1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PowerPC64 port by Mike Corrigan and Dave Engebretsen
4  *   {mikejc|engebret}@us.ibm.com
5  *
6  *    Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
7  *
8  * SMP scalability work:
9  *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
10  *
11  *    Module name: htab.c
12  *
13  *    Description:
14  *      PowerPC Hashed Page Table functions
15  */
16 
17 #undef DEBUG
18 #undef DEBUG_LOW
19 
20 #define pr_fmt(fmt) "hash-mmu: " fmt
21 #include <linux/spinlock.h>
22 #include <linux/errno.h>
23 #include <linux/sched/mm.h>
24 #include <linux/proc_fs.h>
25 #include <linux/stat.h>
26 #include <linux/sysctl.h>
27 #include <linux/export.h>
28 #include <linux/ctype.h>
29 #include <linux/cache.h>
30 #include <linux/init.h>
31 #include <linux/signal.h>
32 #include <linux/memblock.h>
33 #include <linux/context_tracking.h>
34 #include <linux/libfdt.h>
35 #include <linux/pkeys.h>
36 #include <linux/hugetlb.h>
37 #include <linux/cpu.h>
38 #include <linux/pgtable.h>
39 
40 #include <asm/debugfs.h>
41 #include <asm/processor.h>
42 #include <asm/mmu.h>
43 #include <asm/mmu_context.h>
44 #include <asm/page.h>
45 #include <asm/types.h>
46 #include <linux/uaccess.h>
47 #include <asm/machdep.h>
48 #include <asm/prom.h>
49 #include <asm/io.h>
50 #include <asm/eeh.h>
51 #include <asm/tlb.h>
52 #include <asm/cacheflush.h>
53 #include <asm/cputable.h>
54 #include <asm/sections.h>
55 #include <asm/copro.h>
56 #include <asm/udbg.h>
57 #include <asm/code-patching.h>
58 #include <asm/fadump.h>
59 #include <asm/firmware.h>
60 #include <asm/tm.h>
61 #include <asm/trace.h>
62 #include <asm/ps3.h>
63 #include <asm/pte-walk.h>
64 #include <asm/asm-prototypes.h>
65 #include <asm/ultravisor.h>
66 
67 #include <mm/mmu_decl.h>
68 
69 #include "internal.h"
70 
71 
72 #ifdef DEBUG
73 #define DBG(fmt...) udbg_printf(fmt)
74 #else
75 #define DBG(fmt...)
76 #endif
77 
78 #ifdef DEBUG_LOW
79 #define DBG_LOW(fmt...) udbg_printf(fmt)
80 #else
81 #define DBG_LOW(fmt...)
82 #endif
83 
84 #define KB (1024)
85 #define MB (1024*KB)
86 #define GB (1024L*MB)
87 
88 /*
89  * Note:  pte   --> Linux PTE
90  *        HPTE  --> PowerPC Hashed Page Table Entry
91  *
92  * Execution context:
93  *   htab_initialize is called with the MMU off (of course), but
94  *   the kernel has been copied down to zero so it can directly
95  *   reference global data.  At this point it is very difficult
96  *   to print debug info.
97  *
98  */
99 
100 static unsigned long _SDR1;
101 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
102 EXPORT_SYMBOL_GPL(mmu_psize_defs);
103 
104 u8 hpte_page_sizes[1 << LP_BITS];
105 EXPORT_SYMBOL_GPL(hpte_page_sizes);
106 
107 struct hash_pte *htab_address;
108 unsigned long htab_size_bytes;
109 unsigned long htab_hash_mask;
110 EXPORT_SYMBOL_GPL(htab_hash_mask);
111 int mmu_linear_psize = MMU_PAGE_4K;
112 EXPORT_SYMBOL_GPL(mmu_linear_psize);
113 int mmu_virtual_psize = MMU_PAGE_4K;
114 int mmu_vmalloc_psize = MMU_PAGE_4K;
115 #ifdef CONFIG_SPARSEMEM_VMEMMAP
116 int mmu_vmemmap_psize = MMU_PAGE_4K;
117 #endif
118 int mmu_io_psize = MMU_PAGE_4K;
119 int mmu_kernel_ssize = MMU_SEGSIZE_256M;
120 EXPORT_SYMBOL_GPL(mmu_kernel_ssize);
121 int mmu_highuser_ssize = MMU_SEGSIZE_256M;
122 u16 mmu_slb_size = 64;
123 EXPORT_SYMBOL_GPL(mmu_slb_size);
124 #ifdef CONFIG_PPC_64K_PAGES
125 int mmu_ci_restrictions;
126 #endif
127 #ifdef CONFIG_DEBUG_PAGEALLOC
128 static u8 *linear_map_hash_slots;
129 static unsigned long linear_map_hash_count;
130 static DEFINE_SPINLOCK(linear_map_hash_lock);
131 #endif /* CONFIG_DEBUG_PAGEALLOC */
132 struct mmu_hash_ops mmu_hash_ops;
133 EXPORT_SYMBOL(mmu_hash_ops);
134 
135 /*
136  * These are definitions of page sizes arrays to be used when none
137  * is provided by the firmware.
138  */
139 
140 /*
141  * Fallback (4k pages only)
142  */
143 static struct mmu_psize_def mmu_psize_defaults[] = {
144 	[MMU_PAGE_4K] = {
145 		.shift	= 12,
146 		.sllp	= 0,
147 		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
148 		.avpnm	= 0,
149 		.tlbiel = 0,
150 	},
151 };
152 
153 /*
154  * POWER4, GPUL, POWER5
155  *
156  * Support for 16Mb large pages
157  */
158 static struct mmu_psize_def mmu_psize_defaults_gp[] = {
159 	[MMU_PAGE_4K] = {
160 		.shift	= 12,
161 		.sllp	= 0,
162 		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
163 		.avpnm	= 0,
164 		.tlbiel = 1,
165 	},
166 	[MMU_PAGE_16M] = {
167 		.shift	= 24,
168 		.sllp	= SLB_VSID_L,
169 		.penc   = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
170 			    [MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
171 		.avpnm	= 0x1UL,
172 		.tlbiel = 0,
173 	},
174 };
175 
176 /*
177  * 'R' and 'C' update notes:
178  *  - Under pHyp or KVM, the updatepp path will not set C, thus it *will*
179  *     create writeable HPTEs without C set, because the hcall H_PROTECT
180  *     that we use in that case will not update C
181  *  - The above is however not a problem, because we also don't do that
182  *     fancy "no flush" variant of eviction and we use H_REMOVE which will
183  *     do the right thing and thus we don't have the race I described earlier
184  *
185  *    - Under bare metal,  we do have the race, so we need R and C set
186  *    - We make sure R is always set and never lost
187  *    - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping
188  */
189 unsigned long htab_convert_pte_flags(unsigned long pteflags)
190 {
191 	unsigned long rflags = 0;
192 
193 	/* _PAGE_EXEC -> NOEXEC */
194 	if ((pteflags & _PAGE_EXEC) == 0)
195 		rflags |= HPTE_R_N;
196 	/*
197 	 * PPP bits:
198 	 * Linux uses slb key 0 for kernel and 1 for user.
199 	 * kernel RW areas are mapped with PPP=0b000
200 	 * User area is mapped with PPP=0b010 for read/write
201 	 * or PPP=0b011 for read-only (including writeable but clean pages).
202 	 */
203 	if (pteflags & _PAGE_PRIVILEGED) {
204 		/*
205 		 * Kernel read only mapped with ppp bits 0b110
206 		 */
207 		if (!(pteflags & _PAGE_WRITE)) {
208 			if (mmu_has_feature(MMU_FTR_KERNEL_RO))
209 				rflags |= (HPTE_R_PP0 | 0x2);
210 			else
211 				rflags |= 0x3;
212 		}
213 	} else {
214 		if (pteflags & _PAGE_RWX)
215 			rflags |= 0x2;
216 		if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
217 			rflags |= 0x1;
218 	}
219 	/*
220 	 * We can't allow hardware to update hpte bits. Hence always
221 	 * set 'R' bit and set 'C' if it is a write fault
222 	 */
223 	rflags |=  HPTE_R_R;
224 
225 	if (pteflags & _PAGE_DIRTY)
226 		rflags |= HPTE_R_C;
227 	/*
228 	 * Add in WIG bits
229 	 */
230 
231 	if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
232 		rflags |= HPTE_R_I;
233 	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
234 		rflags |= (HPTE_R_I | HPTE_R_G);
235 	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
236 		rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
237 	else
238 		/*
239 		 * Add memory coherence if cache inhibited is not set
240 		 */
241 		rflags |= HPTE_R_M;
242 
243 	rflags |= pte_to_hpte_pkey_bits(pteflags);
244 	return rflags;
245 }
246 
247 int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
248 		      unsigned long pstart, unsigned long prot,
249 		      int psize, int ssize)
250 {
251 	unsigned long vaddr, paddr;
252 	unsigned int step, shift;
253 	int ret = 0;
254 
255 	shift = mmu_psize_defs[psize].shift;
256 	step = 1 << shift;
257 
258 	prot = htab_convert_pte_flags(prot);
259 
260 	DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
261 	    vstart, vend, pstart, prot, psize, ssize);
262 
263 	for (vaddr = vstart, paddr = pstart; vaddr < vend;
264 	     vaddr += step, paddr += step) {
265 		unsigned long hash, hpteg;
266 		unsigned long vsid = get_kernel_vsid(vaddr, ssize);
267 		unsigned long vpn  = hpt_vpn(vaddr, vsid, ssize);
268 		unsigned long tprot = prot;
269 		bool secondary_hash = false;
270 
271 		/*
272 		 * If we hit a bad address return error.
