xref: /linux/arch/powerpc/kvm/tm.S (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
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 * Derived from book3s_hv_rmhandlers.S, which is:
12 *
13 * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
14 *
15 */
16
17#include <asm/reg.h>
18#include <asm/ppc_asm.h>
19#include <asm/asm-offsets.h>
20#include <asm/export.h>
21#include <asm/tm.h>
22#include <asm/cputable.h>
23
24#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
25#define VCPU_GPRS_TM(reg) (((reg) * ULONG_SIZE) + VCPU_GPR_TM)
26
27/*
28 * Save transactional state and TM-related registers.
29 * Called with:
30 * - r3 pointing to the vcpu struct
31 * - r4 points to the MSR with current TS bits:
32 * 	(For HV KVM, it is VCPU_MSR ; For PR KVM, it is host MSR).
33 * This can modify all checkpointed registers, but
34 * restores r1, r2 before exit.
35 */
36_GLOBAL(__kvmppc_save_tm)
37	mflr	r0
38	std	r0, PPC_LR_STKOFF(r1)
39
40	/* Turn on TM. */
41	mfmsr	r8
42	li	r0, 1
43	rldimi	r8, r0, MSR_TM_LG, 63-MSR_TM_LG
44	ori     r8, r8, MSR_FP
45	oris    r8, r8, (MSR_VEC | MSR_VSX)@h
46	mtmsrd	r8
47
48	rldicl. r4, r4, 64 - MSR_TS_S_LG, 62
49	beq	1f	/* TM not active in guest. */
50
51	std	r1, HSTATE_SCRATCH2(r13)
52	std	r3, HSTATE_SCRATCH1(r13)
53
54#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
55BEGIN_FTR_SECTION
56	/* Emulation of the treclaim instruction needs TEXASR before treclaim */
57	mfspr	r6, SPRN_TEXASR
58	std	r6, VCPU_ORIG_TEXASR(r3)
59END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
60#endif
61
62	/* Clear the MSR RI since r1, r13 are all going to be foobar. */
63	li	r5, 0
64	mtmsrd	r5, 1
65
66	li	r3, TM_CAUSE_KVM_RESCHED
67
68	/* All GPRs are volatile at this point. */
69	TRECLAIM(R3)
70
71	/* Temporarily store r13 and r9 so we have some regs to play with */
72	SET_SCRATCH0(r13)
73	GET_PACA(r13)
74	std	r9, PACATMSCRATCH(r13)
75	ld	r9, HSTATE_SCRATCH1(r13)
76
77	/* Get a few more GPRs free. */
78	std	r29, VCPU_GPRS_TM(29)(r9)
79	std	r30, VCPU_GPRS_TM(30)(r9)
80	std	r31, VCPU_GPRS_TM(31)(r9)
81
82	/* Save away PPR and DSCR soon so don't run with user values. */
83	mfspr	r31, SPRN_PPR
84	HMT_MEDIUM
85	mfspr	r30, SPRN_DSCR
86#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
87	ld	r29, HSTATE_DSCR(r13)
88	mtspr	SPRN_DSCR, r29
89#endif
90
91	/* Save all but r9, r13 & r29-r31 */
92	reg = 0
93	.rept	29
94	.if (reg != 9) && (reg != 13)
95	std	reg, VCPU_GPRS_TM(reg)(r9)
96	.endif
97	reg = reg + 1
98	.endr
99	/* ... now save r13 */
100	GET_SCRATCH0(r4)
101	std	r4, VCPU_GPRS_TM(13)(r9)
102	/* ... and save r9 */
103	ld	r4, PACATMSCRATCH(r13)
104	std	r4, VCPU_GPRS_TM(9)(r9)
105
106	/* Reload stack pointer and TOC. */
107	ld	r1, HSTATE_SCRATCH2(r13)
108	ld	r2, PACATOC(r13)
109
110	/* Set MSR RI now we have r1 and r13 back. */
111	li	r5, MSR_RI
112	mtmsrd	r5, 1
113
114	/* Save away checkpinted SPRs. */
115	std	r31, VCPU_PPR_TM(r9)
116	std	r30, VCPU_DSCR_TM(r9)
117	mflr	r5
118	mfcr	r6
119	mfctr	r7
120	mfspr	r8, SPRN_AMR
121	mfspr	r10, SPRN_TAR
122	mfxer	r11
123	std	r5, VCPU_LR_TM(r9)
124	stw	r6, VCPU_CR_TM(r9)
125	std	r7, VCPU_CTR_TM(r9)
126	std	r8, VCPU_AMR_TM(r9)
127	std	r10, VCPU_TAR_TM(r9)
128	std	r11, VCPU_XER_TM(r9)
129
130	/* Restore r12 as trap number. */
131	lwz	r12, VCPU_TRAP(r9)
132
133	/* Save FP/VSX. */
134	addi	r3, r9, VCPU_FPRS_TM
135	bl	store_fp_state
136	addi	r3, r9, VCPU_VRS_TM
137	bl	store_vr_state
138	mfspr	r6, SPRN_VRSAVE
139	stw	r6, VCPU_VRSAVE_TM(r9)
1401:
141	/*
142	 * We need to save these SPRs after the treclaim so that the software
143	 * error code is recorded correctly in the TEXASR.  Also the user may
144	 * change these outside of a transaction, so they must always be
145	 * context switched.
