• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * PowerPC64 port by Mike Corrigan and Dave Engebretsen
3  *   {mikejc|engebret}@us.ibm.com
4  *
5  *    Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
6  *
7  * SMP scalability work:
8  *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
9  *
10  *    Module name: htab.c
11  *
12  *    Description:
13  *      PowerPC Hashed Page Table functions
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License
17  * as published by the Free Software Foundation; either version
18  * 2 of the License, or (at your option) any later version.
19  */
20 
21 #undef DEBUG
22 #undef DEBUG_LOW
23 
24 #include <linux/spinlock.h>
25 #include <linux/errno.h>
26 #include <linux/sched/mm.h>
27 #include <linux/proc_fs.h>
28 #include <linux/stat.h>
29 #include <linux/sysctl.h>
30 #include <linux/export.h>
31 #include <linux/ctype.h>
32 #include <linux/cache.h>
33 #include <linux/init.h>
34 #include <linux/signal.h>
35 #include <linux/memblock.h>
36 #include <linux/context_tracking.h>
37 #include <linux/libfdt.h>
38 #include <linux/cpu.h>
39 
40 #include <asm/debugfs.h>
41 #include <asm/processor.h>
42 #include <asm/pgtable.h>
43 #include <asm/mmu.h>
44 #include <asm/mmu_context.h>
45 #include <asm/page.h>
46 #include <asm/types.h>
47 #include <linux/uaccess.h>
48 #include <asm/machdep.h>
49 #include <asm/prom.h>
50 #include <asm/tlbflush.h>
51 #include <asm/io.h>
52 #include <asm/eeh.h>
53 #include <asm/tlb.h>
54 #include <asm/cacheflush.h>
55 #include <asm/cputable.h>
56 #include <asm/sections.h>
57 #include <asm/copro.h>
58 #include <asm/udbg.h>
59 #include <asm/code-patching.h>
60 #include <asm/fadump.h>
61 #include <asm/firmware.h>
62 #include <asm/tm.h>
63 #include <asm/trace.h>
64 #include <asm/ps3.h>
65 #include <asm/pte-walk.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 /* There are definitions of page sizes arrays to be used when none
131  * is provided by the firmware.
132  */
133 
134 /* Pre-POWER4 CPUs (4k pages only)
135  */
136 static struct mmu_psize_def mmu_psize_defaults_old[] = {
137 	[MMU_PAGE_4K] = {
138 		.shift	= 12,
139 		.sllp	= 0,
140 		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
141 		.avpnm	= 0,
142 		.tlbiel = 0,
143 	},
144 };
145 
146 /* POWER4, GPUL, POWER5
147  *
148  * Support for 16Mb large pages
149  */
150 static struct mmu_psize_def mmu_psize_defaults_gp[] = {
151 	[MMU_PAGE_4K] = {
152 		.shift	= 12,
153 		.sllp	= 0,
154 		.penc   = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1},
155 		.avpnm	= 0,
156 		.tlbiel = 1,
157 	},
158 	[MMU_PAGE_16M] = {
159 		.shift	= 24,
160 		.sllp	= SLB_VSID_L,
161 		.penc   = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0,
162 			    [MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 },
163 		.avpnm	= 0x1UL,
164 		.tlbiel = 0,
165 	},
166 };
167 
168 /*
169  * 'R' and 'C' update notes:
170  *  - Under pHyp or KVM, the updatepp path will not set C, thus it *will*
171  *     create writeable HPTEs without C set, because the hcall H_PROTECT
172  *     that we use in that case will not update C
173  *  - The above is however not a problem, because we also don't do that
174  *     fancy "no flush" variant of eviction and we use H_REMOVE which will
175  *     do the right thing and thus we don't have the race I described earlier
176  *
177  *    - Under bare metal,  we do have the race, so we need R and C set
178  *    - We make sure R is always set and never lost
179  *    - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping
180  */
htab_convert_pte_flags(unsigned long pteflags)181 unsigned long htab_convert_pte_flags(unsigned long pteflags)
182 {
183 	unsigned long rflags = 0;
184 
185 	/* _PAGE_EXEC -> NOEXEC */
186 	if ((pteflags & _PAGE_EXEC) == 0)
187 		rflags |= HPTE_R_N;
188 	/*
189 	 * PPP bits:
190 	 * Linux uses slb key 0 for kernel and 1 for user.
191 	 * kernel RW areas are mapped with PPP=0b000
192 	 * User area is mapped with PPP=0b010 for read/write
193 	 * or PPP=0b011 for read-only (including writeable but clean pages).
194 	 */
195 	if (pteflags & _PAGE_PRIVILEGED) {
196 		/*
197 		 * Kernel read only mapped with ppp bits 0b110
198 		 */
199 		if (!(pteflags & _PAGE_WRITE)) {
200 			if (mmu_has_feature(MMU_FTR_KERNEL_RO))
201 				rflags |= (HPTE_R_PP0 | 0x2);
202 			else
203 				rflags |= 0x3;
204 		}
205 	} else {
206 		if (pteflags & _PAGE_RWX)
207 			rflags |= 0x2;
208 		if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY)))
209 			rflags |= 0x1;
210 	}
211 	/*
212 	 * We can't allow hardware to update hpte bits. Hence always
213 	 * set 'R' bit and set 'C' if it is a write fault
214 	 */
215 	rflags |=  HPTE_R_R;
216 
217 	if (pteflags & _PAGE_DIRTY)
218 		rflags |= HPTE_R_C;
219 	/*
220 	 * Add in WIG bits
221 	 */
222 
223 	if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT)
224 		rflags |= HPTE_R_I;
225 	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT)
226 		rflags |= (HPTE_R_I | HPTE_R_G);
227 	else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO)
228 		rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M);
229 	else
230 		/*
231 		 * Add memory coherence if cache inhibited is not set
232 		 */
233 		rflags |= HPTE_R_M;
234 
235 	return rflags;
236 }
237 
htab_bolt_mapping(unsigned long vstart,unsigned long vend,unsigned long pstart,unsigned long prot,int psize,int ssize)238 int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
239 		      unsigned long pstart, unsigned long prot,
240 		      int psize, int ssize)
241 {
242 	unsigned long vaddr, paddr;
243 	unsigned int step, shift;
244 	int ret = 0;
245 
246 	shift = mmu_psize_defs[psize].shift;
247 	step = 1 << shift;
248 
249 	prot = htab_convert_pte_flags(prot);
250 
251 	DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
252 	    vstart, vend, pstart, prot, psize, ssize);
253 
254 	for (vaddr = vstart, paddr = pstart; vaddr < vend;
255 	     vaddr += step, paddr += step) {
256 		unsigned long hash, hpteg;
257 		unsigned long vsid = get_kernel_vsid(vaddr, ssize);
258 		unsigned long vpn  = hpt_vpn(vaddr, vsid, ssize);
259 		unsigned long tprot = prot;
260 
261 		/*
262 		 * If we hit a bad address return error.
263 		 */
264 		if (!vsid)
265 			return -1;
266 		/* Make kernel text executable */
267 		if (overlaps_kernel_text(vaddr, vaddr + step))
268 			tprot &= ~HPTE_R_N;
269 
270 		/* Make kvm guest trampolines executable */
271 		if (overlaps_kvm_tmp(vaddr, vaddr + step))
272 			tprot &= ~HPTE_R_N;
273 
274 		/*
275 		 * If relocatable, check if it overlaps interrupt vectors that
276 		 * are copied down to real 0. For relocatable kernel
277 		 * (e.g. kdump case) we copy interrupt vectors down to real
278 		 * address 0. Mark that region as executable. This is
279 		 * because on p8 system with relocation on exception feature
280 		 * enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence
281 		 * in order to execute the interrupt handlers in virtual
282 		 * mode the vector region need to be marked as executable.