273 		 */
274 		if (!vsid)
275 			return -1;
276 		/* Make kernel text executable */
277 		if (overlaps_kernel_text(vaddr, vaddr + step))
278 			tprot &= ~HPTE_R_N;
279 
280 		/*
281 		 * If relocatable, check if it overlaps interrupt vectors that
282 		 * are copied down to real 0. For relocatable kernel
283 		 * (e.g. kdump case) we copy interrupt vectors down to real
284 		 * address 0. Mark that region as executable. This is
285 		 * because on p8 system with relocation on exception feature
286 		 * enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence
287 		 * in order to execute the interrupt handlers in virtual
288 		 * mode the vector region need to be marked as executable.
289 		 */
290 		if ((PHYSICAL_START > MEMORY_START) &&
291 			overlaps_interrupt_vector_text(vaddr, vaddr + step))
292 				tprot &= ~HPTE_R_N;
293 
294 		hash = hpt_hash(vpn, shift, ssize);
295 		hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
296 
297 		BUG_ON(!mmu_hash_ops.hpte_insert);
298 repeat:
299 		ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
300 					       HPTE_V_BOLTED, psize, psize,
301 					       ssize);
302 		if (ret == -1) {
303 			/*
304 			 * Try to to keep bolted entries in primary.
305 			 * Remove non bolted entries and try insert again
306 			 */
307 			ret = mmu_hash_ops.hpte_remove(hpteg);
308 			if (ret != -1)
309 				ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
310 							       HPTE_V_BOLTED, psize, psize,
311 							       ssize);
312 			if (ret == -1 && !secondary_hash) {
313 				secondary_hash = true;
314 				hpteg = ((~hash & htab_hash_mask) * HPTES_PER_GROUP);
315 				goto repeat;
316 			}
317 		}
318 
319 		if (ret < 0)
320 			break;
321 
322 		cond_resched();
323 #ifdef CONFIG_DEBUG_PAGEALLOC
324 		if (debug_pagealloc_enabled() &&
325 			(paddr >> PAGE_SHIFT) < linear_map_hash_count)
326 			linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
327 #endif /* CONFIG_DEBUG_PAGEALLOC */
328 	}
329 	return ret < 0 ? ret : 0;
330 }
331 
332 int htab_remove_mapping(unsigned long vstart, unsigned long vend,
333 		      int psize, int ssize)
334 {
335 	unsigned long vaddr;
336 	unsigned int step, shift;
337 	int rc;
338 	int ret = 0;
339 
340 	shift = mmu_psize_defs[psize].shift;
341 	step = 1 << shift;
342 
343 	if (!mmu_hash_ops.hpte_removebolted)
344 		return -ENODEV;
345 
346 	for (vaddr = vstart; vaddr < vend; vaddr += step) {
347 		rc = mmu_hash_ops.hpte_removebolted(vaddr, psize, ssize);
348 		if (rc == -ENOENT) {
349 			ret = -ENOENT;
350 			continue;
351 		}
352 		if (rc < 0)
353 			return rc;
354 	}
355 
356 	return ret;
357 }
358 
359 static bool disable_1tb_segments = false;
360 
361 static int __init parse_disable_1tb_segments(char *p)
362 {
363 	disable_1tb_segments = true;
364 	return 0;
365 }
366 early_param("disable_1tb_segments", parse_disable_1tb_segments);
367 
368 static int __init htab_dt_scan_seg_sizes(unsigned long node,
369 					 const char *uname, int depth,
370 					 void *data)
371 {
372 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
373 	const __be32 *prop;
374 	int size = 0;
375 
376 	/* We are scanning "cpu" nodes only */
377 	if (type == NULL || strcmp(type, "cpu") != 0)
378 		return 0;
379 
380 	prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size);
381 	if (prop == NULL)
382 		return 0;
383 	for (; size >= 4; size -= 4, ++prop) {
384 		if (be32_to_cpu(prop[0]) == 40) {
385 			DBG("1T segment support detected\n");
386 
387 			if (disable_1tb_segments) {
388 				DBG("1T segments disabled by command line\n");
389 				break;
390 			}
391 
392 			cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
393 			return 1;
394 		}
395 	}
396 	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
397 	return 0;
398 }
399 
400 static int __init get_idx_from_shift(unsigned int shift)
401 {
402 	int idx = -1;
403 
404 	switch (shift) {
405 	case 0xc:
406 		idx = MMU_PAGE_4K;
407 		break;
408 	case 0x10:
409 		idx = MMU_PAGE_64K;
410 		break;
411 	case 0x14:
412 		idx = MMU_PAGE_1M;
413 		break;
414 	case 0x18:
415 		idx = MMU_PAGE_16M;
416 		break;
417 	case 0x22:
418 		idx = MMU_PAGE_16G;
419 		break;
420 	}
421 	return idx;
422 }
423 
424 static int __init htab_dt_scan_page_sizes(unsigned long node,
425 					  const char *uname, int depth,
426 					  void *data)
427 {
428 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
429 	const __be32 *prop;
430 	int size = 0;
431 
432 	/* We are scanning "cpu" nodes only */
433 	if (type == NULL || strcmp(type, "cpu") != 0)
434 		return 0;
435 
436 	prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
437 	if (!prop)
438 		return 0;
439 
440 	pr_info("Page sizes from device-tree:\n");
441 	size /= 4;
442 	cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
443 	while(size > 0) {
444 		unsigned int base_shift = be32_to_cpu(prop[0]);
445 		unsigned int slbenc = be32_to_cpu(prop[1]);
446 		unsigned int lpnum = be32_to_cpu(prop[2]);
447 		struct mmu_psize_def *def;
448 		int idx, base_idx;
449 
450 		size -= 3; prop += 3;
451 		base_idx = get_idx_from_shift(base_shift);
452 		if (base_idx < 0) {
453 			/* skip the pte encoding also */
454 			prop += lpnum * 2; size -= lpnum * 2;
455 			continue;
456 		}
457 		def = &mmu_psize_defs[base_idx];
458 		if (base_idx == MMU_PAGE_16M)
459 			cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
460 
461 		def->shift = base_shift;
462 		if (base_shift <= 23)
463 			def->avpnm = 0;
464 		else
465 			def->avpnm = (1 << (base_shift - 23)) - 1;
466 		def->sllp = slbenc;
467 		/*
468 		 * We don't know for sure what's up with tlbiel, so
469 		 * for now we only set it for 4K and 64K pages
470 		 */
471 		if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
472 			def->tlbiel = 1;
473 		else
474 			def->tlbiel = 0;
475 
476 		while (size > 0 && lpnum) {
477 			unsigned int shift = be32_to_cpu(prop[0]);
478 			int penc  = be32_to_cpu(prop[1]);
479 
480 			prop += 2; size -= 2;
481 			lpnum--;
482 
483 			idx = get_idx_from_shift(shift);
484 			if (idx < 0)
485 				continue;
486 
487 			if (penc == -1)
488 				pr_err("Invalid penc for base_shift=%d "
489 				       "shift=%d\n", base_shift, shift);
490 
491 			def->penc[idx] = penc;
492 			pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
493 				" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
494 				base_shift, shift, def->sllp,
495 				def->avpnm, def->tlbiel, def->penc[idx]);
496 		}
497 	}
498 
499 	return 1;
500 }
501 
502 #ifdef CONFIG_HUGETLB_PAGE
503 /*
504  * Scan for 16G memory blocks that have been set aside for huge pages
505  * and reserve those blocks for 16G huge pages.
506  */
507 static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
508 					const char *uname, int depth,
509 					void *data) {
510 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
511 	const __be64 *addr_prop;
512 	const __be32 *page_count_prop;
513 	unsigned int expected_pages;
514 	long unsigned int phys_addr;
515 	long unsigned int block_size;
516 
517 	/* We are scanning "memory" nodes only */
518 	if (type == NULL || strcmp(type, "memory") != 0)
519 		return 0;
520 
521 	/*
522 	 * This property is the log base 2 of the number of virtual pages that
523 	 * will represent this memory block.
524 	 */
525 	page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
526 	if (page_count_prop == NULL)
527 		return 0;
528 	expected_pages = (1 << be32_to_cpu(page_count_prop[0]));
529 	addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
530 	if (addr_prop == NULL)
531 		return 0;
532 	phys_addr = be64_to_cpu(addr_prop[0]);
533 	block_size = be64_to_cpu(addr_prop[1]);
534 	if (block_size != (16 * GB))
535 		return 0;
536 	printk(KERN_INFO "Huge page(16GB) memory: "
537 			"addr = 0x%lX size = 0x%lX pages = %d\n",
538 			phys_addr, block_size, expected_pages);
539 	if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) {
540 		memblock_reserve(phys_addr, block_size * expected_pages);
541 		pseries_add_gpage(phys_addr, block_size, expected_pages);
542 	}
543 	return 0;
544 }
545 #endif /* CONFIG_HUGETLB_PAGE */
546 
547 static void mmu_psize_set_default_penc(void)
548 {
549 	int bpsize, apsize;
550 	for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
551 		for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
552 			mmu_psize_defs[bpsize].penc[apsize] = -1;
553 }
554 
555 #ifdef CONFIG_PPC_64K_PAGES
556 
557 static bool might_have_hea(void)
558 {
559 	/*
560 	 * The HEA ethernet adapter requires awareness of the
561 	 * GX bus. Without that awareness we can easily assume
562 	 * we will never see an HEA ethernet device.
