xref: /openbmc/linux/arch/arm64/kvm/hyp/vgic-v3-sr.c (revision 8c749ce9)
1 /*
2  * Copyright (C) 2012-2015 - ARM Ltd
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <linux/compiler.h>
19 #include <linux/irqchip/arm-gic-v3.h>
20 #include <linux/kvm_host.h>
21 
22 #include <asm/kvm_mmu.h>
23 
24 #include "hyp.h"
25 
26 #define vtr_to_max_lr_idx(v)		((v) & 0xf)
27 #define vtr_to_nr_pri_bits(v)		(((u32)(v) >> 29) + 1)
28 
29 #define read_gicreg(r)							\
30 	({								\
31 		u64 reg;						\
32 		asm volatile("mrs_s %0, " __stringify(r) : "=r" (reg));	\
33 		reg;							\
34 	})
35 
36 #define write_gicreg(v,r)						\
37 	do {								\
38 		u64 __val = (v);					\
39 		asm volatile("msr_s " __stringify(r) ", %0" : : "r" (__val));\
40 	} while (0)
41 
42 /* vcpu is already in the HYP VA space */
43 void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
44 {
45 	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
46 	u64 val;
47 	u32 max_lr_idx, nr_pri_bits;
48 
49 	/*
50 	 * Make sure stores to the GIC via the memory mapped interface
51 	 * are now visible to the system register interface.
52 	 */
53 	dsb(st);
54 
55 	cpu_if->vgic_vmcr  = read_gicreg(ICH_VMCR_EL2);
56 	cpu_if->vgic_misr  = read_gicreg(ICH_MISR_EL2);
57 	cpu_if->vgic_eisr  = read_gicreg(ICH_EISR_EL2);
58 	cpu_if->vgic_elrsr = read_gicreg(ICH_ELSR_EL2);
59 
60 	write_gicreg(0, ICH_HCR_EL2);
61 	val = read_gicreg(ICH_VTR_EL2);
62 	max_lr_idx = vtr_to_max_lr_idx(val);
63 	nr_pri_bits = vtr_to_nr_pri_bits(val);
64 
65 	switch (max_lr_idx) {
66 	case 15:
67 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(15)] = read_gicreg(ICH_LR15_EL2);
68 	case 14:
69 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(14)] = read_gicreg(ICH_LR14_EL2);
70 	case 13:
71 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(13)] = read_gicreg(ICH_LR13_EL2);
72 	case 12:
73 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(12)] = read_gicreg(ICH_LR12_EL2);
74 	case 11:
75 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(11)] = read_gicreg(ICH_LR11_EL2);
76 	case 10:
77 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(10)] = read_gicreg(ICH_LR10_EL2);
78 	case 9:
79 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(9)] = read_gicreg(ICH_LR9_EL2);
80 	case 8:
81 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(8)] = read_gicreg(ICH_LR8_EL2);
82 	case 7:
83 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(7)] = read_gicreg(ICH_LR7_EL2);
84 	case 6:
85 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(6)] = read_gicreg(ICH_LR6_EL2);
86 	case 5:
87 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(5)] = read_gicreg(ICH_LR5_EL2);
88 	case 4:
89 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(4)] = read_gicreg(ICH_LR4_EL2);
90 	case 3:
91 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(3)] = read_gicreg(ICH_LR3_EL2);
92 	case 2:
93 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(2)] = read_gicreg(ICH_LR2_EL2);
94 	case 1:
95 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(1)] = read_gicreg(ICH_LR1_EL2);
96 	case 0:
97 		cpu_if->vgic_lr[VGIC_V3_LR_INDEX(0)] = read_gicreg(ICH_LR0_EL2);
98 	}
99 
100 	switch (nr_pri_bits) {
101 	case 7:
102 		cpu_if->vgic_ap0r[3] = read_gicreg(ICH_AP0R3_EL2);
103 		cpu_if->vgic_ap0r[2] = read_gicreg(ICH_AP0R2_EL2);
104 	case 6:
105 		cpu_if->vgic_ap0r[1] = read_gicreg(ICH_AP0R1_EL2);
106 	default:
107 		cpu_if->vgic_ap0r[0] = read_gicreg(ICH_AP0R0_EL2);
108 	}
109 
110 	switch (nr_pri_bits) {
111 	case 7:
112 		cpu_if->vgic_ap1r[3] = read_gicreg(ICH_AP1R3_EL2);
113 		cpu_if->vgic_ap1r[2] = read_gicreg(ICH_AP1R2_EL2);
114 	case 6:
115 		cpu_if->vgic_ap1r[1] = read_gicreg(ICH_AP1R1_EL2);
116 	default:
117 		cpu_if->vgic_ap1r[0] = read_gicreg(ICH_AP1R0_EL2);
118 	}
119 
120 	val = read_gicreg(ICC_SRE_EL2);
121 	write_gicreg(val | ICC_SRE_EL2_ENABLE, ICC_SRE_EL2);
122 	isb(); /* Make sure ENABLE is set at EL2 before setting SRE at EL1 */
123 	write_gicreg(1, ICC_SRE_EL1);
124 }
125 
126 void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
127 {
128 	struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
129 	u64 val;
130 	u32 max_lr_idx, nr_pri_bits;
131 
132 	/*
133 	 * VFIQEn is RES1 if ICC_SRE_EL1.SRE is 1. This causes a
134 	 * Group0 interrupt (as generated in GICv2 mode) to be
135 	 * delivered as a FIQ to the guest, with potentially fatal
136 	 * consequences. So we must make sure that ICC_SRE_EL1 has
137 	 * been actually programmed with the value we want before
138 	 * starting to mess with the rest of the GIC.
