1 /*
2  * pSeries_lpar.c
3  * Copyright (C) 2001 Todd Inglett, IBM Corporation
4  *
5  * pSeries LPAR support.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  */
21 
22 /* Enables debugging of low-level hash table routines - careful! */
23 #undef DEBUG
24 #define pr_fmt(fmt) "lpar: " fmt
25 
26 #include <linux/kernel.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/console.h>
29 #include <linux/export.h>
30 #include <linux/jump_label.h>
31 #include <linux/delay.h>
32 #include <linux/stop_machine.h>
33 #include <asm/processor.h>
34 #include <asm/mmu.h>
35 #include <asm/page.h>
36 #include <asm/pgtable.h>
37 #include <asm/machdep.h>
38 #include <asm/mmu_context.h>
39 #include <asm/iommu.h>
40 #include <asm/tlb.h>
41 #include <asm/prom.h>
42 #include <asm/cputable.h>
43 #include <asm/udbg.h>
44 #include <asm/smp.h>
45 #include <asm/trace.h>
46 #include <asm/firmware.h>
47 #include <asm/plpar_wrappers.h>
48 #include <asm/kexec.h>
49 #include <asm/fadump.h>
50 #include <asm/asm-prototypes.h>
51 #include <asm/debugfs.h>
52 
53 #include "pseries.h"
54 
55 /* Flag bits for H_BULK_REMOVE */
56 #define HBR_REQUEST	0x4000000000000000UL
57 #define HBR_RESPONSE	0x8000000000000000UL
58 #define HBR_END		0xc000000000000000UL
59 #define HBR_AVPN	0x0200000000000000UL
60 #define HBR_ANDCOND	0x0100000000000000UL
61 
62 
63 /* in hvCall.S */
64 EXPORT_SYMBOL(plpar_hcall);
65 EXPORT_SYMBOL(plpar_hcall9);
66 EXPORT_SYMBOL(plpar_hcall_norets);
67 
68 void vpa_init(int cpu)
69 {
70 	int hwcpu = get_hard_smp_processor_id(cpu);
71 	unsigned long addr;
72 	long ret;
73 	struct paca_struct *pp;
74 	struct dtl_entry *dtl;
75 
76 	/*
77 	 * The spec says it "may be problematic" if CPU x registers the VPA of
78 	 * CPU y. We should never do that, but wail if we ever do.
79 	 */
80 	WARN_ON(cpu != smp_processor_id());
81 
82 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
83 		lppaca_of(cpu).vmxregs_in_use = 1;
84 
85 	if (cpu_has_feature(CPU_FTR_ARCH_207S))
86 		lppaca_of(cpu).ebb_regs_in_use = 1;
87 
88 	addr = __pa(&lppaca_of(cpu));
89 	ret = register_vpa(hwcpu, addr);
90 
91 	if (ret) {
92 		pr_err("WARNING: VPA registration for cpu %d (hw %d) of area "
93 		       "%lx failed with %ld\n", cpu, hwcpu, addr, ret);
94 		return;
95 	}
96 
97 #ifdef CONFIG_PPC_BOOK3S_64
98 	/*
99 	 * PAPR says this feature is SLB-Buffer but firmware never
100 	 * reports that.  All SPLPAR support SLB shadow buffer.
101 	 */
102 	if (!radix_enabled() && firmware_has_feature(FW_FEATURE_SPLPAR)) {
103 		addr = __pa(paca_ptrs[cpu]->slb_shadow_ptr);
104 		ret = register_slb_shadow(hwcpu, addr);
105 		if (ret)
106 			pr_err("WARNING: SLB shadow buffer registration for "
107 			       "cpu %d (hw %d) of area %lx failed with %ld\n",
108 			       cpu, hwcpu, addr, ret);
109 	}
110 #endif /* CONFIG_PPC_BOOK3S_64 */
111 
112 	/*
113 	 * Register dispatch trace log, if one has been allocated.
114 	 */
115 	pp = paca_ptrs[cpu];
116 	dtl = pp->dispatch_log;
117 	if (dtl) {
118 		pp->dtl_ridx = 0;
119 		pp->dtl_curr = dtl;
120 		lppaca_of(cpu).dtl_idx = 0;
121 
122 		/* hypervisor reads buffer length from this field */
123 		dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
124 		ret = register_dtl(hwcpu, __pa(dtl));
125 		if (ret)
126 			pr_err("WARNING: DTL registration of cpu %d (hw %d) "
127 			       "failed with %ld\n", smp_processor_id(),
128 			       hwcpu, ret);
129 		lppaca_of(cpu).dtl_enable_mask = 2;
130 	}
131 }
132 
133 #ifdef CONFIG_PPC_BOOK3S_64
134 
135 static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
136 				     unsigned long vpn, unsigned long pa,
137 				     unsigned long rflags, unsigned long vflags,
138 				     int psize, int apsize, int ssize)
139 {
140 	unsigned long lpar_rc;
141 	unsigned long flags;
142 	unsigned long slot;
143 	unsigned long hpte_v, hpte_r;
144 
145 	if (!(vflags & HPTE_V_BOLTED))
146 		pr_devel("hpte_insert(group=%lx, vpn=%016lx, "
147 			 "pa=%016lx, rflags=%lx, vflags=%lx, psize=%d)\n",
148 			 hpte_group, vpn,  pa, rflags, vflags, psize);
149 
150 	hpte_v = hpte_encode_v(vpn, psize, apsize, ssize) | vflags | HPTE_V_VALID;
151 	hpte_r = hpte_encode_r(pa, psize, apsize) | rflags;
152 
153 	if (!(vflags & HPTE_V_BOLTED))
154 		pr_devel(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);
155 
156 	/* Now fill in the actual HPTE */
157 	/* Set CEC cookie to 0         */
158 	/* Zero page = 0               */
159 	/* I-cache Invalidate = 0      */
160 	/* I-cache synchronize = 0     */
161 	/* Exact = 0                   */
162 	flags = 0;
163 
164 	if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
165 		flags |= H_COALESCE_CAND;
166 
167 	lpar_rc = plpar_pte_enter(flags, hpte_group, hpte_v, hpte_r, &slot);
168 	if (unlikely(lpar_rc == H_PTEG_FULL)) {
169 		pr_devel("Hash table group is full\n");
170 		return -1;
171 	}
172 
173 	/*
174 	 * Since we try and ioremap PHBs we don't own, the pte insert
175 	 * will fail. However we must catch the failure in hash_page
176 	 * or we will loop forever, so return -2 in this case.