283 		 */
284 		if ((PHYSICAL_START > MEMORY_START) &&
285 			overlaps_interrupt_vector_text(vaddr, vaddr + step))
286 				tprot &= ~HPTE_R_N;
287 
288 		hash = hpt_hash(vpn, shift, ssize);
289 		hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
290 
291 		BUG_ON(!mmu_hash_ops.hpte_insert);
292 		ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
293 					       HPTE_V_BOLTED, psize, psize,
294 					       ssize);
295 		if (ret == -1) {
296 			/* Try to remove a non bolted entry */
297 			ret = mmu_hash_ops.hpte_remove(hpteg);
298 			if (ret != -1)
299 				ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
300 							       HPTE_V_BOLTED, psize, psize,
301 							       ssize);
302 		}
303 		if (ret < 0)
304 			break;
305 
306 		cond_resched();
307 #ifdef CONFIG_DEBUG_PAGEALLOC
308 		if (debug_pagealloc_enabled() &&
309 			(paddr >> PAGE_SHIFT) < linear_map_hash_count)
310 			linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
311 #endif /* CONFIG_DEBUG_PAGEALLOC */
312 	}
313 	return ret < 0 ? ret : 0;
314 }
315 
htab_remove_mapping(unsigned long vstart,unsigned long vend,int psize,int ssize)316 int htab_remove_mapping(unsigned long vstart, unsigned long vend,
317 		      int psize, int ssize)
318 {
319 	unsigned long vaddr;
320 	unsigned int step, shift;
321 	int rc;
322 	int ret = 0;
323 
324 	shift = mmu_psize_defs[psize].shift;
325 	step = 1 << shift;
326 
327 	if (!mmu_hash_ops.hpte_removebolted)
328 		return -ENODEV;
329 
330 	for (vaddr = vstart; vaddr < vend; vaddr += step) {
331 		rc = mmu_hash_ops.hpte_removebolted(vaddr, psize, ssize);
332 		if (rc == -ENOENT) {
333 			ret = -ENOENT;
334 			continue;
335 		}
336 		if (rc < 0)
337 			return rc;
338 	}
339 
340 	return ret;
341 }
342 
343 static bool disable_1tb_segments = false;
344 
parse_disable_1tb_segments(char * p)345 static int __init parse_disable_1tb_segments(char *p)
346 {
347 	disable_1tb_segments = true;
348 	return 0;
349 }
350 early_param("disable_1tb_segments", parse_disable_1tb_segments);
351 
htab_dt_scan_seg_sizes(unsigned long node,const char * uname,int depth,void * data)352 static int __init htab_dt_scan_seg_sizes(unsigned long node,
353 					 const char *uname, int depth,
354 					 void *data)
355 {
356 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
357 	const __be32 *prop;
358 	int size = 0;
359 
360 	/* We are scanning "cpu" nodes only */
361 	if (type == NULL || strcmp(type, "cpu") != 0)
362 		return 0;
363 
364 	prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size);
365 	if (prop == NULL)
366 		return 0;
367 	for (; size >= 4; size -= 4, ++prop) {
368 		if (be32_to_cpu(prop[0]) == 40) {
369 			DBG("1T segment support detected\n");
370 
371 			if (disable_1tb_segments) {
372 				DBG("1T segments disabled by command line\n");
373 				break;
374 			}
375 
376 			cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
377 			return 1;
378 		}
379 	}
380 	cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
381 	return 0;
382 }
383 
get_idx_from_shift(unsigned int shift)384 static int __init get_idx_from_shift(unsigned int shift)
385 {
386 	int idx = -1;
387 
388 	switch (shift) {
389 	case 0xc:
390 		idx = MMU_PAGE_4K;
391 		break;
392 	case 0x10:
393 		idx = MMU_PAGE_64K;
394 		break;
395 	case 0x14:
396 		idx = MMU_PAGE_1M;
397 		break;
398 	case 0x18:
399 		idx = MMU_PAGE_16M;
400 		break;
401 	case 0x22:
402 		idx = MMU_PAGE_16G;
403 		break;
404 	}
405 	return idx;
406 }
407 
htab_dt_scan_page_sizes(unsigned long node,const char * uname,int depth,void * data)408 static int __init htab_dt_scan_page_sizes(unsigned long node,
409 					  const char *uname, int depth,
410 					  void *data)
411 {
412 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
413 	const __be32 *prop;
414 	int size = 0;
415 
416 	/* We are scanning "cpu" nodes only */
417 	if (type == NULL || strcmp(type, "cpu") != 0)
418 		return 0;
419 
420 	prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size);
421 	if (!prop)
422 		return 0;
423 
424 	pr_info("Page sizes from device-tree:\n");
425 	size /= 4;
426 	cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
427 	while(size > 0) {
428 		unsigned int base_shift = be32_to_cpu(prop[0]);
429 		unsigned int slbenc = be32_to_cpu(prop[1]);
430 		unsigned int lpnum = be32_to_cpu(prop[2]);
431 		struct mmu_psize_def *def;
432 		int idx, base_idx;
433 
434 		size -= 3; prop += 3;
435 		base_idx = get_idx_from_shift(base_shift);
436 		if (base_idx < 0) {
437 			/* skip the pte encoding also */
438 			prop += lpnum * 2; size -= lpnum * 2;
439 			continue;
440 		}
441 		def = &mmu_psize_defs[base_idx];
442 		if (base_idx == MMU_PAGE_16M)
443 			cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
444 
445 		def->shift = base_shift;
446 		if (base_shift <= 23)
447 			def->avpnm = 0;
448 		else
449 			def->avpnm = (1 << (base_shift - 23)) - 1;
450 		def->sllp = slbenc;
451 		/*
452 		 * We don't know for sure what's up with tlbiel, so
453 		 * for now we only set it for 4K and 64K pages
454 		 */
455 		if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K)
456 			def->tlbiel = 1;
457 		else
458 			def->tlbiel = 0;
459 
460 		while (size > 0 && lpnum) {
461 			unsigned int shift = be32_to_cpu(prop[0]);
462 			int penc  = be32_to_cpu(prop[1]);
463 
464 			prop += 2; size -= 2;
465 			lpnum--;
466 
467 			idx = get_idx_from_shift(shift);
468 			if (idx < 0)
469 				continue;
470 
471 			if (penc == -1)
472 				pr_err("Invalid penc for base_shift=%d "
473 				       "shift=%d\n", base_shift, shift);
474 
475 			def->penc[idx] = penc;
476 			pr_info("base_shift=%d: shift=%d, sllp=0x%04lx,"
477 				" avpnm=0x%08lx, tlbiel=%d, penc=%d\n",
478 				base_shift, shift, def->sllp,
479 				def->avpnm, def->tlbiel, def->penc[idx]);
480 		}
481 	}
482 
483 	return 1;
484 }
485 
486 #ifdef CONFIG_HUGETLB_PAGE
487 /* Scan for 16G memory blocks that have been set aside for huge pages
488  * and reserve those blocks for 16G huge pages.
489  */
htab_dt_scan_hugepage_blocks(unsigned long node,const char * uname,int depth,void * data)490 static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
491 					const char *uname, int depth,
492 					void *data) {
493 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
494 	const __be64 *addr_prop;
495 	const __be32 *page_count_prop;
496 	unsigned int expected_pages;
497 	long unsigned int phys_addr;
498 	long unsigned int block_size;
499 
500 	/* We are scanning "memory" nodes only */
501 	if (type == NULL || strcmp(type, "memory") != 0)
502 		return 0;
503 
504 	/* This property is the log base 2 of the number of virtual pages that
505 	 * will represent this memory block. */
506 	page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
507 	if (page_count_prop == NULL)
508 		return 0;
509 	expected_pages = (1 << be32_to_cpu(page_count_prop[0]));
510 	addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
511 	if (addr_prop == NULL)
512 		return 0;
513 	phys_addr = be64_to_cpu(addr_prop[0]);
514 	block_size = be64_to_cpu(addr_prop[1]);
515 	if (block_size != (16 * GB))
516 		return 0;
517 	printk(KERN_INFO "Huge page(16GB) memory: "
518 			"addr = 0x%lX size = 0x%lX pages = %d\n",
519 			phys_addr, block_size, expected_pages);
520 	if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) {
521 		memblock_reserve(phys_addr, block_size * expected_pages);
522 		pseries_add_gpage(phys_addr, block_size, expected_pages);
523 	}
524 	return 0;
525 }
526 #endif /* CONFIG_HUGETLB_PAGE */
527 
mmu_psize_set_default_penc(void)528 static void mmu_psize_set_default_penc(void)
529 {
530 	int bpsize, apsize;
531 	for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++)
532 		for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++)
533 			mmu_psize_defs[bpsize].penc[apsize] = -1;
534 }
535 
536 #ifdef CONFIG_PPC_64K_PAGES
537 
might_have_hea(void)538 static bool might_have_hea(void)
539 {
540 	/*
541 	 * The HEA ethernet adapter requires awareness of the
542 	 * GX bus. Without that awareness we can easily assume
543 	 * we will never see an HEA ethernet device.
544 	 */
545 #ifdef CONFIG_IBMEBUS
546 	return !cpu_has_feature(CPU_FTR_ARCH_207S) &&
547 		firmware_has_feature(FW_FEATURE_SPLPAR);
548 #else
549 	return false;
550 #endif
551 }
552 
553 #endif /* #ifdef CONFIG_PPC_64K_PAGES */
554 
htab_scan_page_sizes(void)555 static void __init htab_scan_page_sizes(void)
556 {
557 	int rc;
558 
559 	/* se the invalid penc to -1 */
560 	mmu_psize_set_default_penc();
561 
562 	/* Default to 4K pages only */
563 	memcpy(mmu_psize_defs, mmu_psize_defaults_old,
564 	       sizeof(mmu_psize_defaults_old));
565 
566 	/*
567 	 * Try to find the available page sizes in the device-tree
568 	 */
569 	rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
570 	if (rc == 0 && early_mmu_has_feature(MMU_FTR_16M_PAGE)) {
571 		/*
572 		 * Nothing in the device-tree, but the CPU supports 16M pages,
573 		 * so let's fallback on a known size list for 16M capable CPUs.