146	 */
147	mfspr	r7, SPRN_TEXASR
148	std	r7, VCPU_TEXASR(r9)
14911:
150	mfspr	r5, SPRN_TFHAR
151	mfspr	r6, SPRN_TFIAR
152	std	r5, VCPU_TFHAR(r9)
153	std	r6, VCPU_TFIAR(r9)
154
155	ld	r0, PPC_LR_STKOFF(r1)
156	mtlr	r0
157	blr
158
159/*
160 * _kvmppc_save_tm_pr() is a wrapper around __kvmppc_save_tm(), so that it can
161 * be invoked from C function by PR KVM only.
162 */
163_GLOBAL(_kvmppc_save_tm_pr)
164	mflr	r5
165	std	r5, PPC_LR_STKOFF(r1)
166	stdu    r1, -SWITCH_FRAME_SIZE(r1)
167	SAVE_NVGPRS(r1)
168
169	/* save MSR since TM/math bits might be impacted
170	 * by __kvmppc_save_tm().
171	 */
172	mfmsr	r5
173	SAVE_GPR(5, r1)
174
175	/* also save DSCR/CR/TAR so that it can be recovered later */
176	mfspr   r6, SPRN_DSCR
177	SAVE_GPR(6, r1)
178
179	mfcr    r7
180	stw     r7, _CCR(r1)
181
182	mfspr   r8, SPRN_TAR
183	SAVE_GPR(8, r1)
184
185	bl	__kvmppc_save_tm
186
187	REST_GPR(8, r1)
188	mtspr   SPRN_TAR, r8
189
190	ld      r7, _CCR(r1)
191	mtcr	r7
192
193	REST_GPR(6, r1)
194	mtspr   SPRN_DSCR, r6
195
196	/* need preserve current MSR's MSR_TS bits */
197	REST_GPR(5, r1)
198	mfmsr   r6
199	rldicl  r6, r6, 64 - MSR_TS_S_LG, 62
200	rldimi  r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG
201	mtmsrd  r5
202
203	REST_NVGPRS(r1)
204	addi    r1, r1, SWITCH_FRAME_SIZE
205	ld	r5, PPC_LR_STKOFF(r1)
206	mtlr	r5
207	blr
208
209EXPORT_SYMBOL_GPL(_kvmppc_save_tm_pr);
210
211/*
212 * Restore transactional state and TM-related registers.
213 * Called with:
214 *  - r3 pointing to the vcpu struct.
215 *  - r4 is the guest MSR with desired TS bits:
216 * 	For HV KVM, it is VCPU_MSR
217 * 	For PR KVM, it is provided by caller
218 * This potentially modifies all checkpointed registers.
219 * It restores r1, r2 from the PACA.
220 */
221_GLOBAL(__kvmppc_restore_tm)
222	mflr	r0
223	std	r0, PPC_LR_STKOFF(r1)
224
225	/* Turn on TM/FP/VSX/VMX so we can restore them. */
226	mfmsr	r5
227	li	r6, MSR_TM >> 32
228	sldi	r6, r6, 32
229	or	r5, r5, r6
230	ori	r5, r5, MSR_FP
231	oris	r5, r5, (MSR_VEC | MSR_VSX)@h
232	mtmsrd	r5
233
234	/*
235	 * The user may change these outside of a transaction, so they must
236	 * always be context switched.
237	 */
238	ld	r5, VCPU_TFHAR(r3)
239	ld	r6, VCPU_TFIAR(r3)
240	ld	r7, VCPU_TEXASR(r3)
241	mtspr	SPRN_TFHAR, r5
242	mtspr	SPRN_TFIAR, r6
243	mtspr	SPRN_TEXASR, r7
244
245	mr	r5, r4
246	rldicl. r5, r5, 64 - MSR_TS_S_LG, 62
247	beqlr		/* TM not active in guest */
248	std	r1, HSTATE_SCRATCH2(r13)
249
250	/* Make sure the failure summary is set, otherwise we'll program check
251	 * when we trechkpt.  It's possible that this might have been not set
252	 * on a kvmppc_set_one_reg() call but we shouldn't let this crash the
253	 * host.
254	 */
255	oris	r7, r7, (TEXASR_FS)@h
256	mtspr	SPRN_TEXASR, r7
257
258	/*
259	 * We need to load up the checkpointed state for the guest.
