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