574 		 */
575 		memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
576 		       sizeof(mmu_psize_defaults_gp));
577 	}
578 
579 #ifdef CONFIG_HUGETLB_PAGE
580 	/* Reserve 16G huge page memory sections for huge pages */
581 	of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
582 #endif /* CONFIG_HUGETLB_PAGE */
583 }
584 
585 /*
586  * Fill in the hpte_page_sizes[] array.
587  * We go through the mmu_psize_defs[] array looking for all the
588  * supported base/actual page size combinations.  Each combination
589  * has a unique pagesize encoding (penc) value in the low bits of
590  * the LP field of the HPTE.  For actual page sizes less than 1MB,
591  * some of the upper LP bits are used for RPN bits, meaning that
592  * we need to fill in several entries in hpte_page_sizes[].
593  *
594  * In diagrammatic form, with r = RPN bits and z = page size bits:
595  *        PTE LP     actual page size
596  *    rrrr rrrz		>=8KB
597  *    rrrr rrzz		>=16KB
598  *    rrrr rzzz		>=32KB
599  *    rrrr zzzz		>=64KB
600  *    ...
601  *
602  * The zzzz bits are implementation-specific but are chosen so that
603  * no encoding for a larger page size uses the same value in its
604  * low-order N bits as the encoding for the 2^(12+N) byte page size
605  * (if it exists).
606  */
init_hpte_page_sizes(void)607 static void init_hpte_page_sizes(void)
608 {
609 	long int ap, bp;
610 	long int shift, penc;
611 
612 	for (bp = 0; bp < MMU_PAGE_COUNT; ++bp) {
613 		if (!mmu_psize_defs[bp].shift)
614 			continue;	/* not a supported page size */
615 		for (ap = bp; ap < MMU_PAGE_COUNT; ++ap) {
616 			penc = mmu_psize_defs[bp].penc[ap];
617 			if (penc == -1)
618 				continue;
619 			shift = mmu_psize_defs[ap].shift - LP_SHIFT;
620 			if (shift <= 0)
621 				continue;	/* should never happen */
622 			/*
623 			 * For page sizes less than 1MB, this loop
624 			 * replicates the entry for all possible values
625 			 * of the rrrr bits.
626 			 */
627 			while (penc < (1 << LP_BITS)) {
628 				hpte_page_sizes[penc] = (ap << 4) | bp;
629 				penc += 1 << shift;
630 			}
631 		}
632 	}
633 }
634 
htab_init_page_sizes(void)635 static void __init htab_init_page_sizes(void)
636 {
637 	init_hpte_page_sizes();
638 
639 	if (!debug_pagealloc_enabled()) {
640 		/*
641 		 * Pick a size for the linear mapping. Currently, we only
642 		 * support 16M, 1M and 4K which is the default
643 		 */
644 		if (mmu_psize_defs[MMU_PAGE_16M].shift)
645 			mmu_linear_psize = MMU_PAGE_16M;
646 		else if (mmu_psize_defs[MMU_PAGE_1M].shift)
647 			mmu_linear_psize = MMU_PAGE_1M;
648 	}
649 
650 #ifdef CONFIG_PPC_64K_PAGES
651 	/*
652 	 * Pick a size for the ordinary pages. Default is 4K, we support
653 	 * 64K for user mappings and vmalloc if supported by the processor.
654 	 * We only use 64k for ioremap if the processor
655 	 * (and firmware) support cache-inhibited large pages.
656 	 * If not, we use 4k and set mmu_ci_restrictions so that
657 	 * hash_page knows to switch processes that use cache-inhibited
658 	 * mappings to 4k pages.
659 	 */
660 	if (mmu_psize_defs[MMU_PAGE_64K].shift) {
661 		mmu_virtual_psize = MMU_PAGE_64K;
662 		mmu_vmalloc_psize = MMU_PAGE_64K;
663 		if (mmu_linear_psize == MMU_PAGE_4K)
664 			mmu_linear_psize = MMU_PAGE_64K;
665 		if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
666 			/*
667 			 * When running on pSeries using 64k pages for ioremap
668 			 * would stop us accessing the HEA ethernet. So if we
669 			 * have the chance of ever seeing one, stay at 4k.
670 			 */
671 			if (!might_have_hea())
672 				mmu_io_psize = MMU_PAGE_64K;
673 		} else
674 			mmu_ci_restrictions = 1;
675 	}
676 #endif /* CONFIG_PPC_64K_PAGES */
677 
678 #ifdef CONFIG_SPARSEMEM_VMEMMAP
679 	/* We try to use 16M pages for vmemmap if that is supported
680 	 * and we have at least 1G of RAM at boot
681 	 */
682 	if (mmu_psize_defs[MMU_PAGE_16M].shift &&
683 	    memblock_phys_mem_size() >= 0x40000000)
684 		mmu_vmemmap_psize = MMU_PAGE_16M;
685 	else if (mmu_psize_defs[MMU_PAGE_64K].shift)
686 		mmu_vmemmap_psize = MMU_PAGE_64K;
687 	else
688 		mmu_vmemmap_psize = MMU_PAGE_4K;
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 
htab_dt_scan_pftsize(unsigned long node,const char * uname,int depth,void * data)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 
htab_shift_for_mem_size(unsigned long mem_size)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 
htab_get_table_size(void)746 static unsigned long __init htab_get_table_size(void)
747 {
748 	/* If hash size isn't already provided by the platform, we try to
749 	 * retrieve it from the device-tree. If it's not there neither, we
750 	 * calculate it now based on the total RAM size
751 	 */
752 	if (ppc64_pft_size == 0)
753 		of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
754 	if (ppc64_pft_size)
755 		return 1UL << ppc64_pft_size;
756 
757 	return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size());
758 }
759 
760 #ifdef CONFIG_MEMORY_HOTPLUG
resize_hpt_for_hotplug(unsigned long new_mem_size)761 void resize_hpt_for_hotplug(unsigned long new_mem_size)
762 {
763 	unsigned target_hpt_shift;
764 
765 	if (!mmu_hash_ops.resize_hpt)
766 		return;
767 
768 	target_hpt_shift = htab_shift_for_mem_size(new_mem_size);
769 
770 	/*
771 	 * To avoid lots of HPT resizes if memory size is fluctuating
772 	 * across a boundary, we deliberately have some hysterisis
773 	 * here: we immediately increase the HPT size if the target
774 	 * shift exceeds the current shift, but we won't attempt to
775 	 * reduce unless the target shift is at least 2 below the
776 	 * current shift
777 	 */
778 	if ((target_hpt_shift > ppc64_pft_size)
779 	    || (target_hpt_shift < (ppc64_pft_size - 1))) {
780 		int rc;
781 
782 		rc = mmu_hash_ops.resize_hpt(target_hpt_shift);
783 		if (rc)
784 			printk(KERN_WARNING
785 			       "Unable to resize hash page table to target order %d: %d\n",
786 			       target_hpt_shift, rc);
787 	}
788 }
789 
hash__create_section_mapping(unsigned long start,unsigned long end)790 int hash__create_section_mapping(unsigned long start, unsigned long end)
791 {
792 	int rc = htab_bolt_mapping(start, end, __pa(start),
793 				   pgprot_val(PAGE_KERNEL), mmu_linear_psize,
794 				   mmu_kernel_ssize);
795 
796 	if (rc < 0) {
797 		int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
798 					      mmu_kernel_ssize);
799 		BUG_ON(rc2 && (rc2 != -ENOENT));
800 	}
801 	return rc;
802 }
803 
hash__remove_section_mapping(unsigned long start,unsigned long end)804 int hash__remove_section_mapping(unsigned long start, unsigned long end)
805 {
806 	int rc = htab_remove_mapping(start, end, mmu_linear_psize,
807 				     mmu_kernel_ssize);
808 	WARN_ON(rc < 0);
809 	return rc;
810 }
811 #endif /* CONFIG_MEMORY_HOTPLUG */
812 
update_hid_for_hash(void)813 static void update_hid_for_hash(void)
814 {
815 	unsigned long hid0;
816 	unsigned long rb = 3UL << PPC_BITLSHIFT(53); /* IS = 3 */
817 
818 	asm volatile("ptesync": : :"memory");
819 	/* prs = 0, ric = 2, rs = 0, r = 1 is = 3 */
820 	asm volatile(PPC_TLBIE_5(%0, %4, %3, %2, %1)
821 		     : : "r"(rb), "i"(0), "i"(0), "i"(2), "r"(0) : "memory");
822 	asm volatile("eieio; tlbsync; ptesync; isync; slbia": : :"memory");
823 	trace_tlbie(0, 0, rb, 0, 2, 0, 0);
824 
825 	/*
826 	 * now switch the HID
827 	 */
828 	hid0  = mfspr(SPRN_HID0);
829 	hid0 &= ~HID0_POWER9_RADIX;
830 	mtspr(SPRN_HID0, hid0);
831 	asm volatile("isync": : :"memory");
832 
833 	/* Wait for it to happen */
834 	while ((mfspr(SPRN_HID0) & HID0_POWER9_RADIX))
835 		cpu_relax();
836 }
837 
hash_init_partition_table(phys_addr_t hash_table,unsigned long htab_size)838 static void __init hash_init_partition_table(phys_addr_t hash_table,
839 					     unsigned long htab_size)
840 {
841 	mmu_partition_table_init();
842 
843 	/*
844 	 * PS field (VRMA page size) is not used for LPID 0, hence set to 0.
