1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    Copyright IBM Corp. 2007, 2011
4  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
5  */
6 
7 #include <linux/sched.h>
8 #include <linux/kernel.h>
9 #include <linux/errno.h>
10 #include <linux/gfp.h>
11 #include <linux/mm.h>
12 #include <linux/swap.h>
13 #include <linux/smp.h>
14 #include <linux/spinlock.h>
15 #include <linux/rcupdate.h>
16 #include <linux/slab.h>
17 #include <linux/swapops.h>
18 #include <linux/sysctl.h>
19 #include <linux/ksm.h>
20 #include <linux/mman.h>
21 
22 #include <asm/tlb.h>
23 #include <asm/tlbflush.h>
24 #include <asm/mmu_context.h>
25 #include <asm/page-states.h>
26 
pgprot_writecombine(pgprot_t prot)27 pgprot_t pgprot_writecombine(pgprot_t prot)
28 {
29 	/*
30 	 * mio_wb_bit_mask may be set on a different CPU, but it is only set
31 	 * once at init and only read afterwards.
32 	 */
33 	return __pgprot(pgprot_val(prot) | mio_wb_bit_mask);
34 }
35 EXPORT_SYMBOL_GPL(pgprot_writecombine);
36 
pgprot_writethrough(pgprot_t prot)37 pgprot_t pgprot_writethrough(pgprot_t prot)
38 {
39 	/*
40 	 * mio_wb_bit_mask may be set on a different CPU, but it is only set
41 	 * once at init and only read afterwards.
42 	 */
43 	return __pgprot(pgprot_val(prot) & ~mio_wb_bit_mask);
44 }
45 EXPORT_SYMBOL_GPL(pgprot_writethrough);
46 
ptep_ipte_local(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)47 static inline void ptep_ipte_local(struct mm_struct *mm, unsigned long addr,
48 				   pte_t *ptep, int nodat)
49 {
50 	unsigned long opt, asce;
51 
52 	if (MACHINE_HAS_TLB_GUEST) {
53 		opt = 0;
54 		asce = READ_ONCE(mm->context.gmap_asce);
55 		if (asce == 0UL || nodat)
56 			opt |= IPTE_NODAT;
57 		if (asce != -1UL) {
58 			asce = asce ? : mm->context.asce;
59 			opt |= IPTE_GUEST_ASCE;
60 		}
61 		__ptep_ipte(addr, ptep, opt, asce, IPTE_LOCAL);
62 	} else {
63 		__ptep_ipte(addr, ptep, 0, 0, IPTE_LOCAL);
64 	}
65 }
66 
ptep_ipte_global(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)67 static inline void ptep_ipte_global(struct mm_struct *mm, unsigned long addr,
68 				    pte_t *ptep, int nodat)
69 {
70 	unsigned long opt, asce;
71 
72 	if (MACHINE_HAS_TLB_GUEST) {
73 		opt = 0;
74 		asce = READ_ONCE(mm->context.gmap_asce);
75 		if (asce == 0UL || nodat)
76 			opt |= IPTE_NODAT;
77 		if (asce != -1UL) {
78 			asce = asce ? : mm->context.asce;
79 			opt |= IPTE_GUEST_ASCE;
80 		}
81 		__ptep_ipte(addr, ptep, opt, asce, IPTE_GLOBAL);
82 	} else {
83 		__ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
84 	}
85 }
86 
ptep_flush_direct(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)87 static inline pte_t ptep_flush_direct(struct mm_struct *mm,
88 				      unsigned long addr, pte_t *ptep,
89 				      int nodat)
90 {
91 	pte_t old;
92 
93 	old = *ptep;
94 	if (unlikely(pte_val(old) & _PAGE_INVALID))
95 		return old;
96 	atomic_inc(&mm->context.flush_count);
97 	if (MACHINE_HAS_TLB_LC &&
98 	    cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
99 		ptep_ipte_local(mm, addr, ptep, nodat);
100 	else
101 		ptep_ipte_global(mm, addr, ptep, nodat);
102 	atomic_dec(&mm->context.flush_count);
103 	return old;
104 }
105 
ptep_flush_lazy(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int nodat)106 static inline pte_t ptep_flush_lazy(struct mm_struct *mm,
107 				    unsigned long addr, pte_t *ptep,
108 				    int nodat)
109 {
110 	pte_t old;
111 
112 	old = *ptep;
113 	if (unlikely(pte_val(old) & _PAGE_INVALID))
114 		return old;
115 	atomic_inc(&mm->context.flush_count);
116 	if (cpumask_equal(&mm->context.cpu_attach_mask,
117 			  cpumask_of(smp_processor_id()))) {
118 		set_pte(ptep, set_pte_bit(*ptep, __pgprot(_PAGE_INVALID)));
119 		mm->context.flush_mm = 1;
120 	} else
121 		ptep_ipte_global(mm, addr, ptep, nodat);
122 	atomic_dec(&mm->context.flush_count);
123 	return old;
124 }
125 
pgste_get_lock(pte_t * ptep)126 static inline pgste_t pgste_get_lock(pte_t *ptep)
127 {
128 	unsigned long new = 0;
129 #ifdef CONFIG_PGSTE
130 	unsigned long old;
131 
132 	asm(
133 		"	lg	%0,%2\n"
134 		"0:	lgr	%1,%0\n"
135 		"	nihh	%0,0xff7f\n"	/* clear PCL bit in old */
136 		"	oihh	%1,0x0080\n"	/* set PCL bit in new */
137 		"	csg	%0,%1,%2\n"
138 		"	jl	0b\n"
139 		: "=&d" (old), "=&d" (new), "=Q" (ptep[PTRS_PER_PTE])
140 		: "Q" (ptep[PTRS_PER_PTE]) : "cc", "memory");
141 #endif
142 	return __pgste(new);
143 }
144 
pgste_set_unlock(pte_t * ptep,pgste_t pgste)145 static inline void pgste_set_unlock(pte_t *ptep, pgste_t pgste)
146 {
147 #ifdef CONFIG_PGSTE
148 	asm(
149 		"	nihh	%1,0xff7f\n"	/* clear PCL bit */
150 		"	stg	%1,%0\n"
151 		: "=Q" (ptep[PTRS_PER_PTE])
152 		: "d" (pgste_val(pgste)), "Q" (ptep[PTRS_PER_PTE])
153 		: "cc", "memory");
154 #endif
155 }
156 
pgste_get(pte_t * ptep)157 static inline pgste_t pgste_get(pte_t *ptep)
158 {
159 	unsigned long pgste = 0;
160 #ifdef CONFIG_PGSTE
161 	pgste = *(unsigned long *)(ptep + PTRS_PER_PTE);
162 #endif
163 	return __pgste(pgste);
164 }
165 
pgste_set(pte_t * ptep,pgste_t pgste)166 static inline void pgste_set(pte_t *ptep, pgste_t pgste)
167 {
168 #ifdef CONFIG_PGSTE
