1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Page table handling routines for radix page table.
4  *
5  * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
6  */
7 
8 #define pr_fmt(fmt) "radix-mmu: " fmt
9 
10 #include <linux/io.h>
11 #include <linux/kernel.h>
12 #include <linux/sched/mm.h>
13 #include <linux/memblock.h>
14 #include <linux/of.h>
15 #include <linux/of_fdt.h>
16 #include <linux/mm.h>
17 #include <linux/hugetlb.h>
18 #include <linux/string_helpers.h>
19 #include <linux/memory.h>
20 
21 #include <asm/pgalloc.h>
22 #include <asm/mmu_context.h>
23 #include <asm/dma.h>
24 #include <asm/machdep.h>
25 #include <asm/mmu.h>
26 #include <asm/firmware.h>
27 #include <asm/powernv.h>
28 #include <asm/sections.h>
29 #include <asm/smp.h>
30 #include <asm/trace.h>
31 #include <asm/uaccess.h>
32 #include <asm/ultravisor.h>
33 #include <asm/set_memory.h>
34 
35 #include <trace/events/thp.h>
36 
37 #include <mm/mmu_decl.h>
38 
39 unsigned int mmu_base_pid;
40 unsigned long radix_mem_block_size __ro_after_init;
41 
42 static __ref void *early_alloc_pgtable(unsigned long size, int nid,
43 			unsigned long region_start, unsigned long region_end)
44 {
45 	phys_addr_t min_addr = MEMBLOCK_LOW_LIMIT;
46 	phys_addr_t max_addr = MEMBLOCK_ALLOC_ANYWHERE;
47 	void *ptr;
48 
49 	if (region_start)
50 		min_addr = region_start;
51 	if (region_end)
52 		max_addr = region_end;
53 
54 	ptr = memblock_alloc_try_nid(size, size, min_addr, max_addr, nid);
55 
56 	if (!ptr)
57 		panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa max_addr=%pa\n",
58 		      __func__, size, size, nid, &min_addr, &max_addr);
59 
60 	return ptr;
61 }
62 
63 /*
64  * When allocating pud or pmd pointers, we allocate a complete page
65  * of PAGE_SIZE rather than PUD_TABLE_SIZE or PMD_TABLE_SIZE. This
66  * is to ensure that the page obtained from the memblock allocator
67  * can be completely used as page table page and can be freed
68  * correctly when the page table entries are removed.
69  */
70 static int early_map_kernel_page(unsigned long ea, unsigned long pa,
71 			  pgprot_t flags,
72 			  unsigned int map_page_size,
73 			  int nid,
74 			  unsigned long region_start, unsigned long region_end)
75 {
76 	unsigned long pfn = pa >> PAGE_SHIFT;
77 	pgd_t *pgdp;
78 	p4d_t *p4dp;
79 	pud_t *pudp;
80 	pmd_t *pmdp;
81 	pte_t *ptep;
82 
83 	pgdp = pgd_offset_k(ea);
84 	p4dp = p4d_offset(pgdp, ea);
85 	if (p4d_none(*p4dp)) {
86 		pudp = early_alloc_pgtable(PAGE_SIZE, nid,
87 					   region_start, region_end);
88 		p4d_populate(&init_mm, p4dp, pudp);
89 	}
90 	pudp = pud_offset(p4dp, ea);
91 	if (map_page_size == PUD_SIZE) {
92 		ptep = (pte_t *)pudp;
93 		goto set_the_pte;
94 	}
95 	if (pud_none(*pudp)) {
96 		pmdp = early_alloc_pgtable(PAGE_SIZE, nid, region_start,
97 					   region_end);
98 		pud_populate(&init_mm, pudp, pmdp);
99 	}
100 	pmdp = pmd_offset(pudp, ea);
101 	if (map_page_size == PMD_SIZE) {
102 		ptep = pmdp_ptep(pmdp);
103 		goto set_the_pte;
104 	}
105 	if (!pmd_present(*pmdp)) {
106 		ptep = early_alloc_pgtable(PAGE_SIZE, nid,
107 						region_start, region_end);
108 		pmd_populate_kernel(&init_mm, pmdp, ptep);
109 	}
110 	ptep = pte_offset_kernel(pmdp, ea);
111 
112 set_the_pte:
113 	set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
114 	asm volatile("ptesync": : :"memory");
115 	return 0;
116 }
117 
118 /*
119  * nid, region_start, and region_end are hints to try to place the page
120  * table memory in the same node or region.
121  */
122 static int __map_kernel_page(unsigned long ea, unsigned long pa,
123 			  pgprot_t flags,
124 			  unsigned int map_page_size,
125 			  int nid,
126 			  unsigned long region_start, unsigned long region_end)
127 {
128 	unsigned long pfn = pa >> PAGE_SHIFT;
129 	pgd_t *pgdp;
130 	p4d_t *p4dp;
131 	pud_t *pudp;
132 	pmd_t *pmdp;
133 	pte_t *ptep;
134 	/*
135 	 * Make sure task size is correct as per the max adddr
136 	 */
137 	BUILD_BUG_ON(TASK_SIZE_USER64 > RADIX_PGTABLE_RANGE);
138 
139 #ifdef CONFIG_PPC_64K_PAGES
140 	BUILD_BUG_ON(RADIX_KERN_MAP_SIZE != (1UL << MAX_EA_BITS_PER_CONTEXT));
141 #endif
142 
143 	if (unlikely(!slab_is_available()))
144 		return early_map_kernel_page(ea, pa, flags, map_page_size,
145 						nid, region_start, region_end);
146 
147 	/*
148 	 * Should make page table allocation functions be able to take a
149 	 * node, so we can place kernel page tables on the right nodes after
150 	 * boot.
