 phys_addr_t vmlinux_end = __pa_symbol(&_end);
198 phys_addr_t max_mapped_addr;
199 phys_addr_t phys_ram_end, vmlinux_start;
200
201 if (IS_ENABLED(CONFIG_XIP_KERNEL))
202 vmlinux_start = __pa_symbol(&_sdata);
203 else
204 vmlinux_start = __pa_symbol(&_start);
205
206 memblock_enforce_memory_limit(memory_limit);
207
208 /*
209 * Make sure we align the reservation on PMD_SIZE since we will
210 * map the kernel in the linear mapping as read-only: we do not want
211 * any allocation to happen between _end and the next pmd aligned page.
212 */
213 if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
214 vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
215 /*
216 * Reserve from the start of the kernel to the end of the kernel
217 */
218 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
219
220 phys_ram_end = memblock_end_of_DRAM();
221
222 /*
223 * Make sure we align the start of the memory on a PMD boundary so that
224 * at worst, we map the linear mapping with PMD mappings.
225 */
226 if (!IS_ENABLED(CONFIG_XIP_KERNEL))
227 phys_ram_base = memblock_start_of_DRAM() & PMD_MASK;
228
229 /*
230 * In 64-bit, any use of __va/__pa before this point is wrong as we
231 * did not know the start of DRAM before.
232 */
233 if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU))
234 kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base;
235
236 /*
237 * Reserve physical address space that would be mapped to virtual
238 * addresses greater than (void *)(-PAGE_SIZE) because:
239 * - This memory would overlap with ERR_PTR
240 * - This memory belongs to high memory, which is not supported
241 *
242 * This is not applicable to 64-bit kernel, because virtual addresses
243 * after (void *)(-PAGE_SIZE) are not linearly mapped: they are
244 * occupied by kernel mapping. Also it is unrealistic for high memory
245 * to exist on 64-bit platforms.
246 */
247 if (!IS_ENABLED(CONFIG_64BIT)) {
248 max_mapped_addr = __va_to_pa_nodebug(-PAGE_SIZE);
249 memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr);
250 }
251
252 min_low_pfn = PFN_UP(phys_ram_base);
253 max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
254 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
255
256 dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
257 set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
258
259 reserve_initrd_mem();
260
261 /*
262 * No allocation should be done before reserving the memory as defined
263 * in the device tree, otherwise the allocation could end up in a
264 * reserved region.
265 */
266 early_init_fdt_scan_reserved_mem();
267
268 /*
269 * If DTB is built in, no need to reserve its memblock.
270 * Otherwise, do reserve it but avoid using
271 * early_init_fdt_reserve_self() since __pa() does
272 * not work for DTB pointers that are fixmap addresses
273 */
274 if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
275 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
276
277 dma_contiguous_reserve(dma32_phys_limit);
278 if (IS_ENABLED(CONFIG_64BIT))
279 hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
280 }
281
282 #ifdef CONFIG_MMU
283 struct pt_alloc_ops pt_ops __initdata;
284
285 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
286 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
287 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
288
289 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
290
291 #ifdef CONFIG_XIP_KERNEL
292 #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops))
293 #define trampoline_pg_dir ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
294 #define fixmap_pte ((pte_t *)XIP_FIXUP(fixmap_pte))
295 #define early_pg_dir ((pgd_t *)XIP_FIXUP(early_pg_dir))
296 #endif /* CONFIG_XIP_KERNEL */
297
298 static const pgprot_t protection_map[16] = {
299 [VM_NONE] = PAGE_NONE,
300 [VM_READ] = PAGE_READ,
301 [VM_WRITE] = PAGE_COPY,
302 [VM_WRITE | VM_READ] = PAGE_COPY,
303 [VM_EXEC] = PAGE_EXEC,
304 [VM_EXEC | VM_READ] = PAGE_READ_EXEC,
305 [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC,
306 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC,
307 [VM_SHARED] = PAGE_NONE,
308 [VM_SHARED | VM_READ] = PAGE_READ,
309 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
310 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
311 [VM_SHARED | VM_EXEC] = PAGE_EXEC,
312 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READ_EXEC,
313 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC,
314 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC
315 };
316 DECLARE_VM_GET_PAGE_PROT
317
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t prot)318 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
319 {
320 unsigned long addr = __fix_to_virt(idx);
321 pte_t *ptep;
322
323 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
324
325 ptep = &fixmap_pte[pte_index(addr)];
326
327 if (pgprot_val(prot))
328 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
329 else
330 pte_clear(&init_mm, addr, ptep);
331 local_flush_tlb_page(addr);
332 }
333
get_pte_virt_early(phys_addr_t pa)334 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
335 {
336 return (pte_t *)((uintptr_t)pa);
337 }
338
get_pte_virt_fixmap(phys_addr_t pa)339 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
340 {
341 clear_fixmap(FIX_PTE);
342 return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
343 }
344
get_pte_virt_late(phys_addr_t pa)345 static inline pte_t *__init get_pte_virt_late(phys_addr_t pa)
346 {
347 return (pte_t *) __va(pa);
348 }
349
alloc_pte_early(uintptr_t va)350 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
351 {
352 /*
353 * We only create PMD or PGD early mappings so we
354 * should never reach here with MMU disabled.