169 	*(pgste_t *)(ptep + PTRS_PER_PTE) = pgste;
170 #endif
171 }
172 
pgste_update_all(pte_t pte,pgste_t pgste,struct mm_struct * mm)173 static inline pgste_t pgste_update_all(pte_t pte, pgste_t pgste,
174 				       struct mm_struct *mm)
175 {
176 #ifdef CONFIG_PGSTE
177 	unsigned long address, bits, skey;
178 
179 	if (!mm_uses_skeys(mm) || pte_val(pte) & _PAGE_INVALID)
180 		return pgste;
181 	address = pte_val(pte) & PAGE_MASK;
182 	skey = (unsigned long) page_get_storage_key(address);
183 	bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
184 	/* Transfer page changed & referenced bit to guest bits in pgste */
185 	pgste_val(pgste) |= bits << 48;		/* GR bit & GC bit */
186 	/* Copy page access key and fetch protection bit to pgste */
187 	pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
188 	pgste_val(pgste) |= (skey & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
189 #endif
190 	return pgste;
191 
192 }
193 
pgste_set_key(pte_t * ptep,pgste_t pgste,pte_t entry,struct mm_struct * mm)194 static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry,
195 				 struct mm_struct *mm)
196 {
197 #ifdef CONFIG_PGSTE
198 	unsigned long address;
199 	unsigned long nkey;
200 
201 	if (!mm_uses_skeys(mm) || pte_val(entry) & _PAGE_INVALID)
202 		return;
203 	VM_BUG_ON(!(pte_val(*ptep) & _PAGE_INVALID));
204 	address = pte_val(entry) & PAGE_MASK;
205 	/*
206 	 * Set page access key and fetch protection bit from pgste.
207 	 * The guest C/R information is still in the PGSTE, set real
208 	 * key C/R to 0.
209 	 */
210 	nkey = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
211 	nkey |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
212 	page_set_storage_key(address, nkey, 0);
213 #endif
214 }
215 
pgste_set_pte(pte_t * ptep,pgste_t pgste,pte_t entry)216 static inline pgste_t pgste_set_pte(pte_t *ptep, pgste_t pgste, pte_t entry)
217 {
218 #ifdef CONFIG_PGSTE
219 	if ((pte_val(entry) & _PAGE_PRESENT) &&
220 	    (pte_val(entry) & _PAGE_WRITE) &&
221 	    !(pte_val(entry) & _PAGE_INVALID)) {
222 		if (!MACHINE_HAS_ESOP) {
223 			/*
224 			 * Without enhanced suppression-on-protection force
225 			 * the dirty bit on for all writable ptes.
226 			 */
227 			entry = set_pte_bit(entry, __pgprot(_PAGE_DIRTY));
228 			entry = clear_pte_bit(entry, __pgprot(_PAGE_PROTECT));
229 		}
230 		if (!(pte_val(entry) & _PAGE_PROTECT))
231 			/* This pte allows write access, set user-dirty */
232 			pgste_val(pgste) |= PGSTE_UC_BIT;
233 	}
234 #endif
235 	set_pte(ptep, entry);
236 	return pgste;
237 }
238 
pgste_pte_notify(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pgste_t pgste)239 static inline pgste_t pgste_pte_notify(struct mm_struct *mm,
240 				       unsigned long addr,
241 				       pte_t *ptep, pgste_t pgste)
242 {
243 #ifdef CONFIG_PGSTE
244 	unsigned long bits;
245 
246 	bits = pgste_val(pgste) & (PGSTE_IN_BIT | PGSTE_VSIE_BIT);
247 	if (bits) {
248 		pgste_val(pgste) ^= bits;
249 		ptep_notify(mm, addr, ptep, bits);
250 	}
251 #endif
252 	return pgste;
253 }
254 
ptep_xchg_start(struct mm_struct * mm,unsigned long addr,pte_t * ptep)255 static inline pgste_t ptep_xchg_start(struct mm_struct *mm,
256 				      unsigned long addr, pte_t *ptep)
257 {
258 	pgste_t pgste = __pgste(0);
259 
260 	if (mm_has_pgste(mm)) {
261 		pgste = pgste_get_lock(ptep);
262 		pgste = pgste_pte_notify(mm, addr, ptep, pgste);
263 	}
264 	return pgste;
265 }
266 
ptep_xchg_commit(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pgste_t pgste,pte_t old,pte_t new)267 static inline pte_t ptep_xchg_commit(struct mm_struct *mm,
268 				    unsigned long addr, pte_t *ptep,
269 				    pgste_t pgste, pte_t old, pte_t new)
270 {
271 	if (mm_has_pgste(mm)) {
272 		if (pte_val(old) & _PAGE_INVALID)
273 			pgste_set_key(ptep, pgste, new, mm);
274 		if (pte_val(new) & _PAGE_INVALID) {
275 			pgste = pgste_update_all(old, pgste, mm);
276 			if ((pgste_val(pgste) & _PGSTE_GPS_USAGE_MASK) ==
277 			    _PGSTE_GPS_USAGE_UNUSED)
278 				old = set_pte_bit(old, __pgprot(_PAGE_UNUSED));
279 		}
280 		pgste = pgste_set_pte(ptep, pgste, new);
281 		pgste_set_unlock(ptep, pgste);
282 	} else {
283 		set_pte(ptep, new);
284 	}
285 	return old;
286 }
287 
ptep_xchg_direct(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t new)288 pte_t ptep_xchg_direct(struct mm_struct *mm, unsigned long addr,
289 		       pte_t *ptep, pte_t new)
290 {
291 	pgste_t pgste;
292 	pte_t old;
293 	int nodat;
294 
295 	preempt_disable();
296 	pgste = ptep_xchg_start(mm, addr, ptep);
297 	nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
298 	old = ptep_flush_direct(mm, addr, ptep, nodat);
299 	old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
300 	preempt_enable();
301 	return old;
302 }
303 EXPORT_SYMBOL(ptep_xchg_direct);
304 
ptep_xchg_lazy(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t new)305 pte_t ptep_xchg_lazy(struct mm_struct *mm, unsigned long addr,
306 		     pte_t *ptep, pte_t new)
307 {
308 	pgste_t pgste;
309 	pte_t old;
310 	int nodat;
311 
312 	preempt_disable();
313 	pgste = ptep_xchg_start(mm, addr, ptep);
314 	nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
