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	mfsrr0	r12
127	addi	r12, r12, 4
128	mtsrr0	r12
129
130	/* Clean up all state */
131	lwz	r12, HSTATE_SCRATCH1(r13)
132	mtcr	r12
133	PPC_LL	r12, HSTATE_SCRATCH0(r13)
134	GET_SCRATCH0(r13)
135
136	/* And get back into the code */
137	RFI_TO_KERNEL
138#endif
139
140/*
141 * Call kvmppc_handler_trampoline_enter in real mode
142 *
143 * On entry, r4 contains the guest shadow MSR
144 * MSR.EE has to be 0 when calling this function
145 */
146_GLOBAL_TOC(kvmppc_entry_trampoline)
147	mfmsr	r5
148	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
149	toreal(r7)
150
151	li	r6, MSR_IR | MSR_DR
152	andc	r6, r5, r6	/* Clear DR and IR in MSR value */
153	/*
154	 * Set EE in HOST_MSR so that it's enabled when we get into our
155	 * C exit handler function.
156	 */
157	ori	r5, r5, MSR_EE
158	mtsrr0	r7
159	mtsrr1	r6
160	RFI_TO_KERNEL
161
162#include "book3s_segment.S"
163