177 	 */
178 	if (unlikely(lpar_rc != H_SUCCESS)) {
179 		pr_err("Failed hash pte insert with error %ld\n", lpar_rc);
180 		return -2;
181 	}
182 	if (!(vflags & HPTE_V_BOLTED))
183 		pr_devel(" -> slot: %lu\n", slot & 7);
184 
185 	/* Because of iSeries, we have to pass down the secondary
186 	 * bucket bit here as well
187 	 */
188 	return (slot & 7) | (!!(vflags & HPTE_V_SECONDARY) << 3);
189 }
190 
191 static DEFINE_SPINLOCK(pSeries_lpar_tlbie_lock);
192 
193 static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
194 {
195 	unsigned long slot_offset;
196 	unsigned long lpar_rc;
197 	int i;
198 	unsigned long dummy1, dummy2;
199 
200 	/* pick a random slot to start at */
201 	slot_offset = mftb() & 0x7;
202 
203 	for (i = 0; i < HPTES_PER_GROUP; i++) {
204 
205 		/* don't remove a bolted entry */
206 		lpar_rc = plpar_pte_remove(H_ANDCOND, hpte_group + slot_offset,
207 					   (0x1UL << 4), &dummy1, &dummy2);
208 		if (lpar_rc == H_SUCCESS)
209 			return i;
210 
211 		/*
212 		 * The test for adjunct partition is performed before the
213 		 * ANDCOND test.  H_RESOURCE may be returned, so we need to
214 		 * check for that as well.
215 		 */
216 		BUG_ON(lpar_rc != H_NOT_FOUND && lpar_rc != H_RESOURCE);
217 
218 		slot_offset++;
219 		slot_offset &= 0x7;
220 	}
221 
222 	return -1;
223 }
224 
225 static void manual_hpte_clear_all(void)
226 {
227 	unsigned long size_bytes = 1UL << ppc64_pft_size;
228 	unsigned long hpte_count = size_bytes >> 4;
229 	struct {
230 		unsigned long pteh;
231 		unsigned long ptel;
232 	} ptes[4];
233 	long lpar_rc;
234 	unsigned long i, j;
235 
236 	/* Read in batches of 4,
237 	 * invalidate only valid entries not in the VRMA
238 	 * hpte_count will be a multiple of 4
239          */
240 	for (i = 0; i < hpte_count; i += 4) {
241 		lpar_rc = plpar_pte_read_4_raw(0, i, (void *)ptes);
242 		if (lpar_rc != H_SUCCESS) {
243 			pr_info("Failed to read hash page table at %ld err %ld\n",
244 				i, lpar_rc);
245 			continue;
246 		}
247 		for (j = 0; j < 4; j++){
248 			if ((ptes[j].pteh & HPTE_V_VRMA_MASK) ==
249 				HPTE_V_VRMA_MASK)
250 				continue;
251 			if (ptes[j].pteh & HPTE_V_VALID)
252 				plpar_pte_remove_raw(0, i + j, 0,
253 					&(ptes[j].pteh), &(ptes[j].ptel));
254 		}
255 	}
256 }
257 
258 static int hcall_hpte_clear_all(void)
259 {
260 	int rc;
261 
262 	do {
263 		rc = plpar_hcall_norets(H_CLEAR_HPT);
264 	} while (rc == H_CONTINUE);
265 
266 	return rc;
267 }
268 
269 static void pseries_hpte_clear_all(void)
270 {
271 	int rc;
272 
273 	rc = hcall_hpte_clear_all();
274 	if (rc != H_SUCCESS)
275 		manual_hpte_clear_all();
276 
277 #ifdef __LITTLE_ENDIAN__
278 	/*
279 	 * Reset exceptions to big endian.
280 	 *
281 	 * FIXME this is a hack for kexec, we need to reset the exception
282 	 * endian before starting the new kernel and this is a convenient place
283 	 * to do it.
284 	 *
285 	 * This is also called on boot when a fadump happens. In that case we
286 	 * must not change the exception endian mode.
287 	 */
288 	if (firmware_has_feature(FW_FEATURE_SET_MODE) && !is_fadump_active())
289 		pseries_big_endian_exceptions();
290 #endif
291 }
292 
293 /*
294  * NOTE: for updatepp ops we are fortunate that the linux "newpp" bits and
295  * the low 3 bits of flags happen to line up.  So no transform is needed.
296  * We can probably optimize here and assume the high bits of newpp are
297  * already zero.  For now I am paranoid.