315 	old = ptep_flush_lazy(mm, addr, ptep, nodat);
316 	old = ptep_xchg_commit(mm, addr, ptep, pgste, old, new);
317 	preempt_enable();
318 	return old;
319 }
320 EXPORT_SYMBOL(ptep_xchg_lazy);
321 
ptep_modify_prot_start(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep)322 pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
323 			     pte_t *ptep)
324 {
325 	pgste_t pgste;
326 	pte_t old;
327 	int nodat;
328 	struct mm_struct *mm = vma->vm_mm;
329 
330 	preempt_disable();
331 	pgste = ptep_xchg_start(mm, addr, ptep);
332 	nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
333 	old = ptep_flush_lazy(mm, addr, ptep, nodat);
334 	if (mm_has_pgste(mm)) {
335 		pgste = pgste_update_all(old, pgste, mm);
336 		pgste_set(ptep, pgste);
337 	}
338 	return old;
339 }
340 
ptep_modify_prot_commit(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep,pte_t old_pte,pte_t pte)341 void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
342 			     pte_t *ptep, pte_t old_pte, pte_t pte)
343 {
344 	pgste_t pgste;
345 	struct mm_struct *mm = vma->vm_mm;
346 
347 	if (!MACHINE_HAS_NX)
348 		pte = clear_pte_bit(pte, __pgprot(_PAGE_NOEXEC));
349 	if (mm_has_pgste(mm)) {
350 		pgste = pgste_get(ptep);
351 		pgste_set_key(ptep, pgste, pte, mm);
352 		pgste = pgste_set_pte(ptep, pgste, pte);
353 		pgste_set_unlock(ptep, pgste);
354 	} else {
355 		set_pte(ptep, pte);
356 	}
357 	preempt_enable();
358 }
359 
pmdp_idte_local(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)360 static inline void pmdp_idte_local(struct mm_struct *mm,
361 				   unsigned long addr, pmd_t *pmdp)
362 {
363 	if (MACHINE_HAS_TLB_GUEST)
364 		__pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
365 			    mm->context.asce, IDTE_LOCAL);
366 	else
367 		__pmdp_idte(addr, pmdp, 0, 0, IDTE_LOCAL);
368 	if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
369 		gmap_pmdp_idte_local(mm, addr);
370 }
371 
pmdp_idte_global(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)372 static inline void pmdp_idte_global(struct mm_struct *mm,
373 				    unsigned long addr, pmd_t *pmdp)
374 {
375 	if (MACHINE_HAS_TLB_GUEST) {
376 		__pmdp_idte(addr, pmdp, IDTE_NODAT | IDTE_GUEST_ASCE,
377 			    mm->context.asce, IDTE_GLOBAL);
378 		if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
379 			gmap_pmdp_idte_global(mm, addr);
380 	} else if (MACHINE_HAS_IDTE) {
381 		__pmdp_idte(addr, pmdp, 0, 0, IDTE_GLOBAL);
382 		if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
383 			gmap_pmdp_idte_global(mm, addr);
384 	} else {
385 		__pmdp_csp(pmdp);
386 		if (mm_has_pgste(mm) && mm->context.allow_gmap_hpage_1m)
387 			gmap_pmdp_csp(mm, addr);
388 	}
389 }
390 
pmdp_flush_direct(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)391 static inline pmd_t pmdp_flush_direct(struct mm_struct *mm,
392 				      unsigned long addr, pmd_t *pmdp)
393 {
394 	pmd_t old;
395 
396 	old = *pmdp;
397 	if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
398 		return old;
399 	atomic_inc(&mm->context.flush_count);
400 	if (MACHINE_HAS_TLB_LC &&
401 	    cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
402 		pmdp_idte_local(mm, addr, pmdp);
403 	else
404 		pmdp_idte_global(mm, addr, pmdp);
405 	atomic_dec(&mm->context.flush_count);
406 	return old;
407 }
408 
pmdp_flush_lazy(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp)409 static inline pmd_t pmdp_flush_lazy(struct mm_struct *mm,
410 				    unsigned long addr, pmd_t *pmdp)
411 {
412 	pmd_t old;
413 
414 	old = *pmdp;
415 	if (pmd_val(old) & _SEGMENT_ENTRY_INVALID)
416 		return old;
417 	atomic_inc(&mm->context.flush_count);
418 	if (cpumask_equal(&mm->context.cpu_attach_mask,
419 			  cpumask_of(smp_processor_id()))) {
420 		set_pmd(pmdp, set_pmd_bit(*pmdp, __pgprot(_SEGMENT_ENTRY_INVALID)));
421 		mm->context.flush_mm = 1;
422 		if (mm_has_pgste(mm))
423 			gmap_pmdp_invalidate(mm, addr);
424 	} else {
425 		pmdp_idte_global(mm, addr, pmdp);
426 	}
427 	atomic_dec(&mm->context.flush_count);
428 	return old;
429 }
430 
431 #ifdef CONFIG_PGSTE
pmd_lookup(struct mm_struct * mm,unsigned long addr,pmd_t ** pmdp)432 static int pmd_lookup(struct mm_struct *mm, unsigned long addr, pmd_t **pmdp)
433 {
434 	struct vm_area_struct *vma;
435 	pgd_t *pgd;
436 	p4d_t *p4d;
437 	pud_t *pud;
438 
439 	/* We need a valid VMA, otherwise this is clearly a fault. */
440 	vma = vma_lookup(mm, addr);
441 	if (!vma)
442 		return -EFAULT;
443 
444 	pgd = pgd_offset(mm, addr);
445 	if (!pgd_present(*pgd))
446 		return -ENOENT;
447 
448 	p4d = p4d_offset(pgd, addr);
449 	if (!p4d_present(*p4d))
450 		return -ENOENT;
451 
452 	pud = pud_offset(p4d, addr);
453 	if (!pud_present(*pud))
454 		return -ENOENT;
455 
456 	/* Large PUDs are not supported yet. */
457 	if (pud_large(*pud))
458 		return -EFAULT;
459 
460 	*pmdp = pmd_offset(pud, addr);
461 	return 0;
462 }
463 #endif
464 
pmdp_xchg_direct(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp,pmd_t new)465 pmd_t pmdp_xchg_direct(struct mm_struct *mm, unsigned long addr,
466 		       pmd_t *pmdp, pmd_t new)
467 {
468 	pmd_t old;
469 
470 	preempt_disable();