151 	 */
152 	pgdp = pgd_offset_k(ea);
153 	p4dp = p4d_offset(pgdp, ea);
154 	pudp = pud_alloc(&init_mm, p4dp, ea);
155 	if (!pudp)
156 		return -ENOMEM;
157 	if (map_page_size == PUD_SIZE) {
158 		ptep = (pte_t *)pudp;
159 		goto set_the_pte;
160 	}
161 	pmdp = pmd_alloc(&init_mm, pudp, ea);
162 	if (!pmdp)
163 		return -ENOMEM;
164 	if (map_page_size == PMD_SIZE) {
165 		ptep = pmdp_ptep(pmdp);
166 		goto set_the_pte;
167 	}
168 	ptep = pte_alloc_kernel(pmdp, ea);
169 	if (!ptep)
170 		return -ENOMEM;
171 
172 set_the_pte:
173 	set_pte_at(&init_mm, ea, ptep, pfn_pte(pfn, flags));
174 	asm volatile("ptesync": : :"memory");
175 	return 0;
176 }
177 
178 int radix__map_kernel_page(unsigned long ea, unsigned long pa,
179 			  pgprot_t flags,
180 			  unsigned int map_page_size)
181 {
182 	return __map_kernel_page(ea, pa, flags, map_page_size, -1, 0, 0);
183 }
184 
185 #ifdef CONFIG_STRICT_KERNEL_RWX
186 static void radix__change_memory_range(unsigned long start, unsigned long end,
187 				       unsigned long clear)
188 {
189 	unsigned long idx;
190 	pgd_t *pgdp;
191 	p4d_t *p4dp;
192 	pud_t *pudp;
193 	pmd_t *pmdp;
194 	pte_t *ptep;
195 
196 	start = ALIGN_DOWN(start, PAGE_SIZE);
197 	end = PAGE_ALIGN(end); // aligns up
198 
199 	pr_debug("Changing flags on range %lx-%lx removing 0x%lx\n",
200 		 start, end, clear);
201 
202 	for (idx = start; idx < end; idx += PAGE_SIZE) {
203 		pgdp = pgd_offset_k(idx);
204 		p4dp = p4d_offset(pgdp, idx);
205 		pudp = pud_alloc(&init_mm, p4dp, idx);
206 		if (!pudp)
207 			continue;
208 		if (pud_is_leaf(*pudp)) {
209 			ptep = (pte_t *)pudp;
210 			goto update_the_pte;
211 		}
212 		pmdp = pmd_alloc(&init_mm, pudp, idx);
213 		if (!pmdp)
214 			continue;
215 		if (pmd_is_leaf(*pmdp)) {
216 			ptep = pmdp_ptep(pmdp);
217 			goto update_the_pte;
218 		}
219 		ptep = pte_alloc_kernel(pmdp, idx);
220 		if (!ptep)
221 			continue;
222 update_the_pte:
223 		radix__pte_update(&init_mm, idx, ptep, clear, 0, 0);
224 	}
225 
226 	radix__flush_tlb_kernel_range(start, end);
227 }
228 
229 void radix__mark_rodata_ro(void)
230 {
231 	unsigned long start, end;
232 
233 	start = (unsigned long)_stext;
234 	end = (unsigned long)__end_rodata;
235 
236 	radix__change_memory_range(start, end, _PAGE_WRITE);
237 
238 	for (start = PAGE_OFFSET; start < (unsigned long)_stext; start += PAGE_SIZE) {
239 		end = start + PAGE_SIZE;
240 		if (overlaps_interrupt_vector_text(start, end))
241 			radix__change_memory_range(start, end, _PAGE_WRITE);
242 		else
243 			break;
244 	}
245 }
246 
247 void radix__mark_initmem_nx(void)
248 {
249 	unsigned long start = (unsigned long)__init_begin;
250 	unsigned long end = (unsigned long)__init_end;
251 
252 	radix__change_memory_range(start, end, _PAGE_EXEC);
253 }
254 #endif /* CONFIG_STRICT_KERNEL_RWX */
255 
256 static inline void __meminit
257 print_mapping(unsigned long start, unsigned long end, unsigned long size, bool exec)
258 {
259 	char buf[10];
260 
261 	if (end <= start)
262 		return;
263 
264 	string_get_size(size, 1, STRING_UNITS_2, buf, sizeof(buf));
265 
266 	pr_info("Mapped 0x%016lx-0x%016lx with %s pages%s\n", start, end, buf,
267 		exec ? " (exec)" : "");
268 }
269 
270 static unsigned long next_boundary(unsigned long addr, unsigned long end)
271 {
272 #ifdef CONFIG_STRICT_KERNEL_RWX
273 	unsigned long stext_phys;
274 
275 	stext_phys = __pa_symbol(_stext);
276 
277 	// Relocatable kernel running at non-zero real address
278 	if (stext_phys != 0) {
279 		// The end of interrupts code at zero is a rodata boundary
280 		unsigned long end_intr = __pa_symbol(__end_interrupts) - stext_phys;
281 		if (addr < end_intr)
282 			return end_intr;
283 
284 		// Start of relocated kernel text is a rodata boundary
285 		if (addr < stext_phys)
286 			return stext_phys;
287 	}
288 
289 	if (addr < __pa_symbol(__srwx_boundary))
290 		return __pa_symbol(__srwx_boundary);
291 #endif
292 	return end;
293 }
294 