298  */
299 static long pSeries_lpar_hpte_updatepp(unsigned long slot,
300 				       unsigned long newpp,
301 				       unsigned long vpn,
302 				       int psize, int apsize,
303 				       int ssize, unsigned long inv_flags)
304 {
305 	unsigned long lpar_rc;
306 	unsigned long flags;
307 	unsigned long want_v;
308 
309 	want_v = hpte_encode_avpn(vpn, psize, ssize);
310 
311 	flags = (newpp & 7) | H_AVPN;
312 	if (mmu_has_feature(MMU_FTR_KERNEL_RO))
313 		/* Move pp0 into bit 8 (IBM 55) */
314 		flags |= (newpp & HPTE_R_PP0) >> 55;
315 
316 	pr_devel("    update: avpnv=%016lx, hash=%016lx, f=%lx, psize: %d ...",
317 		 want_v, slot, flags, psize);
318 
319 	lpar_rc = plpar_pte_protect(flags, slot, want_v);
320 
321 	if (lpar_rc == H_NOT_FOUND) {
322 		pr_devel("not found !\n");
323 		return -1;
324 	}
325 
326 	pr_devel("ok\n");
327 
328 	BUG_ON(lpar_rc != H_SUCCESS);
329 
330 	return 0;
331 }
332 
333 static long __pSeries_lpar_hpte_find(unsigned long want_v, unsigned long hpte_group)
334 {
335 	long lpar_rc;
336 	unsigned long i, j;
337 	struct {
338 		unsigned long pteh;
339 		unsigned long ptel;
340 	} ptes[4];
341 
342 	for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {
343 
344 		lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);
345 		if (lpar_rc != H_SUCCESS) {
346 			pr_info("Failed to read hash page table at %ld err %ld\n",
347 				hpte_group, lpar_rc);
348 			continue;
349 		}
350 
351 		for (j = 0; j < 4; j++) {
352 			if (HPTE_V_COMPARE(ptes[j].pteh, want_v) &&
353 			    (ptes[j].pteh & HPTE_V_VALID))
354 				return i + j;
355 		}
356 	}
357 
358 	return -1;
359 }
360 
361 static long pSeries_lpar_hpte_find(unsigned long vpn, int psize, int ssize)
362 {
363 	long slot;
364 	unsigned long hash;
365 	unsigned long want_v;
366 	unsigned long hpte_group;
367 
368 	hash = hpt_hash(vpn, mmu_psize_defs[psize].shift, ssize);
369 	want_v = hpte_encode_avpn(vpn, psize, ssize);
370 
371 	/* Bolted entries are always in the primary group */
372 	hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
373 	slot = __pSeries_lpar_hpte_find(want_v, hpte_group);
374 	if (slot < 0)
375 		return -1;
376 	return hpte_group + slot;
377 }
378 
379 static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
380 					     unsigned long ea,
381 					     int psize, int ssize)
382 {
383 	unsigned long vpn;
384 	unsigned long lpar_rc, slot, vsid, flags;
385 
386 	vsid = get_kernel_vsid(ea, ssize);
387 	vpn = hpt_vpn(ea, vsid, ssize);
388 
389 	slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
390 	BUG_ON(slot == -1);
391 
392 	flags = newpp & 7;
393 	if (mmu_has_feature(MMU_FTR_KERNEL_RO))
394 		/* Move pp0 into bit 8 (IBM 55) */
395 		flags |= (newpp & HPTE_R_PP0) >> 55;
396 
397 	lpar_rc = plpar_pte_protect(flags, slot, 0);
398 
399 	BUG_ON(lpar_rc != H_SUCCESS);
400 }
401 
402 static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
403 					 int psize, int apsize,
404 					 int ssize, int local)
405 {
406 	unsigned long want_v;
407 	unsigned long lpar_rc;
408 	unsigned long dummy1, dummy2;
409 
410 	pr_devel("    inval : slot=%lx, vpn=%016lx, psize: %d, local: %d\n",
411 		 slot, vpn, psize, local);
412 
413 	want_v = hpte_encode_avpn(vpn, psize, ssize);
414 	lpar_rc = plpar_pte_remove(H_AVPN, slot, want_v, &dummy1, &dummy2);
415 	if (lpar_rc == H_NOT_FOUND)
416 		return;
417 
418 	BUG_ON(lpar_rc != H_SUCCESS);
419 }
420 
421 
422 /*
423  * As defined in the PAPR's section 14.5.4.1.8
424  * The control mask doesn't include the returned reference and change bit from
425  * the processed PTE.
426  */
427 #define HBLKR_AVPN		0x0100000000000000UL
428 #define HBLKR_CTRL_MASK		0xf800000000000000UL
429 #define HBLKR_CTRL_SUCCESS	0x8000000000000000UL
430 #define HBLKR_CTRL_ERRNOTFOUND	0x8800000000000000UL
431 #define HBLKR_CTRL_ERRBUSY	0xa000000000000000UL
432 
433 /**
434  * H_BLOCK_REMOVE caller.
435  * @idx should point to the latest @param entry set with a PTEX.
436  * If PTE cannot be processed because another CPUs has already locked that
437  * group, those entries are put back in @param starting at index 1.
438  * If entries has to be retried and @retry_busy is set to true, these entries
439  * are retried until success. If @retry_busy is set to false, the returned
440  * is the number of entries yet to process.
441  */
442 static unsigned long call_block_remove(unsigned long idx, unsigned long *param,
443 				       bool retry_busy)
444 {
445 	unsigned long i, rc, new_idx;
446 	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
447 
448 	if (idx < 2) {
449 		pr_warn("Unexpected empty call to H_BLOCK_REMOVE");
450 		return 0;
451 	}
452 again:
453 	new_idx = 0;
454 	if (idx > PLPAR_HCALL9_BUFSIZE) {
455 		pr_err("Too many PTEs (%lu) for H_BLOCK_REMOVE", idx);
456 		idx = PLPAR_HCALL9_BUFSIZE;
457 	} else if (idx < PLPAR_HCALL9_BUFSIZE)
458 		param[idx] = HBR_END;
459 
460 	rc = plpar_hcall9(H_BLOCK_REMOVE, retbuf,
461 			  param[0], /* AVA */
462 			  param[1],  param[2],  param[3],  param[4], /* TS0-7 */
463 			  param[5],  param[6],  param[7],  param[8]);
464 	if (rc == H_SUCCESS)
465 		return 0;
466 
467 	BUG_ON(rc != H_PARTIAL);
468 
469 	/* Check that the unprocessed entries were 'not found' or 'busy' */
470 	for (i = 0; i < idx-1; i++) {
471 		unsigned long ctrl = retbuf[i] & HBLKR_CTRL_MASK;
472 
473 		if (ctrl == HBLKR_CTRL_ERRBUSY) {
474 			param[++new_idx] = param[i+1];
475 			continue;
476 		}
477 
478 		BUG_ON(ctrl != HBLKR_CTRL_SUCCESS
479 		       && ctrl != HBLKR_CTRL_ERRNOTFOUND);
480 	}
481 
482 	/*
483 	 * If there were entries found busy, retry these entries if requested,
484 	 * of if all the entries have to be retried.