471 	old = pmdp_flush_direct(mm, addr, pmdp);
472 	set_pmd(pmdp, new);
473 	preempt_enable();
474 	return old;
475 }
476 EXPORT_SYMBOL(pmdp_xchg_direct);
477 
pmdp_xchg_lazy(struct mm_struct * mm,unsigned long addr,pmd_t * pmdp,pmd_t new)478 pmd_t pmdp_xchg_lazy(struct mm_struct *mm, unsigned long addr,
479 		     pmd_t *pmdp, pmd_t new)
480 {
481 	pmd_t old;
482 
483 	preempt_disable();
484 	old = pmdp_flush_lazy(mm, addr, pmdp);
485 	set_pmd(pmdp, new);
486 	preempt_enable();
487 	return old;
488 }
489 EXPORT_SYMBOL(pmdp_xchg_lazy);
490 
pudp_idte_local(struct mm_struct * mm,unsigned long addr,pud_t * pudp)491 static inline void pudp_idte_local(struct mm_struct *mm,
492 				   unsigned long addr, pud_t *pudp)
493 {
494 	if (MACHINE_HAS_TLB_GUEST)
495 		__pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
496 			    mm->context.asce, IDTE_LOCAL);
497 	else
498 		__pudp_idte(addr, pudp, 0, 0, IDTE_LOCAL);
499 }
500 
pudp_idte_global(struct mm_struct * mm,unsigned long addr,pud_t * pudp)501 static inline void pudp_idte_global(struct mm_struct *mm,
502 				    unsigned long addr, pud_t *pudp)
503 {
504 	if (MACHINE_HAS_TLB_GUEST)
505 		__pudp_idte(addr, pudp, IDTE_NODAT | IDTE_GUEST_ASCE,
506 			    mm->context.asce, IDTE_GLOBAL);
507 	else if (MACHINE_HAS_IDTE)
508 		__pudp_idte(addr, pudp, 0, 0, IDTE_GLOBAL);
509 	else
510 		/*
511 		 * Invalid bit position is the same for pmd and pud, so we can
512 		 * re-use _pmd_csp() here
513 		 */
514 		__pmdp_csp((pmd_t *) pudp);
515 }
516 
pudp_flush_direct(struct mm_struct * mm,unsigned long addr,pud_t * pudp)517 static inline pud_t pudp_flush_direct(struct mm_struct *mm,
518 				      unsigned long addr, pud_t *pudp)
519 {
520 	pud_t old;
521 
522 	old = *pudp;
523 	if (pud_val(old) & _REGION_ENTRY_INVALID)
524 		return old;
525 	atomic_inc(&mm->context.flush_count);
526 	if (MACHINE_HAS_TLB_LC &&
527 	    cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
528 		pudp_idte_local(mm, addr, pudp);
529 	else
530 		pudp_idte_global(mm, addr, pudp);
531 	atomic_dec(&mm->context.flush_count);
532 	return old;
533 }
534 
pudp_xchg_direct(struct mm_struct * mm,unsigned long addr,pud_t * pudp,pud_t new)535 pud_t pudp_xchg_direct(struct mm_struct *mm, unsigned long addr,
536 		       pud_t *pudp, pud_t new)
537 {
538 	pud_t old;
539 
540 	preempt_disable();
541 	old = pudp_flush_direct(mm, addr, pudp);
542 	set_pud(pudp, new);
543 	preempt_enable();
544 	return old;
545 }
546 EXPORT_SYMBOL(pudp_xchg_direct);
547 
548 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
pgtable_trans_huge_deposit(struct mm_struct * mm,pmd_t * pmdp,pgtable_t pgtable)549 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
550 				pgtable_t pgtable)
551 {
552 	struct list_head *lh = (struct list_head *) pgtable;
553 
554 	assert_spin_locked(pmd_lockptr(mm, pmdp));
555 
556 	/* FIFO */
557 	if (!pmd_huge_pte(mm, pmdp))
558 		INIT_LIST_HEAD(lh);
559 	else
560 		list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
561 	pmd_huge_pte(mm, pmdp) = pgtable;
562 }
563 
pgtable_trans_huge_withdraw(struct mm_struct * mm,pmd_t * pmdp)564 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
565 {
566 	struct list_head *lh;
567 	pgtable_t pgtable;
568 	pte_t *ptep;
569 
570 	assert_spin_locked(pmd_lockptr(mm, pmdp));
571 
572 	/* FIFO */
573 	pgtable = pmd_huge_pte(mm, pmdp);
574 	lh = (struct list_head *) pgtable;
575 	if (list_empty(lh))
576 		pmd_huge_pte(mm, pmdp) = NULL;
577 	else {
578 		pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
579 		list_del(lh);
580 	}
581 	ptep = (pte_t *) pgtable;
582 	set_pte(ptep, __pte(_PAGE_INVALID));
583 	ptep++;
584 	set_pte(ptep, __pte(_PAGE_INVALID));
585 	return pgtable;
586 }
587 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
588 
589 #ifdef CONFIG_PGSTE
ptep_set_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t entry)590 void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
591 		     pte_t *ptep, pte_t entry)
592 {
593 	pgste_t pgste;
594 
595 	/* the mm_has_pgste() check is done in set_pte_at() */
596 	preempt_disable();
597 	pgste = pgste_get_lock(ptep);
598 	pgste_val(pgste) &= ~_PGSTE_GPS_ZERO;
599 	pgste_set_key(ptep, pgste, entry, mm);
600 	pgste = pgste_set_pte(ptep, pgste, entry);
601 	pgste_set_unlock(ptep, pgste);
602 	preempt_enable();
603 }
604 
ptep_set_notify(struct mm_struct * mm,unsigned long addr,pte_t * ptep)605 void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
606 {
607 	pgste_t pgste;
608 
609 	preempt_disable();
610 	pgste = pgste_get_lock(ptep);
611 	pgste_val(pgste) |= PGSTE_IN_BIT;
612 	pgste_set_unlock(ptep, pgste);
613 	preempt_enable();
614 }
615 
616 /**
617  * ptep_force_prot - change access rights of a locked pte
618  * @mm: pointer to the process mm_struct
619  * @addr: virtual address in the guest address space
620  * @ptep: pointer to the page table entry
621  * @prot: indicates guest access rights: PROT_NONE, PROT_READ or PROT_WRITE
622  * @bit: pgste bit to set (e.g. for notification)
623  *
624  * Returns 0 if the access rights were changed and -EAGAIN if the current
625  * and requested access rights are incompatible.