563 	 */
564 #ifdef CONFIG_IBMEBUS
565 	return !cpu_has_feature(CPU_FTR_ARCH_207S) &&
566 		firmware_has_feature(FW_FEATURE_SPLPAR);
567 #else
568 	return false;
569 #endif
570 }
571 
572 #endif /* #ifdef CONFIG_PPC_64K_PAGES */
573 
574 static void __init htab_scan_page_sizes(void)
575 {
576 	int rc;
577 
578 	/* se the invalid penc to -1 */
579 	mmu_psize_set_default_penc();
580 
581 	/* Default to 4K pages only */
582 	memcpy(mmu_psize_defs, mmu_psize_defaults,
583 	       sizeof(mmu_psize_defaults));
584 
585 	/*
586 	 * Try to find the available page sizes in the device-tree
587 	 */
588 	rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
589 	if (rc == 0 && early_mmu_has_feature(MMU_FTR_16M_PAGE)) {
590 		/*
591 		 * Nothing in the device-tree, but the CPU supports 16M pages,
592 		 * so let's fallback on a known size list for 16M capable CPUs.
593 		 */
594 		memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
595 		       sizeof(mmu_psize_defaults_gp));
596 	}
597 
598 #ifdef CONFIG_HUGETLB_PAGE
599 	if (!hugetlb_disabled && !early_radix_enabled() ) {
600 		/* Reserve 16G huge page memory sections for huge pages */
601 		of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
602 	}
603 #endif /* CONFIG_HUGETLB_PAGE */
604 }
605 
606 /*
607  * Fill in the hpte_page_sizes[] array.
608  * We go through the mmu_psize_defs[] array looking for all the
609  * supported base/actual page size combinations.  Each combination
610  * has a unique pagesize encoding (penc) value in the low bits of
611  * the LP field of the HPTE.  For actual page sizes less than 1MB,
612  * some of the upper LP bits are used for RPN bits, meaning that
613  * we need to fill in several entries in hpte_page_sizes[].
614  *
615  * In diagrammatic form, with r = RPN bits and z = page size bits:
616  *        PTE LP     actual page size
617  *    rrrr rrrz		>=8KB
618  *    rrrr rrzz		>=16KB
619  *    rrrr rzzz		>=32KB
620  *    rrrr zzzz		>=64KB
621  *    ...
622  *
623  * The zzzz bits are implementation-specific but are chosen so that
624  * no encoding for a larger page size uses the same value in its
625  * low-order N bits as the encoding for the 2^(12+N) byte page size
626  * (if it exists).
627  */
628 static void init_hpte_page_sizes(void)
629 {
630 	long int ap, bp;
631 	long int shift, penc;
632 
633 	for (bp = 0; bp < MMU_PAGE_COUNT; ++bp) {
634 		if (!mmu_psize_defs[bp].shift)
635 			continue;	/* not a supported page size */
636 		for (ap = bp; ap < MMU_PAGE_COUNT; ++ap) {
637 			penc = mmu_psize_defs[bp].penc[ap];
638 			if (penc == -1 || !mmu_psize_defs[ap].shift)
639 				continue;
640 			shift = mmu_psize_defs[ap].shift - LP_SHIFT;
641 			if (shift <= 0)
642 				continue;	/* should never happen */
643 			/*
644 			 * For page sizes less than 1MB, this loop
645 			 * replicates the entry for all possible values
646 			 * of the rrrr bits.
647 			 */
648 			while (penc < (1 << LP_BITS)) {
649 				hpte_page_sizes[penc] = (ap << 4) | bp;
650 				penc += 1 << shift;
651 			}
652 		}
653 	}
654 }
655 
656 static void __init htab_init_page_sizes(void)
657 {
658 	bool aligned = true;
659 	init_hpte_page_sizes();
660 
661 	if (!debug_pagealloc_enabled()) {
662 		/*
663 		 * Pick a size for the linear mapping. Currently, we only
664 		 * support 16M, 1M and 4K which is the default
665 		 */
666 		if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) &&
667 		    (unsigned long)_stext % 0x1000000) {
668 			if (mmu_psize_defs[MMU_PAGE_16M].shift)
669 				pr_warn("Kernel not 16M aligned, disabling 16M linear map alignment\n");
670 			aligned = false;
671 		}
672 
673 		if (mmu_psize_defs[MMU_PAGE_16M].shift && aligned)
674 			mmu_linear_psize = MMU_PAGE_16M;
675 		else if (mmu_psize_defs[MMU_PAGE_1M].shift)
676 			mmu_linear_psize = MMU_PAGE_1M;
677 	}
678 
679 #ifdef CONFIG_PPC_64K_PAGES
680 	/*
681 	 * Pick a size for the ordinary pages. Default is 4K, we support
682 	 * 64K for user mappings and vmalloc if supported by the processor.
683 	 * We only use 64k for ioremap if the processor
684 	 * (and firmware) support cache-inhibited large pages.
685 	 * If not, we use 4k and set mmu_ci_restrictions so that
686 	 * hash_page knows to switch processes that use cache-inhibited
687 	 * mappings to 4k pages.
688 	 */
689 	if (mmu_psize_defs[MMU_PAGE_64K].shift) {
690 		mmu_virtual_psize = MMU_PAGE_64K;
691 		mmu_vmalloc_psize = MMU_PAGE_64K;
692 		if (mmu_linear_psize == MMU_PAGE_4K)
693 			mmu_linear_psize = MMU_PAGE_64K;
694 		if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
695 			/*
696 			 * When running on pSeries using 64k pages for ioremap
697 			 * would stop us accessing the HEA ethernet. So if we
698 			 * have the chance of ever seeing one, stay at 4k.
699 			 */
700 			if (!might_have_hea())
701 				mmu_io_psize = MMU_PAGE_64K;
702 		} else
703 			mmu_ci_restrictions = 1;
704 	}
705 #endif /* CONFIG_PPC_64K_PAGES */
706 
707 #ifdef CONFIG_SPARSEMEM_VMEMMAP
708 	/*
709 	 * We try to use 16M pages for vmemmap if that is supported
710 	 * and we have at least 1G of RAM at boot
711 	 */
712 	if (mmu_psize_defs[MMU_PAGE_16M].shift &&
713 	    memblock_phys_mem_size() >= 0x40000000)
714 		mmu_vmemmap_psize = MMU_PAGE_16M;
715 	else
716 		mmu_vmemmap_psize = mmu_virtual_psize;
717 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
718 
719 	printk(KERN_DEBUG "Page orders: linear mapping = %d, "
720 	       "virtual = %d, io = %d"
721 #ifdef CONFIG_SPARSEMEM_VMEMMAP
722 	       ", vmemmap = %d"
723 #endif
724 	       "\n",
725 	       mmu_psize_defs[mmu_linear_psize].shift,
726 	       mmu_psize_defs[mmu_virtual_psize].shift,
727 	       mmu_psize_defs[mmu_io_psize].shift
728 #ifdef CONFIG_SPARSEMEM_VMEMMAP
729 	       ,mmu_psize_defs[mmu_vmemmap_psize].shift
730 #endif
731 	       );
732 }
733 
734 static int __init htab_dt_scan_pftsize(unsigned long node,
735 				       const char *uname, int depth,
736 				       void *data)
737 {
738 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
739 	const __be32 *prop;
740 
741 	/* We are scanning "cpu" nodes only */
742 	if (type == NULL || strcmp(type, "cpu") != 0)
743 		return 0;
744 
745 	prop = of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
746 	if (prop != NULL) {
747 		/* pft_size[0] is the NUMA CEC cookie */
748 		ppc64_pft_size = be32_to_cpu(prop[1]);
749 		return 1;
750 	}
751 	return 0;
752 }
753 
754 unsigned htab_shift_for_mem_size(unsigned long mem_size)
755 {
756 	unsigned memshift = __ilog2(mem_size);
757 	unsigned pshift = mmu_psize_defs[mmu_virtual_psize].shift;
758 	unsigned pteg_shift;
759 
760 	/* round mem_size up to next power of 2 */
761 	if ((1UL << memshift) < mem_size)
762 		memshift += 1;
763 
764 	/* aim for 2 pages / pteg */
765 	pteg_shift = memshift - (pshift + 1);
766 
767 	/*
768 	 * 2^11 PTEGS of 128 bytes each, ie. 2^18 bytes is the minimum htab
769 	 * size permitted by the architecture.