295 static int __meminit create_physical_mapping(unsigned long start,
296 					     unsigned long end,
297 					     int nid, pgprot_t _prot)
298 {
299 	unsigned long vaddr, addr, mapping_size = 0;
300 	bool prev_exec, exec = false;
301 	pgprot_t prot;
302 	int psize;
303 	unsigned long max_mapping_size = radix_mem_block_size;
304 
305 	if (debug_pagealloc_enabled_or_kfence())
306 		max_mapping_size = PAGE_SIZE;
307 
308 	start = ALIGN(start, PAGE_SIZE);
309 	end   = ALIGN_DOWN(end, PAGE_SIZE);
310 	for (addr = start; addr < end; addr += mapping_size) {
311 		unsigned long gap, previous_size;
312 		int rc;
313 
314 		gap = next_boundary(addr, end) - addr;
315 		if (gap > max_mapping_size)
316 			gap = max_mapping_size;
317 		previous_size = mapping_size;
318 		prev_exec = exec;
319 
320 		if (IS_ALIGNED(addr, PUD_SIZE) && gap >= PUD_SIZE &&
321 		    mmu_psize_defs[MMU_PAGE_1G].shift) {
322 			mapping_size = PUD_SIZE;
323 			psize = MMU_PAGE_1G;
324 		} else if (IS_ALIGNED(addr, PMD_SIZE) && gap >= PMD_SIZE &&
325 			   mmu_psize_defs[MMU_PAGE_2M].shift) {
326 			mapping_size = PMD_SIZE;
327 			psize = MMU_PAGE_2M;
328 		} else {
329 			mapping_size = PAGE_SIZE;
330 			psize = mmu_virtual_psize;
331 		}
332 
333 		vaddr = (unsigned long)__va(addr);
334 
335 		if (overlaps_kernel_text(vaddr, vaddr + mapping_size) ||
336 		    overlaps_interrupt_vector_text(vaddr, vaddr + mapping_size)) {
337 			prot = PAGE_KERNEL_X;
338 			exec = true;
339 		} else {
340 			prot = _prot;
341 			exec = false;
342 		}
343 
344 		if (mapping_size != previous_size || exec != prev_exec) {
345 			print_mapping(start, addr, previous_size, prev_exec);
346 			start = addr;
347 		}
348 
349 		rc = __map_kernel_page(vaddr, addr, prot, mapping_size, nid, start, end);
350 		if (rc)
351 			return rc;
352 
353 		update_page_count(psize, 1);
354 	}
355 
356 	print_mapping(start, addr, mapping_size, exec);
357 	return 0;
358 }
359 
360 static void __init radix_init_pgtable(void)
361 {
362 	unsigned long rts_field;
363 	phys_addr_t start, end;
364 	u64 i;
365 
366 	/* We don't support slb for radix */
367 	slb_set_size(0);
368 
369 	/*
370 	 * Create the linear mapping
371 	 */
372 	for_each_mem_range(i, &start, &end) {
373 		/*
374 		 * The memblock allocator  is up at this point, so the
375 		 * page tables will be allocated within the range. No
376 		 * need or a node (which we don't have yet).
377 		 */
378 
379 		if (end >= RADIX_VMALLOC_START) {
380 			pr_warn("Outside the supported range\n");
381 			continue;
382 		}
383 
384 		WARN_ON(create_physical_mapping(start, end,
385 						-1, PAGE_KERNEL));
386 	}
387 
388 	if (!cpu_has_feature(CPU_FTR_HVMODE) &&
389 			cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
390 		/*
391 		 * Older versions of KVM on these machines prefer if the
392 		 * guest only uses the low 19 PID bits.
393 		 */
394 		mmu_pid_bits = 19;
395 	}
396 	mmu_base_pid = 1;
397 
398 	/*
399 	 * Allocate Partition table and process table for the
400 	 * host.
401 	 */
402 	BUG_ON(PRTB_SIZE_SHIFT > 36);
403 	process_tb = early_alloc_pgtable(1UL << PRTB_SIZE_SHIFT, -1, 0, 0);
404 	/*
405 	 * Fill in the process table.
406 	 */
407 	rts_field = radix__get_tree_size();
408 	process_tb->prtb0 = cpu_to_be64(rts_field | __pa(init_mm.pgd) | RADIX_PGD_INDEX_SIZE);
409 
410 	/*
411 	 * The init_mm context is given the first available (non-zero) PID,
412 	 * which is the "guard PID" and contains no page table. PIDR should
413 	 * never be set to zero because that duplicates the kernel address
414 	 * space at the 0x0... offset (quadrant 0)!
415 	 *
416 	 * An arbitrary PID that may later be allocated by the PID allocator
417 	 * for userspace processes must not be used either, because that
418 	 * would cause stale user mappings for that PID on CPUs outside of
419 	 * the TLB invalidation scheme (because it won't be in mm_cpumask).
420 	 *
421 	 * So permanently carve out one PID for the purpose of a guard PID.