626  */
ptep_force_prot(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int prot,unsigned long bit)627 int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
628 		    pte_t *ptep, int prot, unsigned long bit)
629 {
630 	pte_t entry;
631 	pgste_t pgste;
632 	int pte_i, pte_p, nodat;
633 
634 	pgste = pgste_get_lock(ptep);
635 	entry = *ptep;
636 	/* Check pte entry after all locks have been acquired */
637 	pte_i = pte_val(entry) & _PAGE_INVALID;
638 	pte_p = pte_val(entry) & _PAGE_PROTECT;
639 	if ((pte_i && (prot != PROT_NONE)) ||
640 	    (pte_p && (prot & PROT_WRITE))) {
641 		pgste_set_unlock(ptep, pgste);
642 		return -EAGAIN;
643 	}
644 	/* Change access rights and set pgste bit */
645 	nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
646 	if (prot == PROT_NONE && !pte_i) {
647 		ptep_flush_direct(mm, addr, ptep, nodat);
648 		pgste = pgste_update_all(entry, pgste, mm);
649 		entry = set_pte_bit(entry, __pgprot(_PAGE_INVALID));
650 	}
651 	if (prot == PROT_READ && !pte_p) {
652 		ptep_flush_direct(mm, addr, ptep, nodat);
653 		entry = clear_pte_bit(entry, __pgprot(_PAGE_INVALID));
654 		entry = set_pte_bit(entry, __pgprot(_PAGE_PROTECT));
655 	}
656 	pgste_val(pgste) |= bit;
657 	pgste = pgste_set_pte(ptep, pgste, entry);
658 	pgste_set_unlock(ptep, pgste);
659 	return 0;
660 }
661 
ptep_shadow_pte(struct mm_struct * mm,unsigned long saddr,pte_t * sptep,pte_t * tptep,pte_t pte)662 int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
663 		    pte_t *sptep, pte_t *tptep, pte_t pte)
664 {
665 	pgste_t spgste, tpgste;
666 	pte_t spte, tpte;
667 	int rc = -EAGAIN;
668 
669 	if (!(pte_val(*tptep) & _PAGE_INVALID))
670 		return 0;	/* already shadowed */
671 	spgste = pgste_get_lock(sptep);
672 	spte = *sptep;
673 	if (!(pte_val(spte) & _PAGE_INVALID) &&
674 	    !((pte_val(spte) & _PAGE_PROTECT) &&
675 	      !(pte_val(pte) & _PAGE_PROTECT))) {
676 		pgste_val(spgste) |= PGSTE_VSIE_BIT;
677 		tpgste = pgste_get_lock(tptep);
678 		tpte = __pte((pte_val(spte) & PAGE_MASK) |
679 			     (pte_val(pte) & _PAGE_PROTECT));
680 		/* don't touch the storage key - it belongs to parent pgste */
681 		tpgste = pgste_set_pte(tptep, tpgste, tpte);
682 		pgste_set_unlock(tptep, tpgste);
683 		rc = 1;
684 	}
685 	pgste_set_unlock(sptep, spgste);
686 	return rc;
687 }
688 
ptep_unshadow_pte(struct mm_struct * mm,unsigned long saddr,pte_t * ptep)689 void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep)
690 {
691 	pgste_t pgste;
692 	int nodat;
693 
694 	pgste = pgste_get_lock(ptep);
695 	/* notifier is called by the caller */
696 	nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
697 	ptep_flush_direct(mm, saddr, ptep, nodat);
698 	/* don't touch the storage key - it belongs to parent pgste */
699 	pgste = pgste_set_pte(ptep, pgste, __pte(_PAGE_INVALID));
700 	pgste_set_unlock(ptep, pgste);
701 }
702 
ptep_zap_swap_entry(struct mm_struct * mm,swp_entry_t entry)703 static void ptep_zap_swap_entry(struct mm_struct *mm, swp_entry_t entry)
704 {
705 	if (!non_swap_entry(entry))
706 		dec_mm_counter(mm, MM_SWAPENTS);
707 	else if (is_migration_entry(entry)) {
708 		struct page *page = pfn_swap_entry_to_page(entry);
709 
710 		dec_mm_counter(mm, mm_counter(page));
711 	}
712 	free_swap_and_cache(entry);
713 }
714 
ptep_zap_unused(struct mm_struct * mm,unsigned long addr,pte_t * ptep,int reset)715 void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
716 		     pte_t *ptep, int reset)
717 {
718 	unsigned long pgstev;
719 	pgste_t pgste;
720 	pte_t pte;
721 
722 	/* Zap unused and logically-zero pages */
723 	preempt_disable();
724 	pgste = pgste_get_lock(ptep);
725 	pgstev = pgste_val(pgste);
726 	pte = *ptep;
727 	if (!reset && pte_swap(pte) &&
728 	    ((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED ||
729 	     (pgstev & _PGSTE_GPS_ZERO))) {
730 		ptep_zap_swap_entry(mm, pte_to_swp_entry(pte));
731 		pte_clear(mm, addr, ptep);
732 	}
733 	if (reset)
734 		pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK;
735 	pgste_set_unlock(ptep, pgste);
736 	preempt_enable();
737 }
738 
ptep_zap_key(struct mm_struct * mm,unsigned long addr,pte_t * ptep)739 void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