139 	 */
140 	write_gicreg(cpu_if->vgic_sre, ICC_SRE_EL1);
141 	isb();
142 
143 	write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
144 	write_gicreg(cpu_if->vgic_vmcr, ICH_VMCR_EL2);
145 
146 	val = read_gicreg(ICH_VTR_EL2);
147 	max_lr_idx = vtr_to_max_lr_idx(val);
148 	nr_pri_bits = vtr_to_nr_pri_bits(val);
149 
150 	switch (nr_pri_bits) {
151 	case 7:
152 		 write_gicreg(cpu_if->vgic_ap1r[3], ICH_AP1R3_EL2);
153 		 write_gicreg(cpu_if->vgic_ap1r[2], ICH_AP1R2_EL2);
154 	case 6:
155 		 write_gicreg(cpu_if->vgic_ap1r[1], ICH_AP1R1_EL2);
156 	default:
157 		 write_gicreg(cpu_if->vgic_ap1r[0], ICH_AP1R0_EL2);
158 	}
159 
160 	switch (nr_pri_bits) {
161 	case 7:
162 		 write_gicreg(cpu_if->vgic_ap0r[3], ICH_AP0R3_EL2);
163 		 write_gicreg(cpu_if->vgic_ap0r[2], ICH_AP0R2_EL2);
164 	case 6:
165 		 write_gicreg(cpu_if->vgic_ap0r[1], ICH_AP0R1_EL2);
166 	default:
167 		 write_gicreg(cpu_if->vgic_ap0r[0], ICH_AP0R0_EL2);
168 	}
169 
170 	switch (max_lr_idx) {
171 	case 15:
172 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(15)], ICH_LR15_EL2);
173 	case 14:
174 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(14)], ICH_LR14_EL2);
175 	case 13:
176 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(13)], ICH_LR13_EL2);
177 	case 12:
178 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(12)], ICH_LR12_EL2);
179 	case 11:
180 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(11)], ICH_LR11_EL2);
181 	case 10:
182 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(10)], ICH_LR10_EL2);
183 	case 9:
184 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(9)], ICH_LR9_EL2);
185 	case 8:
186 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(8)], ICH_LR8_EL2);
187 	case 7:
188 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(7)], ICH_LR7_EL2);
189 	case 6:
190 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(6)], ICH_LR6_EL2);
191 	case 5:
192 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(5)], ICH_LR5_EL2);
193 	case 4:
194 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(4)], ICH_LR4_EL2);
195 	case 3:
196 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(3)], ICH_LR3_EL2);
197 	case 2:
198 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(2)], ICH_LR2_EL2);
199 	case 1:
200 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(1)], ICH_LR1_EL2);
201 	case 0:
202 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(0)], ICH_LR0_EL2);
203 	}
204 
205 	/*
206 	 * Ensures that the above will have reached the
207 	 * (re)distributors. This ensure the guest will read the
208 	 * correct values from the memory-mapped interface.
209 	 */
210 	isb();
211 	dsb(sy);
212 
213 	/*
214 	 * Prevent the guest from touching the GIC system registers if
215 	 * SRE isn't enabled for GICv3 emulation.
216 	 */
217 	if (!cpu_if->vgic_sre) {
218 		write_gicreg(read_gicreg(ICC_SRE_EL2) & ~ICC_SRE_EL2_ENABLE,
219 			     ICC_SRE_EL2);
220 	}
221 }
222 
223 static u64 __hyp_text __vgic_v3_read_ich_vtr_el2(void)
224 {
225 	return read_gicreg(ICH_VTR_EL2);
226 }
227 
228 __alias(__vgic_v3_read_ich_vtr_el2) u64 __vgic_v3_get_ich_vtr_el2(void);
229