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/page.h>
24#include <asm/asm-offsets.h>
25
26#ifdef CONFIG_PPC_BOOK3S_64
27#include <asm/exception-64s.h>
28#endif
29
30/*****************************************************************************
31 *                                                                           *
32 *        Real Mode handlers that need to be in low physical memory          *
33 *                                                                           *
34 ****************************************************************************/
35
36#if defined(CONFIG_PPC_BOOK3S_64)
37
38#define LOAD_SHADOW_VCPU(reg)	GET_PACA(reg)
39#define MSR_NOIRQ		MSR_KERNEL & ~(MSR_IR | MSR_DR)
40#define FUNC(name) 		GLUE(.,name)
41
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
54kvmppc_skip_Hinterrupt:
55	/*
56	 * Here all GPRs are unchanged from when the interrupt happened
57	 * except for r13, which is saved in SPRG_SCRATCH0.
58	 */
59	mfspr	r13, SPRN_HSRR0
60	addi	r13, r13, 4
61	mtspr	SPRN_HSRR0, r13
62	GET_SCRATCH0(r13)
63	hrfid
64	b	.
65
66#elif defined(CONFIG_PPC_BOOK3S_32)
67
68#define MSR_NOIRQ		MSR_KERNEL
69#define FUNC(name)		name
70
71.macro INTERRUPT_TRAMPOLINE intno
72
73.global kvmppc_trampoline_\intno
74kvmppc_trampoline_\intno:
75
76	mtspr	SPRN_SPRG_SCRATCH0, r13		/* Save r13 */
77
78	/*
79	 * First thing to do is to find out if we're coming
80	 * from a KVM guest or a Linux process.
81	 *
82	 * To distinguish, we check a magic byte in the PACA/current
83	 */
84	mfspr	r13, SPRN_SPRG_THREAD
85	lwz	r13, THREAD_KVM_SVCPU(r13)
86	/* PPC32 can have a NULL pointer - let's check for that */
87	mtspr   SPRN_SPRG_SCRATCH1, r12		/* Save r12 */
88	mfcr	r12
89	cmpwi	r13, 0
90	bne	1f
912:	mtcr	r12
92	mfspr	r12, SPRN_SPRG_SCRATCH1
93	mfspr	r13, SPRN_SPRG_SCRATCH0		/* r13 = original r13 */
94	b	kvmppc_resume_\intno		/* Get back original handler */
95
961:	tophys(r13, r13)
97	stw	r12, HSTATE_SCRATCH1(r13)
98	mfspr	r12, SPRN_SPRG_SCRATCH1
99	stw	r12, HSTATE_SCRATCH0(r13)
100	lbz	r12, HSTATE_IN_GUEST(r13)
101	cmpwi	r12, KVM_GUEST_MODE_NONE
102	bne	..kvmppc_handler_hasmagic_\intno
103	/* No KVM guest? Then jump back to the Linux handler! */
104	lwz	r12, HSTATE_SCRATCH1(r13)
105	b	2b
106
107	/* Now we know we're handling a KVM guest */
108..kvmppc_handler_hasmagic_\intno:
109
110	/* Should we just skip the faulting instruction? */
111	cmpwi	r12, KVM_GUEST_MODE_SKIP
112	beq	kvmppc_handler_skip_ins
113
114	/* Let's store which interrupt we're handling */
115	li	r12, \intno
116
117	/* Jump into the SLB exit code that goes to the highmem handler */
118	b	kvmppc_handler_trampoline_exit
119
120.endm
121
122INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSTEM_RESET
123INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_MACHINE_CHECK
124INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DATA_STORAGE
125INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_INST_STORAGE
126INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_EXTERNAL
127INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALIGNMENT
128INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PROGRAM
129INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_FP_UNAVAIL
130INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DECREMENTER
131INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSCALL
132INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_TRACE
133INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PERFMON
134INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALTIVEC
135
136/*
137 * Bring us back to the faulting code, but skip the
138 * faulting instruction.