485 	 */
486 	if (new_idx && (retry_busy || new_idx == (PLPAR_HCALL9_BUFSIZE-1))) {
487 		idx = new_idx + 1;
488 		goto again;
489 	}
490 
491 	return new_idx;
492 }
493 
494 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
495 /*
496  * Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
497  * to make sure that we avoid bouncing the hypervisor tlbie lock.
498  */
499 #define PPC64_HUGE_HPTE_BATCH 12
500 
501 static void hugepage_block_invalidate(unsigned long *slot, unsigned long *vpn,
502 				      int count, int psize, int ssize)
503 {
504 	unsigned long param[PLPAR_HCALL9_BUFSIZE];
505 	unsigned long shift, current_vpgb, vpgb;
506 	int i, pix = 0;
507 
508 	shift = mmu_psize_defs[psize].shift;
509 
510 	for (i = 0; i < count; i++) {
511 		/*
512 		 * Shifting 3 bits more on the right to get a
513 		 * 8 pages aligned virtual addresse.
514 		 */
515 		vpgb = (vpn[i] >> (shift - VPN_SHIFT + 3));
516 		if (!pix || vpgb != current_vpgb) {
517 			/*
518 			 * Need to start a new 8 pages block, flush
519 			 * the current one if needed.
520 			 */
521 			if (pix)
522 				(void)call_block_remove(pix, param, true);
523 			current_vpgb = vpgb;
524 			param[0] = hpte_encode_avpn(vpn[i], psize, ssize);
525 			pix = 1;
526 		}
527 
528 		param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot[i];
529 		if (pix == PLPAR_HCALL9_BUFSIZE) {
530 			pix = call_block_remove(pix, param, false);
531 			/*
532 			 * pix = 0 means that all the entries were
533 			 * removed, we can start a new block.
534 			 * Otherwise, this means that there are entries
535 			 * to retry, and pix points to latest one, so
536 			 * we should increment it and try to continue
537 			 * the same block.
538 			 */
539 			if (pix)
540 				pix++;
541 		}
542 	}
543 	if (pix)
544 		(void)call_block_remove(pix, param, true);
545 }
546 
547 static void hugepage_bulk_invalidate(unsigned long *slot, unsigned long *vpn,
548 				     int count, int psize, int ssize)
549 {
550 	unsigned long param[PLPAR_HCALL9_BUFSIZE];
551 	int i = 0, pix = 0, rc;
552 
553 	for (i = 0; i < count; i++) {
554 
555 		if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
556 			pSeries_lpar_hpte_invalidate(slot[i], vpn[i], psize, 0,
557 						     ssize, 0);
558 		} else {
559 			param[pix] = HBR_REQUEST | HBR_AVPN | slot[i];
560 			param[pix+1] = hpte_encode_avpn(vpn[i], psize, ssize);
561 			pix += 2;
562 			if (pix == 8) {
563 				rc = plpar_hcall9(H_BULK_REMOVE, param,
564 						  param[0], param[1], param[2],
565 						  param[3], param[4], param[5],
566 						  param[6], param[7]);
567 				BUG_ON(rc != H_SUCCESS);
568 				pix = 0;
569 			}
570 		}
571 	}
572 	if (pix) {
573 		param[pix] = HBR_END;
574 		rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
575 				  param[2], param[3], param[4], param[5],
576 				  param[6], param[7]);
577 		BUG_ON(rc != H_SUCCESS);
578 	}
579 }
580 
581 static inline void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
582 						      unsigned long *vpn,
583 						      int count, int psize,
584 						      int ssize)
585 {
586 	unsigned long flags = 0;
587 	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
588 
589 	if (lock_tlbie)
590 		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
591 
592 	if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE))
593 		hugepage_block_invalidate(slot, vpn, count, psize, ssize);
594 	else
595 		hugepage_bulk_invalidate(slot, vpn, count, psize, ssize);
596 
597 	if (lock_tlbie)
598 		spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
599 }
600 
601 static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
602 					     unsigned long addr,
603 					     unsigned char *hpte_slot_array,
604 					     int psize, int ssize, int local)
605 {
606 	int i, index = 0;
607 	unsigned long s_addr = addr;
608 	unsigned int max_hpte_count, valid;
609 	unsigned long vpn_array[PPC64_HUGE_HPTE_BATCH];
610 	unsigned long slot_array[PPC64_HUGE_HPTE_BATCH];
611 	unsigned long shift, hidx, vpn = 0, hash, slot;
612 
613 	shift = mmu_psize_defs[psize].shift;
614 	max_hpte_count = 1U << (PMD_SHIFT - shift);
615 
616 	for (i = 0; i < max_hpte_count; i++) {
617 		valid = hpte_valid(hpte_slot_array, i);
618 		if (!valid)
619 			continue;
620 		hidx =  hpte_hash_index(hpte_slot_array, i);
621 
622 		/* get the vpn */
623 		addr = s_addr + (i * (1ul << shift));
624 		vpn = hpt_vpn(addr, vsid, ssize);
625 		hash = hpt_hash(vpn, shift, ssize);
626 		if (hidx & _PTEIDX_SECONDARY)
627 			hash = ~hash;
