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#define MTMSR_EERI(reg)		mtmsrd	(reg),1
41
42	.globl	kvmppc_skip_interrupt
43kvmppc_skip_interrupt:
44	/*
45	 * Here all GPRs are unchanged from when the interrupt happened
46	 * except for r13, which is saved in SPRG_SCRATCH0.
47	 */
48	mfspr	r13, SPRN_SRR0
49	addi	r13, r13, 4
50	mtspr	SPRN_SRR0, r13
51	GET_SCRATCH0(r13)
52	rfid
53	b	.
54
55	.globl	kvmppc_skip_Hinterrupt
56kvmppc_skip_Hinterrupt:
57	/*
58	 * Here all GPRs are unchanged from when the interrupt happened
59	 * except for r13, which is saved in SPRG_SCRATCH0.
60	 */
61	mfspr	r13, SPRN_HSRR0
62	addi	r13, r13, 4
63	mtspr	SPRN_HSRR0, r13
64	GET_SCRATCH0(r13)
65	hrfid
66	b	.
67
68#elif defined(CONFIG_PPC_BOOK3S_32)
69
70#define FUNC(name)		name
71#define MTMSR_EERI(reg)		mtmsr	(reg)
72
73.macro INTERRUPT_TRAMPOLINE intno
74
75.global kvmppc_trampoline_\intno
76kvmppc_trampoline_\intno:
77
78	mtspr	SPRN_SPRG_SCRATCH0, r13		/* Save r13 */
79
80	/*
81	 * First thing to do is to find out if we're coming
82	 * from a KVM guest or a Linux process.
83	 *
84	 * To distinguish, we check a magic byte in the PACA/current
85	 */
86	mfspr	r13, SPRN_SPRG_THREAD
87	lwz	r13, THREAD_KVM_SVCPU(r13)
88	/* PPC32 can have a NULL pointer - let's check for that */
89	mtspr   SPRN_SPRG_SCRATCH1, r12		/* Save r12 */
90	mfcr	r12
91	cmpwi	r13, 0
92	bne	1f
932:	mtcr	r12
94	mfspr	r12, SPRN_SPRG_SCRATCH1
95	mfspr	r13, SPRN_SPRG_SCRATCH0		/* r13 = original r13 */
96	b	kvmppc_resume_\intno		/* Get back original handler */
97
981:	tophys(r13, r13)
99	stw	r12, HSTATE_SCRATCH1(r13)
100	mfspr	r12, SPRN_SPRG_SCRATCH1
101	stw	r12, HSTATE_SCRATCH0(r13)
102	lbz	r12, HSTATE_IN_GUEST(r13)
103	cmpwi	r12, KVM_GUEST_MODE_NONE
104	bne	..kvmppc_handler_hasmagic_\intno
105	/* No KVM guest? Then jump back to the Linux handler! */
106	lwz	r12, HSTATE_SCRATCH1(r13)
107	b	2b
108
109	/* Now we know we're handling a KVM guest */
110..kvmppc_handler_hasmagic_\intno:
111
112	/* Should we just skip the faulting instruction? */
113	cmpwi	r12, KVM_GUEST_MODE_SKIP
114	beq	kvmppc_handler_skip_ins
115
116	/* Let's store which interrupt we're handling */
117	li	r12, \intno
118
119	/* Jump into the SLB exit code that goes to the highmem handler */
120	b	kvmppc_handler_trampoline_exit
121
122.endm
123
124INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSTEM_RESET
125INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_MACHINE_CHECK
126INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DATA_STORAGE
127INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_INST_STORAGE
128INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_EXTERNAL
129INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALIGNMENT
130INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PROGRAM
131INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_FP_UNAVAIL
132INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DECREMENTER
133INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSCALL
134INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_TRACE
135INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PERFMON
136INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALTIVEC
137
138/*
139 * Bring us back to the faulting code, but skip the
140 * faulting instruction.
141 *
142 * This is a generic exit path from the interrupt
143 * trampolines above.
144 *
145 * Input Registers:
146 *
147 * R12            = free
148 * R13            = Shadow VCPU (PACA)
149 * HSTATE.SCRATCH0 = guest R12
150 * HSTATE.SCRATCH1 = guest CR
151 * SPRG_SCRATCH0  = guest R13
152 *
153 */
154kvmppc_handler_skip_ins:
155
156	/* Patch the IP to the next instruction */
157	mfsrr0	r12
158	addi	r12, r12, 4
159	mtsrr0	r12
160
161	/* Clean up all state */
162	lwz	r12, HSTATE_SCRATCH1(r13)
163	mtcr	r12
164	PPC_LL	r12, HSTATE_SCRATCH0(r13)
165	GET_SCRATCH0(r13)
166
167	/* And get back into the code */
168	RFI
169#endif
170
171/*
172 * Call kvmppc_handler_trampoline_enter in real mode
173 *
174 * On entry, r4 contains the guest shadow MSR
175 */
176_GLOBAL(kvmppc_entry_trampoline)
177	mfmsr	r5
178	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
179	toreal(r7)
180
181	li	r9, MSR_RI
182	ori	r9, r9, MSR_EE
183	andc	r9, r5, r9	/* Clear EE and RI in MSR value */
184	li	r6, MSR_IR | MSR_DR
185	ori	r6, r6, MSR_EE
186	andc	r6, r5, r6	/* Clear EE, DR and IR in MSR value */
187	MTMSR_EERI(r9)		/* Clear EE and RI in MSR */
188	mtsrr0	r7		/* before we set srr0/1 */
189	mtsrr1	r6
190	RFI
191
192#if defined(CONFIG_PPC_BOOK3S_32)
193#define STACK_LR	INT_FRAME_SIZE+4
194
195/* load_up_xxx have to run with MSR_DR=0 on Book3S_32 */
196#define MSR_EXT_START						\
197	PPC_STL	r20, _NIP(r1);					\
198	mfmsr	r20;						\
199	LOAD_REG_IMMEDIATE(r3, MSR_DR|MSR_EE);			\
200	andc	r3,r20,r3;		/* Disable DR,EE */	\
201	mtmsr	r3;						\
202	sync
203
204#define MSR_EXT_END						\
205	mtmsr	r20;			/* Enable DR,EE */	\
206	sync;							\
207	PPC_LL	r20, _NIP(r1)
208
209#elif defined(CONFIG_PPC_BOOK3S_64)
210#define STACK_LR	_LINK
211#define MSR_EXT_START
212#define MSR_EXT_END
213#endif
214
215/*
216 * Activate current's external feature (FPU/Altivec/VSX)
217 */
218#define define_load_up(what) 					\
219								\
220_GLOBAL(kvmppc_load_up_ ## what);				\
221	PPC_STLU r1, -INT_FRAME_SIZE(r1);			\
222	mflr	r3;						\
223	PPC_STL	r3, STACK_LR(r1);				\
224	MSR_EXT_START;						\
225								\
226	bl	FUNC(load_up_ ## what);				\
227								\
228	MSR_EXT_END;						\
229	PPC_LL	r3, STACK_LR(r1);				\
230	mtlr	r3;						\
231	addi	r1, r1, INT_FRAME_SIZE;				\
232	blr
233
234define_load_up(fpu)
235#ifdef CONFIG_ALTIVEC
236define_load_up(altivec)
237#endif
238#ifdef CONFIG_VSX
239define_load_up(vsx)
240#endif
241
242#include "book3s_segment.S"
243