1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License, version 2, as
4  * published by the Free Software Foundation.
5  *
6  * This program is distributed in the hope that it will be useful,
7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9  * GNU General Public License for more details.
10  *
11  * You should have received a copy of the GNU General Public License
12  * along with this program; if not, write to the Free Software
13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
14  *
15  * Copyright SUSE Linux Products GmbH 2010
16  *
17  * Authors: Alexander Graf <agraf@suse.de>
18  */
19 
20 #ifndef __ASM_KVM_BOOK3S_64_H__
21 #define __ASM_KVM_BOOK3S_64_H__
22 
23 #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
24 static inline struct kvmppc_book3s_shadow_vcpu *svcpu_get(struct kvm_vcpu *vcpu)
25 {
26 	preempt_disable();
27 	return &get_paca()->shadow_vcpu;
28 }
29 
30 static inline void svcpu_put(struct kvmppc_book3s_shadow_vcpu *svcpu)
31 {
32 	preempt_enable();
33 }
34 #endif
35 
36 #define SPAPR_TCE_SHIFT		12
37 
38 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
39 #define KVM_DEFAULT_HPT_ORDER	24	/* 16MB HPT by default */
40 extern unsigned long kvm_rma_pages;
41 #endif
42 
43 #define VRMA_VSID	0x1ffffffUL	/* 1TB VSID reserved for VRMA */
44 
45 /*
46  * We use a lock bit in HPTE dword 0 to synchronize updates and
47  * accesses to each HPTE, and another bit to indicate non-present
48  * HPTEs.
49  */
50 #define HPTE_V_HVLOCK	0x40UL
51 #define HPTE_V_ABSENT	0x20UL
52 
53 /*
54  * We use this bit in the guest_rpte field of the revmap entry
55  * to indicate a modified HPTE.
56  */
57 #define HPTE_GR_MODIFIED	(1ul << 62)
58 
59 /* These bits are reserved in the guest view of the HPTE */
60 #define HPTE_GR_RESERVED	HPTE_GR_MODIFIED
61 
62 static inline long try_lock_hpte(unsigned long *hpte, unsigned long bits)
63 {
64 	unsigned long tmp, old;
65 
66 	asm volatile("	ldarx	%0,0,%2\n"
67 		     "	and.	%1,%0,%3\n"
68 		     "	bne	2f\n"
69 		     "	ori	%0,%0,%4\n"
70 		     "  stdcx.	%0,0,%2\n"
71 		     "	beq+	2f\n"
72 		     "	mr	%1,%3\n"
73 		     "2:	isync"
74 		     : "=&r" (tmp), "=&r" (old)
75 		     : "r" (hpte), "r" (bits), "i" (HPTE_V_HVLOCK)
76 		     : "cc", "memory");
77 	return old == 0;
78 }
79 
80 static inline int __hpte_actual_psize(unsigned int lp, int psize)
81 {
82 	int i, shift;
83 	unsigned int mask;
84 
85 	/* start from 1 ignoring MMU_PAGE_4K */
86 	for (i = 1; i < MMU_PAGE_COUNT; i++) {
87 
88 		/* invalid penc */
89 		if (mmu_psize_defs[psize].penc[i] == -1)
90 			continue;
91 		/*
92 		 * encoding bits per actual page size
93 		 *        PTE LP     actual page size
94 		 *    rrrr rrrz		>=8KB
95 		 *    rrrr rrzz		>=16KB
96 		 *    rrrr rzzz		>=32KB
97 		 *    rrrr zzzz		>=64KB
98 		 * .......