770 	 */
771 	return max(pteg_shift + 7, 18U);
772 }
773 
774 static unsigned long __init htab_get_table_size(void)
775 {
776 	/*
777 	 * If hash size isn't already provided by the platform, we try to
778 	 * retrieve it from the device-tree. If it's not there neither, we
779 	 * calculate it now based on the total RAM size
780 	 */
781 	if (ppc64_pft_size == 0)
782 		of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
783 	if (ppc64_pft_size)
784 		return 1UL << ppc64_pft_size;
785 
786 	return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size());
787 }
788 
789 #ifdef CONFIG_MEMORY_HOTPLUG
790 static int resize_hpt_for_hotplug(unsigned long new_mem_size)
791 {
792 	unsigned target_hpt_shift;
793 
794 	if (!mmu_hash_ops.resize_hpt)
795 		return 0;
796 
797 	target_hpt_shift = htab_shift_for_mem_size(new_mem_size);
798 
799 	/*
800 	 * To avoid lots of HPT resizes if memory size is fluctuating
801 	 * across a boundary, we deliberately have some hysterisis
802 	 * here: we immediately increase the HPT size if the target
803 	 * shift exceeds the current shift, but we won't attempt to
804 	 * reduce unless the target shift is at least 2 below the
805 	 * current shift
806 	 */
807 	if (target_hpt_shift > ppc64_pft_size ||
808 	    target_hpt_shift < ppc64_pft_size - 1)
809 		return mmu_hash_ops.resize_hpt(target_hpt_shift);
810 
811 	return 0;
812 }
813 
814 int hash__create_section_mapping(unsigned long start, unsigned long end,
815 				 int nid, pgprot_t prot)
816 {
817 	int rc;
818 
819 	if (end >= H_VMALLOC_START) {
820 		pr_warn("Outside the supported range\n");
821 		return -1;
822 	}
823 
824 	resize_hpt_for_hotplug(memblock_phys_mem_size());
825 
826 	rc = htab_bolt_mapping(start, end, __pa(start),
827 			       pgprot_val(prot), mmu_linear_psize,
828 			       mmu_kernel_ssize);
829 
830 	if (rc < 0) {
831 		int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
832 					      mmu_kernel_ssize);
833 		BUG_ON(rc2 && (rc2 != -ENOENT));
834 	}
835 	return rc;
836 }
837 
838 int hash__remove_section_mapping(unsigned long start, unsigned long end)
839 {
840 	int rc = htab_remove_mapping(start, end, mmu_linear_psize,
841 				     mmu_kernel_ssize);
842 	WARN_ON(rc < 0);
843 
844 	if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
845 		pr_warn("Hash collision while resizing HPT\n");
846 
847 	return rc;
848 }
849 #endif /* CONFIG_MEMORY_HOTPLUG */
850 
851 static void __init hash_init_partition_table(phys_addr_t hash_table,
852 					     unsigned long htab_size)
853 {
854 	mmu_partition_table_init();
855 
856 	/*
857 	 * PS field (VRMA page size) is not used for LPID 0, hence set to 0.
858 	 * For now, UPRT is 0 and we have no segment table.
859 	 */
860 	htab_size =  __ilog2(htab_size) - 18;
861 	mmu_partition_table_set_entry(0, hash_table | htab_size, 0, false);
862 	pr_info("Partition table %p\n", partition_tb);
863 }
864 
865 static void __init htab_initialize(void)
866 {
867 	unsigned long table;
868 	unsigned long pteg_count;
869 	unsigned long prot;
870 	unsigned long base = 0, size = 0;
871 	struct memblock_region *reg;
872 
873 	DBG(" -> htab_initialize()\n");
874 
875 	if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
876 		mmu_kernel_ssize = MMU_SEGSIZE_1T;
877 		mmu_highuser_ssize = MMU_SEGSIZE_1T;
878 		printk(KERN_INFO "Using 1TB segments\n");
879 	}
880 
881 	if (stress_slb_enabled)
882 		static_branch_enable(&stress_slb_key);
883 
884 	/*
885 	 * Calculate the required size of the htab.  We want the number of
886 	 * PTEGs to equal one half the number of real pages.
887 	 */
888 	htab_size_bytes = htab_get_table_size();
889 	pteg_count = htab_size_bytes >> 7;
890 
891 	htab_hash_mask = pteg_count - 1;
892 
893 	if (firmware_has_feature(FW_FEATURE_LPAR) ||
894 	    firmware_has_feature(FW_FEATURE_PS3_LV1)) {
895 		/* Using a hypervisor which owns the htab */
896 		htab_address = NULL;
897 		_SDR1 = 0;
898 #ifdef CONFIG_FA_DUMP
899 		/*
900 		 * If firmware assisted dump is active firmware preserves
901 		 * the contents of htab along with entire partition memory.
902 		 * Clear the htab if firmware assisted dump is active so
903 		 * that we dont end up using old mappings.
904 		 */
905 		if (is_fadump_active() && mmu_hash_ops.hpte_clear_all)
906 			mmu_hash_ops.hpte_clear_all();
907 #endif
908 	} else {
909 		unsigned long limit = MEMBLOCK_ALLOC_ANYWHERE;
910 
911 #ifdef CONFIG_PPC_CELL
912 		/*
913 		 * Cell may require the hash table down low when using the
914 		 * Axon IOMMU in order to fit the dynamic region over it, see
915 		 * comments in cell/iommu.c
916 		 */
917 		if (fdt_subnode_offset(initial_boot_params, 0, "axon") > 0) {
918 			limit = 0x80000000;
919 			pr_info("Hash table forced below 2G for Axon IOMMU\n");
920 		}
921 #endif /* CONFIG_PPC_CELL */
922 
923 		table = memblock_phys_alloc_range(htab_size_bytes,
924 						  htab_size_bytes,
925 						  0, limit);
926 		if (!table)
927 			panic("ERROR: Failed to allocate %pa bytes below %pa\n",
928 			      &htab_size_bytes, &limit);
929 
930 		DBG("Hash table allocated at %lx, size: %lx\n", table,
931 		    htab_size_bytes);
932 
933 		htab_address = __va(table);
934 
935 		/* htab absolute addr + encoded htabsize */
936 		_SDR1 = table + __ilog2(htab_size_bytes) - 18;
937 
938 		/* Initialize the HPT with no entries */
939 		memset((void *)table, 0, htab_size_bytes);
940 
941 		if (!cpu_has_feature(CPU_FTR_ARCH_300))
942 			/* Set SDR1 */
943 			mtspr(SPRN_SDR1, _SDR1);
944 		else
945 			hash_init_partition_table(table, htab_size_bytes);
946 	}
947 
948 	prot = pgprot_val(PAGE_KERNEL);
949 
950 #ifdef CONFIG_DEBUG_PAGEALLOC
951 	if (debug_pagealloc_enabled()) {
952 		linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
953 		linear_map_hash_slots = memblock_alloc_try_nid(
954 				linear_map_hash_count, 1, MEMBLOCK_LOW_LIMIT,
955 				ppc64_rma_size,	NUMA_NO_NODE);
956 		if (!linear_map_hash_slots)
957 			panic("%s: Failed to allocate %lu bytes max_addr=%pa\n",
958 			      __func__, linear_map_hash_count, &ppc64_rma_size);
959 	}
960 #endif /* CONFIG_DEBUG_PAGEALLOC */
961 
962 	/* create bolted the linear mapping in the hash table */
963 	for_each_memblock(memory, reg) {
964 		base = (unsigned long)__va(reg->base);
965 		size = reg->size;
966 
967 		DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
968 		    base, size, prot);
969 
970 		if ((base + size) >= H_VMALLOC_START) {
971 			pr_warn("Outside the supported range\n");
972 			continue;
973 		}
974 
975 		BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
976 				prot, mmu_linear_psize, mmu_kernel_ssize));
977 	}
978 	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
979 
980 	/*
981 	 * If we have a memory_limit and we've allocated TCEs then we need to
982 	 * explicitly map the TCE area at the top of RAM. We also cope with the
983 	 * case that the TCEs start below memory_limit.
984 	 * tce_alloc_start/end are 16MB aligned so the mapping should work
985 	 * for either 4K or 16MB pages.
986 	 */
987 	if (tce_alloc_start) {
988 		tce_alloc_start = (unsigned long)__va(tce_alloc_start);
989 		tce_alloc_end = (unsigned long)__va(tce_alloc_end);
990 
991 		if (base + size >= tce_alloc_start)
992 			tce_alloc_start = base + size + 1;
993 
994 		BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
995 					 __pa(tce_alloc_start), prot,
996 					 mmu_linear_psize, mmu_kernel_ssize));
997 	}
998 
999 
1000 	DBG(" <- htab_initialize()\n");
1001 }
1002 #undef KB
1003 #undef MB
1004 
1005 void __init hash__early_init_devtree(void)
1006 {
1007 	/* Initialize segment sizes */
1008 	of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
1009 
1010 	/* Initialize page sizes */
1011 	htab_scan_page_sizes();
1012 }
1013 
1014 static struct hash_mm_context init_hash_mm_context;
1015 void __init hash__early_init_mmu(void)
1016 {
1017 #ifndef CONFIG_PPC_64K_PAGES
1018 	/*
1019 	 * We have code in __hash_page_4K() and elsewhere, which assumes it can
1020 	 * do the following:
1021 	 *   new_pte |= (slot << H_PAGE_F_GIX_SHIFT) & (H_PAGE_F_SECOND | H_PAGE_F_GIX);
1022 	 *
1023 	 * Where the slot number is between 0-15, and values of 8-15 indicate
1024 	 * the secondary bucket. For that code to work H_PAGE_F_SECOND and
1025 	 * H_PAGE_F_GIX must occupy four contiguous bits in the PTE, and
1026 	 * H_PAGE_F_SECOND must be placed above H_PAGE_F_GIX. Assert that here
1027 	 * with a BUILD_BUG_ON().
