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 
38 #include <asm/debugfs.h>
39 #include <asm/processor.h>
40 #include <asm/pgtable.h>
41 #include <asm/mmu.h>
42 #include <asm/mmu_context.h>
43 #include <asm/page.h>
44 #include <asm/types.h>
45 #include <linux/uaccess.h>
46 #include <asm/machdep.h>
47 #include <asm/prom.h>
48 #include <asm/io.h>
49 #include <asm/eeh.h>
50 #include <asm/tlb.h>
51 #include <asm/cacheflush.h>
52 #include <asm/cputable.h>
53 #include <asm/sections.h>
54 #include <asm/copro.h>
55 #include <asm/udbg.h>
56 #include <asm/code-patching.h>
57 #include <asm/fadump.h>
58 #include <asm/firmware.h>
59 #include <asm/tm.h>
60 #include <asm/trace.h>
61 #include <asm/ps3.h>
62 #include <asm/pte-walk.h>
63 #include <asm/asm-prototypes.h>
64 
65 #include <mm/mmu_decl.h>
66 
67 #ifdef DEBUG
68 #define DBG(fmt...) udbg_printf(fmt)
69 #else
70 #define DBG(fmt...)
71 #endif
72 
73 #ifdef DEBUG_LOW
74 #define DBG_LOW(fmt...) udbg_printf(fmt)
75 #else
76 #define DBG_LOW(fmt...)
77 #endif
78 
79 #define KB (1024)
80 #define MB (1024*KB)
81 #define GB (1024L*MB)
82 
83 /*
84  * Note:  pte   --> Linux PTE
85  *        HPTE  --> PowerPC Hashed Page Table Entry
86  *
87  * Execution context:
88  *   htab_initialize is called with the MMU off (of course), but
89  *   the kernel has been copied down to zero so it can directly
90  *   reference global data.  At this point it is very difficult
91  *   to print debug info.
92  *
93  */
94 
95 static unsigned long _SDR1;
96 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
97 EXPORT_SYMBOL_GPL(mmu_psize_defs);
98 
99 u8 hpte_page_sizes[1 << LP_BITS];
100 EXPORT_SYMBOL_GPL(hpte_page_sizes);
101 
102 struct hash_pte *htab_address;
103 unsigned long htab_size_bytes;
104 unsigned long htab_hash_mask;
105 EXPORT_SYMBOL_GPL(htab_hash_mask);
106 int mmu_linear_psize = MMU_PAGE_4K;
107 EXPORT_SYMBOL_GPL(mmu_linear_psize);
108 int mmu_virtual_psize = MMU_PAGE_4K;
109 int mmu_vmalloc_psize = MMU_PAGE_4K;
110 #ifdef CONFIG_SPARSEMEM_VMEMMAP
111 int mmu_vmemmap_psize = MMU_PAGE_4K;
112 #endif
113 int mmu_io_psize = MMU_PAGE_4K;
114 int mmu_kernel_ssize = MMU_SEGSIZE_256M;
115 EXPORT_SYMBOL_GPL(mmu_kernel_ssize);
116 int mmu_highuser_ssize = MMU_SEGSIZE_256M;
117 u16 mmu_slb_size = 64;
118 EXPORT_SYMBOL_GPL(mmu_slb_size);
119 #ifdef CONFIG_PPC_64K_PAGES
120 int mmu_ci_restrictions;
121 #endif
122 #ifdef CONFIG_DEBUG_PAGEALLOC
123 static u8 *linear_map_hash_slots;
124 static unsigned long linear_map_hash_count;
125 static DEFINE_SPINLOCK(linear_map_hash_lock);
126 #endif /* CONFIG_DEBUG_PAGEALLOC */
127 struct mmu_hash_ops mmu_hash_ops;
128 EXPORT_SYMBOL(mmu_hash_ops);
129 
130 /*
131  * These are definitions of page sizes arrays to be used when none
132  * is provided by the firmware.
133  */
134 
135 /*
136  * Fallback (4k pages only)
137  */
138 static struct mmu_psize_def mmu_psize_defaults[] = {
139 	[MMU_PAGE_4K] = {
140 		.shift	= 12,
141 		.sllp	= 0,
142 		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
143 		.avpnm	= 0,
144 		.tlbiel = 0,
145 	},
146 };
147 
148 /*
149  * POWER4, GPUL, POWER5
150  *
151  * Support for 16Mb large pages
152  */
153 static struct mmu_psize_def mmu_psize_defaults_gp[] = {
154 	[MMU_PAGE_4K] = {
155 		.shift	= 12,
156 		.sllp	= 0,
157 		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
158 		.avpnm	= 0,
159 		.tlbiel = 1,
160 	},
161 	[MMU_PAGE_16M] = {
162 		.shift	= 24,
163 		.sllp	= SLB_VSID_L,
164 		.penc   = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
165 			    [MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
166 		.avpnm	= 0x1UL,
167 		.tlbiel = 0,
168 	},
169 };
170 
171 /*
172  * 'R' and 'C' update notes:
173  *  - Under pHyp or KVM, the updatepp path will not set C, thus it *will*
174  *     create writeable HPTEs without C set, because the hcall H_PROTECT
175  *     that we use in that case will not update C
176  *  - The above is however not a problem, because we also don't do that
177  *     fancy "no flush" variant of eviction and we use H_REMOVE which will
178  *     do the right thing and thus we don't have the race I described earlier
179  *
180  *    - Under bare metal,  we do have the race, so we need R and C set
181  *    - We make sure R is always set and never lost
182  *    - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping
183  */
184 unsigned long htab_convert_pte_flags(unsigned long pteflags)
185 {
186 	unsigned long rflags = 0;
187 
188 	/* _PAGE_EXEC -> NOEXEC */
189 	if ((pteflags & _PAGE_EXEC) == 0)
190 		rflags |= HPTE_R_N;
191 	/*
192 	 * PPP bits:
193 	 * Linux uses slb key 0 for kernel and 1 for user.
194 	 * kernel RW areas are mapped with PPP=0b000
195 	 * User area is mapped with PPP=0b010 for read/write
196 	 * or PPP=0b011 for read-only (including writeable but clean pages).
197 	 */
198 	if (pteflags & _PAGE_PRIVILEGED) {
199 		/*
200 		 * Kernel read only mapped with ppp bits 0b110
201 		 */
202 		if (!(pteflags & _PAGE_WRITE)) {
203 			if (mmu_has_feature(MMU_FTR_KERNEL_RO))
204 				rflags |= (HPTE_R_PP0 | 0x2);
205 			else
206 				rflags |= 0x3;
207 		}
208 	} else {
209 		if (pteflags & _PAGE_RWX)
210 			rflags |= 0x2;
211 		if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
212 			rflags |= 0x1;
213 	}
214 	/*
215 	 * We can't allow hardware to update hpte bits. Hence always
216 	 * set 'R' bit and set 'C' if it is a write fault
217 	 */
218 	rflags |=  HPTE_R_R;
219 
220 	if (pteflags & _PAGE_DIRTY)
221 		rflags |= HPTE_R_C;
222 	/*
223 	 * Add in WIG bits
224 	 */
225 
226 	if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
227 		rflags |= HPTE_R_I;
228 	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
229 		rflags |= (HPTE_R_I | HPTE_R_G);
230 	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
231 		rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
232 	else
233 		/*
234 		 * Add memory coherence if cache inhibited is not set
235 		 */
236 		rflags |= HPTE_R_M;
237 
238 	rflags |= pte_to_hpte_pkey_bits(pteflags);
239 	return rflags;
240 }
241 
242 int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
243 		      unsigned long pstart, unsigned long prot,
244 		      int psize, int ssize)
245 {
246 	unsigned long vaddr, paddr;
247 	unsigned int step, shift;
248 	int ret = 0;
249 
250 	shift = mmu_psize_defs[psize].shift;
251 	step = 1 << shift;
252 
253 	prot = htab_convert_pte_flags(prot);
254 
255 	DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
256 	    vstart, vend, pstart, prot, psize, ssize);
257 
258 	for (vaddr = vstart, paddr = pstart; vaddr < vend;
259 	     vaddr += step, paddr += step) {
260 		unsigned long hash, hpteg;
261 		unsigned long vsid = get_kernel_vsid(vaddr, ssize);
262 		unsigned long vpn  = hpt_vpn(vaddr, vsid, ssize);
263 		unsigned long tprot = prot;
264 
265 		/*
266 		 * If we hit a bad address return error.
267 		 */
268 		if (!vsid)
269 			return -1;
270 		/* Make kernel text executable */
271 		if (overlaps_kernel_text(vaddr, vaddr + step))
272 			tprot &= ~HPTE_R_N;
273 
274 		/* Make kvm guest trampolines executable */
275 		if (overlaps_kvm_tmp(vaddr, vaddr + step))
276 			tprot &= ~HPTE_R_N;
277 
278 		/*
279 		 * If relocatable, check if it overlaps interrupt vectors that
280 		 * are copied down to real 0. For relocatable kernel
281 		 * (e.g. kdump case) we copy interrupt vectors down to real
282 		 * address 0. Mark that region as executable. This is
283 		 * because on p8 system with relocation on exception feature
284 		 * enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence
285 		 * in order to execute the interrupt handlers in virtual
286 		 * mode the vector region need to be marked as executable.