845 	 * For now, UPRT is 0 and we have no segment table.
846 	 */
847 	htab_size =  __ilog2(htab_size) - 18;
848 	mmu_partition_table_set_entry(0, hash_table | htab_size, 0);
849 	pr_info("Partition table %p\n", partition_tb);
850 	if (cpu_has_feature(CPU_FTR_POWER9_DD1))
851 		update_hid_for_hash();
852 }
853 
htab_initialize(void)854 static void __init htab_initialize(void)
855 {
856 	unsigned long table;
857 	unsigned long pteg_count;
858 	unsigned long prot;
859 	unsigned long base = 0, size = 0;
860 	struct memblock_region *reg;
861 
862 	DBG(" -> htab_initialize()\n");
863 
864 	if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
865 		mmu_kernel_ssize = MMU_SEGSIZE_1T;
866 		mmu_highuser_ssize = MMU_SEGSIZE_1T;
867 		printk(KERN_INFO "Using 1TB segments\n");
868 	}
869 
870 	/*
871 	 * Calculate the required size of the htab.  We want the number of
872 	 * PTEGs to equal one half the number of real pages.
873 	 */
874 	htab_size_bytes = htab_get_table_size();
875 	pteg_count = htab_size_bytes >> 7;
876 
877 	htab_hash_mask = pteg_count - 1;
878 
879 	if (firmware_has_feature(FW_FEATURE_LPAR) ||
880 	    firmware_has_feature(FW_FEATURE_PS3_LV1)) {
881 		/* Using a hypervisor which owns the htab */
882 		htab_address = NULL;
883 		_SDR1 = 0;
884 		/*
885 		 * On POWER9, we need to do a H_REGISTER_PROC_TBL hcall
886 		 * to inform the hypervisor that we wish to use the HPT.
887 		 */
888 		if (cpu_has_feature(CPU_FTR_ARCH_300))
889 			register_process_table(0, 0, 0);
890 #ifdef CONFIG_FA_DUMP
891 		/*
892 		 * If firmware assisted dump is active firmware preserves
893 		 * the contents of htab along with entire partition memory.
894 		 * Clear the htab if firmware assisted dump is active so
895 		 * that we dont end up using old mappings.
896 		 */
897 		if (is_fadump_active() && mmu_hash_ops.hpte_clear_all)
898 			mmu_hash_ops.hpte_clear_all();
899 #endif
900 	} else {
901 		unsigned long limit = MEMBLOCK_ALLOC_ANYWHERE;
902 
903 #ifdef CONFIG_PPC_CELL
904 		/*
905 		 * Cell may require the hash table down low when using the
906 		 * Axon IOMMU in order to fit the dynamic region over it, see
907 		 * comments in cell/iommu.c
908 		 */
909 		if (fdt_subnode_offset(initial_boot_params, 0, "axon") > 0) {
910 			limit = 0x80000000;
911 			pr_info("Hash table forced below 2G for Axon IOMMU\n");
912 		}
913 #endif /* CONFIG_PPC_CELL */
914 
915 		table = memblock_alloc_base(htab_size_bytes, htab_size_bytes,
916 					    limit);
917 
918 		DBG("Hash table allocated at %lx, size: %lx\n", table,
919 		    htab_size_bytes);
920 
921 		htab_address = __va(table);
922 
923 		/* htab absolute addr + encoded htabsize */
924 		_SDR1 = table + __ilog2(htab_size_bytes) - 18;
925 
926 		/* Initialize the HPT with no entries */
927 		memset((void *)table, 0, htab_size_bytes);
928 
929 		if (!cpu_has_feature(CPU_FTR_ARCH_300))
930 			/* Set SDR1 */
931 			mtspr(SPRN_SDR1, _SDR1);
932 		else
933 			hash_init_partition_table(table, htab_size_bytes);
934 	}
935 
936 	prot = pgprot_val(PAGE_KERNEL);
937 
938 #ifdef CONFIG_DEBUG_PAGEALLOC
939 	if (debug_pagealloc_enabled()) {
940 		linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
941 		linear_map_hash_slots = __va(memblock_alloc_base(
942 				linear_map_hash_count, 1, ppc64_rma_size));
943 		memset(linear_map_hash_slots, 0, linear_map_hash_count);
944 	}
945 #endif /* CONFIG_DEBUG_PAGEALLOC */
946 
947 	/* create bolted the linear mapping in the hash table */
948 	for_each_memblock(memory, reg) {
949 		base = (unsigned long)__va(reg->base);
950 		size = reg->size;
951 
952 		DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
953 		    base, size, prot);
954 
955 		BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
956 				prot, mmu_linear_psize, mmu_kernel_ssize));
957 	}
958 	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
959 
960 	/*
961 	 * If we have a memory_limit and we've allocated TCEs then we need to
962 	 * explicitly map the TCE area at the top of RAM. We also cope with the
963 	 * case that the TCEs start below memory_limit.
964 	 * tce_alloc_start/end are 16MB aligned so the mapping should work
965 	 * for either 4K or 16MB pages.
966 	 */
967 	if (tce_alloc_start) {
968 		tce_alloc_start = (unsigned long)__va(tce_alloc_start);
969 		tce_alloc_end = (unsigned long)__va(tce_alloc_end);
970 
971 		if (base + size >= tce_alloc_start)
972 			tce_alloc_start = base + size + 1;
973 
974 		BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
975 					 __pa(tce_alloc_start), prot,
976 					 mmu_linear_psize, mmu_kernel_ssize));
977 	}
978 
979 
980 	DBG(" <- htab_initialize()\n");
981 }
982 #undef KB
983 #undef MB
984 
hash__early_init_devtree(void)985 void __init hash__early_init_devtree(void)
986 {
987 	/* Initialize segment sizes */
988 	of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
989 
990 	/* Initialize page sizes */
991 	htab_scan_page_sizes();
992 }
993 
hash__early_init_mmu(void)994 void __init hash__early_init_mmu(void)
995 {
996 	/*
997 	 * We have code in __hash_page_64K() and elsewhere, which assumes it can
998 	 * do the following:
999 	 *   new_pte |= (slot << H_PAGE_F_GIX_SHIFT) & (H_PAGE_F_SECOND | H_PAGE_F_GIX);
1000 	 *
1001 	 * Where the slot number is between 0-15, and values of 8-15 indicate
1002 	 * the secondary bucket. For that code to work H_PAGE_F_SECOND and
1003 	 * H_PAGE_F_GIX must occupy four contiguous bits in the PTE, and
1004 	 * H_PAGE_F_SECOND must be placed above H_PAGE_F_GIX. Assert that here
1005 	 * with a BUILD_BUG_ON().