355 */
356 BUG();
357 }
358
alloc_pte_fixmap(uintptr_t va)359 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
360 {
361 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
362 }
363
alloc_pte_late(uintptr_t va)364 static phys_addr_t __init alloc_pte_late(uintptr_t va)
365 {
366 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
367
368 BUG_ON(!ptdesc || !pagetable_pte_ctor(ptdesc));
369 return __pa((pte_t *)ptdesc_address(ptdesc));
370 }
371
create_pte_mapping(pte_t * ptep,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)372 static void __init create_pte_mapping(pte_t *ptep,
373 uintptr_t va, phys_addr_t pa,
374 phys_addr_t sz, pgprot_t prot)
375 {
376 uintptr_t pte_idx = pte_index(va);
377
378 BUG_ON(sz != PAGE_SIZE);
379
380 if (pte_none(ptep[pte_idx]))
381 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
382 }
383
384 #ifndef __PAGETABLE_PMD_FOLDED
385
386 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
387 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
388 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
389
390 #ifdef CONFIG_XIP_KERNEL
391 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
392 #define fixmap_pmd ((pmd_t *)XIP_FIXUP(fixmap_pmd))
393 #define early_pmd ((pmd_t *)XIP_FIXUP(early_pmd))
394 #endif /* CONFIG_XIP_KERNEL */
395
396 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss;
397 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss;
398 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
399
400 #ifdef CONFIG_XIP_KERNEL
401 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d))
402 #define fixmap_p4d ((p4d_t *)XIP_FIXUP(fixmap_p4d))
403 #define early_p4d ((p4d_t *)XIP_FIXUP(early_p4d))
404 #endif /* CONFIG_XIP_KERNEL */
405
406 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss;
407 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss;
408 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE);
409
410 #ifdef CONFIG_XIP_KERNEL
411 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud))
412 #define fixmap_pud ((pud_t *)XIP_FIXUP(fixmap_pud))
413 #define early_pud ((pud_t *)XIP_FIXUP(early_pud))
414 #endif /* CONFIG_XIP_KERNEL */
415
get_pmd_virt_early(phys_addr_t pa)416 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
417 {
418 /* Before MMU is enabled */
419 return (pmd_t *)((uintptr_t)pa);
420 }
421
get_pmd_virt_fixmap(phys_addr_t pa)422 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
423 {
424 clear_fixmap(FIX_PMD);
425 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
426 }
427
get_pmd_virt_late(phys_addr_t pa)428 static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)
429 {
430 return (pmd_t *) __va(pa);
431 }
432
alloc_pmd_early(uintptr_t va)433 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
434 {
435 BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT);
436
437 return (uintptr_t)early_pmd;
438 }
439
alloc_pmd_fixmap(uintptr_t va)440 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
441 {
442 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
443 }
444
alloc_pmd_late(uintptr_t va)445 static phys_addr_t __init alloc_pmd_late(uintptr_t va)
446 {
447 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
448
449 BUG_ON(!ptdesc || !pagetable_pmd_ctor(ptdesc));
450 return __pa((pmd_t *)ptdesc_address(ptdesc));
451 }
452
create_pmd_mapping(pmd_t * pmdp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)453 static void __init create_pmd_mapping(pmd_t *pmdp,
454 uintptr_t va, phys_addr_t pa,
455 phys_addr_t sz, pgprot_t prot)
456 {
457 pte_t *ptep;
458 phys_addr_t pte_phys;
459 uintptr_t pmd_idx = pmd_index(va);
460
461 if (sz == PMD_SIZE) {
462 if (pmd_none(pmdp[pmd_idx]))
463 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
464 return;
465 }
466
467 if (pmd_none(pmdp[pmd_idx])) {
468 pte_phys = pt_ops.alloc_pte(va);
469 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
470 ptep = pt_ops.get_pte_virt(pte_phys);
471 memset(ptep, 0, PAGE_SIZE);
472 } else {
473 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
474 ptep = pt_ops.get_pte_virt(pte_phys);
475 }
476
477 create_pte_mapping(ptep, va, pa, sz, prot);
478 }
479
get_pud_virt_early(phys_addr_t pa)480 static pud_t *__init get_pud_virt_early(phys_addr_t pa)
481 {
482 return (pud_t *)((uintptr_t)pa);
483 }
484
get_pud_virt_fixmap(phys_addr_t pa)485 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa)
486 {
487 clear_fixmap(FIX_PUD);
488 return (pud_t *)set_fixmap_offset(FIX_PUD, pa);
489 }
490
get_pud_virt_late(phys_addr_t pa)491 static pud_t *__init get_pud_virt_late(phys_addr_t pa)
492 {
493 return (pud_t *)__va(pa);
494 }
495
alloc_pud_early(uintptr_t va)496 static phys_addr_t __init alloc_pud_early(uintptr_t va)
497 {
498 /* Only one PUD is available for early mapping */
499 BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
500
501 return (uintptr_t)early_pud;
502 }
503
alloc_pud_fixmap(uintptr_t va)504 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va)
505 {
506 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
507 }
508
alloc_pud_late(uintptr_t va)509 static phys_addr_t alloc_pud_late(uintptr_t va)
510 {
511 unsigned long vaddr;
512
513 vaddr = __get_free_page(GFP_KERNEL);
514 BUG_ON(!vaddr);
515 return __pa(vaddr);
516 }
517
get_p4d_virt_early(phys_addr_t pa)518 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa)
519 {
520 return (p4d_t *)((uintptr_t)pa);
521 }
522
get_p4d_virt_fixmap(phys_addr_t pa)523 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa)
524 {
525 clear_fixmap(FIX_P4D);
526 return (p4d_t *)set_fixmap_offset(FIX_P4D, pa);
527 }
528
get_p4d_virt_late(phys_addr_t pa)529 static p4d_t *__init get_p4d_virt_late(phys_addr_t pa)
530 {
531 return (p4d_t *)__va(pa);
532 }
533
alloc_p4d_early(uintptr_t va)534 static phys_addr_t __init alloc_p4d_early(uintptr_t va)
535 {
536 /* Only one P4D is available for early mapping */
537 BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
538
539 return (uintptr_t)early_p4d;
540 }
541
alloc_p4d_fixmap(uintptr_t va)542 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va)