287 		 */
288 		if ((PHYSICAL_START > MEMORY_START) &&
289 			overlaps_interrupt_vector_text(vaddr, vaddr + step))
290 				tprot &= ~HPTE_R_N;
291 
292 		hash = hpt_hash(vpn, shift, ssize);
293 		hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
294 
295 		BUG_ON(!mmu_hash_ops.hpte_insert);
296 		ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
297 					       HPTE_V_BOLTED, psize, psize,
298 					       ssize);
299 
300 		if (ret < 0)
301 			break;
302 
303 #ifdef CONFIG_DEBUG_PAGEALLOC
304 		if (debug_pagealloc_enabled() &&
305 			(paddr >> PAGE_SHIFT) < linear_map_hash_count)
306 			linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
307 #endif /* CONFIG_DEBUG_PAGEALLOC */
308 	}
309 	return ret < 0 ? ret : 0;
310 }
311 
312 int htab_remove_mapping(unsigned long vstart, unsigned long vend,
313 		      int psize, int ssize)
314 {
315 	unsigned long vaddr;
316 	unsigned int step, shift;
317 	int rc;
318 	int ret = 0;
319 
320 	shift = mmu_psize_defs[psize].shift;
321 	step = 1 << shift;
322 
323 	if (!mmu_hash_ops.hpte_removebolted)
324 		return -ENODEV;
325 
326 	for (vaddr = vstart; vaddr < vend; vaddr += step) {
327 		rc = mmu_hash_ops.hpte_removebolted(vaddr, psize, ssize);
328 		if (rc == -ENOENT) {
329 			ret = -ENOENT;
330 			continue;
331 		}
332 		if (rc < 0)
333 			return rc;
334 	}
335 
336 	return ret;
337 }
338 
339 static bool disable_1tb_segments = false;
340 
341 static int __init parse_disable_1tb_segments(char *p)
342 {
343 	disable_1tb_segments = true;
344 	return 0;
345 }
346 early_param("disable_1tb_segments", parse_disable_1tb_segments);
347 
348 static int __init htab_dt_scan_seg_sizes(unsigned long node,
349 					 const char *uname, int depth,
350 					 void *data)
351 {
352 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
353 	const __be32 *prop;
354 	int size = 0;
355 
356 	/* We are scanning "cpu" nodes only */
357 	if (type == NULL || strcmp(type, "cpu") != 0)
358 		return 0;
359 
360 	prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size);
361 	if (prop == NULL)
362 		return 0;
363 	for (; size >= 4; size -= 4, ++prop) {
364 		if (be32_to_cpu(prop[0]) == 40) {
365 			DBG("1T segment support detected\n");
366 
367 			if (disable_1tb_segments) {
368 				DBG("1T segments disabled by command line\n");
369 				break;
370 			}
371 
372 			cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
373 			return 1;
374 		}
375 	}
376 	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
377 	return 0;
378 }
379 
380 static int __init get_idx_from_shift(unsigned int shift)
381 {
382 	int idx = -1;
383 
384 	switch (shift) {
385 	case 0xc:
386 		idx = MMU_PAGE_4K;
387 		break;
388 	case 0x10:
389 		idx = MMU_PAGE_64K;
390 		break;
391 	case 0x14:
392 		idx = MMU_PAGE_1M;
393 		break;
394 	case 0x18:
395 		idx = MMU_PAGE_16M;
396 		break;
397 	case 0x22:
398 		idx = MMU_PAGE_16G;
399 		break;
400 	}
401 	return idx;
402 }
403 
404 static int __init htab_dt_scan_page_sizes(unsigned long node,
405 					  const char *uname, int depth,
406 					  void *data)
407 {
408 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
409 	const __be32 *prop;
410 	int size = 0;
411 
412 	/* We are scanning "cpu" nodes only */
413 	if (type == NULL || strcmp(type, "cpu") != 0)
414 		return 0;
415 
416 	prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
417 	if (!prop)
418 		return 0;
419 
420 	pr_info("Page sizes from device-tree:\n");
421 	size /= 4;
422 	cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
423 	while(size > 0) {
424 		unsigned int base_shift = be32_to_cpu(prop[0]);
425 		unsigned int slbenc = be32_to_cpu(prop[1]);
426 		unsigned int lpnum = be32_to_cpu(prop[2]);
427 		struct mmu_psize_def *def;
428 		int idx, base_idx;
429 
430 		size -= 3; prop += 3;
431 		base_idx = get_idx_from_shift(base_shift);
432 		if (base_idx < 0) {
433 			/* skip the pte encoding also */
434 			prop += lpnum * 2; size -= lpnum * 2;
435 			continue;
436 		}
437 		def = &mmu_psize_defs[base_idx];
438 		if (base_idx == MMU_PAGE_16M)
439 			cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
440 
441 		def->shift = base_shift;
442 		if (base_shift <= 23)
443 			def->avpnm = 0;
444 		else
445 			def->avpnm = (1 << (base_shift - 23)) - 1;
446 		def->sllp = slbenc;
447 		/*
448 		 * We don't know for sure what's up with tlbiel, so
449 		 * for now we only set it for 4K and 64K pages
450 		 */
451 		if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
452 			def->tlbiel = 1;
453 		else
454 			def->tlbiel = 0;
455 
456 		while (size > 0 && lpnum) {
457 			unsigned int shift = be32_to_cpu(prop[0]);
458 			int penc  = be32_to_cpu(prop[1]);
459 
460 			prop += 2; size -= 2;
461 			lpnum--;
462 
463 			idx = get_idx_from_shift(shift);
464 			if (idx < 0)
465 				continue;
466 
467 			if (penc == -1)
468 				pr_err("Invalid penc for base_shift=%d "
469 				       "shift=%d\n", base_shift, shift);
470 
471 			def->penc[idx] = penc;
472 			pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
473 				" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
474 				base_shift, shift, def->sllp,
475 				def->avpnm, def->tlbiel, def->penc[idx]);
476 		}
477 	}
478 
479 	return 1;
480 }
481 
482 #ifdef CONFIG_HUGETLB_PAGE
483 /*
484  * Scan for 16G memory blocks that have been set aside for huge pages
485  * and reserve those blocks for 16G huge pages.
486  */
487 static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
488 					const char *uname, int depth,
489 					void *data) {
490 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
491 	const __be64 *addr_prop;
492 	const __be32 *page_count_prop;
493 	unsigned int expected_pages;
494 	long unsigned int phys_addr;
495 	long unsigned int block_size;
496 
497 	/* We are scanning "memory" nodes only */
498 	if (type == NULL || strcmp(type, "memory") != 0)
499 		return 0;
500 
501 	/*
502 	 * This property is the log base 2 of the number of virtual pages that
503 	 * will represent this memory block.
504 	 */
505 	page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
506 	if (page_count_prop == NULL)
507 		return 0;
508 	expected_pages = (1 << be32_to_cpu(page_count_prop[0]));
509 	addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
510 	if (addr_prop == NULL)
511 		return 0;
512 	phys_addr = be64_to_cpu(addr_prop[0]);
513 	block_size = be64_to_cpu(addr_prop[1]);
514 	if (block_size != (16 * GB))
515 		return 0;
516 	printk(KERN_INFO "Huge page(16GB) memory: "
517 			"addr = 0x%lX size = 0x%lX pages = %d\n",
518 			phys_addr, block_size, expected_pages);
519 	if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) {
520 		memblock_reserve(phys_addr, block_size * expected_pages);
521 		pseries_add_gpage(phys_addr, block_size, expected_pages);
522 	}
523 	return 0;
524 }
525 #endif /* CONFIG_HUGETLB_PAGE */
526 
527 static void mmu_psize_set_default_penc(void)
528 {
529 	int bpsize, apsize;
530 	for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
531 		for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
532 			mmu_psize_defs[bpsize].penc[apsize] = -1;
533 }
534 
535 #ifdef CONFIG_PPC_64K_PAGES
536 
537 static bool might_have_hea(void)
538 {
539 	/*
540 	 * The HEA ethernet adapter requires awareness of the
541 	 * GX bus. Without that awareness we can easily assume
542 	 * we will never see an HEA ethernet device.