1006 	 */
1007 	BUILD_BUG_ON(H_PAGE_F_SECOND != (1ul  << (H_PAGE_F_GIX_SHIFT + 3)));
1008 
1009 	htab_init_page_sizes();
1010 
1011 	/*
1012 	 * initialize page table size
1013 	 */
1014 	__pte_frag_nr = H_PTE_FRAG_NR;
1015 	__pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
1016 
1017 	__pte_index_size = H_PTE_INDEX_SIZE;
1018 	__pmd_index_size = H_PMD_INDEX_SIZE;
1019 	__pud_index_size = H_PUD_INDEX_SIZE;
1020 	__pgd_index_size = H_PGD_INDEX_SIZE;
1021 	__pmd_cache_index = H_PMD_CACHE_INDEX;
1022 	__pte_table_size = H_PTE_TABLE_SIZE;
1023 	__pmd_table_size = H_PMD_TABLE_SIZE;
1024 	__pud_table_size = H_PUD_TABLE_SIZE;
1025 	__pgd_table_size = H_PGD_TABLE_SIZE;
1026 	/*
1027 	 * 4k use hugepd format, so for hash set then to
1028 	 * zero
1029 	 */
1030 	__pmd_val_bits = 0;
1031 	__pud_val_bits = 0;
1032 	__pgd_val_bits = 0;
1033 
1034 	__kernel_virt_start = H_KERN_VIRT_START;
1035 	__kernel_virt_size = H_KERN_VIRT_SIZE;
1036 	__vmalloc_start = H_VMALLOC_START;
1037 	__vmalloc_end = H_VMALLOC_END;
1038 	__kernel_io_start = H_KERN_IO_START;
1039 	vmemmap = (struct page *)H_VMEMMAP_BASE;
1040 	ioremap_bot = IOREMAP_BASE;
1041 
1042 #ifdef CONFIG_PCI
1043 	pci_io_base = ISA_IO_BASE;
1044 #endif
1045 
1046 	/* Select appropriate backend */
1047 	if (firmware_has_feature(FW_FEATURE_PS3_LV1))
1048 		ps3_early_mm_init();
1049 	else if (firmware_has_feature(FW_FEATURE_LPAR))
1050 		hpte_init_pseries();
1051 	else if (IS_ENABLED(CONFIG_PPC_NATIVE))
1052 		hpte_init_native();
1053 
1054 	if (!mmu_hash_ops.hpte_insert)
1055 		panic("hash__early_init_mmu: No MMU hash ops defined!\n");
1056 
1057 	/* Initialize the MMU Hash table and create the linear mapping
1058 	 * of memory. Has to be done before SLB initialization as this is
1059 	 * currently where the page size encoding is obtained.
1060 	 */
1061 	htab_initialize();
1062 
1063 	pr_info("Initializing hash mmu with SLB\n");
1064 	/* Initialize SLB management */
1065 	slb_initialize();
1066 }
1067 
1068 #ifdef CONFIG_SMP
hash__early_init_mmu_secondary(void)1069 void hash__early_init_mmu_secondary(void)
1070 {
1071 	/* Initialize hash table for that CPU */
1072 	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1073 
1074 		if (cpu_has_feature(CPU_FTR_POWER9_DD1))
1075 			update_hid_for_hash();
1076 
1077 		if (!cpu_has_feature(CPU_FTR_ARCH_300))
1078 			mtspr(SPRN_SDR1, _SDR1);
1079 		else
1080 			mtspr(SPRN_PTCR,
1081 			      __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
1082 	}
1083 	/* Initialize SLB */
1084 	slb_initialize();
1085 }
1086 #endif /* CONFIG_SMP */
1087 
1088 /*
1089  * Called by asm hashtable.S for doing lazy icache flush
1090  */
hash_page_do_lazy_icache(unsigned int pp,pte_t pte,int trap)1091 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
1092 {
1093 	struct page *page;
1094 
1095 	if (!pfn_valid(pte_pfn(pte)))
1096 		return pp;
1097 
1098 	page = pte_page(pte);
1099 
1100 	/* page is dirty */
1101 	if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
1102 		if (trap == 0x400) {
1103 			flush_dcache_icache_page(page);
1104 			set_bit(PG_arch_1, &page->flags);
1105 		} else
1106 			pp |= HPTE_R_N;
1107 	}
1108 	return pp;
1109 }
1110 
1111 #ifdef CONFIG_PPC_MM_SLICES
get_paca_psize(unsigned long addr)1112 static unsigned int get_paca_psize(unsigned long addr)
1113 {
1114 	u64 lpsizes;
1115 	unsigned char *hpsizes;
1116 	unsigned long index, mask_index;
1117 
1118 	if (addr < SLICE_LOW_TOP) {
1119 		lpsizes = get_paca()->mm_ctx_low_slices_psize;
1120 		index = GET_LOW_SLICE_INDEX(addr);
1121 		return (lpsizes >> (index * 4)) & 0xF;
1122 	}
1123 	hpsizes = get_paca()->mm_ctx_high_slices_psize;
1124 	index = GET_HIGH_SLICE_INDEX(addr);
1125 	mask_index = index & 0x1;
1126 	return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xF;
1127 }
1128 
1129 #else
get_paca_psize(unsigned long addr)1130 unsigned int get_paca_psize(unsigned long addr)
1131 {
1132 	return get_paca()->mm_ctx_user_psize;
1133 }
1134 #endif
1135 
1136 /*
1137  * Demote a segment to using 4k pages.
1138  * For now this makes the whole process use 4k pages.
1139  */
1140 #ifdef CONFIG_PPC_64K_PAGES
demote_segment_4k(struct mm_struct * mm,unsigned long addr)1141 void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
1142 {
1143 	if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
1144 		return;
1145 	slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
1146 	copro_flush_all_slbs(mm);
1147 	if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) {
1148 
1149 		copy_mm_to_paca(mm);
1150 		slb_flush_and_rebolt();
1151 	}
1152 }
1153 #endif /* CONFIG_PPC_64K_PAGES */
1154 
1155 #ifdef CONFIG_PPC_SUBPAGE_PROT
1156 /*
1157  * This looks up a 2-bit protection code for a 4k subpage of a 64k page.
1158  * Userspace sets the subpage permissions using the subpage_prot system call.
1159  *
1160  * Result is 0: full permissions, _PAGE_RW: read-only,
1161  * _PAGE_RWX: no access.
1162  */
subpage_protection(struct mm_struct * mm,unsigned long ea)1163 static int subpage_protection(struct mm_struct *mm, unsigned long ea)
1164 {
1165 	struct subpage_prot_table *spt = &mm->context.spt;
1166 	u32 spp = 0;
1167 	u32 **sbpm, *sbpp;
1168 
1169 	if (ea >= spt->maxaddr)
1170 		return 0;
1171 	if (ea < 0x100000000UL) {
1172 		/* addresses below 4GB use spt->low_prot */
1173 		sbpm = spt->low_prot;
1174 	} else {
1175 		sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
1176 		if (!sbpm)
1177 			return 0;
1178 	}
1179 	sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
1180 	if (!sbpp)
1181 		return 0;
1182 	spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
1183 
1184 	/* extract 2-bit bitfield for this 4k subpage */
1185 	spp >>= 30 - 2 * ((ea >> 12) & 0xf);
1186 
1187 	/*
1188 	 * 0 -> full premission
1189 	 * 1 -> Read only
1190 	 * 2 -> no access.
1191 	 * We return the flag that need to be cleared.