543 {
544 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
545 }
546
alloc_p4d_late(uintptr_t va)547 static phys_addr_t alloc_p4d_late(uintptr_t va)
548 {
549 unsigned long vaddr;
550
551 vaddr = __get_free_page(GFP_KERNEL);
552 BUG_ON(!vaddr);
553 return __pa(vaddr);
554 }
555
create_pud_mapping(pud_t * pudp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)556 static void __init create_pud_mapping(pud_t *pudp,
557 uintptr_t va, phys_addr_t pa,
558 phys_addr_t sz, pgprot_t prot)
559 {
560 pmd_t *nextp;
561 phys_addr_t next_phys;
562 uintptr_t pud_index = pud_index(va);
563
564 if (sz == PUD_SIZE) {
565 if (pud_val(pudp[pud_index]) == 0)
566 pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot);
567 return;
568 }
569
570 if (pud_val(pudp[pud_index]) == 0) {
571 next_phys = pt_ops.alloc_pmd(va);
572 pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE);
573 nextp = pt_ops.get_pmd_virt(next_phys);
574 memset(nextp, 0, PAGE_SIZE);
575 } else {
576 next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index]));
577 nextp = pt_ops.get_pmd_virt(next_phys);
578 }
579
580 create_pmd_mapping(nextp, va, pa, sz, prot);
581 }
582
create_p4d_mapping(p4d_t * p4dp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)583 static void __init create_p4d_mapping(p4d_t *p4dp,
584 uintptr_t va, phys_addr_t pa,
585 phys_addr_t sz, pgprot_t prot)
586 {
587 pud_t *nextp;
588 phys_addr_t next_phys;
589 uintptr_t p4d_index = p4d_index(va);
590
591 if (sz == P4D_SIZE) {
592 if (p4d_val(p4dp[p4d_index]) == 0)
593 p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot);
594 return;
595 }
596
597 if (p4d_val(p4dp[p4d_index]) == 0) {
598 next_phys = pt_ops.alloc_pud(va);
599 p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE);
600 nextp = pt_ops.get_pud_virt(next_phys);
601 memset(nextp, 0, PAGE_SIZE);
602 } else {
603 next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index]));
604 nextp = pt_ops.get_pud_virt(next_phys);
605 }
606
607 create_pud_mapping(nextp, va, pa, sz, prot);
608 }
609
610 #define pgd_next_t p4d_t
611 #define alloc_pgd_next(__va) (pgtable_l5_enabled ? \
612 pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ? \
613 pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
614 #define get_pgd_next_virt(__pa) (pgtable_l5_enabled ? \
615 pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ? \
616 pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
617 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
618 (pgtable_l5_enabled ? \
619 create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
620 (pgtable_l4_enabled ? \
621 create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) : \
622 create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
623 #define fixmap_pgd_next (pgtable_l5_enabled ? \
624 (uintptr_t)fixmap_p4d : (pgtable_l4_enabled ? \
625 (uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
626 #define trampoline_pgd_next (pgtable_l5_enabled ? \
627 (uintptr_t)trampoline_p4d : (pgtable_l4_enabled ? \
628 (uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
629 #else
630 #define pgd_next_t pte_t
631 #define alloc_pgd_next(__va) pt_ops.alloc_pte(__va)
632 #define get_pgd_next_virt(__pa) pt_ops.get_pte_virt(__pa)
633 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
634 create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
635 #define fixmap_pgd_next ((uintptr_t)fixmap_pte)
636 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
637 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
638 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0)
639 #endif /* __PAGETABLE_PMD_FOLDED */
640
create_pgd_mapping(pgd_t * pgdp,uintptr_t va,phys_addr_t pa,phys_addr_t sz,pgprot_t prot)641 void __init create_pgd_mapping(pgd_t *pgdp,
642 uintptr_t va, phys_addr_t pa,
643 phys_addr_t sz, pgprot_t prot)
644 {
645 pgd_next_t *nextp;
646 phys_addr_t next_phys;
647 uintptr_t pgd_idx = pgd_index(va);
648
649 if (sz == PGDIR_SIZE) {
650 if (pgd_val(pgdp[pgd_idx]) == 0)
651 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
652 return;
653 }
654
655 if (pgd_val(pgdp[pgd_idx]) == 0) {
656 next_phys = alloc_pgd_next(va);
657 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
658 nextp = get_pgd_next_virt(next_phys);
659 memset(nextp, 0, PAGE_SIZE);
660 } else {
661 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
662 nextp = get_pgd_next_virt(next_phys);
663 }
664
665 create_pgd_next_mapping(nextp, va, pa, sz, prot);
666 }
667
best_map_size(phys_addr_t pa,uintptr_t va,phys_addr_t size)668 static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va,
669 phys_addr_t size)
670 {
671 if (debug_pagealloc_enabled())
672 return PAGE_SIZE;
673
674 if (pgtable_l5_enabled &&
675 !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE)
676 return P4D_SIZE;
677
678 if (pgtable_l4_enabled &&
679 !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE)
680 return PUD_SIZE;
681
682 if (IS_ENABLED(CONFIG_64BIT) &&
683 !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE)
684 return PMD_SIZE;
685
686 return PAGE_SIZE;
687 }
688
689 #ifdef CONFIG_XIP_KERNEL
690 #define phys_ram_base (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base))
691 extern char _xiprom[], _exiprom[], __data_loc;
692
693 /* called from head.S with MMU off */
__copy_data(void)694 asmlinkage void __init __copy_data(void)
695 {
696 void *from = (void *)(&__data_loc);
697 void *to = (void *)CONFIG_PHYS_RAM_BASE;
698 size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata));
699
700 memcpy(to, from, sz);
701 }
702 #endif
703
704 #ifdef CONFIG_STRICT_KERNEL_RWX
pgprot_from_va(uintptr_t va)705 static __init pgprot_t pgprot_from_va(uintptr_t va)
706 {
707 if (is_va_kernel_text(va))
708 return PAGE_KERNEL_READ_EXEC;
709
710 /*
711 * In 64-bit kernel, the kernel mapping is outside the linear mapping so
712 * we must protect its linear mapping alias from being executed and
713 * written.
714 * And rodata section is marked readonly in mark_rodata_ro.