260	 * We need to do this early as it will blow away any GPRs, VSRs and
261	 * some SPRs.
262	 */
263
264	mr	r31, r3
265	addi	r3, r31, VCPU_FPRS_TM
266	bl	load_fp_state
267	addi	r3, r31, VCPU_VRS_TM
268	bl	load_vr_state
269	mr	r3, r31
270	lwz	r7, VCPU_VRSAVE_TM(r3)
271	mtspr	SPRN_VRSAVE, r7
272
273	ld	r5, VCPU_LR_TM(r3)
274	lwz	r6, VCPU_CR_TM(r3)
275	ld	r7, VCPU_CTR_TM(r3)
276	ld	r8, VCPU_AMR_TM(r3)
277	ld	r9, VCPU_TAR_TM(r3)
278	ld	r10, VCPU_XER_TM(r3)
279	mtlr	r5
280	mtcr	r6
281	mtctr	r7
282	mtspr	SPRN_AMR, r8
283	mtspr	SPRN_TAR, r9
284	mtxer	r10
285
286	/*
287	 * Load up PPR and DSCR values but don't put them in the actual SPRs
288	 * till the last moment to avoid running with userspace PPR and DSCR for
289	 * too long.
290	 */
291	ld	r29, VCPU_DSCR_TM(r3)
292	ld	r30, VCPU_PPR_TM(r3)
293
294	std	r2, PACATMSCRATCH(r13) /* Save TOC */
295
296	/* Clear the MSR RI since r1, r13 are all going to be foobar. */
297	li	r5, 0
298	mtmsrd	r5, 1
299
300	/* Load GPRs r0-r28 */
301	reg = 0
302	.rept	29
303	ld	reg, VCPU_GPRS_TM(reg)(r31)
304	reg = reg + 1
305	.endr
306
307	mtspr	SPRN_DSCR, r29
308	mtspr	SPRN_PPR, r30
309
310	/* Load final GPRs */
311	ld	29, VCPU_GPRS_TM(29)(r31)
312	ld	30, VCPU_GPRS_TM(30)(r31)
313	ld	31, VCPU_GPRS_TM(31)(r31)
314
315	/* TM checkpointed state is now setup.  All GPRs are now volatile. */
316	TRECHKPT
317
318	/* Now let's get back the state we need. */
319	HMT_MEDIUM
320	GET_PACA(r13)
321#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
322	ld	r29, HSTATE_DSCR(r13)
323	mtspr	SPRN_DSCR, r29
324#endif
325	ld	r1, HSTATE_SCRATCH2(r13)
326	ld	r2, PACATMSCRATCH(r13)
327
328	/* Set the MSR RI since we have our registers back. */
329	li	r5, MSR_RI
330	mtmsrd	r5, 1
331	ld	r0, PPC_LR_STKOFF(r1)
332	mtlr	r0
333	blr
334
335/*
336 * _kvmppc_restore_tm_pr() is a wrapper around __kvmppc_restore_tm(), so that it
337 * can be invoked from C function by PR KVM only.
338 */
339_GLOBAL(_kvmppc_restore_tm_pr)
340	mflr	r5
341	std	r5, PPC_LR_STKOFF(r1)
342	stdu    r1, -SWITCH_FRAME_SIZE(r1)
343	SAVE_NVGPRS(r1)
344
345	/* save MSR to avoid TM/math bits change */
346	mfmsr	r5
347	SAVE_GPR(5, r1)
348
349	/* also save DSCR/CR/TAR so that it can be recovered later */
350	mfspr   r6, SPRN_DSCR
351	SAVE_GPR(6, r1)
352
353	mfcr    r7
354	stw     r7, _CCR(r1)
355
356	mfspr   r8, SPRN_TAR
357	SAVE_GPR(8, r1)
358
359	bl	__kvmppc_restore_tm
360
361	REST_GPR(8, r1)
362	mtspr   SPRN_TAR, r8
363
364	ld      r7, _CCR(r1)
365	mtcr	r7
366
367	REST_GPR(6, r1)
368	mtspr   SPRN_DSCR, r6
369
370	/* need preserve current MSR's MSR_TS bits */
371	REST_GPR(5, r1)
372	mfmsr   r6
373	rldicl  r6, r6, 64 - MSR_TS_S_LG, 62
374	rldimi  r5, r6, MSR_TS_S_LG, 63 - MSR_TS_T_LG
375	mtmsrd  r5
376
377	REST_NVGPRS(r1)
378	addi    r1, r1, SWITCH_FRAME_SIZE
379	ld	r5, PPC_LR_STKOFF(r1)
380	mtlr	r5
381	blr
382
383EXPORT_SYMBOL_GPL(_kvmppc_restore_tm_pr);
384#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
385