1028 	 */
1029 	BUILD_BUG_ON(H_PAGE_F_SECOND != (1ul  << (H_PAGE_F_GIX_SHIFT + 3)));
1030 #endif /* CONFIG_PPC_64K_PAGES */
1031 
1032 	htab_init_page_sizes();
1033 
1034 	/*
1035 	 * initialize page table size
1036 	 */
1037 	__pte_frag_nr = H_PTE_FRAG_NR;
1038 	__pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
1039 	__pmd_frag_nr = H_PMD_FRAG_NR;
1040 	__pmd_frag_size_shift = H_PMD_FRAG_SIZE_SHIFT;
1041 
1042 	__pte_index_size = H_PTE_INDEX_SIZE;
1043 	__pmd_index_size = H_PMD_INDEX_SIZE;
1044 	__pud_index_size = H_PUD_INDEX_SIZE;
1045 	__pgd_index_size = H_PGD_INDEX_SIZE;
1046 	__pud_cache_index = H_PUD_CACHE_INDEX;
1047 	__pte_table_size = H_PTE_TABLE_SIZE;
1048 	__pmd_table_size = H_PMD_TABLE_SIZE;
1049 	__pud_table_size = H_PUD_TABLE_SIZE;
1050 	__pgd_table_size = H_PGD_TABLE_SIZE;
1051 	/*
1052 	 * 4k use hugepd format, so for hash set then to
1053 	 * zero
1054 	 */
1055 	__pmd_val_bits = HASH_PMD_VAL_BITS;
1056 	__pud_val_bits = HASH_PUD_VAL_BITS;
1057 	__pgd_val_bits = HASH_PGD_VAL_BITS;
1058 
1059 	__kernel_virt_start = H_KERN_VIRT_START;
1060 	__vmalloc_start = H_VMALLOC_START;
1061 	__vmalloc_end = H_VMALLOC_END;
1062 	__kernel_io_start = H_KERN_IO_START;
1063 	__kernel_io_end = H_KERN_IO_END;
1064 	vmemmap = (struct page *)H_VMEMMAP_START;
1065 	ioremap_bot = IOREMAP_BASE;
1066 
1067 #ifdef CONFIG_PCI
1068 	pci_io_base = ISA_IO_BASE;
1069 #endif
1070 
1071 	/* Select appropriate backend */
1072 	if (firmware_has_feature(FW_FEATURE_PS3_LV1))
1073 		ps3_early_mm_init();
1074 	else if (firmware_has_feature(FW_FEATURE_LPAR))
1075 		hpte_init_pseries();
1076 	else if (IS_ENABLED(CONFIG_PPC_NATIVE))
1077 		hpte_init_native();
1078 
1079 	if (!mmu_hash_ops.hpte_insert)
1080 		panic("hash__early_init_mmu: No MMU hash ops defined!\n");
1081 
1082 	/*
1083 	 * Initialize the MMU Hash table and create the linear mapping
1084 	 * of memory. Has to be done before SLB initialization as this is
1085 	 * currently where the page size encoding is obtained.
1086 	 */
1087 	htab_initialize();
1088 
1089 	init_mm.context.hash_context = &init_hash_mm_context;
1090 	mm_ctx_set_slb_addr_limit(&init_mm.context, SLB_ADDR_LIMIT_DEFAULT);
1091 
1092 	pr_info("Initializing hash mmu with SLB\n");
1093 	/* Initialize SLB management */
1094 	slb_initialize();
1095 
1096 	if (cpu_has_feature(CPU_FTR_ARCH_206)
1097 			&& cpu_has_feature(CPU_FTR_HVMODE))
1098 		tlbiel_all();
1099 }
1100 
1101 #ifdef CONFIG_SMP
1102 void hash__early_init_mmu_secondary(void)
1103 {
1104 	/* Initialize hash table for that CPU */
1105 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1106 
1107 		if (!cpu_has_feature(CPU_FTR_ARCH_300))
1108 			mtspr(SPRN_SDR1, _SDR1);
1109 		else
1110 			set_ptcr_when_no_uv(__pa(partition_tb) |
1111 					    (PATB_SIZE_SHIFT - 12));
1112 	}
1113 	/* Initialize SLB */
1114 	slb_initialize();
1115 
1116 	if (cpu_has_feature(CPU_FTR_ARCH_206)
1117 			&& cpu_has_feature(CPU_FTR_HVMODE))
1118 		tlbiel_all();
1119 
1120 #ifdef CONFIG_PPC_MEM_KEYS
1121 	if (mmu_has_feature(MMU_FTR_PKEY))
1122 		mtspr(SPRN_UAMOR, default_uamor);
1123 #endif
1124 }
1125 #endif /* CONFIG_SMP */
1126 
1127 /*
1128  * Called by asm hashtable.S for doing lazy icache flush
1129  */
1130 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
1131 {
1132 	struct page *page;
1133 
1134 	if (!pfn_valid(pte_pfn(pte)))
1135 		return pp;
1136 
1137 	page = pte_page(pte);
1138 
1139 	/* page is dirty */
1140 	if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
1141 		if (trap == 0x400) {
1142 			flush_dcache_icache_page(page);
1143 			set_bit(PG_arch_1, &page->flags);
1144 		} else
1145 			pp |= HPTE_R_N;
1146 	}
1147 	return pp;
1148 }
1149 
1150 #ifdef CONFIG_PPC_MM_SLICES
1151 static unsigned int get_paca_psize(unsigned long addr)
1152 {
1153 	unsigned char *psizes;
1154 	unsigned long index, mask_index;
1155 
1156 	if (addr < SLICE_LOW_TOP) {
1157 		psizes = get_paca()->mm_ctx_low_slices_psize;
1158 		index = GET_LOW_SLICE_INDEX(addr);
1159 	} else {
1160 		psizes = get_paca()->mm_ctx_high_slices_psize;
1161 		index = GET_HIGH_SLICE_INDEX(addr);
1162 	}
1163 	mask_index = index & 0x1;
1164 	return (psizes[index >> 1] >> (mask_index * 4)) & 0xF;
1165 }
1166 
1167 #else
1168 unsigned int get_paca_psize(unsigned long addr)
1169 {
1170 	return get_paca()->mm_ctx_user_psize;
1171 }
1172 #endif
1173 
1174 /*
1175  * Demote a segment to using 4k pages.
1176  * For now this makes the whole process use 4k pages.
1177  */
1178 #ifdef CONFIG_PPC_64K_PAGES
1179 void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
1180 {
1181 	if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
1182 		return;
1183 	slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
1184 	copro_flush_all_slbs(mm);
1185 	if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
1186 
1187 		copy_mm_to_paca(mm);
1188 		slb_flush_and_restore_bolted();
1189 	}
1190 }
1191 #endif /* CONFIG_PPC_64K_PAGES */
1192 
1193 #ifdef CONFIG_PPC_SUBPAGE_PROT
1194 /*
1195  * This looks up a 2-bit protection code for a 4k subpage of a 64k page.
1196  * Userspace sets the subpage permissions using the subpage_prot system call.
1197  *
1198  * Result is 0: full permissions, _PAGE_RW: read-only,
1199  * _PAGE_RWX: no access.
1200  */
1201 static int subpage_protection(struct mm_struct *mm, unsigned long ea)
1202 {
1203 	struct subpage_prot_table *spt = mm_ctx_subpage_prot(&mm->context);
1204 	u32 spp = 0;
1205 	u32 **sbpm, *sbpp;
1206 
1207 	if (!spt)
1208 		return 0;
1209 
1210 	if (ea >= spt->maxaddr)
1211 		return 0;
1212 	if (ea < 0x100000000UL) {
1213 		/* addresses below 4GB use spt->low_prot */
1214 		sbpm = spt->low_prot;
1215 	} else {
1216 		sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
1217 		if (!sbpm)
1218 			return 0;
1219 	}
1220 	sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
1221 	if (!sbpp)
1222 		return 0;
1223 	spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
1224 
1225 	/* extract 2-bit bitfield for this 4k subpage */
1226 	spp >>= 30 - 2 * ((ea >> 12) & 0xf);
1227 
1228 	/*
1229 	 * 0 -> full premission
1230 	 * 1 -> Read only
1231 	 * 2 -> no access.
1232 	 * We return the flag that need to be cleared.