740 {
741 	unsigned long ptev;
742 	pgste_t pgste;
743 
744 	/* Clear storage key ACC and F, but set R/C */
745 	preempt_disable();
746 	pgste = pgste_get_lock(ptep);
747 	pgste_val(pgste) &= ~(PGSTE_ACC_BITS | PGSTE_FP_BIT);
748 	pgste_val(pgste) |= PGSTE_GR_BIT | PGSTE_GC_BIT;
749 	ptev = pte_val(*ptep);
750 	if (!(ptev & _PAGE_INVALID) && (ptev & _PAGE_WRITE))
751 		page_set_storage_key(ptev & PAGE_MASK, PAGE_DEFAULT_KEY, 0);
752 	pgste_set_unlock(ptep, pgste);
753 	preempt_enable();
754 }
755 
756 /*
757  * Test and reset if a guest page is dirty
758  */
ptep_test_and_clear_uc(struct mm_struct * mm,unsigned long addr,pte_t * ptep)759 bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long addr,
760 		       pte_t *ptep)
761 {
762 	pgste_t pgste;
763 	pte_t pte;
764 	bool dirty;
765 	int nodat;
766 
767 	pgste = pgste_get_lock(ptep);
768 	dirty = !!(pgste_val(pgste) & PGSTE_UC_BIT);
769 	pgste_val(pgste) &= ~PGSTE_UC_BIT;
770 	pte = *ptep;
771 	if (dirty && (pte_val(pte) & _PAGE_PRESENT)) {
772 		pgste = pgste_pte_notify(mm, addr, ptep, pgste);
773 		nodat = !!(pgste_val(pgste) & _PGSTE_GPS_NODAT);
774 		ptep_ipte_global(mm, addr, ptep, nodat);
775 		if (MACHINE_HAS_ESOP || !(pte_val(pte) & _PAGE_WRITE))
776 			pte = set_pte_bit(pte, __pgprot(_PAGE_PROTECT));
777 		else
778 			pte = set_pte_bit(pte, __pgprot(_PAGE_INVALID));
779 		set_pte(ptep, pte);
780 	}
781 	pgste_set_unlock(ptep, pgste);
782 	return dirty;
783 }
784 EXPORT_SYMBOL_GPL(ptep_test_and_clear_uc);
785 
set_guest_storage_key(struct mm_struct * mm,unsigned long addr,unsigned char key,bool nq)786 int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
787 			  unsigned char key, bool nq)
788 {
789 	unsigned long keyul, paddr;
790 	spinlock_t *ptl;
791 	pgste_t old, new;
792 	pmd_t *pmdp;
793 	pte_t *ptep;
794 
795 	/*
796 	 * If we don't have a PTE table and if there is no huge page mapped,
797 	 * we can ignore attempts to set the key to 0, because it already is 0.
798 	 */
799 	switch (pmd_lookup(mm, addr, &pmdp)) {
800 	case -ENOENT:
801 		return key ? -EFAULT : 0;
802 	case 0:
803 		break;
804 	default:
805 		return -EFAULT;
806 	}
807 
808 	ptl = pmd_lock(mm, pmdp);
809 	if (!pmd_present(*pmdp)) {
810 		spin_unlock(ptl);
811 		return key ? -EFAULT : 0;
812 	}
813 
814 	if (pmd_large(*pmdp)) {
815 		paddr = pmd_val(*pmdp) & HPAGE_MASK;
816 		paddr |= addr & ~HPAGE_MASK;
817 		/*
818 		 * Huge pmds need quiescing operations, they are
819 		 * always mapped.
820 		 */
821 		page_set_storage_key(paddr, key, 1);
822 		spin_unlock(ptl);
823 		return 0;
824 	}
825 	spin_unlock(ptl);
826 
827 	ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
828 	new = old = pgste_get_lock(ptep);
829 	pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT |
830 			    PGSTE_ACC_BITS | PGSTE_FP_BIT);
831 	keyul = (unsigned long) key;
832 	pgste_val(new) |= (keyul & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48;
833 	pgste_val(new) |= (keyul & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56;
834 	if (!(pte_val(*ptep) & _PAGE_INVALID)) {
835 		unsigned long bits, skey;
836 
837 		paddr = pte_val(*ptep) & PAGE_MASK;
838 		skey = (unsigned long) page_get_storage_key(paddr);
839 		bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED);
840 		skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT);
841 		/* Set storage key ACC and FP */
842 		page_set_storage_key(paddr, skey, !nq);
843 		/* Merge host changed & referenced into pgste  */
844 		pgste_val(new) |= bits << 52;
845 	}
846 	/* changing the guest storage key is considered a change of the page */
847 	if ((pgste_val(new) ^ pgste_val(old)) &
848 	    (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT))
849 		pgste_val(new) |= PGSTE_UC_BIT;
850 
851 	pgste_set_unlock(ptep, new);
852 	pte_unmap_unlock(ptep, ptl);
853 	return 0;
854 }
855 EXPORT_SYMBOL(set_guest_storage_key);
856 
857 /*
858  * Conditionally set a guest storage key (handling csske).
859  * oldkey will be updated when either mr or mc is set and a pointer is given.
860  *
861  * Returns 0 if a guests storage key update wasn't necessary, 1 if the guest
862  * storage key was updated and -EFAULT on access errors.