1192 	 */
1193 	spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 0);
1194 	return spp;
1195 }
1196 
1197 #else /* CONFIG_PPC_SUBPAGE_PROT */
subpage_protection(struct mm_struct * mm,unsigned long ea)1198 static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
1199 {
1200 	return 0;
1201 }
1202 #endif
1203 
hash_failure_debug(unsigned long ea,unsigned long access,unsigned long vsid,unsigned long trap,int ssize,int psize,int lpsize,unsigned long pte)1204 void hash_failure_debug(unsigned long ea, unsigned long access,
1205 			unsigned long vsid, unsigned long trap,
1206 			int ssize, int psize, int lpsize, unsigned long pte)
1207 {
1208 	if (!printk_ratelimit())
1209 		return;
1210 	pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
1211 		ea, access, current->comm);
1212 	pr_info("    trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n",
1213 		trap, vsid, ssize, psize, lpsize, pte);
1214 }
1215 
check_paca_psize(unsigned long ea,struct mm_struct * mm,int psize,bool user_region)1216 static void check_paca_psize(unsigned long ea, struct mm_struct *mm,
1217 			     int psize, bool user_region)
1218 {
1219 	if (user_region) {
1220 		if (psize != get_paca_psize(ea)) {
1221 			copy_mm_to_paca(mm);
1222 			slb_flush_and_rebolt();
1223 		}
1224 	} else if (get_paca()->vmalloc_sllp !=
1225 		   mmu_psize_defs[mmu_vmalloc_psize].sllp) {
1226 		get_paca()->vmalloc_sllp =
1227 			mmu_psize_defs[mmu_vmalloc_psize].sllp;
1228 		slb_vmalloc_update();
1229 	}
1230 }
1231 
1232 /* Result code is:
1233  *  0 - handled
1234  *  1 - normal page fault
1235  * -1 - critical hash insertion error
1236  * -2 - access not permitted by subpage protection mechanism
1237  */
hash_page_mm(struct mm_struct * mm,unsigned long ea,unsigned long access,unsigned long trap,unsigned long flags)1238 int hash_page_mm(struct mm_struct *mm, unsigned long ea,
1239 		 unsigned long access, unsigned long trap,
1240 		 unsigned long flags)
1241 {
1242 	bool is_thp;
1243 	enum ctx_state prev_state = exception_enter();
1244 	pgd_t *pgdir;
1245 	unsigned long vsid;
1246 	pte_t *ptep;
1247 	unsigned hugeshift;
1248 	int rc, user_region = 0;
1249 	int psize, ssize;
1250 
1251 	DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
1252 		ea, access, trap);
1253 	trace_hash_fault(ea, access, trap);
1254 
1255 	/* Get region & vsid */
1256  	switch (REGION_ID(ea)) {
1257 	case USER_REGION_ID:
1258 		user_region = 1;
1259 		if (! mm) {
1260 			DBG_LOW(" user region with no mm !\n");
1261 			rc = 1;
1262 			goto bail;
1263 		}
1264 		psize = get_slice_psize(mm, ea);
1265 		ssize = user_segment_size(ea);
1266 		vsid = get_vsid(mm->context.id, ea, ssize);
1267 		break;
1268 	case VMALLOC_REGION_ID:
1269 		vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
1270 		if (ea < VMALLOC_END)
1271 			psize = mmu_vmalloc_psize;
1272 		else
1273 			psize = mmu_io_psize;
1274 		ssize = mmu_kernel_ssize;
1275 		break;
1276 	default:
1277 		/* Not a valid range
1278 		 * Send the problem up to do_page_fault
1279 		 */
1280 		rc = 1;
1281 		goto bail;
1282 	}
1283 	DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
1284 
1285 	/* Bad address. */
1286 	if (!vsid) {
1287 		DBG_LOW("Bad address!\n");
1288 		rc = 1;
1289 		goto bail;
1290 	}
1291 	/* Get pgdir */
1292 	pgdir = mm->pgd;
1293 	if (pgdir == NULL) {
1294 		rc = 1;
1295 		goto bail;
1296 	}
1297 
1298 	/* Check CPU locality */
1299 	if (user_region && mm_is_thread_local(mm))
1300 		flags |= HPTE_LOCAL_UPDATE;
1301 
1302 #ifndef CONFIG_PPC_64K_PAGES
1303 	/* If we use 4K pages and our psize is not 4K, then we might
1304 	 * be hitting a special driver mapping, and need to align the
1305 	 * address before we fetch the PTE.
1306 	 *
1307 	 * It could also be a hugepage mapping, in which case this is
1308 	 * not necessary, but it's not harmful, either.
1309 	 */
1310 	if (psize != MMU_PAGE_4K)
1311 		ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
1312 #endif /* CONFIG_PPC_64K_PAGES */
1313 
1314 	/* Get PTE and page size from page tables */
1315 	ptep = find_linux_pte(pgdir, ea, &is_thp, &hugeshift);
1316 	if (ptep == NULL || !pte_present(*ptep)) {
1317 		DBG_LOW(" no PTE !\n");
1318 		rc = 1;
1319 		goto bail;
1320 	}
1321 
1322 	/* Add _PAGE_PRESENT to the required access perm */
1323 	access |= _PAGE_PRESENT;
1324 
1325 	/* Pre-check access permissions (will be re-checked atomically
1326 	 * in __hash_page_XX but this pre-check is a fast path
1327 	 */
1328 	if (!check_pte_access(access, pte_val(*ptep))) {
1329 		DBG_LOW(" no access !\n");
1330 		rc = 1;
1331 		goto bail;
1332 	}
1333 
1334 	if (hugeshift) {
1335 		if (is_thp)
1336 			rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep,
1337 					     trap, flags, ssize, psize);
1338 #ifdef CONFIG_HUGETLB_PAGE
1339 		else
1340 			rc = __hash_page_huge(ea, access, vsid, ptep, trap,
1341 					      flags, ssize, hugeshift, psize);
1342 #else
1343 		else {
1344 			/*
1345 			 * if we have hugeshift, and is not transhuge with
1346 			 * hugetlb disabled, something is really wrong.
1347 			 */
1348 			rc = 1;
1349 			WARN_ON(1);
1350 		}
1351 #endif
1352 		if (current->mm == mm)
1353 			check_paca_psize(ea, mm, psize, user_region);
1354 
1355 		goto bail;
1356 	}
1357 
1358 #ifndef CONFIG_PPC_64K_PAGES
1359 	DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
1360 #else
1361 	DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
1362 		pte_val(*(ptep + PTRS_PER_PTE)));
1363 #endif
1364 	/* Do actual hashing */
1365 #ifdef CONFIG_PPC_64K_PAGES
1366 	/* If H_PAGE_4K_PFN is set, make sure this is a 4k segment */
1367 	if ((pte_val(*ptep) & H_PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
1368 		demote_segment_4k(mm, ea);
1369 		psize = MMU_PAGE_4K;
1370 	}
1371 
1372 	/* If this PTE is non-cacheable and we have restrictions on
1373 	 * using non cacheable large pages, then we switch to 4k
1374 	 */
1375 	if (mmu_ci_restrictions && psize == MMU_PAGE_64K && pte_ci(*ptep)) {
1376 		if (user_region) {
1377 			demote_segment_4k(mm, ea);
1378 			psize = MMU_PAGE_4K;
1379 		} else if (ea < VMALLOC_END) {
1380 			/*
1381 			 * some driver did a non-cacheable mapping
1382 			 * in vmalloc space, so switch vmalloc
1383 			 * to 4k pages
1384 			 */
1385 			printk(KERN_ALERT "Reducing vmalloc segment "
1386 			       "to 4kB pages because of "
1387 			       "non-cacheable mapping\n");
1388 			psize = mmu_vmalloc_psize = MMU_PAGE_4K;
1389 			copro_flush_all_slbs(mm);
1390 		}
1391 	}
1392 
1393 #endif /* CONFIG_PPC_64K_PAGES */
1394 
1395 	if (current->mm == mm)
1396 		check_paca_psize(ea, mm, psize, user_region);
1397 
1398 #ifdef CONFIG_PPC_64K_PAGES
1399 	if (psize == MMU_PAGE_64K)
1400 		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1401 				     flags, ssize);
1402 	else
1403 #endif /* CONFIG_PPC_64K_PAGES */
1404 	{
1405 		int spp = subpage_protection(mm, ea);
1406 		if (access & spp)
1407 			rc = -2;
1408 		else
1409 			rc = __hash_page_4K(ea, access, vsid, ptep, trap,
1410 					    flags, ssize, spp);
1411 	}
1412 
1413 	/* Dump some info in case of hash insertion failure, they should
1414 	 * never happen so it is really useful to know if/when they do
1415 	 */
1416 	if (rc == -1)
1417 		hash_failure_debug(ea, access, vsid, trap, ssize, psize,
1418 				   psize, pte_val(*ptep));
1419 #ifndef CONFIG_PPC_64K_PAGES
1420 	DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
1421 #else
1422 	DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
1423 		pte_val(*(ptep + PTRS_PER_PTE)));
1424 #endif
1425 	DBG_LOW(" -> rc=%d\n", rc);
1426 
1427 bail:
1428 	exception_exit(prev_state);
1429 	return rc;
1430 }
1431 EXPORT_SYMBOL_GPL(hash_page_mm);
1432 
hash_page(unsigned long ea,unsigned long access,unsigned long trap,unsigned long dsisr)1433 int hash_page(unsigned long ea, unsigned long access, unsigned long trap,
1434 	      unsigned long dsisr)
1435 {
1436 	unsigned long flags = 0;
1437 	struct mm_struct *mm = current->mm;
1438 
1439 	if (REGION_ID(ea) == VMALLOC_REGION_ID)
1440 		mm = &init_mm;
1441 
1442 	if (dsisr & DSISR_NOHPTE)
1443 		flags |= HPTE_NOHPTE_UPDATE;
1444 
1445 	return hash_page_mm(mm, ea, access, trap, flags);
1446 }
1447 EXPORT_SYMBOL_GPL(hash_page);
1448 
__hash_page(unsigned long ea,unsigned long msr,unsigned long trap,unsigned long dsisr)1449 int __hash_page(unsigned long ea, unsigned long msr, unsigned long trap,
1450 		unsigned long dsisr)
1451 {
1452 	unsigned long access = _PAGE_PRESENT | _PAGE_READ;
1453 	unsigned long flags = 0;
1454 	struct mm_struct *mm = current->mm;
1455 
1456 	if (REGION_ID(ea) == VMALLOC_REGION_ID)
1457 		mm = &init_mm;
1458 
1459 	if (dsisr & DSISR_NOHPTE)
1460 		flags |= HPTE_NOHPTE_UPDATE;
1461 
1462 	if (dsisr & DSISR_ISSTORE)
1463 		access |= _PAGE_WRITE;
1464 	/*
1465 	 * We set _PAGE_PRIVILEGED only when
1466 	 * kernel mode access kernel space.