99 		 */
100 		shift = mmu_psize_defs[i].shift - LP_SHIFT;
101 		if (shift > LP_BITS)
102 			shift = LP_BITS;
103 		mask = (1 << shift) - 1;
104 		if ((lp & mask) == mmu_psize_defs[psize].penc[i])
105 			return i;
106 	}
107 	return -1;
108 }
109 
110 static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
111 					     unsigned long pte_index)
112 {
113 	int b_psize, a_psize;
114 	unsigned int penc;
115 	unsigned long rb = 0, va_low, sllp;
116 	unsigned int lp = (r >> LP_SHIFT) & ((1 << LP_BITS) - 1);
117 
118 	if (!(v & HPTE_V_LARGE)) {
119 		/* both base and actual psize is 4k */
120 		b_psize = MMU_PAGE_4K;
121 		a_psize = MMU_PAGE_4K;
122 	} else {
123 		for (b_psize = 0; b_psize < MMU_PAGE_COUNT; b_psize++) {
124 
125 			/* valid entries have a shift value */
126 			if (!mmu_psize_defs[b_psize].shift)
127 				continue;
128 
129 			a_psize = __hpte_actual_psize(lp, b_psize);
130 			if (a_psize != -1)
131 				break;
132 		}
133 	}
134 	/*
135 	 * Ignore the top 14 bits of va
136 	 * v have top two bits covering segment size, hence move
137 	 * by 16 bits, Also clear the lower HPTE_V_AVPN_SHIFT (7) bits.
138 	 * AVA field in v also have the lower 23 bits ignored.
139 	 * For base page size 4K we need 14 .. 65 bits (so need to
140 	 * collect extra 11 bits)
141 	 * For others we need 14..14+i
142 	 */
143 	/* This covers 14..54 bits of va*/
144 	rb = (v & ~0x7fUL) << 16;		/* AVA field */
145 	/*
146 	 * AVA in v had cleared lower 23 bits. We need to derive
147 	 * that from pteg index
148 	 */
149 	va_low = pte_index >> 3;
150 	if (v & HPTE_V_SECONDARY)
151 		va_low = ~va_low;
152 	/*
153 	 * get the vpn bits from va_low using reverse of hashing.
154 	 * In v we have va with 23 bits dropped and then left shifted
155 	 * HPTE_V_AVPN_SHIFT (7) bits. Now to find vsid we need
156 	 * right shift it with (SID_SHIFT - (23 - 7))
157 	 */
158 	if (!(v & HPTE_V_1TB_SEG))
159 		va_low ^= v >> (SID_SHIFT - 16);
160 	else
161 		va_low ^= v >> (SID_SHIFT_1T - 16);
162 	va_low &= 0x7ff;
163 
164 	switch (b_psize) {
165 	case MMU_PAGE_4K:
166 		sllp = ((mmu_psize_defs[a_psize].sllp & SLB_VSID_L) >> 6) |
167 			((mmu_psize_defs[a_psize].sllp & SLB_VSID_LP) >> 4);
168 		rb |= sllp << 5;	/*  AP field */
169 		rb |= (va_low & 0x7ff) << 12;	/* remaining 11 bits of AVA */
170 		break;
171 	default:
172 	{
173 		int aval_shift;
174 		/*
175 		 * remaining 7bits of AVA/LP fields
176 		 * Also contain the rr bits of LP
177 		 */
178 		rb |= (va_low & 0x7f) << 16;
179 		/*
180 		 * Now clear not needed LP bits based on actual psize
181 		 */
182 		rb &= ~((1ul << mmu_psize_defs[a_psize].shift) - 1);
183 		/*
184 		 * AVAL field 58..77 - base_page_shift bits of va
185 		 * we have space for 58..64 bits, Missing bits should
186 		 * be zero filled. +1 is to take care of L bit shift
187 		 */
188 		aval_shift = 64 - (77 - mmu_psize_defs[b_psize].shift) + 1;
189 		rb |= ((va_low << aval_shift) & 0xfe);
190 
191 		rb |= 1;		/* L field */
192 		penc = mmu_psize_defs[b_psize].penc[a_psize];
193 		rb |= penc << 12;	/* LP field */
194 		break;
195 	}
196 	}
197 	rb |= (v >> 54) & 0x300;		/* B field */
198 	return rb;
199 }
200 