422 	 */
423 	init_mm.context.id = mmu_base_pid;
424 	mmu_base_pid++;
425 }
426 
427 static void __init radix_init_partition_table(void)
428 {
429 	unsigned long rts_field, dw0, dw1;
430 
431 	mmu_partition_table_init();
432 	rts_field = radix__get_tree_size();
433 	dw0 = rts_field | __pa(init_mm.pgd) | RADIX_PGD_INDEX_SIZE | PATB_HR;
434 	dw1 = __pa(process_tb) | (PRTB_SIZE_SHIFT - 12) | PATB_GR;
435 	mmu_partition_table_set_entry(0, dw0, dw1, false);
436 
437 	pr_info("Initializing Radix MMU\n");
438 }
439 
440 static int __init get_idx_from_shift(unsigned int shift)
441 {
442 	int idx = -1;
443 
444 	switch (shift) {
445 	case 0xc:
446 		idx = MMU_PAGE_4K;
447 		break;
448 	case 0x10:
449 		idx = MMU_PAGE_64K;
450 		break;
451 	case 0x15:
452 		idx = MMU_PAGE_2M;
453 		break;
454 	case 0x1e:
455 		idx = MMU_PAGE_1G;
456 		break;
457 	}
458 	return idx;
459 }
460 
461 static int __init radix_dt_scan_page_sizes(unsigned long node,
462 					   const char *uname, int depth,
463 					   void *data)
464 {
465 	int size = 0;
466 	int shift, idx;
467 	unsigned int ap;
468 	const __be32 *prop;
469 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
470 
471 	/* We are scanning "cpu" nodes only */
472 	if (type == NULL || strcmp(type, "cpu") != 0)
473 		return 0;
474 
475 	/* Grab page size encodings */
476 	prop = of_get_flat_dt_prop(node, "ibm,processor-radix-AP-encodings", &size);
477 	if (!prop)
478 		return 0;
479 
480 	pr_info("Page sizes from device-tree:\n");
481 	for (; size >= 4; size -= 4, ++prop) {
482 
483 		struct mmu_psize_def *def;
484 
485 		/* top 3 bit is AP encoding */
486 		shift = be32_to_cpu(prop[0]) & ~(0xe << 28);
487 		ap = be32_to_cpu(prop[0]) >> 29;
488 		pr_info("Page size shift = %d AP=0x%x\n", shift, ap);
489 
490 		idx = get_idx_from_shift(shift);
491 		if (idx < 0)
492 			continue;
493 
494 		def = &mmu_psize_defs[idx];
495 		def->shift = shift;
496 		def->ap  = ap;
497 		def->h_rpt_pgsize = psize_to_rpti_pgsize(idx);
498 	}
499 
500 	/* needed ? */
501 	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
502 	return 1;
503 }
504 
505 #ifdef CONFIG_MEMORY_HOTPLUG
506 static int __init probe_memory_block_size(unsigned long node, const char *uname, int
507 					  depth, void *data)
508 {
509 	unsigned long *mem_block_size = (unsigned long *)data;
510 	const __be32 *prop;
511 	int len;
512 
513 	if (depth != 1)
514 		return 0;
515 
516 	if (strcmp(uname, "ibm,dynamic-reconfiguration-memory"))
517 		return 0;
518 
519 	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
520 
521 	if (!prop || len < dt_root_size_cells * sizeof(__be32))
522 		/*
523 		 * Nothing in the device tree
524 		 */
525 		*mem_block_size = MIN_MEMORY_BLOCK_SIZE;
526 	else
527 		*mem_block_size = of_read_number(prop, dt_root_size_cells);
528 	return 1;
529 }
530 
531 static unsigned long __init radix_memory_block_size(void)
532 {
533 	unsigned long mem_block_size = MIN_MEMORY_BLOCK_SIZE;
534 
535 	/*
536 	 * OPAL firmware feature is set by now. Hence we are ok
537 	 * to test OPAL feature.
538 	 */
539 	if (firmware_has_feature(FW_FEATURE_OPAL))
540 		mem_block_size = 1UL * 1024 * 1024 * 1024;
541 	else
542 		of_scan_flat_dt(probe_memory_block_size, &mem_block_size);
543 
544 	return mem_block_size;
545 }
546 
547 #else   /* CONFIG_MEMORY_HOTPLUG */
548 
549 static unsigned long __init radix_memory_block_size(void)
550 {
551 	return 1UL * 1024 * 1024 * 1024;
552 }
553 
554 #endif /* CONFIG_MEMORY_HOTPLUG */
555 
556 
557 void __init radix__early_init_devtree(void)
558 {
559 	int rc;
560 
561 	/*
562 	 * Try to find the available page sizes in the device-tree
563 	 */
564 	rc = of_scan_flat_dt(radix_dt_scan_page_sizes, NULL);
565 	if (!rc) {
566 		/*
567 		 * No page size details found in device tree.
568 		 * Let's assume we have page 4k and 64k support
569 		 */
570 		mmu_psize_defs[MMU_PAGE_4K].shift = 12;
571 		mmu_psize_defs[MMU_PAGE_4K].ap = 0x0;
572 		mmu_psize_defs[MMU_PAGE_4K].h_rpt_pgsize =
573 			psize_to_rpti_pgsize(MMU_PAGE_4K);
574 
575 		mmu_psize_defs[MMU_PAGE_64K].shift = 16;
576 		mmu_psize_defs[MMU_PAGE_64K].ap = 0x5;
577 		mmu_psize_defs[MMU_PAGE_64K].h_rpt_pgsize =
578 			psize_to_rpti_pgsize(MMU_PAGE_64K);
579 	}
580 
581 	/*
582 	 * Max mapping size used when mapping pages. We don't use
583 	 * ppc_md.memory_block_size() here because this get called
584 	 * early and we don't have machine probe called yet. Also
585 	 * the pseries implementation only check for ibm,lmb-size.
