RISC-V: Make sure memblock reserves the memory containing DT
[linux-2.6-microblaze.git] / arch / riscv / mm / init.c
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  */
6
7 #include <linux/init.h>
8 #include <linux/mm.h>
9 #include <linux/memblock.h>
10 #include <linux/initrd.h>
11 #include <linux/swap.h>
12 #include <linux/sizes.h>
13 #include <linux/of_fdt.h>
14 #include <linux/libfdt.h>
15 #include <linux/set_memory.h>
16
17 #include <asm/fixmap.h>
18 #include <asm/tlbflush.h>
19 #include <asm/sections.h>
20 #include <asm/soc.h>
21 #include <asm/io.h>
22 #include <asm/ptdump.h>
23
24 #include "../kernel/head.h"
25
26 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
27                                                         __page_aligned_bss;
28 EXPORT_SYMBOL(empty_zero_page);
29
30 extern char _start[];
31 void *dtb_early_va;
32
33 static void __init zone_sizes_init(void)
34 {
35         unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
36
37 #ifdef CONFIG_ZONE_DMA32
38         max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
39                         (unsigned long) PFN_PHYS(max_low_pfn)));
40 #endif
41         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
42
43         free_area_init(max_zone_pfns);
44 }
45
46 static void setup_zero_page(void)
47 {
48         memset((void *)empty_zero_page, 0, PAGE_SIZE);
49 }
50
51 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
52 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
53 {
54         pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
55                   (((t) - (b)) >> 10));
56 }
57
58 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
59 {
60         pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
61                   (((t) - (b)) >> 20));
62 }
63
64 static void print_vm_layout(void)
65 {
66         pr_notice("Virtual kernel memory layout:\n");
67         print_mlk("fixmap", (unsigned long)FIXADDR_START,
68                   (unsigned long)FIXADDR_TOP);
69         print_mlm("pci io", (unsigned long)PCI_IO_START,
70                   (unsigned long)PCI_IO_END);
71         print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
72                   (unsigned long)VMEMMAP_END);
73         print_mlm("vmalloc", (unsigned long)VMALLOC_START,
74                   (unsigned long)VMALLOC_END);
75         print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
76                   (unsigned long)high_memory);
77 }
78 #else
79 static void print_vm_layout(void) { }
80 #endif /* CONFIG_DEBUG_VM */
81
82 void __init mem_init(void)
83 {
84 #ifdef CONFIG_FLATMEM
85         BUG_ON(!mem_map);
86 #endif /* CONFIG_FLATMEM */
87
88         high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
89         memblock_free_all();
90
91         mem_init_print_info(NULL);
92         print_vm_layout();
93 }
94
95 #ifdef CONFIG_BLK_DEV_INITRD
96 static void __init setup_initrd(void)
97 {
98         phys_addr_t start;
99         unsigned long size;
100
101         /* Ignore the virtul address computed during device tree parsing */
102         initrd_start = initrd_end = 0;
103
104         if (!phys_initrd_size)
105                 return;
106         /*
107          * Round the memory region to page boundaries as per free_initrd_mem()
108          * This allows us to detect whether the pages overlapping the initrd
109          * are in use, but more importantly, reserves the entire set of pages
110          * as we don't want these pages allocated for other purposes.