201 static inline unsigned long __hpte_page_size(unsigned long h, unsigned long l,
202 					     bool is_base_size)
203 {
204 
205 	int size, a_psize;
206 	/* Look at the 8 bit LP value */
207 	unsigned int lp = (l >> LP_SHIFT) & ((1 << LP_BITS) - 1);
208 
209 	/* only handle 4k, 64k and 16M pages for now */
210 	if (!(h & HPTE_V_LARGE))
211 		return 1ul << 12;
212 	else {
213 		for (size = 0; size < MMU_PAGE_COUNT; size++) {
214 			/* valid entries have a shift value */
215 			if (!mmu_psize_defs[size].shift)
216 				continue;
217 
218 			a_psize = __hpte_actual_psize(lp, size);
219 			if (a_psize != -1) {
220 				if (is_base_size)
221 					return 1ul << mmu_psize_defs[size].shift;
222 				return 1ul << mmu_psize_defs[a_psize].shift;
223 			}
224 		}
225 
226 	}
227 	return 0;
228 }
229 
230 static inline unsigned long hpte_page_size(unsigned long h, unsigned long l)
231 {
232 	return __hpte_page_size(h, l, 0);
233 }
234 
235 static inline unsigned long hpte_base_page_size(unsigned long h, unsigned long l)
236 {
237 	return __hpte_page_size(h, l, 1);
238 }
239 
240 static inline unsigned long hpte_rpn(unsigned long ptel, unsigned long psize)
241 {
242 	return ((ptel & HPTE_R_RPN) & ~(psize - 1)) >> PAGE_SHIFT;
243 }
244 
245 static inline int hpte_is_writable(unsigned long ptel)
246 {
247 	unsigned long pp = ptel & (HPTE_R_PP0 | HPTE_R_PP);
248 
249 	return pp != PP_RXRX && pp != PP_RXXX;
250 }
251 
252 static inline unsigned long hpte_make_readonly(unsigned long ptel)
253 {
254 	if ((ptel & HPTE_R_PP0) || (ptel & HPTE_R_PP) == PP_RWXX)
255 		ptel = (ptel & ~HPTE_R_PP) | PP_RXXX;
256 	else
257 		ptel |= PP_RXRX;
258 	return ptel;
259 }
260 
261 static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type)
262 {
263 	unsigned int wimg = ptel & HPTE_R_WIMG;
264 
265 	/* Handle SAO */
266 	if (wimg == (HPTE_R_W | HPTE_R_I | HPTE_R_M) &&
267 	    cpu_has_feature(CPU_FTR_ARCH_206))
268 		wimg = HPTE_R_M;
269 
270 	if (!io_type)
271 		return wimg == HPTE_R_M;
272 
273 	return (wimg & (HPTE_R_W | HPTE_R_I)) == io_type;
274 }
275 
276 /*
277  * If it's present and writable, atomically set dirty and referenced bits and
278  * return the PTE, otherwise return 0. If we find a transparent hugepage
279  * and if it is marked splitting we return 0;
280  */
281 static inline pte_t kvmppc_read_update_linux_pte(pte_t *ptep, int writing,
282 						 unsigned int hugepage)
283 {
284 	pte_t old_pte, new_pte = __pte(0);
285 
286 	while (1) {
287 		old_pte = pte_val(*ptep);
288 		/*
289 		 * wait until _PAGE_BUSY is clear then set it atomically
290 		 */
291 		if (unlikely(old_pte & _PAGE_BUSY)) {
292 			cpu_relax();
293 			continue;
294 		}
295 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
296 		/* If hugepage and is trans splitting return None */
297 		if (unlikely(hugepage &&
298 			     pmd_trans_splitting(pte_pmd(old_pte))))
299 			return __pte(0);
300 #endif
301 		/* If pte is not present return None */
302 		if (unlikely(!(old_pte & _PAGE_PRESENT)))
303 			return __pte(0);
304 
305 		new_pte = pte_mkyoung(old_pte);
306 		if (writing && pte_write(old_pte))
307 			new_pte = pte_mkdirty(new_pte);
308 
309 		if (old_pte == __cmpxchg_u64((unsigned long *)ptep, old_pte,
