linux/arch/arm64/kvm/vgic-v3-switch.S
Marc Zyngier 754d377260 arm64: KVM: vgic: add GICv3 world switch
Introduce the GICv3 world switch code used to save/restore the
GICv3 context.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-07-11 04:57:37 -07:00

268 lines
6.3 KiB
ArmAsm

/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/linkage.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <asm/assembler.h>
#include <asm/memory.h>
#include <asm/asm-offsets.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_arm.h>
.text
.pushsection .hyp.text, "ax"
/*
* We store LRs in reverse order to let the CPU deal with streaming
* access. Use this macro to make it look saner...
*/
#define LR_OFFSET(n) (VGIC_V3_CPU_LR + (15 - n) * 8)
/*
* Save the VGIC CPU state into memory
* x0: Register pointing to VCPU struct
* Do not corrupt x1!!!
*/
.macro save_vgic_v3_state
// Compute the address of struct vgic_cpu
add x3, x0, #VCPU_VGIC_CPU
// Make sure stores to the GIC via the memory mapped interface
// are now visible to the system register interface
dsb st
// Save all interesting registers
mrs x4, ICH_HCR_EL2
mrs x5, ICH_VMCR_EL2
mrs x6, ICH_MISR_EL2
mrs x7, ICH_EISR_EL2
mrs x8, ICH_ELSR_EL2
str w4, [x3, #VGIC_V3_CPU_HCR]
str w5, [x3, #VGIC_V3_CPU_VMCR]
str w6, [x3, #VGIC_V3_CPU_MISR]
str w7, [x3, #VGIC_V3_CPU_EISR]
str w8, [x3, #VGIC_V3_CPU_ELRSR]
msr ICH_HCR_EL2, xzr
mrs x21, ICH_VTR_EL2
mvn w22, w21
ubfiz w23, w22, 2, 4 // w23 = (15 - ListRegs) * 4
adr x24, 1f
add x24, x24, x23
br x24
1:
mrs x20, ICH_LR15_EL2
mrs x19, ICH_LR14_EL2
mrs x18, ICH_LR13_EL2
mrs x17, ICH_LR12_EL2
mrs x16, ICH_LR11_EL2
mrs x15, ICH_LR10_EL2
mrs x14, ICH_LR9_EL2
mrs x13, ICH_LR8_EL2
mrs x12, ICH_LR7_EL2
mrs x11, ICH_LR6_EL2
mrs x10, ICH_LR5_EL2
mrs x9, ICH_LR4_EL2
mrs x8, ICH_LR3_EL2
mrs x7, ICH_LR2_EL2
mrs x6, ICH_LR1_EL2
mrs x5, ICH_LR0_EL2
adr x24, 1f
add x24, x24, x23
br x24
1:
str x20, [x3, #LR_OFFSET(15)]
str x19, [x3, #LR_OFFSET(14)]
str x18, [x3, #LR_OFFSET(13)]
str x17, [x3, #LR_OFFSET(12)]
str x16, [x3, #LR_OFFSET(11)]
str x15, [x3, #LR_OFFSET(10)]
str x14, [x3, #LR_OFFSET(9)]
str x13, [x3, #LR_OFFSET(8)]
str x12, [x3, #LR_OFFSET(7)]
str x11, [x3, #LR_OFFSET(6)]
str x10, [x3, #LR_OFFSET(5)]
str x9, [x3, #LR_OFFSET(4)]
str x8, [x3, #LR_OFFSET(3)]
str x7, [x3, #LR_OFFSET(2)]
str x6, [x3, #LR_OFFSET(1)]
str x5, [x3, #LR_OFFSET(0)]
tbnz w21, #29, 6f // 6 bits
tbz w21, #30, 5f // 5 bits
// 7 bits
mrs x20, ICH_AP0R3_EL2
str w20, [x3, #(VGIC_V3_CPU_AP0R + 3*4)]
mrs x19, ICH_AP0R2_EL2
str w19, [x3, #(VGIC_V3_CPU_AP0R + 2*4)]
6: mrs x18, ICH_AP0R1_EL2
str w18, [x3, #(VGIC_V3_CPU_AP0R + 1*4)]
5: mrs x17, ICH_AP0R0_EL2
str w17, [x3, #VGIC_V3_CPU_AP0R]
tbnz w21, #29, 6f // 6 bits
tbz w21, #30, 5f // 5 bits
// 7 bits
mrs x20, ICH_AP1R3_EL2
str w20, [x3, #(VGIC_V3_CPU_AP1R + 3*4)]
mrs x19, ICH_AP1R2_EL2
str w19, [x3, #(VGIC_V3_CPU_AP1R + 2*4)]
6: mrs x18, ICH_AP1R1_EL2
str w18, [x3, #(VGIC_V3_CPU_AP1R + 1*4)]
5: mrs x17, ICH_AP1R0_EL2
str w17, [x3, #VGIC_V3_CPU_AP1R]
// Restore SRE_EL1 access and re-enable SRE at EL1.