628 
629 		slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
630 		slot += hidx & _PTEIDX_GROUP_IX;
631 
632 		slot_array[index] = slot;
633 		vpn_array[index] = vpn;
634 		if (index == PPC64_HUGE_HPTE_BATCH - 1) {
635 			/*
636 			 * Now do a bluk invalidate
637 			 */
638 			__pSeries_lpar_hugepage_invalidate(slot_array,
639 							   vpn_array,
640 							   PPC64_HUGE_HPTE_BATCH,
641 							   psize, ssize);
642 			index = 0;
643 		} else
644 			index++;
645 	}
646 	if (index)
647 		__pSeries_lpar_hugepage_invalidate(slot_array, vpn_array,
648 						   index, psize, ssize);
649 }
650 #else
651 static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
652 					     unsigned long addr,
653 					     unsigned char *hpte_slot_array,
654 					     int psize, int ssize, int local)
655 {
656 	WARN(1, "%s called without THP support\n", __func__);
657 }
658 #endif
659 
660 static int pSeries_lpar_hpte_removebolted(unsigned long ea,
661 					  int psize, int ssize)
662 {
663 	unsigned long vpn;
664 	unsigned long slot, vsid;
665 
666 	vsid = get_kernel_vsid(ea, ssize);
667 	vpn = hpt_vpn(ea, vsid, ssize);
668 
669 	slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
670 	if (slot == -1)
671 		return -ENOENT;
672 
673 	/*
674 	 * lpar doesn't use the passed actual page size
675 	 */
676 	pSeries_lpar_hpte_invalidate(slot, vpn, psize, 0, ssize, 0);
677 	return 0;
678 }
679 
680 
681 static inline unsigned long compute_slot(real_pte_t pte,
682 					 unsigned long vpn,
683 					 unsigned long index,
684 					 unsigned long shift,
685 					 int ssize)
686 {
687 	unsigned long slot, hash, hidx;
688 
689 	hash = hpt_hash(vpn, shift, ssize);
690 	hidx = __rpte_to_hidx(pte, index);
691 	if (hidx & _PTEIDX_SECONDARY)
692 		hash = ~hash;
693 	slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
694 	slot += hidx & _PTEIDX_GROUP_IX;
695 	return slot;
696 }
697 
698 /**
699  * The hcall H_BLOCK_REMOVE implies that the virtual pages to processed are
700  * "all within the same naturally aligned 8 page virtual address block".
701  */
702 static void do_block_remove(unsigned long number, struct ppc64_tlb_batch *batch,
703 			    unsigned long *param)
704 {
705 	unsigned long vpn;
706 	unsigned long i, pix = 0;
707 	unsigned long index, shift, slot, current_vpgb, vpgb;
708 	real_pte_t pte;
709 	int psize, ssize;
710 
711 	psize = batch->psize;
712 	ssize = batch->ssize;
713 
714 	for (i = 0; i < number; i++) {
715 		vpn = batch->vpn[i];
716 		pte = batch->pte[i];
717 		pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
718 			/*
719 			 * Shifting 3 bits more on the right to get a
720 			 * 8 pages aligned virtual addresse.
721 			 */
722 			vpgb = (vpn >> (shift - VPN_SHIFT + 3));
723 			if (!pix || vpgb != current_vpgb) {
724 				/*
725 				 * Need to start a new 8 pages block, flush
726 				 * the current one if needed.
727 				 */
728 				if (pix)
729 					(void)call_block_remove(pix, param,
730 								true);
731 				current_vpgb = vpgb;
732 				param[0] = hpte_encode_avpn(vpn, psize,
733 							    ssize);
734 				pix = 1;
735 			}
736 
737 			slot = compute_slot(pte, vpn, index, shift, ssize);
738 			param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot;
739 
740 			if (pix == PLPAR_HCALL9_BUFSIZE) {
741 				pix = call_block_remove(pix, param, false);
742 				/*
743 				 * pix = 0 means that all the entries were
744 				 * removed, we can start a new block.
745 				 * Otherwise, this means that there are entries
746 				 * to retry, and pix points to latest one, so
747 				 * we should increment it and try to continue
748 				 * the same block.
749 				 */
750 				if (pix)
751 					pix++;
752 			}
753 		} pte_iterate_hashed_end();
754 	}
755 
756 	if (pix)
757 		(void)call_block_remove(pix, param, true);
758 }
759 
760 /*
761  * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
762  * lock.
763  */
764 static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
765 {
766 	unsigned long vpn;
767 	unsigned long i, pix, rc;
768 	unsigned long flags = 0;
769 	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
770 	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
771 	unsigned long param[PLPAR_HCALL9_BUFSIZE];
772 	unsigned long index, shift, slot;
773 	real_pte_t pte;
774 	int psize, ssize;
775 
776 	if (lock_tlbie)
777 		spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
778 
779 	if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE)) {
780 		do_block_remove(number, batch, param);
