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 2009
16 *
17 * Authors: Alexander Graf <agraf@suse.de>
18 */
19
20#include <asm/ppc_asm.h>
21#include <asm/kvm_asm.h>
22#include <asm/reg.h>
23#include <asm/mmu.h>
24#include <asm/page.h>
25#include <asm/asm-offsets.h>
26
27#ifdef CONFIG_PPC_BOOK3S_64
28#include <asm/exception-64s.h>
29#endif
30
31/*****************************************************************************
32 *                                                                           *
33 *        Real Mode handlers that need to be in low physical memory          *
34 *                                                                           *
35 ****************************************************************************/
36
37#if defined(CONFIG_PPC_BOOK3S_64)
38
39#define FUNC(name) 		GLUE(.,name)
40
41	.globl	kvmppc_skip_interrupt
42kvmppc_skip_interrupt:
43	/*
44	 * Here all GPRs are unchanged from when the interrupt happened
45	 * except for r13, which is saved in SPRG_SCRATCH0.
46	 */
47	mfspr	r13, SPRN_SRR0
48	addi	r13, r13, 4
49	mtspr	SPRN_SRR0, r13
50	GET_SCRATCH0(r13)
51	rfid
52	b	.
53
54	.globl	kvmppc_skip_Hinterrupt
55kvmppc_skip_Hinterrupt:
56	/*
57	 * Here all GPRs are unchanged from when the interrupt happened
58	 * except for r13, which is saved in SPRG_SCRATCH0.
59	 */
60	mfspr	r13, SPRN_HSRR0
61	addi	r13, r13, 4
62	mtspr	SPRN_HSRR0, r13
63	GET_SCRATCH0(r13)
64	hrfid
65	b	.
66
67#elif defined(CONFIG_PPC_BOOK3S_32)
68
69#define FUNC(name)		name
70#define MTMSR_EERI(reg)		mtmsr	(reg)
71
72.macro INTERRUPT_TRAMPOLINE intno
73
74.global kvmppc_trampoline_\intno
75kvmppc_trampoline_\intno:
76
77	mtspr	SPRN_SPRG_SCRATCH0, r13		/* Save r13 */
78
79	/*
80	 * First thing to do is to find out if we're coming
81	 * from a KVM guest or a Linux process.
82	 *
83	 * To distinguish, we check a magic byte in the PACA/current
84	 */
85	mfspr	r13, SPRN_SPRG_THREAD
86	lwz	r13, THREAD_KVM_SVCPU(r13)
87	/* PPC32 can have a NULL pointer - let's check for that */
88	mtspr   SPRN_SPRG_SCRATCH1, r12		/* Save r12 */
89	mfcr	r12
90	cmpwi	r13, 0
91	bne	1f
922:	mtcr	r12
93	mfspr	r12, SPRN_SPRG_SCRATCH1
94	mfspr	r13, SPRN_SPRG_SCRATCH0		/* r13 = original r13 */
95	b	kvmppc_resume_\intno		/* Get back original handler */
96
971:	tophys(r13, r13)
98	stw	r12, HSTATE_SCRATCH1(r13)
99	mfspr	r12, SPRN_SPRG_SCRATCH1
100	stw	r12, HSTATE_SCRATCH0(r13)
101	lbz	r12, HSTATE_IN_GUEST(r13)
102	cmpwi	r12, KVM_GUEST_MODE_NONE
103	bne	..kvmppc_handler_hasmagic_\intno
104	/* No KVM guest? Then jump back to the Linux handler! */
105	lwz	r12, HSTATE_SCRATCH1(r13)
106	b	2b
107
108	/* Now we know we're handling a KVM guest */
109..kvmppc_handler_hasmagic_\intno:
110
111	/* Should we just skip the faulting instruction? */
112	cmpwi	r12, KVM_GUEST_MODE_SKIP
113	beq	kvmppc_handler_skip_ins
114
115	/* Let's store which interrupt we're handling */
116	li	r12, \intno
117
118	/* Jump into the SLB exit code that goes to the highmem handler */
119	b	kvmppc_handler_trampoline_exit
120
121.endm
122
123INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSTEM_RESET
124INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_MACHINE_CHECK
125INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DATA_STORAGE
126INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_INST_STORAGE
127INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_EXTERNAL
128INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALIGNMENT
129INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PROGRAM
130INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_FP_UNAVAIL
131INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DECREMENTER
132INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSCALL
133INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_TRACE
134INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PERFMON
135INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALTIVEC
136
137/*
138 * Bring us back to the faulting code, but skip the
139 * faulting instruction.