863  */
cond_set_guest_storage_key(struct mm_struct * mm,unsigned long addr,unsigned char key,unsigned char * oldkey,bool nq,bool mr,bool mc)864 int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
865 			       unsigned char key, unsigned char *oldkey,
866 			       bool nq, bool mr, bool mc)
867 {
868 	unsigned char tmp, mask = _PAGE_ACC_BITS | _PAGE_FP_BIT;
869 	int rc;
870 
871 	/* we can drop the pgste lock between getting and setting the key */
872 	if (mr | mc) {
873 		rc = get_guest_storage_key(current->mm, addr, &tmp);
874 		if (rc)
875 			return rc;
876 		if (oldkey)
877 			*oldkey = tmp;
878 		if (!mr)
879 			mask |= _PAGE_REFERENCED;
880 		if (!mc)
881 			mask |= _PAGE_CHANGED;
882 		if (!((tmp ^ key) & mask))
883 			return 0;
884 	}
885 	rc = set_guest_storage_key(current->mm, addr, key, nq);
886 	return rc < 0 ? rc : 1;
887 }
888 EXPORT_SYMBOL(cond_set_guest_storage_key);
889 
890 /*
891  * Reset a guest reference bit (rrbe), returning the reference and changed bit.
892  *
893  * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
894  */
reset_guest_reference_bit(struct mm_struct * mm,unsigned long addr)895 int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
896 {
897 	spinlock_t *ptl;
898 	unsigned long paddr;
899 	pgste_t old, new;
900 	pmd_t *pmdp;
901 	pte_t *ptep;
902 	int cc = 0;
903 
904 	/*
905 	 * If we don't have a PTE table and if there is no huge page mapped,
906 	 * the storage key is 0 and there is nothing for us to do.
907 	 */
908 	switch (pmd_lookup(mm, addr, &pmdp)) {
909 	case -ENOENT:
910 		return 0;
911 	case 0:
912 		break;
913 	default:
914 		return -EFAULT;
915 	}
916 
917 	ptl = pmd_lock(mm, pmdp);
918 	if (!pmd_present(*pmdp)) {
919 		spin_unlock(ptl);
920 		return 0;
921 	}
922 
923 	if (pmd_large(*pmdp)) {
924 		paddr = pmd_val(*pmdp) & HPAGE_MASK;
925 		paddr |= addr & ~HPAGE_MASK;
926 		cc = page_reset_referenced(paddr);
927 		spin_unlock(ptl);
928 		return cc;
929 	}
930 	spin_unlock(ptl);
931 
932 	ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
933 	new = old = pgste_get_lock(ptep);
934 	/* Reset guest reference bit only */
935 	pgste_val(new) &= ~PGSTE_GR_BIT;
936 
937 	if (!(pte_val(*ptep) & _PAGE_INVALID)) {
938 		paddr = pte_val(*ptep) & PAGE_MASK;
939 		cc = page_reset_referenced(paddr);
940 		/* Merge real referenced bit into host-set */
941 		pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
942 	}
943 	/* Reflect guest's logical view, not physical */
944 	cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
945 	/* Changing the guest storage key is considered a change of the page */
946 	if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
947 		pgste_val(new) |= PGSTE_UC_BIT;
948 
949 	pgste_set_unlock(ptep, new);
950 	pte_unmap_unlock(ptep, ptl);
951 	return cc;
952 }
953 EXPORT_SYMBOL(reset_guest_reference_bit);
954 
get_guest_storage_key(struct mm_struct * mm,unsigned long addr,unsigned char * key)955 int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
956 			  unsigned char *key)
957 {
958 	unsigned long paddr;
959 	spinlock_t *ptl;
960 	pgste_t pgste;
961 	pmd_t *pmdp;
962 	pte_t *ptep;
963 
964 	/*
965 	 * If we don't have a PTE table and if there is no huge page mapped,
966 	 * the storage key is 0.
967 	 */
968 	*key = 0;
969 
970 	switch (pmd_lookup(mm, addr, &pmdp)) {
971 	case -ENOENT:
972 		return 0;
973 	case 0:
974 		break;
975 	default:
976 		return -EFAULT;
977 	}
978 
979 	ptl = pmd_lock(mm, pmdp);
980 	if (!pmd_present(*pmdp)) {
981 		spin_unlock(ptl);
982 		return 0;
983 	}
984 
985 	if (pmd_large(*pmdp)) {
986 		paddr = pmd_val(*pmdp) & HPAGE_MASK;
987 		paddr |= addr & ~HPAGE_MASK;
988 		*key = page_get_storage_key(paddr);
989 		spin_unlock(ptl);
990 		return 0;
991 	}
992 	spin_unlock(ptl);
993 
994 	ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
995 	pgste = pgste_get_lock(ptep);
996 	*key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
997 	paddr = pte_val(*ptep) & PAGE_MASK;
998 	if (!(pte_val(*ptep) & _PAGE_INVALID))
999 		*key = page_get_storage_key(paddr);
1000 	/* Reflect guest's logical view, not physical */
1001 	*key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
1002 	pgste_set_unlock(ptep, pgste);
1003 	pte_unmap_unlock(ptep, ptl);
1004 	return 0;
1005 }
1006 EXPORT_SYMBOL(get_guest_storage_key);
1007 
1008 /**
1009  * pgste_perform_essa - perform ESSA actions on the PGSTE.
1010  * @mm: the memory context. It must have PGSTEs, no check is performed here!
1011  * @hva: the host virtual address of the page whose PGSTE is to be processed
1012  * @orc: the specific action to perform, see the ESSA_SET_* macros.
1013  * @oldpte: the PTE will be saved there if the pointer is not NULL.
1014  * @oldpgste: the old PGSTE will be saved there if the pointer is not NULL.
1015  *
1016  * Return: 1 if the page is to be added to the CBRL, otherwise 0,
1017  *	   or < 0 in case of error. -EINVAL is returned for invalid values
1018  *	   of orc, -EFAULT for invalid addresses.
