1/*
2 * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
3 *
4 * Authors:
5 *     Alexander Graf <agraf@suse.de>
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, version 2, as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
19 */
20
21#include <linux/kvm_host.h>
22
23#include <asm/kvm_ppc.h>
24#include <asm/kvm_book3s.h>
25#include <asm/mmu-hash32.h>
26#include <asm/machdep.h>
27#include <asm/mmu_context.h>
28#include <asm/hw_irq.h>
29#include "book3s.h"
30
31/* #define DEBUG_MMU */
32/* #define DEBUG_SR */
33
34#ifdef DEBUG_MMU
35#define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
36#else
37#define dprintk_mmu(a, ...) do { } while(0)
38#endif
39
40#ifdef DEBUG_SR
41#define dprintk_sr(a, ...) printk(KERN_INFO a, __VA_ARGS__)
42#else
43#define dprintk_sr(a, ...) do { } while(0)
44#endif
45
46#if PAGE_SHIFT != 12
47#error Unknown page size
48#endif
49
50#ifdef CONFIG_SMP
51#error XXX need to grab mmu_hash_lock
52#endif
53
54#ifdef CONFIG_PTE_64BIT
55#error Only 32 bit pages are supported for now
56#endif
57
58static ulong htab;
59static u32 htabmask;
60
61void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
62{
63	volatile u32 *pteg;
64
65	/* Remove from host HTAB */
66	pteg = (u32*)pte->slot;
67	pteg[0] = 0;
68
69	/* And make sure it's gone from the TLB too */
70	asm volatile ("sync");
71	asm volatile ("tlbie %0" : : "r" (pte->pte.eaddr) : "memory");
72	asm volatile ("sync");
73	asm volatile ("tlbsync");
74}
75
76/* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
77 * a hash, so we don't waste cycles on looping */
78static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
79{
80	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
81		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
82		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
83		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
84		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
85		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
86		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
87		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
88}
89
90
91static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
92{
93	struct kvmppc_sid_map *map;
94	u16 sid_map_mask;
95
96	if (kvmppc_get_msr(vcpu) & MSR_PR)
97		gvsid |= VSID_PR;
98
99	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
100	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
101	if (map->guest_vsid == gvsid) {
102		dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
103			    gvsid, map->host_vsid);
104		return map;
105	}
106
107	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
108	if (map->guest_vsid == gvsid) {
109		dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
110			    gvsid, map->host_vsid);
111		return map;
112	}
113
114	dprintk_sr("SR: Searching 0x%llx -> not found\n", gvsid);
115	return NULL;
116}
117
118static u32 *kvmppc_mmu_get_pteg(struct kvm_vcpu *vcpu, u32 vsid, u32 eaddr,
119				bool primary)
120{
121	u32 page, hash;
122	ulong pteg = htab;
123
124	page = (eaddr & ~ESID_MASK) >> 12;
125
126	hash = ((vsid ^ page) << 6);
127	if (!primary)
128		hash = ~hash;
129
130	hash &= htabmask;
131
132	pteg |= hash;
133
134	dprintk_mmu("htab: %lx | hash: %x | htabmask: %x | pteg: %lx\n",
135		htab, hash, htabmask, pteg);
136
137	return (u32*)pteg;
138}
139
140extern char etext[];
141
142int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
143			bool iswrite)
144{
145	pfn_t hpaddr;
146	u64 vpn;
147	u64 vsid;
148	struct kvmppc_sid_map *map;
149	volatile u32 *pteg;
150	u32 eaddr = orig_pte->eaddr;
151	u32 pteg0, pteg1;
152	register int rr = 0;
153	bool primary = false;
154	bool evict = false;
155	struct hpte_cache *pte;
156	int r = 0;
157	bool writable;
158
159	/* Get host physical address for gpa */
160	hpaddr = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
161	if (is_error_noslot_pfn(hpaddr)) {
162		printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
163				 orig_pte->raddr);
164		r = -EINVAL;
165		goto out;
166	}
167	hpaddr <<= PAGE_SHIFT;
168
169	/* and write the mapping ea -> hpa into the pt */
170	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
171	map = find_sid_vsid(vcpu, vsid);
172	if (!map) {
173		kvmppc_mmu_map_segment(vcpu, eaddr);
174		map = find_sid_vsid(vcpu, vsid);
175	}
176	BUG_ON(!map);
177
178	vsid = map->host_vsid;
179	vpn = (vsid << (SID_SHIFT - VPN_SHIFT)) |
180		((eaddr & ~ESID_MASK) >> VPN_SHIFT);
181next_pteg:
182	if (rr == 16) {
183		primary = !primary;
184		evict = true;
185		rr = 0;
186	}
187
188	pteg = kvmppc_mmu_get_pteg(vcpu, vsid, eaddr, primary);
189
190	/* not evicting yet */
191	if (!evict && (pteg[rr] & PTE_V)) {
192		rr += 2;
193		goto next_pteg;
194	}
195
196	dprintk_mmu("KVM: old PTEG: %p (%d)\n", pteg, rr);
197	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
198	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
199	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
200	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
201	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
202	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
203	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
204	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
205
206	pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V |
207		(primary ? 0 : PTE_SEC);
208	pteg1 = hpaddr | PTE_M | PTE_R | PTE_C;