781 		goto out;
782 	}
783 
784 	psize = batch->psize;
785 	ssize = batch->ssize;
786 	pix = 0;
787 	for (i = 0; i < number; i++) {
788 		vpn = batch->vpn[i];
789 		pte = batch->pte[i];
790 		pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
791 			slot = compute_slot(pte, vpn, index, shift, ssize);
792 			if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
793 				/*
794 				 * lpar doesn't use the passed actual page size
795 				 */
796 				pSeries_lpar_hpte_invalidate(slot, vpn, psize,
797 							     0, ssize, local);
798 			} else {
799 				param[pix] = HBR_REQUEST | HBR_AVPN | slot;
800 				param[pix+1] = hpte_encode_avpn(vpn, psize,
801 								ssize);
802 				pix += 2;
803 				if (pix == 8) {
804 					rc = plpar_hcall9(H_BULK_REMOVE, param,
805 						param[0], param[1], param[2],
806 						param[3], param[4], param[5],
807 						param[6], param[7]);
808 					BUG_ON(rc != H_SUCCESS);
809 					pix = 0;
810 				}
811 			}
812 		} pte_iterate_hashed_end();
813 	}
814 	if (pix) {
815 		param[pix] = HBR_END;
816 		rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
817 				  param[2], param[3], param[4], param[5],
818 				  param[6], param[7]);
819 		BUG_ON(rc != H_SUCCESS);
820 	}
821 
822 out:
823 	if (lock_tlbie)
824 		spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
825 }
826 
827 static int __init disable_bulk_remove(char *str)
828 {
829 	if (strcmp(str, "off") == 0 &&
830 	    firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
831 		pr_info("Disabling BULK_REMOVE firmware feature");
832 		powerpc_firmware_features &= ~FW_FEATURE_BULK_REMOVE;
833 	}
834 	return 1;
835 }
836 
837 __setup("bulk_remove=", disable_bulk_remove);
838 
839 #define HPT_RESIZE_TIMEOUT	10000 /* ms */
840 
841 struct hpt_resize_state {
842 	unsigned long shift;
843 	int commit_rc;
844 };
845 
846 static int pseries_lpar_resize_hpt_commit(void *data)
847 {
848 	struct hpt_resize_state *state = data;
849 
850 	state->commit_rc = plpar_resize_hpt_commit(0, state->shift);
851 	if (state->commit_rc != H_SUCCESS)
852 		return -EIO;
853 
854 	/* Hypervisor has transitioned the HTAB, update our globals */
855 	ppc64_pft_size = state->shift;
856 	htab_size_bytes = 1UL << ppc64_pft_size;
857 	htab_hash_mask = (htab_size_bytes >> 7) - 1;
858 
859 	return 0;
860 }
861 
862 /* Must be called in user context */
863 static int pseries_lpar_resize_hpt(unsigned long shift)
864 {
865 	struct hpt_resize_state state = {
866 		.shift = shift,
867 		.commit_rc = H_FUNCTION,
868 	};
869 	unsigned int delay, total_delay = 0;
870 	int rc;
871 	ktime_t t0, t1, t2;
872 
873 	might_sleep();
874 
875 	if (!firmware_has_feature(FW_FEATURE_HPT_RESIZE))
876 		return -ENODEV;
877 
878 	pr_info("Attempting to resize HPT to shift %lu\n", shift);
879 
880 	t0 = ktime_get();
881 
882 	rc = plpar_resize_hpt_prepare(0, shift);
883 	while (H_IS_LONG_BUSY(rc)) {
884 		delay = get_longbusy_msecs(rc);
885 		total_delay += delay;
886 		if (total_delay > HPT_RESIZE_TIMEOUT) {
887 			/* prepare with shift==0 cancels an in-progress resize */
888 			rc = plpar_resize_hpt_prepare(0, 0);
889 			if (rc != H_SUCCESS)
890 				pr_warn("Unexpected error %d cancelling timed out HPT resize\n",
891 				       rc);
892 			return -ETIMEDOUT;
893 		}
894 		msleep(delay);
895 		rc = plpar_resize_hpt_prepare(0, shift);
896 	};
897 
898 	switch (rc) {
899 	case H_SUCCESS:
900 		/* Continue on */
901 		break;
902 
903 	case H_PARAMETER:
904 		return -EINVAL;
905 	case H_RESOURCE:
906 		return -EPERM;
907 	default:
908 		pr_warn("Unexpected error %d from H_RESIZE_HPT_PREPARE\n", rc);
909 		return -EIO;
910 	}
911 
912 	t1 = ktime_get();
913 
914 	rc = stop_machine(pseries_lpar_resize_hpt_commit, &state, NULL);
915 
916 	t2 = ktime_get();
917 
918 	if (rc != 0) {
919 		switch (state.commit_rc) {
920 		case H_PTEG_FULL:
921 			pr_warn("Hash collision while resizing HPT\n");
922 			return -ENOSPC;
923 
924 		default:
925 			pr_warn("Unexpected error %d from H_RESIZE_HPT_COMMIT\n",
926 				state.commit_rc);
927 			return -EIO;
928 		};
929 	}
930 
931 	pr_info("HPT resize to shift %lu complete (%lld ms / %lld ms)\n",
932 		shift, (long long) ktime_ms_delta(t1, t0),
933 		(long long) ktime_ms_delta(t2, t1));
934 
935 	return 0;
936 }
937 
938 static int pseries_lpar_register_process_table(unsigned long base,
939 			unsigned long page_size, unsigned long table_size)
940 {
941 	long rc;
942 	unsigned long flags = 0;
943 
944 	if (table_size)
945 		flags |= PROC_TABLE_NEW;