543 	 */
544 #ifdef CONFIG_IBMEBUS
545 	return !cpu_has_feature(CPU_FTR_ARCH_207S) &&
546 		firmware_has_feature(FW_FEATURE_SPLPAR);
547 #else
548 	return false;
549 #endif
550 }
551 
552 #endif /* #ifdef CONFIG_PPC_64K_PAGES */
553 
554 static void __init htab_scan_page_sizes(void)
555 {
556 	int rc;
557 
558 	/* se the invalid penc to -1 */
559 	mmu_psize_set_default_penc();
560 
561 	/* Default to 4K pages only */
562 	memcpy(mmu_psize_defs, mmu_psize_defaults,
563 	       sizeof(mmu_psize_defaults));
564 
565 	/*
566 	 * Try to find the available page sizes in the device-tree
567 	 */
568 	rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
569 	if (rc == 0 && early_mmu_has_feature(MMU_FTR_16M_PAGE)) {
570 		/*
571 		 * Nothing in the device-tree, but the CPU supports 16M pages,
572 		 * so let's fallback on a known size list for 16M capable CPUs.
573 		 */
574 		memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
575 		       sizeof(mmu_psize_defaults_gp));
576 	}
577 
578 #ifdef CONFIG_HUGETLB_PAGE
579 	if (!hugetlb_disabled) {
580 		/* Reserve 16G huge page memory sections for huge pages */
581 		of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
582 	}
583 #endif /* CONFIG_HUGETLB_PAGE */
584 }
585 
586 /*
587  * Fill in the hpte_page_sizes[] array.
588  * We go through the mmu_psize_defs[] array looking for all the
589  * supported base/actual page size combinations.  Each combination
590  * has a unique pagesize encoding (penc) value in the low bits of
591  * the LP field of the HPTE.  For actual page sizes less than 1MB,
592  * some of the upper LP bits are used for RPN bits, meaning that
593  * we need to fill in several entries in hpte_page_sizes[].
594  *
595  * In diagrammatic form, with r = RPN bits and z = page size bits:
596  *        PTE LP     actual page size
597  *    rrrr rrrz		>=8KB
598  *    rrrr rrzz		>=16KB
599  *    rrrr rzzz		>=32KB
600  *    rrrr zzzz		>=64KB
601  *    ...
602  *
603  * The zzzz bits are implementation-specific but are chosen so that
604  * no encoding for a larger page size uses the same value in its
605  * low-order N bits as the encoding for the 2^(12+N) byte page size
606  * (if it exists).
607  */
608 static void init_hpte_page_sizes(void)
609 {
610 	long int ap, bp;
611 	long int shift, penc;
612 
613 	for (bp = 0; bp < MMU_PAGE_COUNT; ++bp) {
614 		if (!mmu_psize_defs[bp].shift)
615 			continue;	/* not a supported page size */
616 		for (ap = bp; ap < MMU_PAGE_COUNT; ++ap) {
617 			penc = mmu_psize_defs[bp].penc[ap];
618 			if (penc == -1 || !mmu_psize_defs[ap].shift)
619 				continue;
620 			shift = mmu_psize_defs[ap].shift - LP_SHIFT;
621 			if (shift <= 0)
622 				continue;	/* should never happen */
623 			/*
624 			 * For page sizes less than 1MB, this loop
625 			 * replicates the entry for all possible values
626 			 * of the rrrr bits.
627 			 */
628 			while (penc < (1 << LP_BITS)) {
629 				hpte_page_sizes[penc] = (ap << 4) | bp;
630 				penc += 1 << shift;
631 			}
632 		}
633 	}
634 }
635 
636 static void __init htab_init_page_sizes(void)
637 {
638 	init_hpte_page_sizes();
639 
640 	if (!debug_pagealloc_enabled()) {
641 		/*
642 		 * Pick a size for the linear mapping. Currently, we only
643 		 * support 16M, 1M and 4K which is the default
644 		 */
645 		if (mmu_psize_defs[MMU_PAGE_16M].shift)
646 			mmu_linear_psize = MMU_PAGE_16M;
647 		else if (mmu_psize_defs[MMU_PAGE_1M].shift)
648 			mmu_linear_psize = MMU_PAGE_1M;
649 	}
650 
651 #ifdef CONFIG_PPC_64K_PAGES
652 	/*
653 	 * Pick a size for the ordinary pages. Default is 4K, we support
654 	 * 64K for user mappings and vmalloc if supported by the processor.
655 	 * We only use 64k for ioremap if the processor
656 	 * (and firmware) support cache-inhibited large pages.
657 	 * If not, we use 4k and set mmu_ci_restrictions so that
658 	 * hash_page knows to switch processes that use cache-inhibited
659 	 * mappings to 4k pages.
660 	 */
661 	if (mmu_psize_defs[MMU_PAGE_64K].shift) {
662 		mmu_virtual_psize = MMU_PAGE_64K;
663 		mmu_vmalloc_psize = MMU_PAGE_64K;
664 		if (mmu_linear_psize == MMU_PAGE_4K)
665 			mmu_linear_psize = MMU_PAGE_64K;
666 		if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
667 			/*
668 			 * When running on pSeries using 64k pages for ioremap
669 			 * would stop us accessing the HEA ethernet. So if we
670 			 * have the chance of ever seeing one, stay at 4k.
671 			 */
672 			if (!might_have_hea())
673 				mmu_io_psize = MMU_PAGE_64K;
674 		} else
675 			mmu_ci_restrictions = 1;
676 	}
677 #endif /* CONFIG_PPC_64K_PAGES */
678 
679 #ifdef CONFIG_SPARSEMEM_VMEMMAP
680 	/*
681 	 * We try to use 16M pages for vmemmap if that is supported
682 	 * and we have at least 1G of RAM at boot
683 	 */
684 	if (mmu_psize_defs[MMU_PAGE_16M].shift &&
685 	    memblock_phys_mem_size() >= 0x40000000)
686 		mmu_vmemmap_psize = MMU_PAGE_16M;
687 	else
688 		mmu_vmemmap_psize = mmu_virtual_psize;
689 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
690 
691 	printk(KERN_DEBUG "Page orders: linear mapping = %d, "
692 	       "virtual = %d, io = %d"
693 #ifdef CONFIG_SPARSEMEM_VMEMMAP
694 	       ", vmemmap = %d"
695 #endif
696 	       "\n",
697 	       mmu_psize_defs[mmu_linear_psize].shift,
698 	       mmu_psize_defs[mmu_virtual_psize].shift,
699 	       mmu_psize_defs[mmu_io_psize].shift
700 #ifdef CONFIG_SPARSEMEM_VMEMMAP
701 	       ,mmu_psize_defs[mmu_vmemmap_psize].shift
702 #endif
703 	       );
704 }
705 
706 static int __init htab_dt_scan_pftsize(unsigned long node,
707 				       const char *uname, int depth,
708 				       void *data)
709 {
710 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
711 	const __be32 *prop;
712 
713 	/* We are scanning "cpu" nodes only */
714 	if (type == NULL || strcmp(type, "cpu") != 0)
715 		return 0;
716 
717 	prop = of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
718 	if (prop != NULL) {
719 		/* pft_size[0] is the NUMA CEC cookie */
720 		ppc64_pft_size = be32_to_cpu(prop[1]);
721 		return 1;
722 	}
723 	return 0;
724 }
725 
726 unsigned htab_shift_for_mem_size(unsigned long mem_size)
727 {
728 	unsigned memshift = __ilog2(mem_size);
729 	unsigned pshift = mmu_psize_defs[mmu_virtual_psize].shift;
730 	unsigned pteg_shift;
731 
732 	/* round mem_size up to next power of 2 */
733 	if ((1UL << memshift) < mem_size)
734 		memshift += 1;
735 
736 	/* aim for 2 pages / pteg */
737 	pteg_shift = memshift - (pshift + 1);
738 
739 	/*
740 	 * 2^11 PTEGS of 128 bytes each, ie. 2^18 bytes is the minimum htab
741 	 * size permitted by the architecture.
742 	 */
743 	return max(pteg_shift + 7, 18U);
744 }
745 
746 static unsigned long __init htab_get_table_size(void)
747 {
748 	/*
749 	 * If hash size isn't already provided by the platform, we try to
750 	 * retrieve it from the device-tree. If it's not there neither, we
751 	 * calculate it now based on the total RAM size
752 	 */
753 	if (ppc64_pft_size == 0)
754 		of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
755 	if (ppc64_pft_size)
756 		return 1UL << ppc64_pft_size;
757 
758 	return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size());
759 }
760 
761 #ifdef CONFIG_MEMORY_HOTPLUG
762 int resize_hpt_for_hotplug(unsigned long new_mem_size)
763 {
764 	unsigned target_hpt_shift;
765 
766 	if (!mmu_hash_ops.resize_hpt)
767 		return 0;
768 
769 	target_hpt_shift = htab_shift_for_mem_size(new_mem_size);
770 
771 	/*
772 	 * To avoid lots of HPT resizes if memory size is fluctuating
773 	 * across a boundary, we deliberately have some hysterisis
774 	 * here: we immediately increase the HPT size if the target
775 	 * shift exceeds the current shift, but we won't attempt to
776 	 * reduce unless the target shift is at least 2 below the
777 	 * current shift
778 	 */
779 	if (target_hpt_shift > ppc64_pft_size ||
780 	    target_hpt_shift < ppc64_pft_size - 1)
781 		return mmu_hash_ops.resize_hpt(target_hpt_shift);
782 
783 	return 0;
784 }
785 
786 int hash__create_section_mapping(unsigned long start, unsigned long end, int nid)
787 {
788 	int rc;
789 
790 	if (end >= H_VMALLOC_START) {
791 		pr_warn("Outside the supported range\n");
792 		return -1;
793 	}
794 
795 	rc = htab_bolt_mapping(start, end, __pa(start),
796 			       pgprot_val(PAGE_KERNEL), mmu_linear_psize,
797 			       mmu_kernel_ssize);
798 
799 	if (rc < 0) {
800 		int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
801 					      mmu_kernel_ssize);
802 		BUG_ON(rc2 && (rc2 != -ENOENT));
803 	}
804 	return rc;
805 }
806 
807 int hash__remove_section_mapping(unsigned long start, unsigned long end)
808 {
809 	int rc = htab_remove_mapping(start, end, mmu_linear_psize,
810 				     mmu_kernel_ssize);
811 	WARN_ON(rc < 0);
812 	return rc;
813 }
814 #endif /* CONFIG_MEMORY_HOTPLUG */
815 
816 static void __init hash_init_partition_table(phys_addr_t hash_table,
817 					     unsigned long htab_size)
818 {
819 	mmu_partition_table_init();
820 
821 	/*
822 	 * PS field (VRMA page size) is not used for LPID 0, hence set to 0.