586 	 * All hypervisor supporting radix do expose that device
587 	 * tree node.
588 	 */
589 	radix_mem_block_size = radix_memory_block_size();
590 	return;
591 }
592 
593 void __init radix__early_init_mmu(void)
594 {
595 	unsigned long lpcr;
596 
597 #ifdef CONFIG_PPC_64S_HASH_MMU
598 #ifdef CONFIG_PPC_64K_PAGES
599 	/* PAGE_SIZE mappings */
600 	mmu_virtual_psize = MMU_PAGE_64K;
601 #else
602 	mmu_virtual_psize = MMU_PAGE_4K;
603 #endif
604 
605 #ifdef CONFIG_SPARSEMEM_VMEMMAP
606 	/* vmemmap mapping */
607 	if (mmu_psize_defs[MMU_PAGE_2M].shift) {
608 		/*
609 		 * map vmemmap using 2M if available
610 		 */
611 		mmu_vmemmap_psize = MMU_PAGE_2M;
612 	} else
613 		mmu_vmemmap_psize = mmu_virtual_psize;
614 #endif
615 #endif
616 	/*
617 	 * initialize page table size
618 	 */
619 	__pte_index_size = RADIX_PTE_INDEX_SIZE;
620 	__pmd_index_size = RADIX_PMD_INDEX_SIZE;
621 	__pud_index_size = RADIX_PUD_INDEX_SIZE;
622 	__pgd_index_size = RADIX_PGD_INDEX_SIZE;
623 	__pud_cache_index = RADIX_PUD_INDEX_SIZE;
624 	__pte_table_size = RADIX_PTE_TABLE_SIZE;
625 	__pmd_table_size = RADIX_PMD_TABLE_SIZE;
626 	__pud_table_size = RADIX_PUD_TABLE_SIZE;
627 	__pgd_table_size = RADIX_PGD_TABLE_SIZE;
628 
629 	__pmd_val_bits = RADIX_PMD_VAL_BITS;
630 	__pud_val_bits = RADIX_PUD_VAL_BITS;
631 	__pgd_val_bits = RADIX_PGD_VAL_BITS;
632 
633 	__kernel_virt_start = RADIX_KERN_VIRT_START;
634 	__vmalloc_start = RADIX_VMALLOC_START;
635 	__vmalloc_end = RADIX_VMALLOC_END;
636 	__kernel_io_start = RADIX_KERN_IO_START;
637 	__kernel_io_end = RADIX_KERN_IO_END;
638 	vmemmap = (struct page *)RADIX_VMEMMAP_START;
639 	ioremap_bot = IOREMAP_BASE;
640 
641 #ifdef CONFIG_PCI
642 	pci_io_base = ISA_IO_BASE;
643 #endif
644 	__pte_frag_nr = RADIX_PTE_FRAG_NR;
645 	__pte_frag_size_shift = RADIX_PTE_FRAG_SIZE_SHIFT;
646 	__pmd_frag_nr = RADIX_PMD_FRAG_NR;
647 	__pmd_frag_size_shift = RADIX_PMD_FRAG_SIZE_SHIFT;
648 
649 	radix_init_pgtable();
650 
651 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
652 		lpcr = mfspr(SPRN_LPCR);
653 		mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
654 		radix_init_partition_table();
655 	} else {
656 		radix_init_pseries();
657 	}
658 
659 	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
660 
661 	/* Switch to the guard PID before turning on MMU */
662 	radix__switch_mmu_context(NULL, &init_mm);
663 	tlbiel_all();
664 }
665 
666 void radix__early_init_mmu_secondary(void)
667 {
668 	unsigned long lpcr;
669 	/*
670 	 * update partition table control register and UPRT
671 	 */
672 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
673 		lpcr = mfspr(SPRN_LPCR);
674 		mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
675 
676 		set_ptcr_when_no_uv(__pa(partition_tb) |
677 				    (PATB_SIZE_SHIFT - 12));
678 	}
679 
680 	radix__switch_mmu_context(NULL, &init_mm);
681 	tlbiel_all();
682 
683 	/* Make sure userspace can't change the AMR */
684 	mtspr(SPRN_UAMOR, 0);
685 }
686 
687 /* Called during kexec sequence with MMU off */
688 notrace void radix__mmu_cleanup_all(void)
689 {
690 	unsigned long lpcr;
691 
692 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
693 		lpcr = mfspr(SPRN_LPCR);
694 		mtspr(SPRN_LPCR, lpcr & ~LPCR_UPRT);
695 		set_ptcr_when_no_uv(0);
696 		powernv_set_nmmu_ptcr(0);
697 		radix__flush_tlb_all();
698 	}
699 }
700 
701 #ifdef CONFIG_MEMORY_HOTPLUG
702 static void free_pte_table(pte_t *pte_start, pmd_t *pmd)
703 {
704 	pte_t *pte;
705 	int i;
706 
707 	for (i = 0; i < PTRS_PER_PTE; i++) {
708 		pte = pte_start + i;
709 		if (!pte_none(*pte))
710 			return;
711 	}
712 
713 	pte_free_kernel(&init_mm, pte_start);
714 	pmd_clear(pmd);
715 }
716 
717 static void free_pmd_table(pmd_t *pmd_start, pud_t *pud)
718 {
719 	pmd_t *pmd;
720 	int i;
721 
722 	for (i = 0; i < PTRS_PER_PMD; i++) {
723 		pmd = pmd_start + i;
724 		if (!pmd_none(*pmd))
725 			return;
726 	}
727 
728 	pmd_free(&init_mm, pmd_start);
729 	pud_clear(pud);
730 }
731 
732 static void free_pud_table(pud_t *pud_start, p4d_t *p4d)
733 {
734 	pud_t *pud;
735 	int i;
736 
737 	for (i = 0; i < PTRS_PER_PUD; i++) {
738 		pud = pud_start + i;
739 		if (!pud_none(*pud))
740 			return;
741 	}
742 
743 	pud_free(&init_mm, pud_start);
744 	p4d_clear(p4d);
745 }
746 