715 */
716 if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
717 return PAGE_KERNEL_READ;
718
719 return PAGE_KERNEL;
720 }
721
mark_rodata_ro(void)722 void mark_rodata_ro(void)
723 {
724 set_kernel_memory(__start_rodata, _data, set_memory_ro);
725 if (IS_ENABLED(CONFIG_64BIT))
726 set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
727 set_memory_ro);
728
729 debug_checkwx();
730 }
731 #else
pgprot_from_va(uintptr_t va)732 static __init pgprot_t pgprot_from_va(uintptr_t va)
733 {
734 if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
735 return PAGE_KERNEL;
736
737 return PAGE_KERNEL_EXEC;
738 }
739 #endif /* CONFIG_STRICT_KERNEL_RWX */
740
741 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
742 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa);
743
disable_pgtable_l5(void)744 static void __init disable_pgtable_l5(void)
745 {
746 pgtable_l5_enabled = false;
747 kernel_map.page_offset = PAGE_OFFSET_L4;
748 satp_mode = SATP_MODE_48;
749 }
750
disable_pgtable_l4(void)751 static void __init disable_pgtable_l4(void)
752 {
753 pgtable_l4_enabled = false;
754 kernel_map.page_offset = PAGE_OFFSET_L3;
755 satp_mode = SATP_MODE_39;
756 }
757
print_no4lvl(char * p)758 static int __init print_no4lvl(char *p)
759 {
760 pr_info("Disabled 4-level and 5-level paging");
761 return 0;
762 }
763 early_param("no4lvl", print_no4lvl);
764
print_no5lvl(char * p)765 static int __init print_no5lvl(char *p)
766 {
767 pr_info("Disabled 5-level paging");
768 return 0;
769 }
770 early_param("no5lvl", print_no5lvl);
771
772 /*
773 * There is a simple way to determine if 4-level is supported by the
774 * underlying hardware: establish 1:1 mapping in 4-level page table mode
775 * then read SATP to see if the configuration was taken into account
776 * meaning sv48 is supported.
777 */
set_satp_mode(uintptr_t dtb_pa)778 static __init void set_satp_mode(uintptr_t dtb_pa)
779 {
780 u64 identity_satp, hw_satp;
781 uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK;
782 u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa);
783
784 if (satp_mode_cmdline == SATP_MODE_57) {
785 disable_pgtable_l5();
786 } else if (satp_mode_cmdline == SATP_MODE_48) {
787 disable_pgtable_l5();
788 disable_pgtable_l4();
789 return;
790 }
791
792 create_p4d_mapping(early_p4d,
793 set_satp_mode_pmd, (uintptr_t)early_pud,
794 P4D_SIZE, PAGE_TABLE);
795 create_pud_mapping(early_pud,
796 set_satp_mode_pmd, (uintptr_t)early_pmd,
797 PUD_SIZE, PAGE_TABLE);
798 /* Handle the case where set_satp_mode straddles 2 PMDs */
799 create_pmd_mapping(early_pmd,
800 set_satp_mode_pmd, set_satp_mode_pmd,
801 PMD_SIZE, PAGE_KERNEL_EXEC);
802 create_pmd_mapping(early_pmd,
803 set_satp_mode_pmd + PMD_SIZE,
804 set_satp_mode_pmd + PMD_SIZE,
805 PMD_SIZE, PAGE_KERNEL_EXEC);
806 retry:
807 create_pgd_mapping(early_pg_dir,
808 set_satp_mode_pmd,
809 pgtable_l5_enabled ?
810 (uintptr_t)early_p4d : (uintptr_t)early_pud,
811 PGDIR_SIZE, PAGE_TABLE);
812
813 identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode;
814
815 local_flush_tlb_all();
816 csr_write(CSR_SATP, identity_satp);
817 hw_satp = csr_swap(CSR_SATP, 0ULL);
818 local_flush_tlb_all();
819
820 if (hw_satp != identity_satp) {
821 if (pgtable_l5_enabled) {
822 disable_pgtable_l5();
823 memset(early_pg_dir, 0, PAGE_SIZE);
824 goto retry;
825 }
826 disable_pgtable_l4();
827 }
828
829 memset(early_pg_dir, 0, PAGE_SIZE);
830 memset(early_p4d, 0, PAGE_SIZE);
831 memset(early_pud, 0, PAGE_SIZE);
832 memset(early_pmd, 0, PAGE_SIZE);
833 }
834 #endif
835
836 /*
837 * setup_vm() is called from head.S with MMU-off.
838 *
839 * Following requirements should be honoured for setup_vm() to work
840 * correctly:
841 * 1) It should use PC-relative addressing for accessing kernel symbols.
842 * To achieve this we always use GCC cmodel=medany.
843 * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
844 * so disable compiler instrumentation when FTRACE is enabled.
845 *
846 * Currently, the above requirements are honoured by using custom CFLAGS
847 * for init.o in mm/Makefile.
848 */
849
850 #ifndef __riscv_cmodel_medany
851 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
852 #endif
853
854 #ifdef CONFIG_RELOCATABLE
855 extern unsigned long __rela_dyn_start, __rela_dyn_end;
856
relocate_kernel(void)857 static void __init relocate_kernel(void)
858 {
859 Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start;
860 /*
861 * This holds the offset between the linked virtual address and the
862 * relocated virtual address.
863 */
864 uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR;
865 /*
866 * This holds the offset between kernel linked virtual address and
867 * physical address.
868 */
869 uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr;
870
871 for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) {
872 Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset);
873 Elf64_Addr relocated_addr = rela->r_addend;
874
875 if (rela->r_info != R_RISCV_RELATIVE)
876 continue;
877
878 /*
879 * Make sure to not relocate vdso symbols like rt_sigreturn
880 * which are linked from the address 0 in vmlinux since
881 * vdso symbol addresses are actually used as an offset from
882 * mm->context.vdso in VDSO_OFFSET macro.