823 	 * For now, UPRT is 0 and we have no segment table.
824 	 */
825 	htab_size =  __ilog2(htab_size) - 18;
826 	mmu_partition_table_set_entry(0, hash_table | htab_size, 0);
827 	pr_info("Partition table %p\n", partition_tb);
828 }
829 
830 static void __init htab_initialize(void)
831 {
832 	unsigned long table;
833 	unsigned long pteg_count;
834 	unsigned long prot;
835 	unsigned long base = 0, size = 0;
836 	struct memblock_region *reg;
837 
838 	DBG(" -> htab_initialize()\n");
839 
840 	if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
841 		mmu_kernel_ssize = MMU_SEGSIZE_1T;
842 		mmu_highuser_ssize = MMU_SEGSIZE_1T;
843 		printk(KERN_INFO "Using 1TB segments\n");
844 	}
845 
846 	/*
847 	 * Calculate the required size of the htab.  We want the number of
848 	 * PTEGs to equal one half the number of real pages.
849 	 */
850 	htab_size_bytes = htab_get_table_size();
851 	pteg_count = htab_size_bytes >> 7;
852 
853 	htab_hash_mask = pteg_count - 1;
854 
855 	if (firmware_has_feature(FW_FEATURE_LPAR) ||
856 	    firmware_has_feature(FW_FEATURE_PS3_LV1)) {
857 		/* Using a hypervisor which owns the htab */
858 		htab_address = NULL;
859 		_SDR1 = 0;
860 		/*
861 		 * On POWER9, we need to do a H_REGISTER_PROC_TBL hcall
862 		 * to inform the hypervisor that we wish to use the HPT.
863 		 */
864 		if (cpu_has_feature(CPU_FTR_ARCH_300))
865 			register_process_table(0, 0, 0);
866 #ifdef CONFIG_FA_DUMP
867 		/*
868 		 * If firmware assisted dump is active firmware preserves
869 		 * the contents of htab along with entire partition memory.
870 		 * Clear the htab if firmware assisted dump is active so
871 		 * that we dont end up using old mappings.
872 		 */
873 		if (is_fadump_active() && mmu_hash_ops.hpte_clear_all)
874 			mmu_hash_ops.hpte_clear_all();
875 #endif
876 	} else {
877 		unsigned long limit = MEMBLOCK_ALLOC_ANYWHERE;
878 
879 #ifdef CONFIG_PPC_CELL
880 		/*
881 		 * Cell may require the hash table down low when using the
882 		 * Axon IOMMU in order to fit the dynamic region over it, see
883 		 * comments in cell/iommu.c
884 		 */
885 		if (fdt_subnode_offset(initial_boot_params, 0, "axon") > 0) {
886 			limit = 0x80000000;
887 			pr_info("Hash table forced below 2G for Axon IOMMU\n");
888 		}
889 #endif /* CONFIG_PPC_CELL */
890 
891 		table = memblock_phys_alloc_range(htab_size_bytes,
892 						  htab_size_bytes,
893 						  0, limit);
894 		if (!table)
895 			panic("ERROR: Failed to allocate %pa bytes below %pa\n",
896 			      &htab_size_bytes, &limit);
897 
898 		DBG("Hash table allocated at %lx, size: %lx\n", table,
899 		    htab_size_bytes);
900 
901 		htab_address = __va(table);
902 
903 		/* htab absolute addr + encoded htabsize */
904 		_SDR1 = table + __ilog2(htab_size_bytes) - 18;
905 
906 		/* Initialize the HPT with no entries */
907 		memset((void *)table, 0, htab_size_bytes);
908 
909 		if (!cpu_has_feature(CPU_FTR_ARCH_300))
910 			/* Set SDR1 */
911 			mtspr(SPRN_SDR1, _SDR1);
912 		else
913 			hash_init_partition_table(table, htab_size_bytes);
914 	}
915 
916 	prot = pgprot_val(PAGE_KERNEL);
917 
918 #ifdef CONFIG_DEBUG_PAGEALLOC
919 	if (debug_pagealloc_enabled()) {
920 		linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
921 		linear_map_hash_slots = memblock_alloc_try_nid(
922 				linear_map_hash_count, 1, MEMBLOCK_LOW_LIMIT,
923 				ppc64_rma_size,	NUMA_NO_NODE);
924 		if (!linear_map_hash_slots)
925 			panic("%s: Failed to allocate %lu bytes max_addr=%pa\n",
926 			      __func__, linear_map_hash_count, &ppc64_rma_size);
927 	}
928 #endif /* CONFIG_DEBUG_PAGEALLOC */
929 
930 	/* create bolted the linear mapping in the hash table */
931 	for_each_memblock(memory, reg) {
932 		base = (unsigned long)__va(reg->base);
933 		size = reg->size;
934 
935 		DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
936 		    base, size, prot);
937 
938 		if ((base + size) >= H_VMALLOC_START) {
939 			pr_warn("Outside the supported range\n");
940 			continue;
941 		}
942 
943 		BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
944 				prot, mmu_linear_psize, mmu_kernel_ssize));
945 	}
946 	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
947 
948 	/*
949 	 * If we have a memory_limit and we've allocated TCEs then we need to
950 	 * explicitly map the TCE area at the top of RAM. We also cope with the
951 	 * case that the TCEs start below memory_limit.
952 	 * tce_alloc_start/end are 16MB aligned so the mapping should work
953 	 * for either 4K or 16MB pages.
954 	 */
955 	if (tce_alloc_start) {
956 		tce_alloc_start = (unsigned long)__va(tce_alloc_start);
957 		tce_alloc_end = (unsigned long)__va(tce_alloc_end);
958 
959 		if (base + size >= tce_alloc_start)
960 			tce_alloc_start = base + size + 1;
961 
962 		BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
963 					 __pa(tce_alloc_start), prot,
964 					 mmu_linear_psize, mmu_kernel_ssize));
965 	}
966 
967 
968 	DBG(" <- htab_initialize()\n");
969 }
970 #undef KB
971 #undef MB
972 
973 void __init hash__early_init_devtree(void)
974 {
975 	/* Initialize segment sizes */
976 	of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
977 
978 	/* Initialize page sizes */
979 	htab_scan_page_sizes();
980 }
981 
982 static struct hash_mm_context init_hash_mm_context;
983 void __init hash__early_init_mmu(void)
984 {
985 #ifndef CONFIG_PPC_64K_PAGES
986 	/*
987 	 * We have code in __hash_page_4K() and elsewhere, which assumes it can
988 	 * do the following:
989 	 *   new_pte |= (slot << H_PAGE_F_GIX_SHIFT) & (H_PAGE_F_SECOND | H_PAGE_F_GIX);
990 	 *
991 	 * Where the slot number is between 0-15, and values of 8-15 indicate
992 	 * the secondary bucket. For that code to work H_PAGE_F_SECOND and
993 	 * H_PAGE_F_GIX must occupy four contiguous bits in the PTE, and
994 	 * H_PAGE_F_SECOND must be placed above H_PAGE_F_GIX. Assert that here
995 	 * with a BUILD_BUG_ON().
