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#if defined(_CALL_ELF) && _CALL_ELF == 2
40#define FUNC(name) 		name
41#else
42#define FUNC(name) 		GLUE(.,name)
43#endif
44
45#elif defined(CONFIG_PPC_BOOK3S_32)
46
47#define FUNC(name)		name
48
49.macro INTERRUPT_TRAMPOLINE intno
50
51.global kvmppc_trampoline_\intno
52kvmppc_trampoline_\intno:
53
54	mtspr	SPRN_SPRG_SCRATCH0, r13		/* Save r13 */
55
56	/*
57	 * First thing to do is to find out if we're coming
58	 * from a KVM guest or a Linux process.
59	 *
60	 * To distinguish, we check a magic byte in the PACA/current
61	 */
62	mfspr	r13, SPRN_SPRG_THREAD
63	lwz	r13, THREAD_KVM_SVCPU(r13)
64	/* PPC32 can have a NULL pointer - let's check for that */
65	mtspr   SPRN_SPRG_SCRATCH1, r12		/* Save r12 */
66	mfcr	r12
67	cmpwi	r13, 0
68	bne	1f
692:	mtcr	r12
70	mfspr	r12, SPRN_SPRG_SCRATCH1
71	mfspr	r13, SPRN_SPRG_SCRATCH0		/* r13 = original r13 */
72	b	kvmppc_resume_\intno		/* Get back original handler */
73
741:	tophys(r13, r13)
75	stw	r12, HSTATE_SCRATCH1(r13)
76	mfspr	r12, SPRN_SPRG_SCRATCH1
77	stw	r12, HSTATE_SCRATCH0(r13)
78	lbz	r12, HSTATE_IN_GUEST(r13)
79	cmpwi	r12, KVM_GUEST_MODE_NONE
80	bne	..kvmppc_handler_hasmagic_\intno
81	/* No KVM guest? Then jump back to the Linux handler! */
82	lwz	r12, HSTATE_SCRATCH1(r13)
83	b	2b
84
85	/* Now we know we're handling a KVM guest */
86..kvmppc_handler_hasmagic_\intno:
87
88	/* Should we just skip the faulting instruction? */
89	cmpwi	r12, KVM_GUEST_MODE_SKIP
90	beq	kvmppc_handler_skip_ins
91
92	/* Let's store which interrupt we're handling */
93	li	r12, \intno
94
95	/* Jump into the SLB exit code that goes to the highmem handler */
96	b	kvmppc_handler_trampoline_exit
97
98.endm
99
100INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSTEM_RESET
101INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_MACHINE_CHECK
102INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DATA_STORAGE
103INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_INST_STORAGE
104INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_EXTERNAL
105INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALIGNMENT
106INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PROGRAM
107INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_FP_UNAVAIL
108INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DECREMENTER
109INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSCALL
110INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_TRACE
111INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PERFMON
112INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALTIVEC
113
114/*
115 * Bring us back to the faulting code, but skip the
116 * faulting instruction.
117 *
118 * This is a generic exit path from the interrupt
119 * trampolines above.
120 *
121 * Input Registers:
122 *
123 * R12            = free
124 * R13            = Shadow VCPU (PACA)
125 * HSTATE.SCRATCH0 = guest R12
126 * HSTATE.SCRATCH1 = guest CR
127 * SPRG_SCRATCH0  = guest R13
128 *
129 */
130kvmppc_handler_skip_ins:
131
132	/* Patch the IP to the next instruction */
133	mfsrr0	r12
134	addi	r12, r12, 4
135	mtsrr0	r12
136
137	/* Clean up all state */
138	lwz	r12, HSTATE_SCRATCH1(r13)
139	mtcr	r12
140	PPC_LL	r12, HSTATE_SCRATCH0(r13)
141	GET_SCRATCH0(r13)
142
143	/* And get back into the code */
144	RFI
145#endif
146
147/*
148 * Call kvmppc_handler_trampoline_enter in real mode
149 *
150 * On entry, r4 contains the guest shadow MSR
151 * MSR.EE has to be 0 when calling this function
152 */
153_GLOBAL_TOC(kvmppc_entry_trampoline)
154	mfmsr	r5
155	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
156	toreal(r7)
157
158	li	r6, MSR_IR | MSR_DR
159	andc	r6, r5, r6	/* Clear DR and IR in MSR value */
160	/*
161	 * Set EE in HOST_MSR so that it's enabled when we get into our
162	 * C exit handler function.
163	 */
164	ori	r5, r5, MSR_EE
165	mtsrr0	r7
166	mtsrr1	r6
167	RFI
168
169#include "book3s_segment.S"
170