1467 	 *
1468 	 * _PAGE_PRIVILEGED is NOT set
1469 	 * 1) when kernel mode access user space
1470 	 * 2) user space access kernel space.
1471 	 */
1472 	access |= _PAGE_PRIVILEGED;
1473 	if ((msr & MSR_PR) || (REGION_ID(ea) == USER_REGION_ID))
1474 		access &= ~_PAGE_PRIVILEGED;
1475 
1476 	if (trap == 0x400)
1477 		access |= _PAGE_EXEC;
1478 
1479 	return hash_page_mm(mm, ea, access, trap, flags);
1480 }
1481 
1482 #ifdef CONFIG_PPC_MM_SLICES
should_hash_preload(struct mm_struct * mm,unsigned long ea)1483 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1484 {
1485 	int psize = get_slice_psize(mm, ea);
1486 
1487 	/* We only prefault standard pages for now */
1488 	if (unlikely(psize != mm->context.user_psize))
1489 		return false;
1490 
1491 	/*
1492 	 * Don't prefault if subpage protection is enabled for the EA.
1493 	 */
1494 	if (unlikely((psize == MMU_PAGE_4K) && subpage_protection(mm, ea)))
1495 		return false;
1496 
1497 	return true;
1498 }
1499 #else
should_hash_preload(struct mm_struct * mm,unsigned long ea)1500 static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
1501 {
1502 	return true;
1503 }
1504 #endif
1505 
hash_preload(struct mm_struct * mm,unsigned long ea,unsigned long access,unsigned long trap)1506 void hash_preload(struct mm_struct *mm, unsigned long ea,
1507 		  unsigned long access, unsigned long trap)
1508 {
1509 	int hugepage_shift;
1510 	unsigned long vsid;
1511 	pgd_t *pgdir;
1512 	pte_t *ptep;
1513 	unsigned long flags;
1514 	int rc, ssize, update_flags = 0;
1515 
1516 	BUG_ON(REGION_ID(ea) != USER_REGION_ID);
1517 
1518 	if (!should_hash_preload(mm, ea))
1519 		return;
1520 
1521 	DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
1522 		" trap=%lx\n", mm, mm->pgd, ea, access, trap);
1523 
1524 	/* Get Linux PTE if available */
1525 	pgdir = mm->pgd;
1526 	if (pgdir == NULL)
1527 		return;
1528 
1529 	/* Get VSID */
1530 	ssize = user_segment_size(ea);
1531 	vsid = get_vsid(mm->context.id, ea, ssize);
1532 	if (!vsid)
1533 		return;
1534 	/*
1535 	 * Hash doesn't like irqs. Walking linux page table with irq disabled
1536 	 * saves us from holding multiple locks.
1537 	 */
1538 	local_irq_save(flags);
1539 
1540 	/*
1541 	 * THP pages use update_mmu_cache_pmd. We don't do
1542 	 * hash preload there. Hence can ignore THP here
1543 	 */
1544 	ptep = find_current_mm_pte(pgdir, ea, NULL, &hugepage_shift);
1545 	if (!ptep)
1546 		goto out_exit;
1547 
1548 	WARN_ON(hugepage_shift);
1549 #ifdef CONFIG_PPC_64K_PAGES
1550 	/* If either H_PAGE_4K_PFN or cache inhibited is set (and we are on
1551 	 * a 64K kernel), then we don't preload, hash_page() will take
1552 	 * care of it once we actually try to access the page.
1553 	 * That way we don't have to duplicate all of the logic for segment
1554 	 * page size demotion here
1555 	 */
1556 	if ((pte_val(*ptep) & H_PAGE_4K_PFN) || pte_ci(*ptep))
1557 		goto out_exit;
1558 #endif /* CONFIG_PPC_64K_PAGES */
1559 
1560 	/* Is that local to this CPU ? */
1561 	if (mm_is_thread_local(mm))
1562 		update_flags |= HPTE_LOCAL_UPDATE;
1563 
1564 	/* Hash it in */
1565 #ifdef CONFIG_PPC_64K_PAGES
1566 	if (mm->context.user_psize == MMU_PAGE_64K)
1567 		rc = __hash_page_64K(ea, access, vsid, ptep, trap,
1568 				     update_flags, ssize);
1569 	else
1570 #endif /* CONFIG_PPC_64K_PAGES */
1571 		rc = __hash_page_4K(ea, access, vsid, ptep, trap, update_flags,
1572 				    ssize, subpage_protection(mm, ea));
1573 
1574 	/* Dump some info in case of hash insertion failure, they should
1575 	 * never happen so it is really useful to know if/when they do
1576 	 */
1577 	if (rc == -1)
1578 		hash_failure_debug(ea, access, vsid, trap, ssize,
1579 				   mm->context.user_psize,
1580 				   mm->context.user_psize,
1581 				   pte_val(*ptep));
1582 out_exit:
1583 	local_irq_restore(flags);
1584 }
1585 
1586 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
tm_flush_hash_page(int local)1587 static inline void tm_flush_hash_page(int local)
1588 {
1589 	/*
1590 	 * Transactions are not aborted by tlbiel, only tlbie. Without, syncing a
1591 	 * page back to a block device w/PIO could pick up transactional data
1592 	 * (bad!) so we force an abort here. Before the sync the page will be
1593 	 * made read-only, which will flush_hash_page. BIG ISSUE here: if the
1594 	 * kernel uses a page from userspace without unmapping it first, it may
1595 	 * see the speculated version.
1596 	 */
1597 	if (local && cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
1598 	    MSR_TM_ACTIVE(current->thread.regs->msr)) {
1599 		tm_enable();
1600 		tm_abort(TM_CAUSE_TLBI);
1601 	}
1602 }
1603 #else
tm_flush_hash_page(int local)1604 static inline void tm_flush_hash_page(int local)
1605 {
1606 }
1607 #endif
1608 
1609 /* WARNING: This is called from hash_low_64.S, if you change this prototype,
1610  *          do not forget to update the assembly call site !
1611  */
flush_hash_page(unsigned long vpn,real_pte_t pte,int psize,int ssize,unsigned long flags)1612 void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize,
1613 		     unsigned long flags)
1614 {
1615 	unsigned long hash, index, shift, hidx, slot;
1616 	int local = flags & HPTE_LOCAL_UPDATE;
1617 
1618 	DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn);
1619 	pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
1620 		hash = hpt_hash(vpn, shift, ssize);
1621 		hidx = __rpte_to_hidx(pte, index);
1622 		if (hidx & _PTEIDX_SECONDARY)
1623 			hash = ~hash;
1624 		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1625 		slot += hidx & _PTEIDX_GROUP_IX;
1626 		DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx);
1627 		/*
1628 		 * We use same base page size and actual psize, because we don't
1629 		 * use these functions for hugepage
1630 		 */
1631 		mmu_hash_ops.hpte_invalidate(slot, vpn, psize, psize,
1632 					     ssize, local);
1633 	} pte_iterate_hashed_end();
1634 
1635 	tm_flush_hash_page(local);
1636 }
1637 
1638 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
flush_hash_hugepage(unsigned long vsid,unsigned long addr,pmd_t * pmdp,unsigned int psize,int ssize,unsigned long flags)1639 void flush_hash_hugepage(unsigned long vsid, unsigned long addr,
1640 			 pmd_t *pmdp, unsigned int psize, int ssize,
1641 			 unsigned long flags)
1642 {
1643 	int i, max_hpte_count, valid;
1644 	unsigned long s_addr;
1645 	unsigned char *hpte_slot_array;
1646 	unsigned long hidx, shift, vpn, hash, slot;
1647 	int local = flags & HPTE_LOCAL_UPDATE;
1648 
1649 	s_addr = addr & HPAGE_PMD_MASK;
1650 	hpte_slot_array = get_hpte_slot_array(pmdp);
1651 	/*
1652 	 * IF we try to do a HUGE PTE update after a withdraw is done.