996 	 */
997 	BUILD_BUG_ON(H_PAGE_F_SECOND != (1ul  << (H_PAGE_F_GIX_SHIFT + 3)));
998 #endif /* CONFIG_PPC_64K_PAGES */
999 
1000 	htab_init_page_sizes();
1001 
1002 	/*
1003 	 * initialize page table size
1004 	 */
1005 	__pte_frag_nr = H_PTE_FRAG_NR;
1006 	__pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
1007 	__pmd_frag_nr = H_PMD_FRAG_NR;
1008 	__pmd_frag_size_shift = H_PMD_FRAG_SIZE_SHIFT;
1009 
1010 	__pte_index_size = H_PTE_INDEX_SIZE;
1011 	__pmd_index_size = H_PMD_INDEX_SIZE;
1012 	__pud_index_size = H_PUD_INDEX_SIZE;
1013 	__pgd_index_size = H_PGD_INDEX_SIZE;
1014 	__pud_cache_index = H_PUD_CACHE_INDEX;
1015 	__pte_table_size = H_PTE_TABLE_SIZE;
1016 	__pmd_table_size = H_PMD_TABLE_SIZE;
1017 	__pud_table_size = H_PUD_TABLE_SIZE;
1018 	__pgd_table_size = H_PGD_TABLE_SIZE;
1019 	/*
1020 	 * 4k use hugepd format, so for hash set then to
1021 	 * zero
1022 	 */
1023 	__pmd_val_bits = HASH_PMD_VAL_BITS;
1024 	__pud_val_bits = HASH_PUD_VAL_BITS;
1025 	__pgd_val_bits = HASH_PGD_VAL_BITS;
1026 
1027 	__kernel_virt_start = H_KERN_VIRT_START;
1028 	__vmalloc_start = H_VMALLOC_START;
1029 	__vmalloc_end = H_VMALLOC_END;
1030 	__kernel_io_start = H_KERN_IO_START;
1031 	__kernel_io_end = H_KERN_IO_END;
1032 	vmemmap = (struct page *)H_VMEMMAP_START;
1033 	ioremap_bot = IOREMAP_BASE;
1034 
1035 #ifdef CONFIG_PCI
1036 	pci_io_base = ISA_IO_BASE;
1037 #endif
1038 
1039 	/* Select appropriate backend */
1040 	if (firmware_has_feature(FW_FEATURE_PS3_LV1))
1041 		ps3_early_mm_init();
1042 	else if (firmware_has_feature(FW_FEATURE_LPAR))
1043 		hpte_init_pseries();
1044 	else if (IS_ENABLED(CONFIG_PPC_NATIVE))
1045 		hpte_init_native();
1046 
1047 	if (!mmu_hash_ops.hpte_insert)
1048 		panic("hash__early_init_mmu: No MMU hash ops defined!\n");
1049 
1050 	/*
1051 	 * Initialize the MMU Hash table and create the linear mapping
1052 	 * of memory. Has to be done before SLB initialization as this is
1053 	 * currently where the page size encoding is obtained.
1054 	 */
1055 	htab_initialize();
1056 
1057 	init_mm.context.hash_context = &init_hash_mm_context;
1058 	mm_ctx_set_slb_addr_limit(&init_mm.context, SLB_ADDR_LIMIT_DEFAULT);
1059 
1060 	pr_info("Initializing hash mmu with SLB\n");
1061 	/* Initialize SLB management */
1062 	slb_initialize();
1063 
1064 	if (cpu_has_feature(CPU_FTR_ARCH_206)
1065 			&& cpu_has_feature(CPU_FTR_HVMODE))
1066 		tlbiel_all();
1067 }
1068 
1069 #ifdef CONFIG_SMP
1070 void hash__early_init_mmu_secondary(void)
1071 {
1072 	/* Initialize hash table for that CPU */
1073 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1074 
1075 		if (!cpu_has_feature(CPU_FTR_ARCH_300))
1076 			mtspr(SPRN_SDR1, _SDR1);
1077 		else
1078 			mtspr(SPRN_PTCR,
1079 			      __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
1080 	}
1081 	/* Initialize SLB */
1082 	slb_initialize();
1083 
1084 	if (cpu_has_feature(CPU_FTR_ARCH_206)
1085 			&& cpu_has_feature(CPU_FTR_HVMODE))
1086 		tlbiel_all();
1087 }
1088 #endif /* CONFIG_SMP */
1089 
1090 /*
1091  * Called by asm hashtable.S for doing lazy icache flush
1092  */
1093 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
1094 {
1095 	struct page *page;
1096 
1097 	if (!pfn_valid(pte_pfn(pte)))
1098 		return pp;
1099 
1100 	page = pte_page(pte);
1101 
1102 	/* page is dirty */
1103 	if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
1104 		if (trap == 0x400) {
1105 			flush_dcache_icache_page(page);
1106 			set_bit(PG_arch_1, &page->flags);
1107 		} else
1108 			pp |= HPTE_R_N;
1109 	}
1110 	return pp;
1111 }
1112 
1113 #ifdef CONFIG_PPC_MM_SLICES
1114 static unsigned int get_paca_psize(unsigned long addr)
1115 {
1116 	unsigned char *psizes;
1117 	unsigned long index, mask_index;
1118 
1119 	if (addr < SLICE_LOW_TOP) {
1120 		psizes = get_paca()->mm_ctx_low_slices_psize;
1121 		index = GET_LOW_SLICE_INDEX(addr);
1122 	} else {
1123 		psizes = get_paca()->mm_ctx_high_slices_psize;
1124 		index = GET_HIGH_SLICE_INDEX(addr);
1125 	}
1126 	mask_index = index & 0x1;
1127 	return (psizes[index >> 1] >> (mask_index * 4)) & 0xF;
1128 }
1129 
1130 #else
1131 unsigned int get_paca_psize(unsigned long addr)
1132 {
1133 	return get_paca()->mm_ctx_user_psize;
1134 }
1135 #endif
1136 
1137 /*
1138  * Demote a segment to using 4k pages.
1139  * For now this makes the whole process use 4k pages.
1140  */
1141 #ifdef CONFIG_PPC_64K_PAGES
1142 void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
1143 {
1144 	if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
1145 		return;
1146 	slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
1147 	copro_flush_all_slbs(mm);
1148 	if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
1149 
1150 		copy_mm_to_paca(mm);
1151 		slb_flush_and_restore_bolted();
1152 	}
1153 }
1154 #endif /* CONFIG_PPC_64K_PAGES */
1155 
1156 #ifdef CONFIG_PPC_SUBPAGE_PROT
1157 /*
1158  * This looks up a 2-bit protection code for a 4k subpage of a 64k page.
1159  * Userspace sets the subpage permissions using the subpage_prot system call.
1160  *
1161  * Result is 0: full permissions, _PAGE_RW: read-only,
1162  * _PAGE_RWX: no access.
1163  */
1164 static int subpage_protection(struct mm_struct *mm, unsigned long ea)
1165 {
1166 	struct subpage_prot_table *spt = mm_ctx_subpage_prot(&mm->context);
1167 	u32 spp = 0;
1168 	u32 **sbpm, *sbpp;
1169 
1170 	if (!spt)
1171 		return 0;
1172 
1173 	if (ea >= spt->maxaddr)
1174 		return 0;
1175 	if (ea < 0x100000000UL) {
1176 		/* addresses below 4GB use spt->low_prot */
1177 		sbpm = spt->low_prot;
1178 	} else {
1179 		sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
1180 		if (!sbpm)
1181 			return 0;
1182 	}
1183 	sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
1184 	if (!sbpp)
1185 		return 0;
1186 	spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
1187 
1188 	/* extract 2-bit bitfield for this 4k subpage */
1189 	spp >>= 30 - 2 * ((ea >> 12) & 0xf);
1190 
1191 	/*
1192 	 * 0 -> full premission
1193 	 * 1 -> Read only
1194 	 * 2 -> no access.
1195 	 * We return the flag that need to be cleared.