111          */
112         start = round_down(phys_initrd_start, PAGE_SIZE);
113         size = phys_initrd_size + (phys_initrd_start - start);
114         size = round_up(size, PAGE_SIZE);
115
116         if (!memblock_is_region_memory(start, size)) {
117                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
118                        (u64)start, size);
119                 goto disable;
120         }
121
122         if (memblock_is_region_reserved(start, size)) {
123                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
124                        (u64)start, size);
125                 goto disable;
126         }
127
128         memblock_reserve(start, size);
129         /* Now convert initrd to virtual addresses */
130         initrd_start = (unsigned long)__va(phys_initrd_start);
131         initrd_end = initrd_start + phys_initrd_size;
132         initrd_below_start_ok = 1;
133
134         pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
135                 (void *)(initrd_start), size);
136         return;
137 disable:
138         pr_cont(" - disabling initrd\n");
139         initrd_start = 0;
140         initrd_end = 0;
141 }
142 #endif /* CONFIG_BLK_DEV_INITRD */
143
144 static phys_addr_t dtb_early_pa __initdata;
145
146 void __init setup_bootmem(void)
147 {
148         struct memblock_region *reg;
149         phys_addr_t mem_size = 0;
150         phys_addr_t total_mem = 0;
151         phys_addr_t mem_start, end = 0;
152         phys_addr_t vmlinux_end = __pa_symbol(&_end);
153         phys_addr_t vmlinux_start = __pa_symbol(&_start);
154
155         /* Find the memory region containing the kernel */
156         for_each_memblock(memory, reg) {
157                 end = reg->base + reg->size;
158                 if (!total_mem)
159                         mem_start = reg->base;
160                 if (reg->base <= vmlinux_start && vmlinux_end <= end)
161                         BUG_ON(reg->size == 0);
162                 total_mem = total_mem + reg->size;
163         }
164
165         /*
166          * Remove memblock from the end of usable area to the
167          * end of region
168          */
169         mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET);
170         if (mem_start + mem_size < end)
171                 memblock_remove(mem_start + mem_size,
172                                 end - mem_start - mem_size);
173
174         /* Reserve from the start of the kernel to the end of the kernel */
175         memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
176
177         max_pfn = PFN_DOWN(memblock_end_of_DRAM());
178         max_low_pfn = max_pfn;
179         set_max_mapnr(max_low_pfn);
180
181 #ifdef CONFIG_BLK_DEV_INITRD
182         setup_initrd();
183 #endif /* CONFIG_BLK_DEV_INITRD */
184
185         /*
186          * Avoid using early_init_fdt_reserve_self() since __pa() does
187          * not work for DTB pointers that are fixmap addresses
188          */
189         memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
190
191         early_init_fdt_scan_reserved_mem();
192         memblock_allow_resize();
193         memblock_dump_all();
194
195         for_each_memblock(memory, reg) {
196                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
197                 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
198
199                 memblock_set_node(PFN_PHYS(start_pfn),
200                                   PFN_PHYS(end_pfn - start_pfn),
201                                   &memblock.memory, 0);
202         }
203 }
204
205 #ifdef CONFIG_MMU
206 unsigned long va_pa_offset;
207 EXPORT_SYMBOL(va_pa_offset);
208 unsigned long pfn_base;
209 EXPORT_SYMBOL(pfn_base);
210
211 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
212 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
213 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
214 static bool mmu_enabled;
215
216 #define MAX_EARLY_MAPPING_SIZE  SZ_128M
217
218 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
219
220 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
221 {
222         unsigned long addr = __fix_to_virt(idx);
223         pte_t *ptep;
224
225         BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
226
227         ptep = &fixmap_pte[pte_index(addr)];
228
229         if (pgprot_val(prot))
230                 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
231         else
232                 pte_clear(&init_mm, addr, ptep);
233         local_flush_tlb_page(addr);
234 }
235
236 static pte_t *__init get_pte_virt(phys_addr_t pa)
237 {
238         if (mmu_enabled) {
239                 clear_fixmap(FIX_PTE);
240                 return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
241         } else {
242                 return (pte_t *)((uintptr_t)pa);
243         }
244 }
245
246 static phys_addr_t __init alloc_pte(uintptr_t va)
247 {
248         /*
249          * We only create PMD or PGD early mappings so we
250          * should never reach here with MMU disabled.
251          */
252         BUG_ON(!mmu_enabled);
253
254         return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
255 }
256
257 static void __init create_pte_mapping(pte_t *ptep,
258                                       uintptr_t va, phys_addr_t pa,
259                                       phys_addr_t sz, pgprot_t prot)
260 {
261         uintptr_t pte_idx = pte_index(va);
262
263         BUG_ON(sz != PAGE_SIZE);
264
265         if (pte_none(ptep[pte_idx]))
266                 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
267 }
268
269 #ifndef __PAGETABLE_PMD_FOLDED
270
271 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
272 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
273
274 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
275 #define NUM_EARLY_PMDS          1UL
276 #else
277 #define NUM_EARLY_PMDS          (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
278 #endif
279 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
280
281 static pmd_t *__init get_pmd_virt(phys_addr_t pa)
282 {
283         if (mmu_enabled) {
284                 clear_fixmap(FIX_PMD);
285                 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