883 */
884 if (relocated_addr >= KERNEL_LINK_ADDR)
885 relocated_addr += reloc_offset;
886
887 *(Elf64_Addr *)addr = relocated_addr;
888 }
889 }
890 #endif /* CONFIG_RELOCATABLE */
891
892 #ifdef CONFIG_XIP_KERNEL
create_kernel_page_table(pgd_t * pgdir,__always_unused bool early)893 static void __init create_kernel_page_table(pgd_t *pgdir,
894 __always_unused bool early)
895 {
896 uintptr_t va, end_va;
897
898 /* Map the flash resident part */
899 end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
900 for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
901 create_pgd_mapping(pgdir, va,
902 kernel_map.xiprom + (va - kernel_map.virt_addr),
903 PMD_SIZE, PAGE_KERNEL_EXEC);
904
905 /* Map the data in RAM */
906 end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size;
907 for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += PMD_SIZE)
908 create_pgd_mapping(pgdir, va,
909 kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
910 PMD_SIZE, PAGE_KERNEL);
911 }
912 #else
create_kernel_page_table(pgd_t * pgdir,bool early)913 static void __init create_kernel_page_table(pgd_t *pgdir, bool early)
914 {
915 uintptr_t va, end_va;
916
917 end_va = kernel_map.virt_addr + kernel_map.size;
918 for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE)
919 create_pgd_mapping(pgdir, va,
920 kernel_map.phys_addr + (va - kernel_map.virt_addr),
921 PMD_SIZE,
922 early ?
923 PAGE_KERNEL_EXEC : pgprot_from_va(va));
924 }
925 #endif
926
927 /*
928 * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel,
929 * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR
930 * entry.
931 */
create_fdt_early_page_table(uintptr_t fix_fdt_va,uintptr_t dtb_pa)932 static void __init create_fdt_early_page_table(uintptr_t fix_fdt_va,
933 uintptr_t dtb_pa)
934 {
935 #ifndef CONFIG_BUILTIN_DTB
936 uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
937
938 /* Make sure the fdt fixmap address is always aligned on PMD size */
939 BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE));
940
941 /* In 32-bit only, the fdt lies in its own PGD */
942 if (!IS_ENABLED(CONFIG_64BIT)) {
943 create_pgd_mapping(early_pg_dir, fix_fdt_va,
944 pa, MAX_FDT_SIZE, PAGE_KERNEL);
945 } else {
946 create_pmd_mapping(fixmap_pmd, fix_fdt_va,
947 pa, PMD_SIZE, PAGE_KERNEL);
948 create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE,
949 pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
950 }
951
952 dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1));
953 #else
954 /*
955 * For 64-bit kernel, __va can't be used since it would return a linear
956 * mapping address whereas dtb_early_va will be used before
957 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the
958 * kernel is mapped in the linear mapping, that makes no difference.
959 */
960 dtb_early_va = kernel_mapping_pa_to_va(dtb_pa);
961 #endif
962
963 dtb_early_pa = dtb_pa;
964 }
965
966 /*
967 * MMU is not enabled, the page tables are allocated directly using
968 * early_pmd/pud/p4d and the address returned is the physical one.
969 */
pt_ops_set_early(void)970 static void __init pt_ops_set_early(void)
971 {
972 pt_ops.alloc_pte = alloc_pte_early;
973 pt_ops.get_pte_virt = get_pte_virt_early;
974 #ifndef __PAGETABLE_PMD_FOLDED
975 pt_ops.alloc_pmd = alloc_pmd_early;
976 pt_ops.get_pmd_virt = get_pmd_virt_early;
977 pt_ops.alloc_pud = alloc_pud_early;
978 pt_ops.get_pud_virt = get_pud_virt_early;
979 pt_ops.alloc_p4d = alloc_p4d_early;
980 pt_ops.get_p4d_virt = get_p4d_virt_early;
981 #endif
982 }
983
984 /*
985 * MMU is enabled but page table setup is not complete yet.
986 * fixmap page table alloc functions must be used as a means to temporarily
987 * map the allocated physical pages since the linear mapping does not exist yet.
988 *
989 * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va,
990 * but it will be used as described above.
991 */
pt_ops_set_fixmap(void)992 static void __init pt_ops_set_fixmap(void)
993 {
994 pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap);
995 pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap);
996 #ifndef __PAGETABLE_PMD_FOLDED
997 pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap);
998 pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap);
999 pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap);
1000 pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap);
1001 pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap);
1002 pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap);
1003 #endif
1004 }
1005
1006 /*
1007 * MMU is enabled and page table setup is complete, so from now, we can use
1008 * generic page allocation functions to setup page table.
1009 */
pt_ops_set_late(void)1010 static void __init pt_ops_set_late(void)
1011 {
1012 pt_ops.alloc_pte = alloc_pte_late;
1013 pt_ops.get_pte_virt = get_pte_virt_late;
1014 #ifndef __PAGETABLE_PMD_FOLDED
1015 pt_ops.alloc_pmd = alloc_pmd_late;
1016 pt_ops.get_pmd_virt = get_pmd_virt_late;
1017 pt_ops.alloc_pud = alloc_pud_late;
1018 pt_ops.get_pud_virt = get_pud_virt_late;
1019 pt_ops.alloc_p4d = alloc_p4d_late;
1020 pt_ops.get_p4d_virt = get_p4d_virt_late;
1021 #endif
1022 }
1023
1024 #ifdef CONFIG_RANDOMIZE_BASE
1025 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa);
1026 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa);
1027
print_nokaslr(char * p)1028 static int __init print_nokaslr(char *p)
1029 {
1030 pr_info("Disabled KASLR");
1031 return 0;
1032 }
1033 early_param("nokaslr", print_nokaslr);
1034
kaslr_offset(void)1035 unsigned long kaslr_offset(void)
1036 {
1037 return kernel_map.virt_offset;
1038 }
1039 #endif
1040
setup_vm(uintptr_t dtb_pa)1041 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1042 {
1043 pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd;
1044
1045 #ifdef CONFIG_RANDOMIZE_BASE
1046 if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) {
1047 u64 kaslr_seed = __pi_get_kaslr_seed(dtb_pa);
1048 u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start);
1049 u32 nr_pos;
1050
1051 /*
1052 * Compute the number of positions available: we are limited
1053 * by the early page table that only has one PUD and we must
1054 * be aligned on PMD_SIZE.