747 static void remove_pte_table(pte_t *pte_start, unsigned long addr,
748 			     unsigned long end)
749 {
750 	unsigned long next;
751 	pte_t *pte;
752 
753 	pte = pte_start + pte_index(addr);
754 	for (; addr < end; addr = next, pte++) {
755 		next = (addr + PAGE_SIZE) & PAGE_MASK;
756 		if (next > end)
757 			next = end;
758 
759 		if (!pte_present(*pte))
760 			continue;
761 
762 		if (!PAGE_ALIGNED(addr) || !PAGE_ALIGNED(next)) {
763 			/*
764 			 * The vmemmap_free() and remove_section_mapping()
765 			 * codepaths call us with aligned addresses.
766 			 */
767 			WARN_ONCE(1, "%s: unaligned range\n", __func__);
768 			continue;
769 		}
770 
771 		pte_clear(&init_mm, addr, pte);
772 	}
773 }
774 
775 static void __meminit remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
776 			     unsigned long end)
777 {
778 	unsigned long next;
779 	pte_t *pte_base;
780 	pmd_t *pmd;
781 
782 	pmd = pmd_start + pmd_index(addr);
783 	for (; addr < end; addr = next, pmd++) {
784 		next = pmd_addr_end(addr, end);
785 
786 		if (!pmd_present(*pmd))
787 			continue;
788 
789 		if (pmd_is_leaf(*pmd)) {
790 			if (!IS_ALIGNED(addr, PMD_SIZE) ||
791 			    !IS_ALIGNED(next, PMD_SIZE)) {
792 				WARN_ONCE(1, "%s: unaligned range\n", __func__);
793 				continue;
794 			}
795 			pte_clear(&init_mm, addr, (pte_t *)pmd);
796 			continue;
797 		}
798 
799 		pte_base = (pte_t *)pmd_page_vaddr(*pmd);
800 		remove_pte_table(pte_base, addr, next);
801 		free_pte_table(pte_base, pmd);
802 	}
803 }
804 
805 static void __meminit remove_pud_table(pud_t *pud_start, unsigned long addr,
806 			     unsigned long end)
807 {
808 	unsigned long next;
809 	pmd_t *pmd_base;
810 	pud_t *pud;
811 
812 	pud = pud_start + pud_index(addr);
813 	for (; addr < end; addr = next, pud++) {
814 		next = pud_addr_end(addr, end);
815 
816 		if (!pud_present(*pud))
817 			continue;
818 
819 		if (pud_is_leaf(*pud)) {
820 			if (!IS_ALIGNED(addr, PUD_SIZE) ||
821 			    !IS_ALIGNED(next, PUD_SIZE)) {
822 				WARN_ONCE(1, "%s: unaligned range\n", __func__);
823 				continue;
824 			}
825 			pte_clear(&init_mm, addr, (pte_t *)pud);
826 			continue;
827 		}
828 
829 		pmd_base = pud_pgtable(*pud);
830 		remove_pmd_table(pmd_base, addr, next);
831 		free_pmd_table(pmd_base, pud);
832 	}
833 }
834 
835 static void __meminit remove_pagetable(unsigned long start, unsigned long end)
836 {
837 	unsigned long addr, next;
838 	pud_t *pud_base;
839 	pgd_t *pgd;
840 	p4d_t *p4d;
841 
842 	spin_lock(&init_mm.page_table_lock);
843 
844 	for (addr = start; addr < end; addr = next) {
845 		next = pgd_addr_end(addr, end);
846 
847 		pgd = pgd_offset_k(addr);
848 		p4d = p4d_offset(pgd, addr);
849 		if (!p4d_present(*p4d))
850 			continue;
851 
852 		if (p4d_is_leaf(*p4d)) {
853 			if (!IS_ALIGNED(addr, P4D_SIZE) ||
854 			    !IS_ALIGNED(next, P4D_SIZE)) {
855 				WARN_ONCE(1, "%s: unaligned range\n", __func__);
856 				continue;
857 			}
858 
859 			pte_clear(&init_mm, addr, (pte_t *)pgd);
860 			continue;
861 		}
862 
863 		pud_base = p4d_pgtable(*p4d);
864 		remove_pud_table(pud_base, addr, next);
865 		free_pud_table(pud_base, p4d);
866 	}
867 
868 	spin_unlock(&init_mm.page_table_lock);
869 	radix__flush_tlb_kernel_range(start, end);
870 }
871 
872 int __meminit radix__create_section_mapping(unsigned long start,
873 					    unsigned long end, int nid,
874 					    pgprot_t prot)
875 {
876 	if (end >= RADIX_VMALLOC_START) {
877 		pr_warn("Outside the supported range\n");
878 		return -1;
879 	}
880 
881 	return create_physical_mapping(__pa(start), __pa(end),
882 				       nid, prot);
883 }
884 
885 int __meminit radix__remove_section_mapping(unsigned long start, unsigned long end)
886 {
887 	remove_pagetable(start, end);
888 	return 0;
889 }
890 #endif /* CONFIG_MEMORY_HOTPLUG */
891 
892 #ifdef CONFIG_SPARSEMEM_VMEMMAP
893 static int __map_kernel_page_nid(unsigned long ea, unsigned long pa,
894 				 pgprot_t flags, unsigned int map_page_size,
895 				 int nid)
896 {
897 	return __map_kernel_page(ea, pa, flags, map_page_size, nid, 0, 0);
898 }
899 
900 int __meminit radix__vmemmap_create_mapping(unsigned long start,
901 				      unsigned long page_size,
902 				      unsigned long phys)
903 {
904 	/* Create a PTE encoding */