140 *
141 * This is a generic exit path from the interrupt
142 * trampolines above.
143 *
144 * Input Registers:
145 *
146 * R12            = free
147 * R13            = Shadow VCPU (PACA)
148 * HSTATE.SCRATCH0 = guest R12
149 * HSTATE.SCRATCH1 = guest CR
150 * SPRG_SCRATCH0  = guest R13
151 *
152 */
153kvmppc_handler_skip_ins:
154
155	/* Patch the IP to the next instruction */
156	mfsrr0	r12
157	addi	r12, r12, 4
158	mtsrr0	r12
159
160	/* Clean up all state */
161	lwz	r12, HSTATE_SCRATCH1(r13)
162	mtcr	r12
163	PPC_LL	r12, HSTATE_SCRATCH0(r13)
164	GET_SCRATCH0(r13)
165
166	/* And get back into the code */
167	RFI
168#endif
169
170/*
171 * Call kvmppc_handler_trampoline_enter in real mode
172 *
173 * On entry, r4 contains the guest shadow MSR
174 */
175_GLOBAL(kvmppc_entry_trampoline)
176	mfmsr	r5
177	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
178	toreal(r7)
179
180	li	r9, MSR_RI
181	ori	r9, r9, MSR_EE
182	andc	r9, r5, r9	/* Clear EE and RI in MSR value */
183	li	r6, MSR_IR | MSR_DR
184	ori	r6, r6, MSR_EE
185	andc	r6, r5, r6	/* Clear EE, DR and IR in MSR value */
186	MTMSR_EERI(r9)		/* Clear EE and RI in MSR */
187	mtsrr0	r7		/* before we set srr0/1 */
188	mtsrr1	r6
189	RFI
190
191#if defined(CONFIG_PPC_BOOK3S_32)
192#define STACK_LR	INT_FRAME_SIZE+4
193
194/* load_up_xxx have to run with MSR_DR=0 on Book3S_32 */
195#define MSR_EXT_START						\
196	PPC_STL	r20, _NIP(r1);					\
197	mfmsr	r20;						\
198	LOAD_REG_IMMEDIATE(r3, MSR_DR|MSR_EE);			\
199	andc	r3,r20,r3;		/* Disable DR,EE */	\
200	mtmsr	r3;						\
201	sync
202
203#define MSR_EXT_END						\
204	mtmsr	r20;			/* Enable DR,EE */	\
205	sync;							\
206	PPC_LL	r20, _NIP(r1)
207
208#elif defined(CONFIG_PPC_BOOK3S_64)
209#define STACK_LR	_LINK
210#define MSR_EXT_START
211#define MSR_EXT_END
212#endif
213
214/*
215 * Activate current's external feature (FPU/Altivec/VSX)
216 */
217#define define_load_up(what) 					\
218								\
219_GLOBAL(kvmppc_load_up_ ## what);				\
220	PPC_STLU r1, -INT_FRAME_SIZE(r1);			\
221	mflr	r3;						\
222	PPC_STL	r3, STACK_LR(r1);				\
223	MSR_EXT_START;						\
224								\
225	bl	FUNC(load_up_ ## what);				\
226								\
227	MSR_EXT_END;						\
228	PPC_LL	r3, STACK_LR(r1);				\
229	mtlr	r3;						\
230	addi	r1, r1, INT_FRAME_SIZE;				\
231	blr
232
233define_load_up(fpu)
234#ifdef CONFIG_ALTIVEC
235define_load_up(altivec)
236#endif
237#ifdef CONFIG_VSX
238define_load_up(vsx)
239#endif
240
241#include "book3s_segment.S"
242