1019  */
pgste_perform_essa(struct mm_struct * mm,unsigned long hva,int orc,unsigned long * oldpte,unsigned long * oldpgste)1020 int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
1021 			unsigned long *oldpte, unsigned long *oldpgste)
1022 {
1023 	struct vm_area_struct *vma;
1024 	unsigned long pgstev;
1025 	spinlock_t *ptl;
1026 	pgste_t pgste;
1027 	pte_t *ptep;
1028 	int res = 0;
1029 
1030 	WARN_ON_ONCE(orc > ESSA_MAX);
1031 	if (unlikely(orc > ESSA_MAX))
1032 		return -EINVAL;
1033 
1034 	vma = vma_lookup(mm, hva);
1035 	if (!vma || is_vm_hugetlb_page(vma))
1036 		return -EFAULT;
1037 	ptep = get_locked_pte(mm, hva, &ptl);
1038 	if (unlikely(!ptep))
1039 		return -EFAULT;
1040 	pgste = pgste_get_lock(ptep);
1041 	pgstev = pgste_val(pgste);
1042 	if (oldpte)
1043 		*oldpte = pte_val(*ptep);
1044 	if (oldpgste)
1045 		*oldpgste = pgstev;
1046 
1047 	switch (orc) {
1048 	case ESSA_GET_STATE:
1049 		break;
1050 	case ESSA_SET_STABLE:
1051 		pgstev &= ~(_PGSTE_GPS_USAGE_MASK | _PGSTE_GPS_NODAT);
1052 		pgstev |= _PGSTE_GPS_USAGE_STABLE;
1053 		break;
1054 	case ESSA_SET_UNUSED:
1055 		pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1056 		pgstev |= _PGSTE_GPS_USAGE_UNUSED;
1057 		if (pte_val(*ptep) & _PAGE_INVALID)
1058 			res = 1;
1059 		break;
1060 	case ESSA_SET_VOLATILE:
1061 		pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1062 		pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1063 		if (pte_val(*ptep) & _PAGE_INVALID)
1064 			res = 1;
1065 		break;
1066 	case ESSA_SET_POT_VOLATILE:
1067 		pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1068 		if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1069 			pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE;
1070 			break;
1071 		}
1072 		if (pgstev & _PGSTE_GPS_ZERO) {
1073 			pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1074 			break;
1075 		}
1076 		if (!(pgstev & PGSTE_GC_BIT)) {
1077 			pgstev |= _PGSTE_GPS_USAGE_VOLATILE;
1078 			res = 1;
1079 			break;
1080 		}
1081 		break;
1082 	case ESSA_SET_STABLE_RESIDENT:
1083 		pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1084 		pgstev |= _PGSTE_GPS_USAGE_STABLE;
1085 		/*
1086 		 * Since the resident state can go away any time after this
1087 		 * call, we will not make this page resident. We can revisit
1088 		 * this decision if a guest will ever start using this.
1089 		 */
1090 		break;
1091 	case ESSA_SET_STABLE_IF_RESIDENT:
1092 		if (!(pte_val(*ptep) & _PAGE_INVALID)) {
1093 			pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1094 			pgstev |= _PGSTE_GPS_USAGE_STABLE;
1095 		}
1096 		break;
1097 	case ESSA_SET_STABLE_NODAT:
1098 		pgstev &= ~_PGSTE_GPS_USAGE_MASK;
1099 		pgstev |= _PGSTE_GPS_USAGE_STABLE | _PGSTE_GPS_NODAT;
1100 		break;
1101 	default:
1102 		/* we should never get here! */
1103 		break;
1104 	}
1105 	/* If we are discarding a page, set it to logical zero */
1106 	if (res)
1107 		pgstev |= _PGSTE_GPS_ZERO;
1108 
1109 	pgste_val(pgste) = pgstev;
1110 	pgste_set_unlock(ptep, pgste);
1111 	pte_unmap_unlock(ptep, ptl);
1112 	return res;
1113 }
1114 EXPORT_SYMBOL(pgste_perform_essa);
1115 
1116 /**
1117  * set_pgste_bits - set specific PGSTE bits.
1118  * @mm: the memory context. It must have PGSTEs, no check is performed here!
1119  * @hva: the host virtual address of the page whose PGSTE is to be processed
1120  * @bits: a bitmask representing the bits that will be touched
1121  * @value: the values of the bits to be written. Only the bits in the mask
1122  *	   will be written.
1123  *
1124  * Return: 0 on success, < 0 in case of error.
1125  */
set_pgste_bits(struct mm_struct * mm,unsigned long hva,unsigned long bits,unsigned long value)1126 int set_pgste_bits(struct mm_struct *mm, unsigned long hva,
1127 			unsigned long bits, unsigned long value)
1128 {
1129 	struct vm_area_struct *vma;
1130 	spinlock_t *ptl;
1131 	pgste_t new;
1132 	pte_t *ptep;
1133 
1134 	vma = vma_lookup(mm, hva);
1135 	if (!vma || is_vm_hugetlb_page(vma))
1136 		return -EFAULT;
1137 	ptep = get_locked_pte(mm, hva, &ptl);
1138 	if (unlikely(!ptep))
1139 		return -EFAULT;
1140 	new = pgste_get_lock(ptep);
1141 
1142 	pgste_val(new) &= ~bits;
1143 	pgste_val(new) |= value & bits;
1144 
1145 	pgste_set_unlock(ptep, new);
1146 	pte_unmap_unlock(ptep, ptl);
1147 	return 0;
1148 }
1149 EXPORT_SYMBOL(set_pgste_bits);
1150 
1151 /**
1152  * get_pgste - get the current PGSTE for the given address.
1153  * @mm: the memory context. It must have PGSTEs, no check is performed here!
1154  * @hva: the host virtual address of the page whose PGSTE is to be processed
1155  * @pgstep: will be written with the current PGSTE for the given address.
1156  *
1157  * Return: 0 on success, < 0 in case of error.
1158  */
get_pgste(struct mm_struct * mm,unsigned long hva,unsigned long * pgstep)1159 int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep)
1160 {
1161 	struct vm_area_struct *vma;
1162 	spinlock_t *ptl;
1163 	pte_t *ptep;
1164 
1165 	vma = vma_lookup(mm, hva);
1166 	if (!vma || is_vm_hugetlb_page(vma))
1167 		return -EFAULT;
1168 	ptep = get_locked_pte(mm, hva, &ptl);
1169 	if (unlikely(!ptep))
1170 		return -EFAULT;
1171 	*pgstep = pgste_val(pgste_get(ptep));
1172 	pte_unmap_unlock(ptep, ptl);
1173 	return 0;
1174 }
1175 EXPORT_SYMBOL(get_pgste);
1176 #endif
1177