286         } else {
287                 return (pmd_t *)((uintptr_t)pa);
288         }
289 }
290
291 static phys_addr_t __init alloc_pmd(uintptr_t va)
292 {
293         uintptr_t pmd_num;
294
295         if (mmu_enabled)
296                 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
297
298         pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
299         BUG_ON(pmd_num >= NUM_EARLY_PMDS);
300         return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
301 }
302
303 static void __init create_pmd_mapping(pmd_t *pmdp,
304                                       uintptr_t va, phys_addr_t pa,
305                                       phys_addr_t sz, pgprot_t prot)
306 {
307         pte_t *ptep;
308         phys_addr_t pte_phys;
309         uintptr_t pmd_idx = pmd_index(va);
310
311         if (sz == PMD_SIZE) {
312                 if (pmd_none(pmdp[pmd_idx]))
313                         pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
314                 return;
315         }
316
317         if (pmd_none(pmdp[pmd_idx])) {
318                 pte_phys = alloc_pte(va);
319                 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
320                 ptep = get_pte_virt(pte_phys);
321                 memset(ptep, 0, PAGE_SIZE);
322         } else {
323                 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
324                 ptep = get_pte_virt(pte_phys);
325         }
326
327         create_pte_mapping(ptep, va, pa, sz, prot);
328 }
329
330 #define pgd_next_t              pmd_t
331 #define alloc_pgd_next(__va)    alloc_pmd(__va)
332 #define get_pgd_next_virt(__pa) get_pmd_virt(__pa)
333 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)      \
334         create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
335 #define fixmap_pgd_next         fixmap_pmd
336 #else
337 #define pgd_next_t              pte_t
338 #define alloc_pgd_next(__va)    alloc_pte(__va)
339 #define get_pgd_next_virt(__pa) get_pte_virt(__pa)
340 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)      \
341         create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
342 #define fixmap_pgd_next         fixmap_pte
343 #endif
344
345 static void __init create_pgd_mapping(pgd_t *pgdp,
346                                       uintptr_t va, phys_addr_t pa,
347                                       phys_addr_t sz, pgprot_t prot)
348 {
349         pgd_next_t *nextp;
350         phys_addr_t next_phys;
351         uintptr_t pgd_idx = pgd_index(va);
352
353         if (sz == PGDIR_SIZE) {
354                 if (pgd_val(pgdp[pgd_idx]) == 0)
355                         pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
356                 return;
357         }
358
359         if (pgd_val(pgdp[pgd_idx]) == 0) {
360                 next_phys = alloc_pgd_next(va);
361                 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
362                 nextp = get_pgd_next_virt(next_phys);
363                 memset(nextp, 0, PAGE_SIZE);
364         } else {
365                 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
366                 nextp = get_pgd_next_virt(next_phys);
367         }
368
369         create_pgd_next_mapping(nextp, va, pa, sz, prot);
370 }
371
372 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
373 {
374         /* Upgrade to PMD_SIZE mappings whenever possible */
375         if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
376                 return PAGE_SIZE;
377
378         return PMD_SIZE;
379 }
380
381 /*
382  * setup_vm() is called from head.S with MMU-off.
383  *
384  * Following requirements should be honoured for setup_vm() to work
385  * correctly:
386  * 1) It should use PC-relative addressing for accessing kernel symbols.
387  *    To achieve this we always use GCC cmodel=medany.
388  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
389  *    so disable compiler instrumentation when FTRACE is enabled.
390  *
391  * Currently, the above requirements are honoured by using custom CFLAGS
392  * for init.o in mm/Makefile.
393  */
394
395 #ifndef __riscv_cmodel_medany
396 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
397 #endif
398
399 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
400 {
401         uintptr_t va, end_va;
402         uintptr_t load_pa = (uintptr_t)(&_start);
403         uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
404         uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
405
406         va_pa_offset = PAGE_OFFSET - load_pa;
407         pfn_base = PFN_DOWN(load_pa);
408
409         /*
410          * Enforce boot alignment requirements of RV32 and
411          * RV64 by only allowing PMD or PGD mappings.
412          */
413         BUG_ON(map_size == PAGE_SIZE);
414
415         /* Sanity check alignment and size */
416         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
417         BUG_ON((load_pa % map_size) != 0);
418         BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
419
420         /* Setup early PGD for fixmap */
421         create_pgd_mapping(early_pg_dir, FIXADDR_START,
422                            (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
423
424 #ifndef __PAGETABLE_PMD_FOLDED
425         /* Setup fixmap PMD */
426         create_pmd_mapping(fixmap_pmd, FIXADDR_START,
427                            (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
428         /* Setup trampoline PGD and PMD */
429         create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
430                            (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
431         create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
432                            load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
433 #else
434         /* Setup trampoline PGD */
435         create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
436                            load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
437 #endif
438
439         /*
440          * Setup early PGD covering entire kernel which will allows
441          * us to reach paging_init(). We map all memory banks later
442          * in setup_vm_final() below.