209
210	if (orig_pte->may_write && writable) {
211		pteg1 |= PP_RWRW;
212		mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
213	} else {
214		pteg1 |= PP_RWRX;
215	}
216
217	if (orig_pte->may_execute)
218		kvmppc_mmu_flush_icache(hpaddr >> PAGE_SHIFT);
219
220	local_irq_disable();
221
222	if (pteg[rr]) {
223		pteg[rr] = 0;
224		asm volatile ("sync");
225	}
226	pteg[rr + 1] = pteg1;
227	pteg[rr] = pteg0;
228	asm volatile ("sync");
229
230	local_irq_enable();
231
232	dprintk_mmu("KVM: new PTEG: %p\n", pteg);
233	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
234	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
235	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
236	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
237	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
238	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
239	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
240	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
241
242
243	/* Now tell our Shadow PTE code about the new page */
244
245	pte = kvmppc_mmu_hpte_cache_next(vcpu);
246	if (!pte) {
247		kvm_release_pfn_clean(hpaddr >> PAGE_SHIFT);
248		r = -EAGAIN;
249		goto out;
250	}
251
252	dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
253		    orig_pte->may_write ? 'w' : '-',
254		    orig_pte->may_execute ? 'x' : '-',
255		    orig_pte->eaddr, (ulong)pteg, vpn,
256		    orig_pte->vpage, hpaddr);
257
258	pte->slot = (ulong)&pteg[rr];
259	pte->host_vpn = vpn;
260	pte->pte = *orig_pte;
261	pte->pfn = hpaddr >> PAGE_SHIFT;
262
263	kvmppc_mmu_hpte_cache_map(vcpu, pte);
264
265	kvm_release_pfn_clean(hpaddr >> PAGE_SHIFT);
266out:
267	return r;
268}
269
270void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
271{
272	kvmppc_mmu_pte_vflush(vcpu, pte->vpage, 0xfffffffffULL);
273}
274
275static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
276{
277	struct kvmppc_sid_map *map;
278	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
279	u16 sid_map_mask;
280	static int backwards_map = 0;
281
282	if (kvmppc_get_msr(vcpu) & MSR_PR)
283		gvsid |= VSID_PR;
284
285	/* We might get collisions that trap in preceding order, so let's
286	   map them differently */
287
288	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
289	if (backwards_map)
290		sid_map_mask = SID_MAP_MASK - sid_map_mask;
291
292	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
293
294	/* Make sure we're taking the other map next time */
295	backwards_map = !backwards_map;
296
297	/* Uh-oh ... out of mappings. Let's flush! */
298	if (vcpu_book3s->vsid_next >= VSID_POOL_SIZE) {
299		vcpu_book3s->vsid_next = 0;
300		memset(vcpu_book3s->sid_map, 0,
301		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
302		kvmppc_mmu_pte_flush(vcpu, 0, 0);
303		kvmppc_mmu_flush_segments(vcpu);
304	}
305	map->host_vsid = vcpu_book3s->vsid_pool[vcpu_book3s->vsid_next];
306	vcpu_book3s->vsid_next++;
307
308	map->guest_vsid = gvsid;
309	map->valid = true;
310
311	return map;
312}
313
314int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
315{
316	u32 esid = eaddr >> SID_SHIFT;
317	u64 gvsid;
318	u32 sr;
319	struct kvmppc_sid_map *map;
320	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
321	int r = 0;
322
323	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
324		/* Invalidate an entry */
325		svcpu->sr[esid] = SR_INVALID;
326		r = -ENOENT;
327		goto out;
328	}
329
330	map = find_sid_vsid(vcpu, gvsid);
331	if (!map)
332		map = create_sid_map(vcpu, gvsid);
333
334	map->guest_esid = esid;
335	sr = map->host_vsid | SR_KP;
336	svcpu->sr[esid] = sr;
337
338	dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);
339
340out:
341	svcpu_put(svcpu);
342	return r;
343}
344
345void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
346{
347	int i;
348	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
349
350	dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));
351	for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)
352		svcpu->sr[i] = SR_INVALID;
353
354	svcpu_put(svcpu);
355}
356
357void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
358{
359	int i;
360
361	kvmppc_mmu_hpte_destroy(vcpu);
362	preempt_disable();
363	for (i = 0; i < SID_CONTEXTS; i++)
364		__destroy_context(to_book3s(vcpu)->context_id[i]);
365	preempt_enable();
366}
367
368/* From mm/mmu_context_hash32.c */
369#define CTX_TO_VSID(c, id)	((((c) * (897 * 16)) + (id * 0x111)) & 0xffffff)
370
371int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
372{
373	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
374	int err;
375	ulong sdr1;
376	int i;
377	int j;
378
379	for (i = 0; i < SID_CONTEXTS; i++) {
380		err = __init_new_context();
381		if (err < 0)
382			goto init_fail;
383		vcpu3s->context_id[i] = err;
384
385		/* Remember context id for this combination */
386		for (j = 0; j < 16; j++)
387			vcpu3s->vsid_pool[(i * 16) + j] = CTX_TO_VSID(err, j);
388	}
389
390	vcpu3s->vsid_next = 0;
391
392	/* Remember where the HTAB is */
393	asm ( "mfsdr1 %0" : "=r"(sdr1) );
394	htabmask = ((sdr1 & 0x1FF) << 16) | 0xFFC0;
395	htab = (ulong)__va(sdr1 & 0xffff0000);
396
397	kvmppc_mmu_hpte_init(vcpu);
398
399	return 0;
400
401init_fail:
402	for (j = 0; j < i; j++) {
403		if (!vcpu3s->context_id[j])
404			continue;
405
406		__destroy_context(to_book3s(vcpu)->context_id[j]);
407	}
408
409	return -1;
410}
411