1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *
4 * Copyright SUSE Linux Products GmbH 2009
5 *
6 * Authors: Alexander Graf <agraf@suse.de>
7 */
8
9#include <asm/ppc_asm.h>
10#include <asm/kvm_asm.h>
11#include <asm/reg.h>
12#include <asm/mmu.h>
13#include <asm/page.h>
14#include <asm/asm-offsets.h>
15#include <asm/asm-compat.h>
16
17#ifdef CONFIG_PPC_BOOK3S_64
18#include <asm/exception-64s.h>
19#endif
20
21/*****************************************************************************
22 * *
23 * Real Mode handlers that need to be in low physical memory *
24 * *
25 ****************************************************************************/
26
27#if defined(CONFIG_PPC_BOOK3S_64)
28
29#ifdef CONFIG_PPC64_ELF_ABI_V2
30#define FUNC(name) name
31#else
32#define FUNC(name) GLUE(.,name)
33#endif
34
35#elif defined(CONFIG_PPC_BOOK3S_32)
36
37#define FUNC(name) name
38
39#define RFI_TO_KERNEL rfi
40#define RFI_TO_GUEST rfi
41
42.macro INTERRUPT_TRAMPOLINE intno
43
44.global kvmppc_trampoline_\intno
45kvmppc_trampoline_\intno:
46
47 mtspr SPRN_SPRG_SCRATCH0, r13 /* Save r13 */
48
49 /*
50 * First thing to do is to find out if we're coming
51 * from a KVM guest or a Linux process.
52 *
53 * To distinguish, we check a magic byte in the PACA/current
54 */
55 mfspr r13, SPRN_SPRG_THREAD
56 lwz r13, THREAD_KVM_SVCPU(r13)
57 /* PPC32 can have a NULL pointer - let's check for that */
58 mtspr SPRN_SPRG_SCRATCH1, r12 /* Save r12 */
59 mfcr r12
60 cmpwi r13, 0
61 bne 1f
622: mtcr r12
63 mfspr r12, SPRN_SPRG_SCRATCH1
64 mfspr r13, SPRN_SPRG_SCRATCH0 /* r13 = original r13 */
65 b kvmppc_resume_\intno /* Get back original handler */
66
671: tophys(r13, r13)
68 stw r12, HSTATE_SCRATCH1(r13)
69 mfspr r12, SPRN_SPRG_SCRATCH1
70 stw r12, HSTATE_SCRATCH0(r13)
71 lbz r12, HSTATE_IN_GUEST(r13)
72 cmpwi r12, KVM_GUEST_MODE_NONE
73 bne ..kvmppc_handler_hasmagic_\intno
74 /* No KVM guest? Then jump back to the Linux handler! */
75 lwz r12, HSTATE_SCRATCH1(r13)
76 b 2b
77
78 /* Now we know we're handling a KVM guest */
79..kvmppc_handler_hasmagic_\intno:
80
81 /* Should we just skip the faulting instruction? */
82 cmpwi r12, KVM_GUEST_MODE_SKIP
83 beq kvmppc_handler_skip_ins
84
85 /* Let's store which interrupt we're handling */
86 li r12, \intno
87
88 /* Jump into the SLB exit code that goes to the highmem handler */
89 b kvmppc_handler_trampoline_exit
90
91.endm
92
93INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSTEM_RESET
94INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_MACHINE_CHECK
95INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DATA_STORAGE
96INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_INST_STORAGE
97INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_EXTERNAL
98INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALIGNMENT
99INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PROGRAM
100INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_FP_UNAVAIL
101INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DECREMENTER
102INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSCALL
103INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_TRACE
104INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PERFMON
105INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALTIVEC
106
107/*
108 * Bring us back to the faulting code, but skip the
109 * faulting instruction.
110 *
111 * This is a generic exit path from the interrupt
112 * trampolines above.
113 *
114 * Input Registers:
115 *
116 * R12 = free
117 * R13 = Shadow VCPU (PACA)
118 * HSTATE.SCRATCH0 = guest R12
119 * HSTATE.SCRATCH1 = guest CR
120 * SPRG_SCRATCH0 = guest R13
121 *
122 */
123kvmppc_handler_skip_ins:
124
125 /* Patch the IP to the next instruction */
126 /* Note that prefixed instructions are disabled in PR KVM for now */
127 mfsrr0 r12
128 addi r12, r12, 4
129 mtsrr0 r12
130
131 /* Clean up all state */
132 lwz r12, HSTATE_SCRATCH1(r13)
133 mtcr r12
134 PPC_LL r12, HSTATE_SCRATCH0(r13)
135 GET_SCRATCH0(r13)
136
137 /* And get back into the code */
138 RFI_TO_KERNEL
139#endif
140
141/*
142 * Call kvmppc_handler_trampoline_enter in real mode
143 *
144 * On entry, r4 contains the guest shadow MSR
145 * MSR.EE has to be 0 when calling this function
146 */
147_GLOBAL_TOC(kvmppc_entry_trampoline)
148 mfmsr r5
149 LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
150 toreal(r7)
151
152 li r6, MSR_IR | MSR_DR
153 andc r6, r5, r6 /* Clear DR and IR in MSR value */
154 /*
155 * Set EE in HOST_MSR so that it's enabled when we get into our
156 * C exit handler function.
157 */
158 ori r5, r5, MSR_EE
159 mtsrr0 r7
160 mtsrr1 r6
161 RFI_TO_KERNEL
162
163#include "book3s_segment.S"
164

source code of linux/arch/powerpc/kvm/book3s_rmhandlers.S