1233 	 */
1234 	spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 0);
1235 	return spp;
1236 }
1237 
1238 #else /* CONFIG_PPC_SUBPAGE_PROT */
1239 static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
1240 {
1241 	return 0;
1242 }
1243 #endif
1244 
1245 void hash_failure_debug(unsigned long ea, unsigned long access,
1246 			unsigned long vsid, unsigned long trap,
1247 			int ssize, int psize, int lpsize, unsigned long pte)
1248 {
1249 	if (!printk_ratelimit())
1250 		return;
1251 	pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
1252 		ea, access, current->comm);
1253 	pr_info("    trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
1254 		trap, vsid, ssize, psize, lpsize, pte);
1255 }
1256 
1257 static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
1258 			     int psize, bool user_region)
1259 {
1260 	if (user_region) {
1261 		if (psize != get_paca_psize(ea)) {
1262 			copy_mm_to_paca(mm);
1263 			slb_flush_and_restore_bolted();
1264 		}
1265 	} else if (get_paca()->vmalloc_sllp !=
1266 		   mmu_psize_defs[mmu_vmalloc_psize].sllp) {
1267 		get_paca()->vmalloc_sllp =
1268 			mmu_psize_defs[mmu_vmalloc_psize].sllp;
1269 		slb_vmalloc_update();
1270 	}
1271 }
1272 
1273 /*
1274  * Result code is:
1275  *  0 - handled
1276  *  1 - normal page fault
1277  * -1 - critical hash insertion error
1278  * -2 - access not permitted by subpage protection mechanism
1279  */
1280 int hash_page_mm(struct mm_struct *mm, unsigned long ea,
1281 		 unsigned long access, unsigned long trap,
1282 		 unsigned long flags)
1283 {
1284 	bool is_thp;
1285 	enum ctx_state prev_state = exception_enter();
1286 	pgd_t *pgdir;
1287 	unsigned long vsid;
1288 	pte_t *ptep;
1289 	unsigned hugeshift;
1290 	int rc, user_region = 0;
1291 	int psize, ssize;
1292 
1293 	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
1294 		ea, access, trap);
1295 	trace_hash_fault(ea, access, trap);
1296 
1297 	/* Get region & vsid */
1298 	switch (get_region_id(ea)) {
1299 	case USER_REGION_ID:
1300 		user_region = 1;
1301 		if (! mm) {
1302 			DBG_LOW(" user region with no mm !\n");
1303 			rc = 1;
1304 			goto bail;
1305 		}
1306 		psize = get_slice_psize(mm, ea);
1307 		ssize = user_segment_size(ea);
1308 		vsid = get_user_vsid(&mm->context, ea, ssize);
1309 		break;
1310 	case VMALLOC_REGION_ID:
1311 		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1312 		psize = mmu_vmalloc_psize;
1313 		ssize = mmu_kernel_ssize;
1314 		break;
1315 
1316 	case IO_REGION_ID:
1317 		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1318 		psize = mmu_io_psize;
1319 		ssize = mmu_kernel_ssize;
1320 		break;
1321 	default:
1322 		/*
1323 		 * Not a valid range
1324 		 * Send the problem up to do_page_fault()
1325 		 */
1326 		rc = 1;
1327 		goto bail;
1328 	}
1329 	DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
1330 
1331 	/* Bad address. */
1332 	if (!vsid) {
1333 		DBG_LOW("Bad address!\n");
1334 		rc = 1;
1335 		goto bail;
1336 	}
1337 	/* Get pgdir */
1338 	pgdir = mm->pgd;
1339 	if (pgdir == NULL) {
1340 		rc = 1;
1341 		goto bail;
1342 	}
1343 
1344 	/* Check CPU locality */
1345 	if (user_region && mm_is_thread_local(mm))
1346 		flags |= HPTE_LOCAL_UPDATE;
1347 
1348 #ifndef CONFIG_PPC_64K_PAGES
1349 	/*
1350 	 * If we use 4K pages and our psize is not 4K, then we might
1351 	 * be hitting a special driver mapping, and need to align the
1352 	 * address before we fetch the PTE.
1353 	 *
1354 	 * It could also be a hugepage mapping, in which case this is
1355 	 * not necessary, but it's not harmful, either.
1356 	 */
1357 	if (psize != MMU_PAGE_4K)
1358 		ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
1359 #endif /* CONFIG_PPC_64K_PAGES */
1360 
1361 	/* Get PTE and page size from page tables */
1362 	ptep = find_linux_pte(pgdir, ea, &is_thp, &hugeshift);
1363 	if (ptep == NULL || !pte_present(*ptep)) {
1364 		DBG_LOW(" no PTE !\n");
1365 		rc = 1;
1366 		goto bail;
1367 	}
1368 
1369 	/*
1370 	 * Add _PAGE_PRESENT to the required access perm. If there are parallel
1371 	 * updates to the pte that can possibly clear _PAGE_PTE, catch that too.
1372 	 *
1373 	 * We can safely use the return pte address in rest of the function
1374 	 * because we do set H_PAGE_BUSY which prevents further updates to pte
1375 	 * from generic code.
1376 	 */
1377 	access |= _PAGE_PRESENT | _PAGE_PTE;
1378 
1379 	/*
1380 	 * Pre-check access permissions (will be re-checked atomically
1381 	 * in __hash_page_XX but this pre-check is a fast path
1382 	 */
1383 	if (!check_pte_access(access, pte_val(*ptep))) {
1384 		DBG_LOW(" no access !\n");
1385 		rc = 1;
1386 		goto bail;
1387 	}
1388 
1389 	if (hugeshift) {
1390 		if (is_thp)
1391 			rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
1392 					     trap, flags, ssize, psize);
1393 #ifdef CONFIG_HUGETLB_PAGE
1394 		else
1395 			rc = __hash_page_huge(ea, access, vsid, ptep, trap,
1396 					      flags, ssize, hugeshift, psize);
1397 #else
1398 		else {
1399 			/*
1400 			 * if we have hugeshift, and is not transhuge with
1401 			 * hugetlb disabled, something is really wrong.
1402 			 */
1403 			rc = 1;
1404 			WARN_ON(1);
1405 		}
1406 #endif
1407 		if (current->mm == mm)
1408 			check_paca_psize(ea, mm, psize, user_region);
1409 
1410 		goto bail;
1411 	}
1412 
1413 #ifndef CONFIG_PPC_64K_PAGES
1414 	DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
1415 #else
1416 	DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
1417 		pte_val(*(ptep + PTRS_PER_PTE)));
1418 #endif
1419 	/* Do actual hashing */
1420 #ifdef CONFIG_PPC_64K_PAGES
1421 	/* If H_PAGE_4K_PFN is set, make sure this is a 4k segment */
1422 	if ((pte_val(*ptep) & H_PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
1423 		demote_segment_4k(mm, ea);
1424 		psize = MMU_PAGE_4K;
1425 	}
1426 
1427 	/*
1428 	 * If this PTE is non-cacheable and we have restrictions on
1429 	 * using non cacheable large pages, then we switch to 4k
1430 	 */
1431 	if (mmu_ci_restrictions && psize == MMU_PAGE_64K && pte_ci(*ptep)) {
1432 		if (user_region) {
1433 			demote_segment_4k(mm, ea);
1434 			psize = MMU_PAGE_4K;
1435 		} else if (ea < VMALLOC_END) {
1436 			/*
1437 			 * some driver did a non-cacheable mapping
1438 			 * in vmalloc space, so switch vmalloc
1439 			 * to 4k pages
1440 			 */
1441 			printk(KERN_ALERT "Reducing vmalloc segment "
1442 			       "to 4kB pages because of "
1443 			       "non-cacheable mapping\n");
1444 			psize = mmu_vmalloc_psize = MMU_PAGE_4K;
1445 			copro_flush_all_slbs(mm);
1446 		}
1447 	}
1448 
1449 #endif /* CONFIG_PPC_64K_PAGES */
1450 
1451 	if (current->mm == mm)
1452 		check_paca_psize(ea, mm, psize, user_region);
1453 
1454 #ifdef CONFIG_PPC_64K_PAGES
1455 	if (psize == MMU_PAGE_64K)
1456 		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1457 				     flags, ssize);
1458 	else
1459 #endif /* CONFIG_PPC_64K_PAGES */
1460 	{
1461 		int spp = subpage_protection(mm, ea);
1462 		if (access & spp)
1463 			rc = -2;
1464 		else
1465 			rc = __hash_page_4K(ea, access, vsid, ptep, trap,
1466 					    flags, ssize, spp);
1467 	}
1468 
1469 	/*
1470 	 * Dump some info in case of hash insertion failure, they should
1471 	 * never happen so it is really useful to know if/when they do
1472 	 */
1473 	if (rc == -1)
1474 		hash_failure_debug(ea, access, vsid, trap, ssize, psize,
1475 				   psize, pte_val(*ptep));
1476 #ifndef CONFIG_PPC_64K_PAGES
1477 	DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
1478 #else
1479 	DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
1480 		pte_val(*(ptep + PTRS_PER_PTE)));
1481 #endif
1482 	DBG_LOW(" -> rc=%d\n", rc);
1483 
1484 bail:
1485 	exception_exit(prev_state);
1486 	return rc;
1487 }
1488 EXPORT_SYMBOL_GPL(hash_page_mm);
1489 
1490 int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
1491 	      unsigned long dsisr)
1492 {
1493 	unsigned long flags = 0;
1494 	struct mm_struct *mm = current->mm;
1495 
1496 	if ((get_region_id(ea) == VMALLOC_REGION_ID) ||
1497 	    (get_region_id(ea) == IO_REGION_ID))
1498 		mm = &init_mm;
1499 
1500 	if (dsisr & DSISR_NOHPTE)
1501 		flags |= HPTE_NOHPTE_UPDATE;
1502 
1503 	return hash_page_mm(mm, ea, access, trap, flags);
1504 }
1505 EXPORT_SYMBOL_GPL(hash_page);
1506 
1507 int __hash_page(unsigned long trap, unsigned long ea, unsigned long dsisr,
1508 		unsigned long msr)
1509 {
1510 	unsigned long access = _PAGE_PRESENT | _PAGE_READ;
1511 	unsigned long flags = 0;
1512 	struct mm_struct *mm = current->mm;
1513 	unsigned int region_id = get_region_id(ea);
1514 
1515 	if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID))
1516 		mm = &init_mm;
1517 
1518 	if (dsisr & DSISR_NOHPTE)
1519 		flags |= HPTE_NOHPTE_UPDATE;
1520 
1521 	if (dsisr & DSISR_ISSTORE)
1522 		access |= _PAGE_WRITE;
1523 	/*
1524 	 * We set _PAGE_PRIVILEGED only when
1525 	 * kernel mode access kernel space.
1526 	 *
1527 	 * _PAGE_PRIVILEGED is NOT set
1528 	 * 1) when kernel mode access user space
1529 	 * 2) user space access kernel space.