1196 	 */
1197 	spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 0);
1198 	return spp;
1199 }
1200 
1201 #else /* CONFIG_PPC_SUBPAGE_PROT */
1202 static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
1203 {
1204 	return 0;
1205 }
1206 #endif
1207 
1208 void hash_failure_debug(unsigned long ea, unsigned long access,
1209 			unsigned long vsid, unsigned long trap,
1210 			int ssize, int psize, int lpsize, unsigned long pte)
1211 {
1212 	if (!printk_ratelimit())
1213 		return;
1214 	pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
1215 		ea, access, current->comm);
1216 	pr_info("    trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
1217 		trap, vsid, ssize, psize, lpsize, pte);
1218 }
1219 
1220 static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
1221 			     int psize, bool user_region)
1222 {
1223 	if (user_region) {
1224 		if (psize != get_paca_psize(ea)) {
1225 			copy_mm_to_paca(mm);
1226 			slb_flush_and_restore_bolted();
1227 		}
1228 	} else if (get_paca()->vmalloc_sllp !=
1229 		   mmu_psize_defs[mmu_vmalloc_psize].sllp) {
1230 		get_paca()->vmalloc_sllp =
1231 			mmu_psize_defs[mmu_vmalloc_psize].sllp;
1232 		slb_vmalloc_update();
1233 	}
1234 }
1235 
1236 /*
1237  * Result code is:
1238  *  0 - handled
1239  *  1 - normal page fault
1240  * -1 - critical hash insertion error
1241  * -2 - access not permitted by subpage protection mechanism
1242  */
1243 int hash_page_mm(struct mm_struct *mm, unsigned long ea,
1244 		 unsigned long access, unsigned long trap,
1245 		 unsigned long flags)
1246 {
1247 	bool is_thp;
1248 	enum ctx_state prev_state = exception_enter();
1249 	pgd_t *pgdir;
1250 	unsigned long vsid;
1251 	pte_t *ptep;
1252 	unsigned hugeshift;
1253 	int rc, user_region = 0;
1254 	int psize, ssize;
1255 
1256 	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
1257 		ea, access, trap);
1258 	trace_hash_fault(ea, access, trap);
1259 
1260 	/* Get region & vsid */
1261 	switch (get_region_id(ea)) {
1262 	case USER_REGION_ID:
1263 		user_region = 1;
1264 		if (! mm) {
1265 			DBG_LOW(" user region with no mm !\n");
1266 			rc = 1;
1267 			goto bail;
1268 		}
1269 		psize = get_slice_psize(mm, ea);
1270 		ssize = user_segment_size(ea);
1271 		vsid = get_user_vsid(&mm->context, ea, ssize);
1272 		break;
1273 	case VMALLOC_REGION_ID:
1274 		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1275 		psize = mmu_vmalloc_psize;
1276 		ssize = mmu_kernel_ssize;
1277 		break;
1278 
1279 	case IO_REGION_ID:
1280 		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1281 		psize = mmu_io_psize;
1282 		ssize = mmu_kernel_ssize;
1283 		break;
1284 	default:
1285 		/*
1286 		 * Not a valid range
1287 		 * Send the problem up to do_page_fault()
1288 		 */
1289 		rc = 1;
1290 		goto bail;
1291 	}
1292 	DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
1293 
1294 	/* Bad address. */
1295 	if (!vsid) {
1296 		DBG_LOW("Bad address!\n");
1297 		rc = 1;
1298 		goto bail;
1299 	}
1300 	/* Get pgdir */
1301 	pgdir = mm->pgd;
1302 	if (pgdir == NULL) {
1303 		rc = 1;
1304 		goto bail;
1305 	}
1306 
1307 	/* Check CPU locality */
1308 	if (user_region && mm_is_thread_local(mm))
1309 		flags |= HPTE_LOCAL_UPDATE;
1310 
1311 #ifndef CONFIG_PPC_64K_PAGES
1312 	/*
1313 	 * If we use 4K pages and our psize is not 4K, then we might
1314 	 * be hitting a special driver mapping, and need to align the
1315 	 * address before we fetch the PTE.
1316 	 *
1317 	 * It could also be a hugepage mapping, in which case this is
1318 	 * not necessary, but it's not harmful, either.
1319 	 */
1320 	if (psize != MMU_PAGE_4K)
1321 		ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
1322 #endif /* CONFIG_PPC_64K_PAGES */
1323 
1324 	/* Get PTE and page size from page tables */
1325 	ptep = find_linux_pte(pgdir, ea, &is_thp, &hugeshift);
1326 	if (ptep == NULL || !pte_present(*ptep)) {
1327 		DBG_LOW(" no PTE !\n");
1328 		rc = 1;
1329 		goto bail;
1330 	}
1331 
1332 	/* Add _PAGE_PRESENT to the required access perm */
1333 	access |= _PAGE_PRESENT;
1334 
1335 	/*
1336 	 * Pre-check access permissions (will be re-checked atomically
1337 	 * in __hash_page_XX but this pre-check is a fast path
1338 	 */
1339 	if (!check_pte_access(access, pte_val(*ptep))) {
1340 		DBG_LOW(" no access !\n");
1341 		rc = 1;
1342 		goto bail;
1343 	}
1344 
1345 	if (hugeshift) {
1346 		if (is_thp)
1347 			rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
1348 					     trap, flags, ssize, psize);
1349 #ifdef CONFIG_HUGETLB_PAGE
1350 		else
1351 			rc = __hash_page_huge(ea, access, vsid, ptep, trap,
1352 					      flags, ssize, hugeshift, psize);
1353 #else
1354 		else {
1355 			/*
1356 			 * if we have hugeshift, and is not transhuge with
1357 			 * hugetlb disabled, something is really wrong.
1358 			 */
1359 			rc = 1;
1360 			WARN_ON(1);
1361 		}
1362 #endif
1363 		if (current->mm == mm)
1364 			check_paca_psize(ea, mm, psize, user_region);
1365 
1366 		goto bail;
1367 	}
1368 
1369 #ifndef CONFIG_PPC_64K_PAGES
1370 	DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
1371 #else
1372 	DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
1373 		pte_val(*(ptep + PTRS_PER_PTE)));
1374 #endif
1375 	/* Do actual hashing */
1376 #ifdef CONFIG_PPC_64K_PAGES
1377 	/* If H_PAGE_4K_PFN is set, make sure this is a 4k segment */
1378 	if ((pte_val(*ptep) & H_PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
1379 		demote_segment_4k(mm, ea);
1380 		psize = MMU_PAGE_4K;
1381 	}
1382 
1383 	/*
1384 	 * If this PTE is non-cacheable and we have restrictions on
1385 	 * using non cacheable large pages, then we switch to 4k
1386 	 */
1387 	if (mmu_ci_restrictions && psize == MMU_PAGE_64K && pte_ci(*ptep)) {
1388 		if (user_region) {
1389 			demote_segment_4k(mm, ea);
1390 			psize = MMU_PAGE_4K;
1391 		} else if (ea < VMALLOC_END) {
1392 			/*
1393 			 * some driver did a non-cacheable mapping
1394 			 * in vmalloc space, so switch vmalloc
1395 			 * to 4k pages
1396 			 */
1397 			printk(KERN_ALERT "Reducing vmalloc segment "
1398 			       "to 4kB pages because of "
1399 			       "non-cacheable mapping\n");
1400 			psize = mmu_vmalloc_psize = MMU_PAGE_4K;
1401 			copro_flush_all_slbs(mm);
1402 		}
1403 	}
1404 
1405 #endif /* CONFIG_PPC_64K_PAGES */
1406 
1407 	if (current->mm == mm)
1408 		check_paca_psize(ea, mm, psize, user_region);
1409 
1410 #ifdef CONFIG_PPC_64K_PAGES
1411 	if (psize == MMU_PAGE_64K)
1412 		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1413 				     flags, ssize);
1414 	else
1415 #endif /* CONFIG_PPC_64K_PAGES */
1416 	{
1417 		int spp = subpage_protection(mm, ea);
1418 		if (access & spp)
1419 			rc = -2;
1420 		else
1421 			rc = __hash_page_4K(ea, access, vsid, ptep, trap,
1422 					    flags, ssize, spp);
1423 	}
1424 
1425 	/*
1426 	 * Dump some info in case of hash insertion failure, they should
1427 	 * never happen so it is really useful to know if/when they do
1428 	 */
1429 	if (rc == -1)
1430 		hash_failure_debug(ea, access, vsid, trap, ssize, psize,
1431 				   psize, pte_val(*ptep));
1432 #ifndef CONFIG_PPC_64K_PAGES
1433 	DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
1434 #else
1435 	DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
1436 		pte_val(*(ptep + PTRS_PER_PTE)));
1437 #endif
1438 	DBG_LOW(" -> rc=%d\n", rc);
1439 
1440 bail:
1441 	exception_exit(prev_state);
1442 	return rc;
1443 }
1444 EXPORT_SYMBOL_GPL(hash_page_mm);
1445 
1446 int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
1447 	      unsigned long dsisr)
1448 {
1449 	unsigned long flags = 0;
1450 	struct mm_struct *mm = current->mm;
1451 
1452 	if ((get_region_id(ea) == VMALLOC_REGION_ID) ||
1453 	    (get_region_id(ea) == IO_REGION_ID))
1454 		mm = &init_mm;
1455 
1456 	if (dsisr & DSISR_NOHPTE)
1457 		flags |= HPTE_NOHPTE_UPDATE;
1458 
1459 	return hash_page_mm(mm, ea, access, trap, flags);
1460 }
1461 EXPORT_SYMBOL_GPL(hash_page);
1462 
1463 int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
1464 		unsigned long dsisr)
1465 {
1466 	unsigned long access = _PAGE_PRESENT | _PAGE_READ;
1467 	unsigned long flags = 0;
1468 	struct mm_struct *mm = current->mm;
1469 	unsigned int region_id = get_region_id(ea);
1470 
1471 	if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID))
1472 		mm = &init_mm;
1473 
1474 	if (dsisr & DSISR_NOHPTE)
1475 		flags |= HPTE_NOHPTE_UPDATE;
1476 
1477 	if (dsisr & DSISR_ISSTORE)
1478 		access |= _PAGE_WRITE;
1479 	/*
1480 	 * We set _PAGE_PRIVILEGED only when
1481 	 * kernel mode access kernel space.
1482 	 *
1483 	 * _PAGE_PRIVILEGED is NOT set
1484 	 * 1) when kernel mode access user space
1485 	 * 2) user space access kernel space.