946 	if (radix_enabled())
947 		flags |= PROC_TABLE_RADIX | PROC_TABLE_GTSE;
948 	else
949 		flags |= PROC_TABLE_HPT_SLB;
950 	for (;;) {
951 		rc = plpar_hcall_norets(H_REGISTER_PROC_TBL, flags, base,
952 					page_size, table_size);
953 		if (!H_IS_LONG_BUSY(rc))
954 			break;
955 		mdelay(get_longbusy_msecs(rc));
956 	}
957 	if (rc != H_SUCCESS) {
958 		pr_err("Failed to register process table (rc=%ld)\n", rc);
959 		BUG();
960 	}
961 	return rc;
962 }
963 
964 void __init hpte_init_pseries(void)
965 {
966 	mmu_hash_ops.hpte_invalidate	 = pSeries_lpar_hpte_invalidate;
967 	mmu_hash_ops.hpte_updatepp	 = pSeries_lpar_hpte_updatepp;
968 	mmu_hash_ops.hpte_updateboltedpp = pSeries_lpar_hpte_updateboltedpp;
969 	mmu_hash_ops.hpte_insert	 = pSeries_lpar_hpte_insert;
970 	mmu_hash_ops.hpte_remove	 = pSeries_lpar_hpte_remove;
971 	mmu_hash_ops.hpte_removebolted   = pSeries_lpar_hpte_removebolted;
972 	mmu_hash_ops.flush_hash_range	 = pSeries_lpar_flush_hash_range;
973 	mmu_hash_ops.hpte_clear_all      = pseries_hpte_clear_all;
974 	mmu_hash_ops.hugepage_invalidate = pSeries_lpar_hugepage_invalidate;
975 	register_process_table		 = pseries_lpar_register_process_table;
976 
977 	if (firmware_has_feature(FW_FEATURE_HPT_RESIZE))
978 		mmu_hash_ops.resize_hpt = pseries_lpar_resize_hpt;
979 }
980 
981 void radix_init_pseries(void)
982 {
983 	pr_info("Using radix MMU under hypervisor\n");
984 	register_process_table = pseries_lpar_register_process_table;
985 }
986 
987 #ifdef CONFIG_PPC_SMLPAR
988 #define CMO_FREE_HINT_DEFAULT 1
989 static int cmo_free_hint_flag = CMO_FREE_HINT_DEFAULT;
990 
991 static int __init cmo_free_hint(char *str)
992 {
993 	char *parm;
994 	parm = strstrip(str);
995 
996 	if (strcasecmp(parm, "no") == 0 || strcasecmp(parm, "off") == 0) {
997 		pr_info("%s: CMO free page hinting is not active.\n", __func__);
998 		cmo_free_hint_flag = 0;
999 		return 1;
1000 	}
1001 
1002 	cmo_free_hint_flag = 1;
1003 	pr_info("%s: CMO free page hinting is active.\n", __func__);
1004 
1005 	if (strcasecmp(parm, "yes") == 0 || strcasecmp(parm, "on") == 0)
1006 		return 1;
1007 
1008 	return 0;
1009 }
1010 
1011 __setup("cmo_free_hint=", cmo_free_hint);
1012 
1013 static void pSeries_set_page_state(struct page *page, int order,
1014 				   unsigned long state)
1015 {
1016 	int i, j;
1017 	unsigned long cmo_page_sz, addr;
1018 
1019 	cmo_page_sz = cmo_get_page_size();
1020 	addr = __pa((unsigned long)page_address(page));
1021 
1022 	for (i = 0; i < (1 << order); i++, addr += PAGE_SIZE) {
1023 		for (j = 0; j < PAGE_SIZE; j += cmo_page_sz)
1024 			plpar_hcall_norets(H_PAGE_INIT, state, addr + j, 0);
1025 	}
1026 }
1027 
1028 void arch_free_page(struct page *page, int order)
1029 {
1030 	if (radix_enabled())
1031 		return;
1032 	if (!cmo_free_hint_flag || !firmware_has_feature(FW_FEATURE_CMO))
1033 		return;
1034 
1035 	pSeries_set_page_state(page, order, H_PAGE_SET_UNUSED);
1036 }
1037 EXPORT_SYMBOL(arch_free_page);
1038 
1039 #endif /* CONFIG_PPC_SMLPAR */
1040 #endif /* CONFIG_PPC_BOOK3S_64 */
1041 
1042 #ifdef CONFIG_TRACEPOINTS
1043 #ifdef CONFIG_JUMP_LABEL
1044 struct static_key hcall_tracepoint_key = STATIC_KEY_INIT;
1045 
1046 int hcall_tracepoint_regfunc(void)
1047 {
1048 	static_key_slow_inc(&hcall_tracepoint_key);
1049 	return 0;
1050 }
1051 
1052 void hcall_tracepoint_unregfunc(void)
1053 {
1054 	static_key_slow_dec(&hcall_tracepoint_key);
1055 }
1056 #else
1057 /*
1058  * We optimise our hcall path by placing hcall_tracepoint_refcount
1059  * directly in the TOC so we can check if the hcall tracepoints are
1060  * enabled via a single load.
1061  */
1062 
1063 /* NB: reg/unreg are called while guarded with the tracepoints_mutex */
1064 extern long hcall_tracepoint_refcount;
1065 
1066 int hcall_tracepoint_regfunc(void)
1067 {
1068 	hcall_tracepoint_refcount++;
1069 	return 0;
1070 }
1071 
1072 void hcall_tracepoint_unregfunc(void)
1073 {
1074 	hcall_tracepoint_refcount--;
1075 }
1076 #endif
1077 
1078 /*
1079  * Since the tracing code might execute hcalls we need to guard against
1080  * recursion. One example of this are spinlocks calling H_YIELD on
1081  * shared processor partitions.
1082  */
1083 static DEFINE_PER_CPU(unsigned int, hcall_trace_depth);
1084 
1085 
1086 void __trace_hcall_entry(unsigned long opcode, unsigned long *args)
1087 {
1088 	unsigned long flags;
1089 	unsigned int *depth;
1090 
1091 	/*
1092 	 * We cannot call tracepoints inside RCU idle regions which
1093 	 * means we must not trace H_CEDE.