905 	unsigned long flags = _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_KERNEL_RW;
906 	int nid = early_pfn_to_nid(phys >> PAGE_SHIFT);
907 	int ret;
908 
909 	if ((start + page_size) >= RADIX_VMEMMAP_END) {
910 		pr_warn("Outside the supported range\n");
911 		return -1;
912 	}
913 
914 	ret = __map_kernel_page_nid(start, phys, __pgprot(flags), page_size, nid);
915 	BUG_ON(ret);
916 
917 	return 0;
918 }
919 
920 #ifdef CONFIG_MEMORY_HOTPLUG
921 void __meminit radix__vmemmap_remove_mapping(unsigned long start, unsigned long page_size)
922 {
923 	remove_pagetable(start, start + page_size);
924 }
925 #endif
926 #endif
927 
928 #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE)
929 void radix__kernel_map_pages(struct page *page, int numpages, int enable)
930 {
931 	unsigned long addr;
932 
933 	addr = (unsigned long)page_address(page);
934 
935 	if (enable)
936 		set_memory_p(addr, numpages);
937 	else
938 		set_memory_np(addr, numpages);
939 }
940 #endif
941 
942 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
943 
944 unsigned long radix__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
945 				  pmd_t *pmdp, unsigned long clr,
946 				  unsigned long set)
947 {
948 	unsigned long old;
949 
950 #ifdef CONFIG_DEBUG_VM
951 	WARN_ON(!radix__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
952 	assert_spin_locked(pmd_lockptr(mm, pmdp));
953 #endif
954 
955 	old = radix__pte_update(mm, addr, (pte_t *)pmdp, clr, set, 1);
956 	trace_hugepage_update(addr, old, clr, set);
957 
958 	return old;
959 }
960 
961 pmd_t radix__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
962 			pmd_t *pmdp)
963 
964 {
965 	pmd_t pmd;
966 
967 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
968 	VM_BUG_ON(radix__pmd_trans_huge(*pmdp));
969 	VM_BUG_ON(pmd_devmap(*pmdp));
970 	/*
971 	 * khugepaged calls this for normal pmd
972 	 */
973 	pmd = *pmdp;
974 	pmd_clear(pmdp);
975 
976 	radix__flush_tlb_collapsed_pmd(vma->vm_mm, address);
977 
978 	return pmd;
979 }
980 
981 /*
982  * For us pgtable_t is pte_t *. Inorder to save the deposisted
983  * page table, we consider the allocated page table as a list
984  * head. On withdraw we need to make sure we zero out the used
985  * list_head memory area.
986  */
987 void radix__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
988 				 pgtable_t pgtable)
989 {
990 	struct list_head *lh = (struct list_head *) pgtable;
991 
992 	assert_spin_locked(pmd_lockptr(mm, pmdp));
993 
994 	/* FIFO */
995 	if (!pmd_huge_pte(mm, pmdp))
996 		INIT_LIST_HEAD(lh);
997 	else
998 		list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
999 	pmd_huge_pte(mm, pmdp) = pgtable;
1000 }
1001 
1002 pgtable_t radix__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
1003 {
1004 	pte_t *ptep;
1005 	pgtable_t pgtable;
1006 	struct list_head *lh;
1007 
1008 	assert_spin_locked(pmd_lockptr(mm, pmdp));
1009 
1010 	/* FIFO */
1011 	pgtable = pmd_huge_pte(mm, pmdp);
1012 	lh = (struct list_head *) pgtable;
1013 	if (list_empty(lh))
1014 		pmd_huge_pte(mm, pmdp) = NULL;
1015 	else {
1016 		pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
1017 		list_del(lh);
1018 	}
1019 	ptep = (pte_t *) pgtable;
1020 	*ptep = __pte(0);
1021 	ptep++;
1022 	*ptep = __pte(0);
1023 	return pgtable;
1024 }
1025 
1026 pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm,
1027 				     unsigned long addr, pmd_t *pmdp)
1028 {
1029 	pmd_t old_pmd;
1030 	unsigned long old;
1031 
1032 	old = radix__pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
1033 	old_pmd = __pmd(old);
1034 	return old_pmd;
1035 }
1036 
1037 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1038 
1039 void radix__ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep,
1040 				  pte_t entry, unsigned long address, int psize)
1041 {
1042 	struct mm_struct *mm = vma->vm_mm;
1043 	unsigned long set = pte_val(entry) & (_PAGE_DIRTY | _PAGE_SOFT_DIRTY |
1044 					      _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
1045 
1046 	unsigned long change = pte_val(entry) ^ pte_val(*ptep);
1047 	/*
1048 	 * On POWER9, the NMMU is not able to relax PTE access permissions
1049 	 * for a translation with a TLB. The PTE must be invalidated, TLB
1050 	 * flushed before the new PTE is installed.