1055 */
1056 nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE;
1057
1058 kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE;
1059 }
1060 #endif
1061
1062 kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset;
1063
1064 #ifdef CONFIG_XIP_KERNEL
1065 #ifdef CONFIG_64BIT
1066 kernel_map.page_offset = PAGE_OFFSET_L3;
1067 #else
1068 kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
1069 #endif
1070 kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
1071 kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
1072
1073 phys_ram_base = CONFIG_PHYS_RAM_BASE;
1074 kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
1075 kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
1076
1077 kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
1078 #else
1079 kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL);
1080 kernel_map.phys_addr = (uintptr_t)(&_start);
1081 kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
1082 #endif
1083
1084 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
1085 set_satp_mode(dtb_pa);
1086 #endif
1087
1088 /*
1089 * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem,
1090 * where we have the system memory layout: this allows us to align
1091 * the physical and virtual mappings and then make use of PUD/P4D/PGD
1092 * for the linear mapping. This is only possible because the kernel
1093 * mapping lies outside the linear mapping.
1094 * In 32-bit however, as the kernel resides in the linear mapping,
1095 * setup_vm_final can not change the mapping established here,
1096 * otherwise the same kernel addresses would get mapped to different
1097 * physical addresses (if the start of dram is different from the
1098 * kernel physical address start).
1099 */
1100 kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ?
1101 0UL : PAGE_OFFSET - kernel_map.phys_addr;
1102 kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
1103
1104 /*
1105 * The default maximal physical memory size is KERN_VIRT_SIZE for 32-bit
1106 * kernel, whereas for 64-bit kernel, the end of the virtual address
1107 * space is occupied by the modules/BPF/kernel mappings which reduces
1108 * the available size of the linear mapping.
1109 */
1110 memory_limit = KERN_VIRT_SIZE - (IS_ENABLED(CONFIG_64BIT) ? SZ_4G : 0);
1111
1112 /* Sanity check alignment and size */
1113 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
1114 BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0);
1115
1116 #ifdef CONFIG_64BIT
1117 /*
1118 * The last 4K bytes of the addressable memory can not be mapped because
1119 * of IS_ERR_VALUE macro.
1120 */
1121 BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
1122 #endif
1123
1124 #ifdef CONFIG_RELOCATABLE
1125 /*
1126 * Early page table uses only one PUD, which makes it possible
1127 * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset
1128 * makes the kernel cross over a PUD_SIZE boundary, raise a bug
1129 * since a part of the kernel would not get mapped.
1130 */
1131 BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size);
1132 relocate_kernel();
1133 #endif
1134
1135 apply_early_boot_alternatives();
1136 pt_ops_set_early();
1137
1138 /* Setup early PGD for fixmap */
1139 create_pgd_mapping(early_pg_dir, FIXADDR_START,
1140 fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1141
1142 #ifndef __PAGETABLE_PMD_FOLDED
1143 /* Setup fixmap P4D and PUD */
1144 if (pgtable_l5_enabled)
1145 create_p4d_mapping(fixmap_p4d, FIXADDR_START,
1146 (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
1147 /* Setup fixmap PUD and PMD */
1148 if (pgtable_l4_enabled)
1149 create_pud_mapping(fixmap_pud, FIXADDR_START,
1150 (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE);
1151 create_pmd_mapping(fixmap_pmd, FIXADDR_START,
1152 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
1153 /* Setup trampoline PGD and PMD */
1154 create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1155 trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
1156 if (pgtable_l5_enabled)
1157 create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
1158 (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
1159 if (pgtable_l4_enabled)
1160 create_pud_mapping(trampoline_pud, kernel_map.virt_addr,
1161 (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE);
1162 #ifdef CONFIG_XIP_KERNEL
1163 create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1164 kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
1165 #else
1166 create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
1167 kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
1168 #endif
1169 #else
1170 /* Setup trampoline PGD */
1171 create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
1172 kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
1173 #endif
1174
1175 /*
1176 * Setup early PGD covering entire kernel which will allow
1177 * us to reach paging_init(). We map all memory banks later
1178 * in setup_vm_final() below.
1179 */
1180 create_kernel_page_table(early_pg_dir, true);
1181
1182 /* Setup early mapping for FDT early scan */
1183 create_fdt_early_page_table(__fix_to_virt(FIX_FDT), dtb_pa);
1184
1185 /*
1186 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
1187 * range can not span multiple pmds.
1188 */
1189 BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
1190 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
1191
1192 #ifndef __PAGETABLE_PMD_FOLDED
1193 /*
1194 * Early ioremap fixmap is already created as it lies within first 2MB
1195 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
1196 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
1197 * the user if not.
1198 */
1199 fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
1200 fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
1201 if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
1202 WARN_ON(1);
1203 pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
1204 pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
1205 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
1206 fix_to_virt(FIX_BTMAP_BEGIN));
1207 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
1208 fix_to_virt(FIX_BTMAP_END));
1209
1210 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
1211 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
1212 }
1213 #endif
1214
1215 pt_ops_set_fixmap();
1216 }
1217
create_linear_mapping_range(phys_addr_t start,phys_addr_t end,uintptr_t fixed_map_size)1218 static void __init create_linear_mapping_range(phys_addr_t start,
1219 phys_addr_t end,
1220 uintptr_t fixed_map_size)
1221 {
1222 phys_addr_t pa;
1223 uintptr_t va, map_size;
1224
1225 for (pa = start; pa < end; pa += map_size) {
1226 va = (uintptr_t)__va(pa);
1227 map_size = fixed_map_size ? fixed_map_size :
1228 best_map_size(pa, va, end - pa);
1229
1230 create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
1231 pgprot_from_va(va));
1232 }
1233 }
1234
create_linear_mapping_page_table(void)1235 static void __init create_linear_mapping_page_table(void)
1236 {
1237 phys_addr_t start, end;
1238 phys_addr_t kfence_pool __maybe_unused;
1239 u64 i;
1240
1241 #ifdef CONFIG_STRICT_KERNEL_RWX
1242 phys_addr_t ktext_start = __pa_symbol(_start);
1243 phys_addr_t ktext_size = __init_data_begin - _start;
1244 phys_addr_t krodata_start = __pa_symbol(__start_rodata);
1245 phys_addr_t krodata_size = _data - __start_rodata;
1246
1247 /* Isolate kernel text and rodata so they don't get mapped with a PUD */
1248 memblock_mark_nomap(ktext_start, ktext_size);
1249 memblock_mark_nomap(krodata_start, krodata_size);
1250 #endif
1251
1252 #ifdef CONFIG_KFENCE
1253 /*
1254 * kfence pool must be backed by PAGE_SIZE mappings, so allocate it
1255 * before we setup the linear mapping so that we avoid using hugepages
1256 * for this region.