310 					     new_pte))
311 			break;
312 	}
313 	return new_pte;
314 }
315 
316 
317 /* Return HPTE cache control bits corresponding to Linux pte bits */
318 static inline unsigned long hpte_cache_bits(unsigned long pte_val)
319 {
320 #if _PAGE_NO_CACHE == HPTE_R_I && _PAGE_WRITETHRU == HPTE_R_W
321 	return pte_val & (HPTE_R_W | HPTE_R_I);
322 #else
323 	return ((pte_val & _PAGE_NO_CACHE) ? HPTE_R_I : 0) +
324 		((pte_val & _PAGE_WRITETHRU) ? HPTE_R_W : 0);
325 #endif
326 }
327 
328 static inline bool hpte_read_permission(unsigned long pp, unsigned long key)
329 {
330 	if (key)
331 		return PP_RWRX <= pp && pp <= PP_RXRX;
332 	return 1;
333 }
334 
335 static inline bool hpte_write_permission(unsigned long pp, unsigned long key)
336 {
337 	if (key)
338 		return pp == PP_RWRW;
339 	return pp <= PP_RWRW;
340 }
341 
342 static inline int hpte_get_skey_perm(unsigned long hpte_r, unsigned long amr)
343 {
344 	unsigned long skey;
345 
346 	skey = ((hpte_r & HPTE_R_KEY_HI) >> 57) |
347 		((hpte_r & HPTE_R_KEY_LO) >> 9);
348 	return (amr >> (62 - 2 * skey)) & 3;
349 }
350 
351 static inline void lock_rmap(unsigned long *rmap)
352 {
353 	do {
354 		while (test_bit(KVMPPC_RMAP_LOCK_BIT, rmap))
355 			cpu_relax();
356 	} while (test_and_set_bit_lock(KVMPPC_RMAP_LOCK_BIT, rmap));
357 }
358 
359 static inline void unlock_rmap(unsigned long *rmap)
360 {
361 	__clear_bit_unlock(KVMPPC_RMAP_LOCK_BIT, rmap);
362 }
363 
364 static inline bool slot_is_aligned(struct kvm_memory_slot *memslot,
365 				   unsigned long pagesize)
366 {
367 	unsigned long mask = (pagesize >> PAGE_SHIFT) - 1;
368 
369 	if (pagesize <= PAGE_SIZE)
370 		return 1;
371 	return !(memslot->base_gfn & mask) && !(memslot->npages & mask);
372 }
373 
374 /*
375  * This works for 4k, 64k and 16M pages on POWER7,
376  * and 4k and 16M pages on PPC970.
377  */
378 static inline unsigned long slb_pgsize_encoding(unsigned long psize)
379 {
380 	unsigned long senc = 0;
381 
382 	if (psize > 0x1000) {
383 		senc = SLB_VSID_L;
384 		if (psize == 0x10000)
385 			senc |= SLB_VSID_LP_01;
386 	}
387 	return senc;
388 }
389 
390 static inline int is_vrma_hpte(unsigned long hpte_v)
391 {
392 	return (hpte_v & ~0xffffffUL) ==
393 		(HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)));
394 }
395 
396 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
397 /*
398  * Note modification of an HPTE; set the HPTE modified bit
399  * if anyone is interested.
400  */
401 static inline void note_hpte_modification(struct kvm *kvm,
402 					  struct revmap_entry *rev)
403 {
404 	if (atomic_read(&kvm->arch.hpte_mod_interest))
405 		rev->guest_rpte |= HPTE_GR_MODIFIED;
406 }
407 
408 /*
409  * Like kvm_memslots(), but for use in real mode when we can't do
410  * any RCU stuff (since the secondary threads are offline from the
411  * kernel's point of view), and we can't print anything.
412  * Thus we use rcu_dereference_raw() rather than rcu_dereference_check().
413  */
414 static inline struct kvm_memslots *kvm_memslots_raw(struct kvm *kvm)
415 {
416 	return rcu_dereference_raw_notrace(kvm->memslots);
417 }
418 
419 #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
420 
421 #endif /* __ASM_KVM_BOOK3S_64_H__ */
422