1653 	 * we will find the below NULL. This happens when we do
1654 	 * split_huge_page_pmd
1655 	 */
1656 	if (!hpte_slot_array)
1657 		return;
1658 
1659 	if (mmu_hash_ops.hugepage_invalidate) {
1660 		mmu_hash_ops.hugepage_invalidate(vsid, s_addr, hpte_slot_array,
1661 						 psize, ssize, local);
1662 		goto tm_abort;
1663 	}
1664 	/*
1665 	 * No bluk hpte removal support, invalidate each entry
1666 	 */
1667 	shift = mmu_psize_defs[psize].shift;
1668 	max_hpte_count = HPAGE_PMD_SIZE >> shift;
1669 	for (i = 0; i < max_hpte_count; i++) {
1670 		/*
1671 		 * 8 bits per each hpte entries
1672 		 * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit]
1673 		 */
1674 		valid = hpte_valid(hpte_slot_array, i);
1675 		if (!valid)
1676 			continue;
1677 		hidx =  hpte_hash_index(hpte_slot_array, i);
1678 
1679 		/* get the vpn */
1680 		addr = s_addr + (i * (1ul << shift));
1681 		vpn = hpt_vpn(addr, vsid, ssize);
1682 		hash = hpt_hash(vpn, shift, ssize);
1683 		if (hidx & _PTEIDX_SECONDARY)
1684 			hash = ~hash;
1685 
1686 		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1687 		slot += hidx & _PTEIDX_GROUP_IX;
1688 		mmu_hash_ops.hpte_invalidate(slot, vpn, psize,
1689 					     MMU_PAGE_16M, ssize, local);
1690 	}
1691 tm_abort:
1692 	tm_flush_hash_page(local);
1693 }
1694 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1695 
flush_hash_range(unsigned long number,int local)1696 void flush_hash_range(unsigned long number, int local)
1697 {
1698 	if (mmu_hash_ops.flush_hash_range)
1699 		mmu_hash_ops.flush_hash_range(number, local);
1700 	else {
1701 		int i;
1702 		struct ppc64_tlb_batch *batch =
1703 			this_cpu_ptr(&ppc64_tlb_batch);
1704 
1705 		for (i = 0; i < number; i++)
1706 			flush_hash_page(batch->vpn[i], batch->pte[i],
1707 					batch->psize, batch->ssize, local);
1708 	}
1709 }
1710 
1711 /*
1712  * low_hash_fault is called when we the low level hash code failed
1713  * to instert a PTE due to an hypervisor error
1714  */
low_hash_fault(struct pt_regs * regs,unsigned long address,int rc)1715 void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
1716 {
1717 	enum ctx_state prev_state = exception_enter();
1718 
1719 	if (user_mode(regs)) {
1720 #ifdef CONFIG_PPC_SUBPAGE_PROT
1721 		if (rc == -2)
1722 			_exception(SIGSEGV, regs, SEGV_ACCERR, address);
1723 		else
1724 #endif
1725 			_exception(SIGBUS, regs, BUS_ADRERR, address);
1726 	} else
1727 		bad_page_fault(regs, address, SIGBUS);
1728 
1729 	exception_exit(prev_state);
1730 }
1731 
hpte_insert_repeating(unsigned long hash,unsigned long vpn,unsigned long pa,unsigned long rflags,unsigned long vflags,int psize,int ssize)1732 long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
1733 			   unsigned long pa, unsigned long rflags,
1734 			   unsigned long vflags, int psize, int ssize)
1735 {
1736 	unsigned long hpte_group;
1737 	long slot;
1738 
1739 repeat:
1740 	hpte_group = ((hash & htab_hash_mask) *
1741 		       HPTES_PER_GROUP) & ~0x7UL;
1742 
1743 	/* Insert into the hash table, primary slot */
1744 	slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, vflags,
1745 					psize, psize, ssize);
1746 
1747 	/* Primary is full, try the secondary */
1748 	if (unlikely(slot == -1)) {
1749 		hpte_group = ((~hash & htab_hash_mask) *
1750 			      HPTES_PER_GROUP) & ~0x7UL;
1751 		slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags,
1752 						vflags | HPTE_V_SECONDARY,
1753 						psize, psize, ssize);
1754 		if (slot == -1) {
1755 			if (mftb() & 0x1)
1756 				hpte_group = ((hash & htab_hash_mask) *
1757 					      HPTES_PER_GROUP)&~0x7UL;
1758 
1759 			mmu_hash_ops.hpte_remove(hpte_group);
1760 			goto repeat;
1761 		}
1762 	}
1763 
1764 	return slot;
1765 }
1766 
1767 #ifdef CONFIG_DEBUG_PAGEALLOC
kernel_map_linear_page(unsigned long vaddr,unsigned long lmi)1768 static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
1769 {
1770 	unsigned long hash;
1771 	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1772 	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1773 	unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
1774 	long ret;
1775 
1776 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1777 
1778 	/* Don't create HPTE entries for bad address */
1779 	if (!vsid)
1780 		return;
1781 
1782 	ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode,
1783 				    HPTE_V_BOLTED,
1784 				    mmu_linear_psize, mmu_kernel_ssize);
1785 
1786 	BUG_ON (ret < 0);
1787 	spin_lock(&linear_map_hash_lock);
1788 	BUG_ON(linear_map_hash_slots[lmi] & 0x80);
1789 	linear_map_hash_slots[lmi] = ret | 0x80;
1790 	spin_unlock(&linear_map_hash_lock);
1791 }
1792 
kernel_unmap_linear_page(unsigned long vaddr,unsigned long lmi)1793 static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
1794 {
1795 	unsigned long hash, hidx, slot;
1796 	unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1797 	unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize);
1798 
1799 	hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize);
1800 	spin_lock(&linear_map_hash_lock);
1801 	BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
1802 	hidx = linear_map_hash_slots[lmi] & 0x7f;
1803 	linear_map_hash_slots[lmi] = 0;
1804 	spin_unlock(&linear_map_hash_lock);
1805 	if (hidx & _PTEIDX_SECONDARY)
1806 		hash = ~hash;
1807 	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1808 	slot += hidx & _PTEIDX_GROUP_IX;
1809 	mmu_hash_ops.hpte_invalidate(slot, vpn, mmu_linear_psize,
1810 				     mmu_linear_psize,
1811 				     mmu_kernel_ssize, 0);
1812 }
1813 
__kernel_map_pages(struct page * page,int numpages,int enable)1814 void __kernel_map_pages(struct page *page, int numpages, int enable)
1815 {
1816 	unsigned long flags, vaddr, lmi;
1817 	int i;
1818 
1819 	local_irq_save(flags);
1820 	for (i = 0; i < numpages; i++, page++) {
1821 		vaddr = (unsigned long)page_address(page);
1822 		lmi = __pa(vaddr) >> PAGE_SHIFT;
1823 		if (lmi >= linear_map_hash_count)
1824 			continue;
1825 		if (enable)
1826 			kernel_map_linear_page(vaddr, lmi);
1827 		else
1828 			kernel_unmap_linear_page(vaddr, lmi);
1829 	}
1830 	local_irq_restore(flags);
1831 }
1832 #endif /* CONFIG_DEBUG_PAGEALLOC */
1833 
hash__setup_initial_memory_limit(phys_addr_t first_memblock_base,phys_addr_t first_memblock_size)1834 void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base,
1835 				phys_addr_t first_memblock_size)
1836 {
1837 	/* We don't currently support the first MEMBLOCK not mapping 0
1838 	 * physical on those processors
1839 	 */
1840 	BUG_ON(first_memblock_base != 0);
1841 
1842 	/* On LPAR systems, the first entry is our RMA region,
1843 	 * non-LPAR 64-bit hash MMU systems don't have a limitation
1844 	 * on real mode access, but using the first entry works well
1845 	 * enough. We also clamp it to 1G to avoid some funky things
1846 	 * such as RTAS bugs etc...
1847 	 */
1848 	ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
1849 
1850 	/* Finally limit subsequent allocations */
1851 	memblock_set_current_limit(ppc64_rma_size);
1852 }
1853 
1854 #ifdef CONFIG_DEBUG_FS
1855 
hpt_order_get(void * data,u64 * val)1856 static int hpt_order_get(void *data, u64 *val)
1857 {
1858 	*val = ppc64_pft_size;
1859 	return 0;
1860 }
1861 
hpt_order_set(void * data,u64 val)1862 static int hpt_order_set(void *data, u64 val)
1863 {
1864 	int ret;
1865 
1866 	if (!mmu_hash_ops.resize_hpt)
1867 		return -ENODEV;
1868 
1869 	cpus_read_lock();
1870 	ret = mmu_hash_ops.resize_hpt(val);
1871 	cpus_read_unlock();
1872 
1873 	return ret;
1874 }
1875 
1876 DEFINE_SIMPLE_ATTRIBUTE(fops_hpt_order, hpt_order_get, hpt_order_set, "%llu\n");
1877 
hash64_debugfs(void)1878 static int __init hash64_debugfs(void)
1879 {
1880 	if (!debugfs_create_file("hpt_order", 0600, powerpc_debugfs_root,
1881 				 NULL, &fops_hpt_order)) {
1882 		pr_err("lpar: unable to create hpt_order debugsfs file\n");
1883 	}
1884 
1885 	return 0;
1886 }
1887 machine_device_initcall(pseries, hash64_debugfs);
1888 #endif /* CONFIG_DEBUG_FS */
1889