1530 	 */
1531 	access |= _PAGE_PRIVILEGED;
1532 	if ((msr & MSR_PR) || (region_id == USER_REGION_ID))
1533 		access &= ~_PAGE_PRIVILEGED;
1534 
1535 	if (trap == 0x400)
1536 		access |= _PAGE_EXEC;
1537 
1538 	return hash_page_mm(mm, ea, access, trap, flags);
1539 }
1540 
1541 #ifdef CONFIG_PPC_MM_SLICES
1542 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1543 {
1544 	int psize = get_slice_psize(mm, ea);
1545 
1546 	/* We only prefault standard pages for now */
1547 	if (unlikely(psize != mm_ctx_user_psize(&mm->context)))
1548 		return false;
1549 
1550 	/*
1551 	 * Don't prefault if subpage protection is enabled for the EA.
1552 	 */
1553 	if (unlikely((psize == MMU_PAGE_4K) && subpage_protection(mm, ea)))
1554 		return false;
1555 
1556 	return true;
1557 }
1558 #else
1559 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1560 {
1561 	return true;
1562 }
1563 #endif
1564 
1565 static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea,
1566 			 bool is_exec, unsigned long trap)
1567 {
1568 	unsigned long vsid;
1569 	pgd_t *pgdir;
1570 	int rc, ssize, update_flags = 0;
1571 	unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0);
1572 	unsigned long flags;
1573 
1574 	BUG_ON(get_region_id(ea) != USER_REGION_ID);
1575 
1576 	if (!should_hash_preload(mm, ea))
1577 		return;
1578 
1579 	DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
1580 		" trap=%lx\n", mm, mm->pgd, ea, access, trap);
1581 
1582 	/* Get Linux PTE if available */
1583 	pgdir = mm->pgd;
1584 	if (pgdir == NULL)
1585 		return;
1586 
1587 	/* Get VSID */
1588 	ssize = user_segment_size(ea);
1589 	vsid = get_user_vsid(&mm->context, ea, ssize);
1590 	if (!vsid)
1591 		return;
1592 
1593 #ifdef CONFIG_PPC_64K_PAGES
1594 	/* If either H_PAGE_4K_PFN or cache inhibited is set (and we are on
1595 	 * a 64K kernel), then we don't preload, hash_page() will take
1596 	 * care of it once we actually try to access the page.
1597 	 * That way we don't have to duplicate all of the logic for segment
1598 	 * page size demotion here
1599 	 * Called with  PTL held, hence can be sure the value won't change in
1600 	 * between.
1601 	 */
1602 	if ((pte_val(*ptep) & H_PAGE_4K_PFN) || pte_ci(*ptep))
1603 		return;
1604 #endif /* CONFIG_PPC_64K_PAGES */
1605 
1606 	/*
1607 	 * __hash_page_* must run with interrupts off, as it sets the
1608 	 * H_PAGE_BUSY bit. It's possible for perf interrupts to hit at any
1609 	 * time and may take a hash fault reading the user stack, see
1610 	 * read_user_stack_slow() in the powerpc/perf code.
1611 	 *
1612 	 * If that takes a hash fault on the same page as we lock here, it
1613 	 * will bail out when seeing H_PAGE_BUSY set, and retry the access
1614 	 * leading to an infinite loop.
1615 	 *
1616 	 * Disabling interrupts here does not prevent perf interrupts, but it
1617 	 * will prevent them taking hash faults (see the NMI test in
1618 	 * do_hash_page), then read_user_stack's copy_from_user_nofault will
1619 	 * fail and perf will fall back to read_user_stack_slow(), which
1620 	 * walks the Linux page tables.
1621 	 *
1622 	 * Interrupts must also be off for the duration of the
1623 	 * mm_is_thread_local test and update, to prevent preempt running the
1624 	 * mm on another CPU (XXX: this may be racy vs kthread_use_mm).
1625 	 */
1626 	local_irq_save(flags);
1627 
1628 	/* Is that local to this CPU ? */
1629 	if (mm_is_thread_local(mm))
1630 		update_flags |= HPTE_LOCAL_UPDATE;
1631 
1632 	/* Hash it in */
1633 #ifdef CONFIG_PPC_64K_PAGES
1634 	if (mm_ctx_user_psize(&mm->context) == MMU_PAGE_64K)
1635 		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1636 				     update_flags, ssize);
1637 	else
1638 #endif /* CONFIG_PPC_64K_PAGES */
1639 		rc = __hash_page_4K(ea, access, vsid, ptep, trap, update_flags,
1640 				    ssize, subpage_protection(mm, ea));
1641 
1642 	/* Dump some info in case of hash insertion failure, they should
1643 	 * never happen so it is really useful to know if/when they do
1644 	 */
1645 	if (rc == -1)
1646 		hash_failure_debug(ea, access, vsid, trap, ssize,
1647 				   mm_ctx_user_psize(&mm->context),
1648 				   mm_ctx_user_psize(&mm->context),
1649 				   pte_val(*ptep));
1650 
1651 	local_irq_restore(flags);
1652 }
1653 
1654 /*
1655  * This is called at the end of handling a user page fault, when the
1656  * fault has been handled by updating a PTE in the linux page tables.
1657  * We use it to preload an HPTE into the hash table corresponding to
1658  * the updated linux PTE.
1659  *
1660  * This must always be called with the pte lock held.
1661  */
1662 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
1663 		      pte_t *ptep)
1664 {
1665 	/*
1666 	 * We don't need to worry about _PAGE_PRESENT here because we are
1667 	 * called with either mm->page_table_lock held or ptl lock held
1668 	 */
1669 	unsigned long trap;
1670 	bool is_exec;
1671 
1672 	if (radix_enabled())
1673 		return;
1674 
1675 	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
1676 	if (!pte_young(*ptep) || address >= TASK_SIZE)
1677 		return;
1678 
1679 	/*
1680 	 * We try to figure out if we are coming from an instruction
1681 	 * access fault and pass that down to __hash_page so we avoid
1682 	 * double-faulting on execution of fresh text. We have to test
1683 	 * for regs NULL since init will get here first thing at boot.
1684 	 *
1685 	 * We also avoid filling the hash if not coming from a fault.
1686 	 */
1687 
1688 	trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
1689 	switch (trap) {
1690 	case 0x300:
1691 		is_exec = false;
1692 		break;
1693 	case 0x400:
1694 		is_exec = true;
1695 		break;
1696 	default:
1697 		return;
1698 	}
1699 
1700 	hash_preload(vma->vm_mm, ptep, address, is_exec, trap);
1701 }
1702 
1703 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1704 static inline void tm_flush_hash_page(int local)
1705 {
1706 	/*
1707 	 * Transactions are not aborted by tlbiel, only tlbie. Without, syncing a
1708 	 * page back to a block device w/PIO could pick up transactional data
1709 	 * (bad!) so we force an abort here. Before the sync the page will be
1710 	 * made read-only, which will flush_hash_page. BIG ISSUE here: if the
1711 	 * kernel uses a page from userspace without unmapping it first, it may
1712 	 * see the speculated version.
1713 	 */
1714 	if (local && cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
1715 	    MSR_TM_ACTIVE(current->thread.regs->msr)) {
1716 		tm_enable();
1717 		tm_abort(TM_CAUSE_TLBI);
1718 	}
1719 }
1720 #else
1721 static inline void tm_flush_hash_page(int local)
1722 {
1723 }
1724 #endif
1725 
1726 /*
1727  * Return the global hash slot, corresponding to the given PTE, which contains
1728  * the HPTE.
1729  */
1730 unsigned long pte_get_hash_gslot(unsigned long vpn, unsigned long shift,
1731 		int ssize, real_pte_t rpte, unsigned int subpg_index)
1732 {
1733 	unsigned long hash, gslot, hidx;
1734 
1735 	hash = hpt_hash(vpn, shift, ssize);
1736 	hidx = __rpte_to_hidx(rpte, subpg_index);
1737 	if (hidx & _PTEIDX_SECONDARY)
1738 		hash = ~hash;
1739 	gslot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1740 	gslot += hidx & _PTEIDX_GROUP_IX;
1741 	return gslot;
1742 }
1743 
1744 void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
1745 		     unsigned long flags)
1746 {
1747 	unsigned long index, shift, gslot;
1748 	int local = flags & HPTE_LOCAL_UPDATE;
1749 
1750 	DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
1751 	pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
1752 		gslot = pte_get_hash_gslot(vpn, shift, ssize, pte, index);
1753 		DBG_LOW(" sub %ld: gslot=%lx\n", index, gslot);
1754 		/*
1755 		 * We use same base page size and actual psize, because we don't
1756 		 * use these functions for hugepage
1757 		 */
1758 		mmu_hash_ops.hpte_invalidate(gslot, vpn, psize, psize,
1759 					     ssize, local);
1760 	} pte_iterate_hashed_end();
1761 
1762 	tm_flush_hash_page(local);
1763 }
1764 
1765 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1766 void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
1767 			 pmd_t *pmdp, unsigned int psize, int ssize,
1768 			 unsigned long flags)
1769 {
1770 	int i, max_hpte_count, valid;
1771 	unsigned long s_addr;
1772 	unsigned char *hpte_slot_array;
1773 	unsigned long hidx, shift, vpn, hash, slot;
1774 	int local = flags & HPTE_LOCAL_UPDATE;
1775 
1776 	s_addr = addr & HPAGE_PMD_MASK;
1777 	hpte_slot_array = get_hpte_slot_array(pmdp);
1778 	/*
1779 	 * IF we try to do a HUGE PTE update after a withdraw is done.