mrs x5, ICC_SRE_EL2
orr x5, x5, #ICC_SRE_EL2_ENABLE
msr ICC_SRE_EL2, x5
isb
mov x5, #1
msr ICC_SRE_EL1, x5
.endm
/*
* Restore the VGIC CPU state from memory
* x0: Register pointing to VCPU struct
*/
.macro restore_vgic_v3_state
// Disable SRE_EL1 access. Necessary, otherwise
// ICH_VMCR_EL2.VFIQEn becomes one, and FIQ happens...
msr ICC_SRE_EL1, xzr
isb
// Compute the address of struct vgic_cpu
add x3, x0, #VCPU_VGIC_CPU
// Restore all interesting registers
ldr w4, [x3, #VGIC_V3_CPU_HCR]
ldr w5, [x3, #VGIC_V3_CPU_VMCR]
msr ICH_HCR_EL2, x4
msr ICH_VMCR_EL2, x5
mrs x21, ICH_VTR_EL2
tbnz w21, #29, 6f // 6 bits
tbz w21, #30, 5f // 5 bits
// 7 bits
ldr w20, [x3, #(VGIC_V3_CPU_AP1R + 3*4)]
msr ICH_AP1R3_EL2, x20
ldr w19, [x3, #(VGIC_V3_CPU_AP1R + 2*4)]
msr ICH_AP1R2_EL2, x19
6: ldr w18, [x3, #(VGIC_V3_CPU_AP1R + 1*4)]
msr ICH_AP1R1_EL2, x18
5: ldr w17, [x3, #VGIC_V3_CPU_AP1R]
msr ICH_AP1R0_EL2, x17
tbnz w21, #29, 6f // 6 bits
tbz w21, #30, 5f // 5 bits
// 7 bits
ldr w20, [x3, #(VGIC_V3_CPU_AP0R + 3*4)]
msr ICH_AP0R3_EL2, x20
ldr w19, [x3, #(VGIC_V3_CPU_AP0R + 2*4)]
msr ICH_AP0R2_EL2, x19
6: ldr w18, [x3, #(VGIC_V3_CPU_AP0R + 1*4)]
msr ICH_AP0R1_EL2, x18
5: ldr w17, [x3, #VGIC_V3_CPU_AP0R]
msr ICH_AP0R0_EL2, x17
and w22, w21, #0xf
mvn w22, w21
ubfiz w23, w22, 2, 4 // w23 = (15 - ListRegs) * 4
adr x24, 1f
add x24, x24, x23
br x24
1:
ldr x20, [x3, #LR_OFFSET(15)]
ldr x19, [x3, #LR_OFFSET(14)]
ldr x18, [x3, #LR_OFFSET(13)]
ldr x17, [x3, #LR_OFFSET(12)]
ldr x16, [x3, #LR_OFFSET(11)]
ldr x15, [x3, #LR_OFFSET(10)]
ldr x14, [x3, #LR_OFFSET(9)]
ldr x13, [x3, #LR_OFFSET(8)]
ldr x12, [x3, #LR_OFFSET(7)]
ldr x11, [x3, #LR_OFFSET(6)]
ldr x10, [x3, #LR_OFFSET(5)]
ldr x9, [x3, #LR_OFFSET(4)]
ldr x8, [x3, #LR_OFFSET(3)]
ldr x7, [x3, #LR_OFFSET(2)]
ldr x6, [x3, #LR_OFFSET(1)]
ldr x5, [x3, #LR_OFFSET(0)]
adr x24, 1f
add x24, x24, x23
br x24
1:
msr ICH_LR15_EL2, x20
msr ICH_LR14_EL2, x19
msr ICH_LR13_EL2, x18
msr ICH_LR12_EL2, x17
msr ICH_LR11_EL2, x16
msr ICH_LR10_EL2, x15
msr ICH_LR9_EL2, x14
msr ICH_LR8_EL2, x13
msr ICH_LR7_EL2, x12
msr ICH_LR6_EL2, x11
msr ICH_LR5_EL2, x10
msr ICH_LR4_EL2, x9
msr ICH_LR3_EL2, x8
msr ICH_LR2_EL2, x7
msr ICH_LR1_EL2, x6
msr ICH_LR0_EL2, x5
// Ensure that the above will have reached the
// (re)distributors. This ensure the guest will read
// the correct values from the memory-mapped interface.
isb
dsb sy
// Prevent the guest from touching the GIC system registers
mrs x5, ICC_SRE_EL2
and x5, x5, #~ICC_SRE_EL2_ENABLE
msr ICC_SRE_EL2, x5
.endm
ENTRY(__save_vgic_v3_state)
save_vgic_v3_state
ret
ENDPROC(__save_vgic_v3_state)
ENTRY(__restore_vgic_v3_state)
restore_vgic_v3_state
ret
ENDPROC(__restore_vgic_v3_state)
ENTRY(__vgic_v3_get_ich_vtr_el2)
mrs x0, ICH_VTR_EL2
ret
ENDPROC(__vgic_v3_get_ich_vtr_el2)
.popsection