1257 */
1258 kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
1259 BUG_ON(!kfence_pool);
1260
1261 memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE);
1262 __kfence_pool = __va(kfence_pool);
1263 #endif
1264
1265 /* Map all memory banks in the linear mapping */
1266 for_each_mem_range(i, &start, &end) {
1267 if (start >= end)
1268 break;
1269 if (start <= __pa(PAGE_OFFSET) &&
1270 __pa(PAGE_OFFSET) < end)
1271 start = __pa(PAGE_OFFSET);
1272 if (end >= __pa(PAGE_OFFSET) + memory_limit)
1273 end = __pa(PAGE_OFFSET) + memory_limit;
1274
1275 create_linear_mapping_range(start, end, 0);
1276 }
1277
1278 #ifdef CONFIG_STRICT_KERNEL_RWX
1279 create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0);
1280 create_linear_mapping_range(krodata_start,
1281 krodata_start + krodata_size, 0);
1282
1283 memblock_clear_nomap(ktext_start, ktext_size);
1284 memblock_clear_nomap(krodata_start, krodata_size);
1285 #endif
1286
1287 #ifdef CONFIG_KFENCE
1288 create_linear_mapping_range(kfence_pool,
1289 kfence_pool + KFENCE_POOL_SIZE,
1290 PAGE_SIZE);
1291
1292 memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
1293 #endif
1294 }
1295
setup_vm_final(void)1296 static void __init setup_vm_final(void)
1297 {
1298 /* Setup swapper PGD for fixmap */
1299 #if !defined(CONFIG_64BIT)
1300 /*
1301 * In 32-bit, the device tree lies in a pgd entry, so it must be copied
1302 * directly in swapper_pg_dir in addition to the pgd entry that points
1303 * to fixmap_pte.
1304 */
1305 unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT));
1306
1307 set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]);
1308 #endif
1309 create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
1310 __pa_symbol(fixmap_pgd_next),
1311 PGDIR_SIZE, PAGE_TABLE);
1312
1313 /* Map the linear mapping */
1314 create_linear_mapping_page_table();
1315
1316 /* Map the kernel */
1317 if (IS_ENABLED(CONFIG_64BIT))
1318 create_kernel_page_table(swapper_pg_dir, false);
1319
1320 #ifdef CONFIG_KASAN
1321 kasan_swapper_init();
1322 #endif
1323
1324 /* Clear fixmap PTE and PMD mappings */
1325 clear_fixmap(FIX_PTE);
1326 clear_fixmap(FIX_PMD);
1327 clear_fixmap(FIX_PUD);
1328 clear_fixmap(FIX_P4D);
1329
1330 /* Move to swapper page table */
1331 csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode);
1332 local_flush_tlb_all();
1333
1334 pt_ops_set_late();
1335 }
1336 #else
setup_vm(uintptr_t dtb_pa)1337 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
1338 {
1339 dtb_early_va = (void *)dtb_pa;
1340 dtb_early_pa = dtb_pa;
1341 }
1342
setup_vm_final(void)1343 static inline void setup_vm_final(void)
1344 {
1345 }
1346 #endif /* CONFIG_MMU */
1347
1348 /* Reserve 128M low memory by default for swiotlb buffer */
1349 #define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20)
1350
reserve_crashkernel_low(unsigned long long low_size)1351 static int __init reserve_crashkernel_low(unsigned long long low_size)
1352 {
1353 unsigned long long low_base;
1354
1355 low_base = memblock_phys_alloc_range(low_size, PMD_SIZE, 0, dma32_phys_limit);
1356 if (!low_base) {
1357 pr_err("cannot allocate crashkernel low memory (size:0x%llx).\n", low_size);
1358 return -ENOMEM;
1359 }
1360
1361 pr_info("crashkernel low memory reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
1362 low_base, low_base + low_size, low_size >> 20);
1363
1364 crashk_low_res.start = low_base;
1365 crashk_low_res.end = low_base + low_size - 1;
1366
1367 return 0;
1368 }
1369
1370 /*
1371 * reserve_crashkernel() - reserves memory for crash kernel
1372 *
1373 * This function reserves memory area given in "crashkernel=" kernel command
1374 * line parameter. The memory reserved is used by dump capture kernel when
1375 * primary kernel is crashing.
1376 */
reserve_crashkernel(void)1377 static void __init reserve_crashkernel(void)
1378 {
1379 unsigned long long crash_base = 0;
1380 unsigned long long crash_size = 0;
1381 unsigned long long crash_low_size = 0;
1382 unsigned long search_start = memblock_start_of_DRAM();
1383 unsigned long search_end = (unsigned long)dma32_phys_limit;
1384 char *cmdline = boot_command_line;
1385 bool fixed_base = false;
1386 bool high = false;
1387
1388 int ret = 0;
1389
1390 if (!IS_ENABLED(CONFIG_KEXEC_CORE))
1391 return;
1392 /*
1393 * Don't reserve a region for a crash kernel on a crash kernel
1394 * since it doesn't make much sense and we have limited memory
1395 * resources.