1094 	 */
1095 	if (opcode == H_CEDE)
1096 		return;
1097 
1098 	local_irq_save(flags);
1099 
1100 	depth = this_cpu_ptr(&hcall_trace_depth);
1101 
1102 	if (*depth)
1103 		goto out;
1104 
1105 	(*depth)++;
1106 	preempt_disable();
1107 	trace_hcall_entry(opcode, args);
1108 	(*depth)--;
1109 
1110 out:
1111 	local_irq_restore(flags);
1112 }
1113 
1114 void __trace_hcall_exit(long opcode, long retval, unsigned long *retbuf)
1115 {
1116 	unsigned long flags;
1117 	unsigned int *depth;
1118 
1119 	if (opcode == H_CEDE)
1120 		return;
1121 
1122 	local_irq_save(flags);
1123 
1124 	depth = this_cpu_ptr(&hcall_trace_depth);
1125 
1126 	if (*depth)
1127 		goto out;
1128 
1129 	(*depth)++;
1130 	trace_hcall_exit(opcode, retval, retbuf);
1131 	preempt_enable();
1132 	(*depth)--;
1133 
1134 out:
1135 	local_irq_restore(flags);
1136 }
1137 #endif
1138 
1139 /**
1140  * h_get_mpp
1141  * H_GET_MPP hcall returns info in 7 parms
1142  */
1143 int h_get_mpp(struct hvcall_mpp_data *mpp_data)
1144 {
1145 	int rc;
1146 	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
1147 
1148 	rc = plpar_hcall9(H_GET_MPP, retbuf);
1149 
1150 	mpp_data->entitled_mem = retbuf[0];
1151 	mpp_data->mapped_mem = retbuf[1];
1152 
1153 	mpp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
1154 	mpp_data->pool_num = retbuf[2] & 0xffff;
1155 
1156 	mpp_data->mem_weight = (retbuf[3] >> 7 * 8) & 0xff;
1157 	mpp_data->unallocated_mem_weight = (retbuf[3] >> 6 * 8) & 0xff;
1158 	mpp_data->unallocated_entitlement = retbuf[3] & 0xffffffffffffUL;
1159 
1160 	mpp_data->pool_size = retbuf[4];
1161 	mpp_data->loan_request = retbuf[5];
1162 	mpp_data->backing_mem = retbuf[6];
1163 
1164 	return rc;
1165 }
1166 EXPORT_SYMBOL(h_get_mpp);
1167 
1168 int h_get_mpp_x(struct hvcall_mpp_x_data *mpp_x_data)
1169 {
1170 	int rc;
1171 	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };
1172 
1173 	rc = plpar_hcall9(H_GET_MPP_X, retbuf);
1174 
1175 	mpp_x_data->coalesced_bytes = retbuf[0];
1176 	mpp_x_data->pool_coalesced_bytes = retbuf[1];
1177 	mpp_x_data->pool_purr_cycles = retbuf[2];
1178 	mpp_x_data->pool_spurr_cycles = retbuf[3];
1179 
1180 	return rc;
1181 }
1182 
1183 static unsigned long vsid_unscramble(unsigned long vsid, int ssize)
1184 {
1185 	unsigned long protovsid;
1186 	unsigned long va_bits = VA_BITS;
1187 	unsigned long modinv, vsid_modulus;
1188 	unsigned long max_mod_inv, tmp_modinv;
1189 
1190 	if (!mmu_has_feature(MMU_FTR_68_BIT_VA))
1191 		va_bits = 65;
1192 
1193 	if (ssize == MMU_SEGSIZE_256M) {
1194 		modinv = VSID_MULINV_256M;
1195 		vsid_modulus = ((1UL << (va_bits - SID_SHIFT)) - 1);
1196 	} else {
1197 		modinv = VSID_MULINV_1T;
1198 		vsid_modulus = ((1UL << (va_bits - SID_SHIFT_1T)) - 1);
1199 	}
1200 
1201 	/*
1202 	 * vsid outside our range.
1203 	 */
1204 	if (vsid >= vsid_modulus)
1205 		return 0;
1206 
1207 	/*
1208 	 * If modinv is the modular multiplicate inverse of (x % vsid_modulus)
1209 	 * and vsid = (protovsid * x) % vsid_modulus, then we say:
1210 	 *   protovsid = (vsid * modinv) % vsid_modulus
1211 	 */
1212 
1213 	/* Check if (vsid * modinv) overflow (63 bits) */
1214 	max_mod_inv = 0x7fffffffffffffffull / vsid;
1215 	if (modinv < max_mod_inv)
1216 		return (vsid * modinv) % vsid_modulus;
1217 
1218 	tmp_modinv = modinv/max_mod_inv;
1219 	modinv %= max_mod_inv;
1220 
1221 	protovsid = (((vsid * max_mod_inv) % vsid_modulus) * tmp_modinv) % vsid_modulus;
1222 	protovsid = (protovsid + vsid * modinv) % vsid_modulus;
1223 
1224 	return protovsid;
1225 }
1226 
1227 static int __init reserve_vrma_context_id(void)
1228 {
1229 	unsigned long protovsid;
1230 
1231 	/*
1232 	 * Reserve context ids which map to reserved virtual addresses. For now
1233 	 * we only reserve the context id which maps to the VRMA VSID. We ignore
1234 	 * the addresses in "ibm,adjunct-virtual-addresses" because we don't
1235 	 * enable adjunct support via the "ibm,client-architecture-support"
1236 	 * interface.
1237 	 */
1238 	protovsid = vsid_unscramble(VRMA_VSID, MMU_SEGSIZE_1T);
1239 	hash__reserve_context_id(protovsid >> ESID_BITS_1T);
1240 	return 0;
1241 }
1242 machine_device_initcall(pseries, reserve_vrma_context_id);
1243 
1244 #ifdef CONFIG_DEBUG_FS
1245 /* debugfs file interface for vpa data */
1246 static ssize_t vpa_file_read(struct file *filp, char __user *buf, size_t len,
1247 			      loff_t *pos)
1248 {
1249 	int cpu = (long)filp->private_data;
1250 	struct lppaca *lppaca = &lppaca_of(cpu);
1251 
1252 	return simple_read_from_buffer(buf, len, pos, lppaca,
1253 				sizeof(struct lppaca));
1254 }
1255 
1256 static const struct file_operations vpa_fops = {
1257 	.open		= simple_open,
1258 	.read		= vpa_file_read,
1259 	.llseek		= default_llseek,
1260 };
1261 
1262 static int __init vpa_debugfs_init(void)
1263 {
1264 	char name[16];
1265 	long i;
1266 	static struct dentry *vpa_dir;
1267 
1268 	if (!firmware_has_feature(FW_FEATURE_SPLPAR))
1269 		return 0;
1270 
1271 	vpa_dir = debugfs_create_dir("vpa", powerpc_debugfs_root);
1272 	if (!vpa_dir) {
1273 		pr_warn("%s: can't create vpa root dir\n", __func__);
1274 		return -ENOMEM;
1275 	}
1276 
1277 	/* set up the per-cpu vpa file*/
1278 	for_each_possible_cpu(i) {
1279 		struct dentry *d;
1280 
1281 		sprintf(name, "cpu-%ld", i);
1282 
1283 		d = debugfs_create_file(name, 0400, vpa_dir, (void *)i,
1284 					&vpa_fops);
1285 		if (!d) {
1286 			pr_warn("%s: can't create per-cpu vpa file\n",
1287 					__func__);
1288 			return -ENOMEM;
1289 		}
1290 	}
1291 
1292 	return 0;
1293 }
1294 machine_arch_initcall(pseries, vpa_debugfs_init);
1295 #endif /* CONFIG_DEBUG_FS */
1296