443          */
444         end_va = PAGE_OFFSET + load_sz;
445         for (va = PAGE_OFFSET; va < end_va; va += map_size)
446                 create_pgd_mapping(early_pg_dir, va,
447                                    load_pa + (va - PAGE_OFFSET),
448                                    map_size, PAGE_KERNEL_EXEC);
449
450         /* Create fixed mapping for early FDT parsing */
451         end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
452         for (va = __fix_to_virt(FIX_FDT); va < end_va; va += PAGE_SIZE)
453                 create_pte_mapping(fixmap_pte, va,
454                                    dtb_pa + (va - __fix_to_virt(FIX_FDT)),
455                                    PAGE_SIZE, PAGE_KERNEL);
456
457         /* Save pointer to DTB for early FDT parsing */
458         dtb_early_va = (void *)fix_to_virt(FIX_FDT) + (dtb_pa & ~PAGE_MASK);
459         /* Save physical address for memblock reservation */
460         dtb_early_pa = dtb_pa;
461 }
462
463 static void __init setup_vm_final(void)
464 {
465         uintptr_t va, map_size;
466         phys_addr_t pa, start, end;
467         struct memblock_region *reg;
468
469         /* Set mmu_enabled flag */
470         mmu_enabled = true;
471
472         /* Setup swapper PGD for fixmap */
473         create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
474                            __pa_symbol(fixmap_pgd_next),
475                            PGDIR_SIZE, PAGE_TABLE);
476
477         /* Map all memory banks */
478         for_each_memblock(memory, reg) {
479                 start = reg->base;
480                 end = start + reg->size;
481
482                 if (start >= end)
483                         break;
484                 if (memblock_is_nomap(reg))
485                         continue;
486                 if (start <= __pa(PAGE_OFFSET) &&
487                     __pa(PAGE_OFFSET) < end)
488                         start = __pa(PAGE_OFFSET);
489
490                 map_size = best_map_size(start, end - start);
491                 for (pa = start; pa < end; pa += map_size) {
492                         va = (uintptr_t)__va(pa);
493                         create_pgd_mapping(swapper_pg_dir, va, pa,
494                                            map_size, PAGE_KERNEL_EXEC);
495                 }
496         }
497
498         /* Clear fixmap PTE and PMD mappings */
499         clear_fixmap(FIX_PTE);
500         clear_fixmap(FIX_PMD);
501
502         /* Move to swapper page table */
503         csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
504         local_flush_tlb_all();
505 }
506 #else
507 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
508 {
509 #ifdef CONFIG_BUILTIN_DTB
510         dtb_early_va = soc_lookup_builtin_dtb();
511         if (!dtb_early_va) {
512                 /* Fallback to first available DTS */
513                 dtb_early_va = (void *) __dtb_start;
514         }
515 #else
516         dtb_early_va = (void *)dtb_pa;
517 #endif
518         dtb_early_pa = dtb_pa;
519 }
520
521 static inline void setup_vm_final(void)
522 {
523 }
524 #endif /* CONFIG_MMU */
525
526 #ifdef CONFIG_STRICT_KERNEL_RWX
527 void mark_rodata_ro(void)
528 {
529         unsigned long text_start = (unsigned long)_text;
530         unsigned long text_end = (unsigned long)_etext;
531         unsigned long rodata_start = (unsigned long)__start_rodata;
532         unsigned long data_start = (unsigned long)_data;
533         unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
534
535         set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
536         set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
537         set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
538         set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
539
540         debug_checkwx();
541 }
542 #endif
543
544 static void __init resource_init(void)
545 {
546         struct memblock_region *region;
547
548         for_each_memblock(memory, region) {
549                 struct resource *res;
550
551                 res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
552                 if (!res)
553                         panic("%s: Failed to allocate %zu bytes\n", __func__,
554                               sizeof(struct resource));
555
556                 if (memblock_is_nomap(region)) {
557                         res->name = "reserved";
558                         res->flags = IORESOURCE_MEM;
559                 } else {
560                         res->name = "System RAM";
561                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
562                 }
563                 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
564                 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
565
566                 request_resource(&iomem_resource, res);
567         }
568 }
569
570 void __init paging_init(void)
571 {
572         setup_vm_final();
573         sparse_init();
574         setup_zero_page();
575         zone_sizes_init();
576         resource_init();
577 }
578
579 #ifdef CONFIG_SPARSEMEM_VMEMMAP
580 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
581                                struct vmem_altmap *altmap)
582 {
583         return vmemmap_populate_basepages(start, end, node, NULL);
584 }
585 #endif