1396 */
1397 if (is_kdump_kernel()) {
1398 pr_info("crashkernel: ignoring reservation request\n");
1399 return;
1400 }
1401
1402 ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
1403 &crash_size, &crash_base);
1404 if (ret == -ENOENT) {
1405 /* Fallback to crashkernel=X,[high,low] */
1406 ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base);
1407 if (ret || !crash_size)
1408 return;
1409
1410 /*
1411 * crashkernel=Y,low is valid only when crashkernel=X,high
1412 * is passed.
1413 */
1414 ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base);
1415 if (ret == -ENOENT)
1416 crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
1417 else if (ret)
1418 return;
1419
1420 search_start = (unsigned long)dma32_phys_limit;
1421 search_end = memblock_end_of_DRAM();
1422 high = true;
1423 } else if (ret || !crash_size) {
1424 /* Invalid argument value specified */
1425 return;
1426 }
1427
1428 crash_size = PAGE_ALIGN(crash_size);
1429
1430 if (crash_base) {
1431 fixed_base = true;
1432 search_start = crash_base;
1433 search_end = crash_base + crash_size;
1434 }
1435
1436 /*
1437 * Current riscv boot protocol requires 2MB alignment for
1438 * RV64 and 4MB alignment for RV32 (hugepage size)
1439 *
1440 * Try to alloc from 32bit addressible physical memory so that
1441 * swiotlb can work on the crash kernel.
1442 */
1443 crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
1444 search_start, search_end);
1445 if (crash_base == 0) {
1446 /*
1447 * For crashkernel=size[KMG]@offset[KMG], print out failure
1448 * message if can't reserve the specified region.
1449 */
1450 if (fixed_base) {
1451 pr_warn("crashkernel: allocating failed with given size@offset\n");
1452 return;
1453 }
1454
1455 if (high) {
1456 /*
1457 * For crashkernel=size[KMG],high, if the first attempt was
1458 * for high memory, fall back to low memory.
1459 */
1460 search_start = memblock_start_of_DRAM();
1461 search_end = (unsigned long)dma32_phys_limit;
1462 } else {
1463 /*
1464 * For crashkernel=size[KMG], if the first attempt was for
1465 * low memory, fall back to high memory, the minimum required
1466 * low memory will be reserved later.
1467 */
1468 search_start = (unsigned long)dma32_phys_limit;
1469 search_end = memblock_end_of_DRAM();
1470 crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
1471 }
1472
1473 crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
1474 search_start, search_end);
1475 if (crash_base == 0) {
1476 pr_warn("crashkernel: couldn't allocate %lldKB\n",
1477 crash_size >> 10);
1478 return;
1479 }
1480 }
1481
1482 if ((crash_base >= dma32_phys_limit) && crash_low_size &&
1483 reserve_crashkernel_low(crash_low_size)) {
1484 memblock_phys_free(crash_base, crash_size);
1485 return;
1486 }
1487
1488 pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
1489 crash_base, crash_base + crash_size, crash_size >> 20);
1490
1491 crashk_res.start = crash_base;
1492 crashk_res.end = crash_base + crash_size - 1;
1493 }
1494
paging_init(void)1495 void __init paging_init(void)
1496 {
1497 setup_bootmem();
1498 setup_vm_final();
1499
1500 /* Depend on that Linear Mapping is ready */
1501 memblock_allow_resize();
1502 }
1503
misc_mem_init(void)1504 void __init misc_mem_init(void)
1505 {
1506 early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
1507 arch_numa_init();
1508 sparse_init();
1509 #ifdef CONFIG_SPARSEMEM_VMEMMAP
1510 /* The entire VMEMMAP region has been populated. Flush TLB for this region */
1511 local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END);
1512 #endif
1513 zone_sizes_init();
1514 reserve_crashkernel();
1515 memblock_dump_all();
1516 }
1517
1518 #ifdef CONFIG_SPARSEMEM_VMEMMAP
vmemmap_populate(unsigned long start,unsigned long end,int node,struct vmem_altmap * altmap)1519 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
1520 struct vmem_altmap *altmap)
1521 {
1522 return vmemmap_populate_basepages(start, end, node, NULL);
1523 }
1524 #endif
1525
1526 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
1527 /*
1528 * Pre-allocates page-table pages for a specific area in the kernel
1529 * page-table. Only the level which needs to be synchronized between
1530 * all page-tables is allocated because the synchronization can be
1531 * expensive.
1532 */
preallocate_pgd_pages_range(unsigned long start,unsigned long end,const char * area)1533 static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end,
1534 const char *area)
1535 {
1536 unsigned long addr;
1537 const char *lvl;
1538
1539 for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
1540 pgd_t *pgd = pgd_offset_k(addr);
1541 p4d_t *p4d;
1542 pud_t *pud;
1543 pmd_t *pmd;
1544
1545 lvl = "p4d";
1546 p4d = p4d_alloc(&init_mm, pgd, addr);
1547 if (!p4d)
1548 goto failed;
1549
1550 if (pgtable_l5_enabled)
1551 continue;
1552
1553 lvl = "pud";
1554 pud = pud_alloc(&init_mm, p4d, addr);
1555 if (!pud)
1556 goto failed;
1557
1558 if (pgtable_l4_enabled)
1559 continue;
1560
1561 lvl = "pmd";
1562 pmd = pmd_alloc(&init_mm, pud, addr);
1563 if (!pmd)
1564 goto failed;
1565 }
1566 return;
1567
1568 failed:
1569 /*
1570 * The pages have to be there now or they will be missing in
1571 * process page-tables later.
1572 */
1573 panic("Failed to pre-allocate %s pages for %s area\n", lvl, area);
1574 }
1575
pgtable_cache_init(void)1576 void __init pgtable_cache_init(void)
1577 {
1578 preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc");
1579 if (IS_ENABLED(CONFIG_MODULES))
1580 preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules");
1581 }
1582 #endif
1583