1486 	 */
1487 	access |= _PAGE_PRIVILEGED;
1488 	if ((msr & MSR_PR) || (region_id == USER_REGION_ID))
1489 		access &= ~_PAGE_PRIVILEGED;
1490 
1491 	if (trap == 0x400)
1492 		access |= _PAGE_EXEC;
1493 
1494 	return hash_page_mm(mm, ea, access, trap, flags);
1495 }
1496 
1497 #ifdef CONFIG_PPC_MM_SLICES
1498 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1499 {
1500 	int psize = get_slice_psize(mm, ea);
1501 
1502 	/* We only prefault standard pages for now */
1503 	if (unlikely(psize != mm_ctx_user_psize(&mm->context)))
1504 		return false;
1505 
1506 	/*
1507 	 * Don't prefault if subpage protection is enabled for the EA.
1508 	 */
1509 	if (unlikely((psize == MMU_PAGE_4K) && subpage_protection(mm, ea)))
1510 		return false;
1511 
1512 	return true;
1513 }
1514 #else
1515 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1516 {
1517 	return true;
1518 }
1519 #endif
1520 
1521 void hash_preload(struct mm_struct *mm, unsigned long ea,
1522 		  bool is_exec, unsigned long trap)
1523 {
1524 	int hugepage_shift;
1525 	unsigned long vsid;
1526 	pgd_t *pgdir;
1527 	pte_t *ptep;
1528 	unsigned long flags;
1529 	int rc, ssize, update_flags = 0;
1530 	unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0);
1531 
1532 	BUG_ON(get_region_id(ea) != USER_REGION_ID);
1533 
1534 	if (!should_hash_preload(mm, ea))
1535 		return;
1536 
1537 	DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
1538 		" trap=%lx\n", mm, mm->pgd, ea, access, trap);
1539 
1540 	/* Get Linux PTE if available */
1541 	pgdir = mm->pgd;
1542 	if (pgdir == NULL)
1543 		return;
1544 
1545 	/* Get VSID */
1546 	ssize = user_segment_size(ea);
1547 	vsid = get_user_vsid(&mm->context, ea, ssize);
1548 	if (!vsid)
1549 		return;
1550 	/*
1551 	 * Hash doesn't like irqs. Walking linux page table with irq disabled
1552 	 * saves us from holding multiple locks.
1553 	 */
1554 	local_irq_save(flags);
1555 
1556 	/*
1557 	 * THP pages use update_mmu_cache_pmd. We don't do
1558 	 * hash preload there. Hence can ignore THP here
1559 	 */
1560 	ptep = find_current_mm_pte(pgdir, ea, NULL, &hugepage_shift);
1561 	if (!ptep)
1562 		goto out_exit;
1563 
1564 	WARN_ON(hugepage_shift);
1565 #ifdef CONFIG_PPC_64K_PAGES
1566 	/* If either H_PAGE_4K_PFN or cache inhibited is set (and we are on
1567 	 * a 64K kernel), then we don't preload, hash_page() will take
1568 	 * care of it once we actually try to access the page.
1569 	 * That way we don't have to duplicate all of the logic for segment
1570 	 * page size demotion here
1571 	 */
1572 	if ((pte_val(*ptep) & H_PAGE_4K_PFN) || pte_ci(*ptep))
1573 		goto out_exit;
1574 #endif /* CONFIG_PPC_64K_PAGES */
1575 
1576 	/* Is that local to this CPU ? */
1577 	if (mm_is_thread_local(mm))
1578 		update_flags |= HPTE_LOCAL_UPDATE;
1579 
1580 	/* Hash it in */
1581 #ifdef CONFIG_PPC_64K_PAGES
1582 	if (mm_ctx_user_psize(&mm->context) == MMU_PAGE_64K)
1583 		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1584 				     update_flags, ssize);
1585 	else
1586 #endif /* CONFIG_PPC_64K_PAGES */
1587 		rc = __hash_page_4K(ea, access, vsid, ptep, trap, update_flags,
1588 				    ssize, subpage_protection(mm, ea));
1589 
1590 	/* Dump some info in case of hash insertion failure, they should
1591 	 * never happen so it is really useful to know if/when they do
1592 	 */
1593 	if (rc == -1)
1594 		hash_failure_debug(ea, access, vsid, trap, ssize,
1595 				   mm_ctx_user_psize(&mm->context),
1596 				   mm_ctx_user_psize(&mm->context),
1597 				   pte_val(*ptep));
1598 out_exit:
1599 	local_irq_restore(flags);
1600 }
1601 
1602 #ifdef CONFIG_PPC_MEM_KEYS
1603 /*
1604  * Return the protection key associated with the given address and the
1605  * mm_struct.
1606  */
1607 u16 get_mm_addr_key(struct mm_struct *mm, unsigned long address)
1608 {
1609 	pte_t *ptep;
1610 	u16 pkey = 0;
1611 	unsigned long flags;
1612 
1613 	if (!mm || !mm->pgd)
1614 		return 0;
1615 
1616 	local_irq_save(flags);
1617 	ptep = find_linux_pte(mm->pgd, address, NULL, NULL);
1618 	if (ptep)
1619 		pkey = pte_to_pkey_bits(pte_val(READ_ONCE(*ptep)));
1620 	local_irq_restore(flags);
1621 
1622 	return pkey;
1623 }
1624 #endif /* CONFIG_PPC_MEM_KEYS */
1625 
1626 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1627 static inline void tm_flush_hash_page(int local)
1628 {
1629 	/*
1630 	 * Transactions are not aborted by tlbiel, only tlbie. Without, syncing a
1631 	 * page back to a block device w/PIO could pick up transactional data
1632 	 * (bad!) so we force an abort here. Before the sync the page will be
1633 	 * made read-only, which will flush_hash_page. BIG ISSUE here: if the
1634 	 * kernel uses a page from userspace without unmapping it first, it may
1635 	 * see the speculated version.
1636 	 */
1637 	if (local && cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
1638 	    MSR_TM_ACTIVE(current->thread.regs->msr)) {
1639 		tm_enable();
1640 		tm_abort(TM_CAUSE_TLBI);
1641 	}
1642 }
1643 #else
1644 static inline void tm_flush_hash_page(int local)
1645 {
1646 }
1647 #endif
1648 
1649 /*
1650  * Return the global hash slot, corresponding to the given PTE, which contains
1651  * the HPTE.
1652  */
1653 unsigned long pte_get_hash_gslot(unsigned long vpn, unsigned long shift,
1654 		int ssize, real_pte_t rpte, unsigned int subpg_index)
1655 {
1656 	unsigned long hash, gslot, hidx;
1657 
1658 	hash = hpt_hash(vpn, shift, ssize);
1659 	hidx = __rpte_to_hidx(rpte, subpg_index);
1660 	if (hidx & _PTEIDX_SECONDARY)
1661 		hash = ~hash;
1662 	gslot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1663 	gslot += hidx & _PTEIDX_GROUP_IX;
1664 	return gslot;
1665 }
1666 
1667 /*
1668  * WARNING: This is called from hash_low_64.S, if you change this prototype,
1669  *          do not forget to update the assembly call site !
1670  */
1671 void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
1672 		     unsigned long flags)
1673 {
1674 	unsigned long index, shift, gslot;
1675 	int local = flags & HPTE_LOCAL_UPDATE;
1676 
1677 	DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
1678 	pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
1679 		gslot = pte_get_hash_gslot(vpn, shift, ssize, pte, index);
1680 		DBG_LOW(" sub %ld: gslot=%lx\n", index, gslot);
1681 		/*
1682 		 * We use same base page size and actual psize, because we don't
1683 		 * use these functions for hugepage
1684 		 */
1685 		mmu_hash_ops.hpte_invalidate(gslot, vpn, psize, psize,
1686 					     ssize, local);
1687 	} pte_iterate_hashed_end();
1688 
1689 	tm_flush_hash_page(local);
1690 }
1691 
1692 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1693 void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
1694 			 pmd_t *pmdp, unsigned int psize, int ssize,
1695 			 unsigned long flags)
1696 {
1697 	int i, max_hpte_count, valid;
1698 	unsigned long s_addr;
1699 	unsigned char *hpte_slot_array;
1700 	unsigned long hidx, shift, vpn, hash, slot;
1701 	int local = flags & HPTE_LOCAL_UPDATE;
1702 
1703 	s_addr = addr & HPAGE_PMD_MASK;
1704 	hpte_slot_array = get_hpte_slot_array(pmdp);
1705 	/*
1706 	 * IF we try to do a HUGE PTE update after a withdraw is done.