139 *
140 * This is a generic exit path from the interrupt
141 * trampolines above.
142 *
143 * Input Registers:
144 *
145 * R12            = free
146 * R13            = Shadow VCPU (PACA)
147 * HSTATE.SCRATCH0 = guest R12
148 * HSTATE.SCRATCH1 = guest CR
149 * SPRG_SCRATCH0  = guest R13
150 *
151 */
152kvmppc_handler_skip_ins:
153
154	/* Patch the IP to the next instruction */
155	mfsrr0	r12
156	addi	r12, r12, 4
157	mtsrr0	r12
158
159	/* Clean up all state */
160	lwz	r12, HSTATE_SCRATCH1(r13)
161	mtcr	r12
162	PPC_LL	r12, HSTATE_SCRATCH0(r13)
163	GET_SCRATCH0(r13)
164
165	/* And get back into the code */
166	RFI
167#endif
168
169/*
170 * This trampoline brings us back to a real mode handler
171 *
172 * Input Registers:
173 *
174 * R5 = SRR0
175 * R6 = SRR1
176 * LR = real-mode IP
177 *
178 */
179.global kvmppc_handler_lowmem_trampoline
180kvmppc_handler_lowmem_trampoline:
181
182	mtsrr0	r5
183	mtsrr1	r6
184	blr
185kvmppc_handler_lowmem_trampoline_end:
186
187/*
188 * Call a function in real mode
189 *
190 * Input Registers:
191 *
192 * R3 = function
193 * R4 = MSR
194 * R5 = scratch register
195 *
196 */
197_GLOBAL(kvmppc_rmcall)
198	LOAD_REG_IMMEDIATE(r5, MSR_NOIRQ)
199	mtmsr	r5		/* Disable relocation and interrupts, so mtsrr
200				   doesn't get interrupted */
201	sync
202	mtsrr0	r3
203	mtsrr1	r4
204	RFI
205
206#if defined(CONFIG_PPC_BOOK3S_32)
207#define STACK_LR	INT_FRAME_SIZE+4
208
209/* load_up_xxx have to run with MSR_DR=0 on Book3S_32 */
210#define MSR_EXT_START						\
211	PPC_STL	r20, _NIP(r1);					\
212	mfmsr	r20;						\
213	LOAD_REG_IMMEDIATE(r3, MSR_DR|MSR_EE);			\
214	andc	r3,r20,r3;		/* Disable DR,EE */	\
215	mtmsr	r3;						\
216	sync
217
218#define MSR_EXT_END						\
219	mtmsr	r20;			/* Enable DR,EE */	\
220	sync;							\
221	PPC_LL	r20, _NIP(r1)
222
223#elif defined(CONFIG_PPC_BOOK3S_64)
224#define STACK_LR	_LINK
225#define MSR_EXT_START
226#define MSR_EXT_END
227#endif
228
229/*
230 * Activate current's external feature (FPU/Altivec/VSX)
231 */
232#define define_load_up(what) 					\
233								\
234_GLOBAL(kvmppc_load_up_ ## what);				\
235	PPC_STLU r1, -INT_FRAME_SIZE(r1);			\
236	mflr	r3;						\
237	PPC_STL	r3, STACK_LR(r1);				\
238	MSR_EXT_START;						\
239								\
240	bl	FUNC(load_up_ ## what);				\
241								\
242	MSR_EXT_END;						\
243	PPC_LL	r3, STACK_LR(r1);				\
244	mtlr	r3;						\
245	addi	r1, r1, INT_FRAME_SIZE;				\
246	blr
247
248define_load_up(fpu)
249#ifdef CONFIG_ALTIVEC
250define_load_up(altivec)
251#endif
252#ifdef CONFIG_VSX
253define_load_up(vsx)
254#endif
255
256#include "book3s_segment.S"
257