1051 	 *
1052 	 * This only needs to be done for radix, because hash translation does
1053 	 * flush when updating the linux pte (and we don't support NMMU
1054 	 * accelerators on HPT on POWER9 anyway XXX: do we?).
1055 	 *
1056 	 * POWER10 (and P9P) NMMU does behave as per ISA.
1057 	 */
1058 	if (!cpu_has_feature(CPU_FTR_ARCH_31) && (change & _PAGE_RW) &&
1059 	    atomic_read(&mm->context.copros) > 0) {
1060 		unsigned long old_pte, new_pte;
1061 
1062 		old_pte = __radix_pte_update(ptep, _PAGE_PRESENT, _PAGE_INVALID);
1063 		new_pte = old_pte | set;
1064 		radix__flush_tlb_page_psize(mm, address, psize);
1065 		__radix_pte_update(ptep, _PAGE_INVALID, new_pte);
1066 	} else {
1067 		__radix_pte_update(ptep, 0, set);
1068 		/*
1069 		 * Book3S does not require a TLB flush when relaxing access
1070 		 * restrictions when the address space (modulo the POWER9 nest
1071 		 * MMU issue above) because the MMU will reload the PTE after
1072 		 * taking an access fault, as defined by the architecture. See
1073 		 * "Setting a Reference or Change Bit or Upgrading Access
1074 		 *  Authority (PTE Subject to Atomic Hardware Updates)" in
1075 		 *  Power ISA Version 3.1B.
1076 		 */
1077 	}
1078 	/* See ptesync comment in radix__set_pte_at */
1079 }
1080 
1081 void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
1082 				    unsigned long addr, pte_t *ptep,
1083 				    pte_t old_pte, pte_t pte)
1084 {
1085 	struct mm_struct *mm = vma->vm_mm;
1086 
1087 	/*
1088 	 * POWER9 NMMU must flush the TLB after clearing the PTE before
1089 	 * installing a PTE with more relaxed access permissions, see
1090 	 * radix__ptep_set_access_flags.
1091 	 */
1092 	if (!cpu_has_feature(CPU_FTR_ARCH_31) &&
1093 	    is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) &&
1094 	    (atomic_read(&mm->context.copros) > 0))
1095 		radix__flush_tlb_page(vma, addr);
1096 
1097 	set_pte_at(mm, addr, ptep, pte);
1098 }
1099 
1100 int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
1101 {
1102 	pte_t *ptep = (pte_t *)pud;
1103 	pte_t new_pud = pfn_pte(__phys_to_pfn(addr), prot);
1104 
1105 	if (!radix_enabled())
1106 		return 0;
1107 
1108 	set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pud);
1109 
1110 	return 1;
1111 }
1112 
1113 int pud_clear_huge(pud_t *pud)
1114 {
1115 	if (pud_is_leaf(*pud)) {
1116 		pud_clear(pud);
1117 		return 1;
1118 	}
1119 
1120 	return 0;
1121 }
1122 
1123 int pud_free_pmd_page(pud_t *pud, unsigned long addr)
1124 {
1125 	pmd_t *pmd;
1126 	int i;
1127 
1128 	pmd = pud_pgtable(*pud);
1129 	pud_clear(pud);
1130 
1131 	flush_tlb_kernel_range(addr, addr + PUD_SIZE);
1132 
1133 	for (i = 0; i < PTRS_PER_PMD; i++) {
1134 		if (!pmd_none(pmd[i])) {
1135 			pte_t *pte;
1136 			pte = (pte_t *)pmd_page_vaddr(pmd[i]);
1137 
1138 			pte_free_kernel(&init_mm, pte);
1139 		}
1140 	}
1141 
1142 	pmd_free(&init_mm, pmd);
1143 
1144 	return 1;
1145 }
1146 
1147 int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
1148 {
1149 	pte_t *ptep = (pte_t *)pmd;
1150 	pte_t new_pmd = pfn_pte(__phys_to_pfn(addr), prot);
1151 
1152 	if (!radix_enabled())
1153 		return 0;
1154 
1155 	set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pmd);
1156 
1157 	return 1;
1158 }
1159 
1160 int pmd_clear_huge(pmd_t *pmd)
1161 {
1162 	if (pmd_is_leaf(*pmd)) {
1163 		pmd_clear(pmd);
1164 		return 1;
1165 	}
1166 
1167 	return 0;
1168 }
1169 
1170 int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
1171 {
1172 	pte_t *pte;
1173 
1174 	pte = (pte_t *)pmd_page_vaddr(*pmd);
1175 	pmd_clear(pmd);
1176 
1177 	flush_tlb_kernel_range(addr, addr + PMD_SIZE);
1178 
1179 	pte_free_kernel(&init_mm, pte);
1180 
1181 	return 1;
1182 }
1183