1707 	 * we will find the below NULL. This happens when we do
1708 	 * split_huge_page_pmd
1709 	 */
1710 	if (!hpte_slot_array)
1711 		return;
1712 
1713 	if (mmu_hash_ops.hugepage_invalidate) {
1714 		mmu_hash_ops.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
1715 						 psize, ssize, local);
1716 		goto tm_abort;
1717 	}
1718 	/*
1719 	 * No bluk hpte removal support, invalidate each entry
1720 	 */
1721 	shift = mmu_psize_defs[psize].shift;
1722 	max_hpte_count = HPAGE_PMD_SIZE >> shift;
1723 	for (i = 0; i < max_hpte_count; i++) {
1724 		/*
1725 		 * 8 bits per each hpte entries
1726 		 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
1727 		 */
1728 		valid = hpte_valid(hpte_slot_array, i);
1729 		if (!valid)
1730 			continue;
1731 		hidx =  hpte_hash_index(hpte_slot_array, i);
1732 
1733 		/* get the vpn */
1734 		addr = s_addr + (i * (1ul << shift));
1735 		vpn = hpt_vpn(addr, vsid, ssize);
1736 		hash = hpt_hash(vpn, shift, ssize);
1737 		if (hidx & _PTEIDX_SECONDARY)
1738 			hash = ~hash;
1739 
1740 		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1741 		slot += hidx & _PTEIDX_GROUP_IX;
1742 		mmu_hash_ops.hpte_invalidate(slot, vpn, psize,
1743 					     MMU_PAGE_16M, ssize, local);
1744 	}
1745 tm_abort:
1746 	tm_flush_hash_page(local);
1747 }
1748 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1749 
1750 void flush_hash_range(unsigned long number, int local)
1751 {
1752 	if (mmu_hash_ops.flush_hash_range)
1753 		mmu_hash_ops.flush_hash_range(number, local);
1754 	else {
1755 		int i;
1756 		struct ppc64_tlb_batch *batch =
1757 			this_cpu_ptr(&ppc64_tlb_batch);
1758 
1759 		for (i = 0; i < number; i++)
1760 			flush_hash_page(batch->vpn[i], batch->pte[i],
1761 					batch->psize, batch->ssize, local);
1762 	}
1763 }
1764 
1765 /*
1766  * low_hash_fault is called when we the low level hash code failed
1767  * to instert a PTE due to an hypervisor error
1768  */
1769 void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
1770 {
1771 	enum ctx_state prev_state = exception_enter();
1772 
1773 	if (user_mode(regs)) {
1774 #ifdef CONFIG_PPC_SUBPAGE_PROT
1775 		if (rc == -2)
1776 			_exception(SIGSEGV, regs, SEGV_ACCERR, address);
1777 		else
1778 #endif
1779 			_exception(SIGBUS, regs, BUS_ADRERR, address);
1780 	} else
1781 		bad_page_fault(regs, address, SIGBUS);
1782 
1783 	exception_exit(prev_state);
1784 }
1785 
1786 long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
1787 			   unsigned long pa, unsigned long rflags,
1788 			   unsigned long vflags, int psize, int ssize)
1789 {
1790 	unsigned long hpte_group;
1791 	long slot;
1792 
1793 repeat:
1794 	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1795 
1796 	/* Insert into the hash table, primary slot */
1797 	slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
1798 					psize, psize, ssize);
1799 
1800 	/* Primary is full, try the secondary */
1801 	if (unlikely(slot == -1)) {
1802 		hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP;
1803 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags,
1804 						vflags | HPTE_V_SECONDARY,
1805 						psize, psize, ssize);
1806 		if (slot == -1) {
1807 			if (mftb() & 0x1)
1808 				hpte_group = (hash & htab_hash_mask) *
1809 						HPTES_PER_GROUP;
1810 
1811 			mmu_hash_ops.hpte_remove(hpte_group);
1812 			goto repeat;
1813 		}
1814 	}
1815 
1816 	return slot;
1817 }
1818 
1819 #ifdef CONFIG_DEBUG_PAGEALLOC
1820 static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
1821 {
1822 	unsigned long hash;
1823 	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1824 	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1825 	unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
1826 	long ret;
1827 
1828 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1829 
1830 	/* Don't create HPTE entries for bad address */
1831 	if (!vsid)
1832 		return;
1833 
1834 	ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
1835 				    HPTE_V_BOLTED,
1836 				    mmu_linear_psize, mmu_kernel_ssize);
1837 
1838 	BUG_ON (ret < 0);
1839 	spin_lock(&linear_map_hash_lock);
1840 	BUG_ON(linear_map_hash_slots[lmi] & 0x80);
1841 	linear_map_hash_slots[lmi] = ret | 0x80;
1842 	spin_unlock(&linear_map_hash_lock);
1843 }
1844 
1845 static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
1846 {
1847 	unsigned long hash, hidx, slot;
1848 	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1849 	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1850 
1851 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1852 	spin_lock(&linear_map_hash_lock);
1853 	BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
1854 	hidx = linear_map_hash_slots[lmi] & 0x7f;
1855 	linear_map_hash_slots[lmi] = 0;
1856 	spin_unlock(&linear_map_hash_lock);
1857 	if (hidx & _PTEIDX_SECONDARY)
1858 		hash = ~hash;
1859 	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1860 	slot += hidx & _PTEIDX_GROUP_IX;
1861 	mmu_hash_ops.hpte_invalidate(slot, vpn, mmu_linear_psize,
1862 				     mmu_linear_psize,
1863 				     mmu_kernel_ssize, 0);
1864 }
1865 
1866 void __kernel_map_pages(struct page *page, int numpages, int enable)
1867 {
1868 	unsigned long flags, vaddr, lmi;
1869 	int i;
1870 
1871 	local_irq_save(flags);
1872 	for (i = 0; i < numpages; i++, page++) {
1873 		vaddr = (unsigned long)page_address(page);
1874 		lmi = __pa(vaddr) >> PAGE_SHIFT;
1875 		if (lmi >= linear_map_hash_count)
1876 			continue;
1877 		if (enable)
1878 			kernel_map_linear_page(vaddr, lmi);
1879 		else
1880 			kernel_unmap_linear_page(vaddr, lmi);
1881 	}
1882 	local_irq_restore(flags);
1883 }
1884 #endif /* CONFIG_DEBUG_PAGEALLOC */
1885 
1886 void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base,
1887 				phys_addr_t first_memblock_size)
1888 {
1889 	/*
1890 	 * We don't currently support the first MEMBLOCK not mapping 0
1891 	 * physical on those processors
1892 	 */
1893 	BUG_ON(first_memblock_base != 0);
1894 
1895 	/*
1896 	 * On virtualized systems the first entry is our RMA region aka VRMA,
1897 	 * non-virtualized 64-bit hash MMU systems don't have a limitation
1898 	 * on real mode access.
1899 	 *
1900 	 * For guests on platforms before POWER9, we clamp the it limit to 1G
1901 	 * to avoid some funky things such as RTAS bugs etc...
1902 	 */
1903 	if (!early_cpu_has_feature(CPU_FTR_HVMODE)) {
1904 		ppc64_rma_size = first_memblock_size;
1905 		if (!early_cpu_has_feature(CPU_FTR_ARCH_300))
1906 			ppc64_rma_size = min_t(u64, ppc64_rma_size, 0x40000000);
1907 
1908 		/* Finally limit subsequent allocations */
1909 		memblock_set_current_limit(ppc64_rma_size);
1910 	} else {
1911 		ppc64_rma_size = ULONG_MAX;
1912 	}
1913 }
1914 
1915 #ifdef CONFIG_DEBUG_FS
1916 
1917 static int hpt_order_get(void *data, u64 *val)
1918 {
1919 	*val = ppc64_pft_size;
1920 	return 0;
1921 }
1922 
1923 static int hpt_order_set(void *data, u64 val)
1924 {
1925 	if (!mmu_hash_ops.resize_hpt)
1926 		return -ENODEV;
1927 
1928 	return mmu_hash_ops.resize_hpt(val);
1929 }
1930 
1931 DEFINE_DEBUGFS_ATTRIBUTE(fops_hpt_order, hpt_order_get, hpt_order_set, "%llu\n");
1932 
1933 static int __init hash64_debugfs(void)
1934 {
1935 	if (!debugfs_create_file_unsafe("hpt_order", 0600, powerpc_debugfs_root,
1936 					NULL, &fops_hpt_order)) {
1937 		pr_err("lpar: unable to create hpt_order debugsfs file\n");
1938 	}
1939 
1940 	return 0;
1941 }
1942 machine_device_initcall(pseries, hash64_debugfs);
1943 #endif /* CONFIG_DEBUG_FS */
1944 
1945 void __init print_system_hash_info(void)
1946 {
1947 	pr_info("ppc64_pft_size    = 0x%llx\n", ppc64_pft_size);
1948 
1949 	if (htab_hash_mask)
1950 		pr_info("htab_hash_mask    = 0x%lx\n", htab_hash_mask);
1951 	pr_info("kernel vmalloc start   = 0x%lx\n", KERN_VIRT_START);
1952 	pr_info("kernel IO start        = 0x%lx\n", KERN_IO_START);
1953 	pr_info("kernel vmemmap start   = 0x%lx\n", (unsigned long)vmemmap);
1954 }
1955