1780 	 * we will find the below NULL. This happens when we do
1781 	 * split_huge_pmd
1782 	 */
1783 	if (!hpte_slot_array)
1784 		return;
1785 
1786 	if (mmu_hash_ops.hugepage_invalidate) {
1787 		mmu_hash_ops.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
1788 						 psize, ssize, local);
1789 		goto tm_abort;
1790 	}
1791 	/*
1792 	 * No bluk hpte removal support, invalidate each entry
1793 	 */
1794 	shift = mmu_psize_defs[psize].shift;
1795 	max_hpte_count = HPAGE_PMD_SIZE >> shift;
1796 	for (i = 0; i < max_hpte_count; i++) {
1797 		/*
1798 		 * 8 bits per each hpte entries
1799 		 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
1800 		 */
1801 		valid = hpte_valid(hpte_slot_array, i);
1802 		if (!valid)
1803 			continue;
1804 		hidx =  hpte_hash_index(hpte_slot_array, i);
1805 
1806 		/* get the vpn */
1807 		addr = s_addr + (i * (1ul << shift));
1808 		vpn = hpt_vpn(addr, vsid, ssize);
1809 		hash = hpt_hash(vpn, shift, ssize);
1810 		if (hidx & _PTEIDX_SECONDARY)
1811 			hash = ~hash;
1812 
1813 		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1814 		slot += hidx & _PTEIDX_GROUP_IX;
1815 		mmu_hash_ops.hpte_invalidate(slot, vpn, psize,
1816 					     MMU_PAGE_16M, ssize, local);
1817 	}
1818 tm_abort:
1819 	tm_flush_hash_page(local);
1820 }
1821 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1822 
1823 void flush_hash_range(unsigned long number, int local)
1824 {
1825 	if (mmu_hash_ops.flush_hash_range)
1826 		mmu_hash_ops.flush_hash_range(number, local);
1827 	else {
1828 		int i;
1829 		struct ppc64_tlb_batch *batch =
1830 			this_cpu_ptr(&ppc64_tlb_batch);
1831 
1832 		for (i = 0; i < number; i++)
1833 			flush_hash_page(batch->vpn[i], batch->pte[i],
1834 					batch->psize, batch->ssize, local);
1835 	}
1836 }
1837 
1838 /*
1839  * low_hash_fault is called when we the low level hash code failed
1840  * to instert a PTE due to an hypervisor error
1841  */
1842 void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
1843 {
1844 	enum ctx_state prev_state = exception_enter();
1845 
1846 	if (user_mode(regs)) {
1847 #ifdef CONFIG_PPC_SUBPAGE_PROT
1848 		if (rc == -2)
1849 			_exception(SIGSEGV, regs, SEGV_ACCERR, address);
1850 		else
1851 #endif
1852 			_exception(SIGBUS, regs, BUS_ADRERR, address);
1853 	} else
1854 		bad_page_fault(regs, address, SIGBUS);
1855 
1856 	exception_exit(prev_state);
1857 }
1858 
1859 long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
1860 			   unsigned long pa, unsigned long rflags,
1861 			   unsigned long vflags, int psize, int ssize)
1862 {
1863 	unsigned long hpte_group;
1864 	long slot;
1865 
1866 repeat:
1867 	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1868 
1869 	/* Insert into the hash table, primary slot */
1870 	slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
1871 					psize, psize, ssize);
1872 
1873 	/* Primary is full, try the secondary */
1874 	if (unlikely(slot == -1)) {
1875 		hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
1876 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags,
1877 						vflags | HPTE_V_SECONDARY,
1878 						psize, psize, ssize);
1879 		if (slot == -1) {
1880 			if (mftb() & 0x1)
1881 				hpte_group = (hash & htab_hash_mask) *
1882 						HPTES_PER_GROUP;
1883 
1884 			mmu_hash_ops.hpte_remove(hpte_group);
1885 			goto repeat;
1886 		}
1887 	}
1888 
1889 	return slot;
1890 }
1891 
1892 #ifdef CONFIG_DEBUG_PAGEALLOC
1893 static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
1894 {
1895 	unsigned long hash;
1896 	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1897 	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1898 	unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
1899 	long ret;
1900 
1901 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1902 
1903 	/* Don't create HPTE entries for bad address */
1904 	if (!vsid)
1905 		return;
1906 
1907 	ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
1908 				    HPTE_V_BOLTED,
1909 				    mmu_linear_psize, mmu_kernel_ssize);
1910 
1911 	BUG_ON (ret < 0);
1912 	spin_lock(&linear_map_hash_lock);
1913 	BUG_ON(linear_map_hash_slots[lmi] & 0x80);
1914 	linear_map_hash_slots[lmi] = ret | 0x80;
1915 	spin_unlock(&linear_map_hash_lock);
1916 }
1917 
1918 static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
1919 {
1920 	unsigned long hash, hidx, slot;
1921 	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1922 	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1923 
1924 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1925 	spin_lock(&linear_map_hash_lock);
1926 	BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
1927 	hidx = linear_map_hash_slots[lmi] & 0x7f;
1928 	linear_map_hash_slots[lmi] = 0;
1929 	spin_unlock(&linear_map_hash_lock);
1930 	if (hidx & _PTEIDX_SECONDARY)
1931 		hash = ~hash;
1932 	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1933 	slot += hidx & _PTEIDX_GROUP_IX;
1934 	mmu_hash_ops.hpte_invalidate(slot, vpn, mmu_linear_psize,
1935 				     mmu_linear_psize,
1936 				     mmu_kernel_ssize, 0);
1937 }
1938 
1939 void __kernel_map_pages(struct page *page, int numpages, int enable)
1940 {
1941 	unsigned long flags, vaddr, lmi;
1942 	int i;
1943 
1944 	local_irq_save(flags);
1945 	for (i = 0; i < numpages; i++, page++) {
1946 		vaddr = (unsigned long)page_address(page);
1947 		lmi = __pa(vaddr) >> PAGE_SHIFT;
1948 		if (lmi >= linear_map_hash_count)
1949 			continue;
1950 		if (enable)
1951 			kernel_map_linear_page(vaddr, lmi);
1952 		else
1953 			kernel_unmap_linear_page(vaddr, lmi);
1954 	}
1955 	local_irq_restore(flags);
1956 }
1957 #endif /* CONFIG_DEBUG_PAGEALLOC */
1958 
1959 void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base,
1960 				phys_addr_t first_memblock_size)
1961 {
1962 	/*
1963 	 * We don't currently support the first MEMBLOCK not mapping 0
1964 	 * physical on those processors
1965 	 */
1966 	BUG_ON(first_memblock_base != 0);
1967 
1968 	/*
1969 	 * On virtualized systems the first entry is our RMA region aka VRMA,
1970 	 * non-virtualized 64-bit hash MMU systems don't have a limitation
1971 	 * on real mode access.
1972 	 *
1973 	 * For guests on platforms before POWER9, we clamp the it limit to 1G
1974 	 * to avoid some funky things such as RTAS bugs etc...
1975 	 *
1976 	 * On POWER9 we limit to 1TB in case the host erroneously told us that
1977 	 * the RMA was >1TB. Effective address bits 0:23 are treated as zero
1978 	 * (meaning the access is aliased to zero i.e. addr = addr % 1TB)
1979 	 * for virtual real mode addressing and so it doesn't make sense to
1980 	 * have an area larger than 1TB as it can't be addressed.
1981 	 */
1982 	if (!early_cpu_has_feature(CPU_FTR_HVMODE)) {
1983 		ppc64_rma_size = first_memblock_size;
1984 		if (!early_cpu_has_feature(CPU_FTR_ARCH_300))
1985 			ppc64_rma_size = min_t(u64, ppc64_rma_size, 0x40000000);
1986 		else
1987 			ppc64_rma_size = min_t(u64, ppc64_rma_size,
1988 					       1UL << SID_SHIFT_1T);
1989 
1990 		/* Finally limit subsequent allocations */
1991 		memblock_set_current_limit(ppc64_rma_size);
1992 	} else {
1993 		ppc64_rma_size = ULONG_MAX;
1994 	}
1995 }
1996 
1997 #ifdef CONFIG_DEBUG_FS
1998 
1999 static int hpt_order_get(void *data, u64 *val)
2000 {
2001 	*val = ppc64_pft_size;
2002 	return 0;
2003 }
2004 
2005 static int hpt_order_set(void *data, u64 val)
2006 {
2007 	int ret;
2008 
2009 	if (!mmu_hash_ops.resize_hpt)
2010 		return -ENODEV;
2011 
2012 	cpus_read_lock();
2013 	ret = mmu_hash_ops.resize_hpt(val);
2014 	cpus_read_unlock();
2015 
2016 	return ret;
2017 }
2018 
2019 DEFINE_DEBUGFS_ATTRIBUTE(fops_hpt_order, hpt_order_get, hpt_order_set, "%llu\n");
2020 
2021 static int __init hash64_debugfs(void)
2022 {
2023 	debugfs_create_file("hpt_order", 0600, powerpc_debugfs_root, NULL,
2024 			    &fops_hpt_order);
2025 	return 0;
2026 }
2027 machine_device_initcall(pseries, hash64_debugfs);
2028 #endif /* CONFIG_DEBUG_FS */
2029 
2030 void __init print_system_hash_info(void)
2031 {
2032 	pr_info("ppc64_pft_size    = 0x%llx\n", ppc64_pft_size);
2033 
2034 	if (htab_hash_mask)
2035 		pr_info("htab_hash_mask    = 0x%lx\n", htab_hash_mask);
2036 }
2037