genode/repos/base-hw/src/core/spec/arm_v7/virtualization/mode_transition.s

176 lines
6.2 KiB
ArmAsm

/*
* \brief Transition between virtual/host mode
* \author Stefan Kalkowski
* \date 2015-02-16
*/
/*
* Copyright (C) 2015 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
/* core includes */
.include "macros.s"
.macro _vm_exit exception_type
str r0, [sp]
mrc p15, 4, r0, c1, c1, 0 /* read HCR register */
tst r0, #1 /* check VM bit */
ldreq r0, [sp]
beq _host_to_vm
mov r0, #\exception_type
str r0, [sp, #17*4]
b _vm_to_host
.endm /* _vm_exit */
.section .text
/* space for a copy of the host context */
.p2align 2
.global _vt_host_context_ptr
_vt_host_context_ptr:
.space CONTEXT_PTR_SIZE
/* space for a vm context-pointer per CPU */
.p2align 2
.global _vt_vm_context_ptr
_vt_vm_context_ptr:
.rept NR_OF_CPUS
.space CONTEXT_PTR_SIZE
.endr
_host_to_vm:
msr elr_hyp, r2
msr spsr_cxfs, r3 /* load cpsr */
mcrr p15, 6, r5, r6, c2 /* write VTTBR */
mcr p15, 0, r7, c1, c0, 0 /* write SCTRL */
mcr p15, 4, r8, c1, c1, 3 /* write HSTR */
mcr p15, 4, r9, c1, c1, 0 /* write HCR register */
mcr p15, 0, r12, c2, c0, 2 /* write TTBRC */
sub sp, r0, #46*4
ldm r0!, {r1-r12}
mcr p15, 0, r1, c2, c0, 0 /* write TTBR0 */
mcr p15, 0, r2, c2, c0, 1 /* write TTBR1 */
mcr p15, 0, r3, c10, c2, 0 /* write PRRR */
mcr p15, 0, r4, c10, c2, 1 /* write NMRR */
mcr p15, 0, r5, c3, c0, 0 /* write DACR */
mcr p15, 0, r6, c5, c0, 0 /* write DFSR */
mcr p15, 0, r7, c5, c0, 1 /* write IFSR */
mcr p15, 0, r8, c5, c1, 0 /* write ADFSR */
mcr p15, 0, r9, c5, c1, 1 /* write AIFSR */
mcr p15, 0, r10, c6, c0, 0 /* write DFAR */
mcr p15, 0, r11, c6, c0, 2 /* write IFAR */
mcr p15, 0, r12, c13, c0, 1 /* write CIDR */
ldm r0, {r1-r4}
mcr p15, 0, r1, c13, c0, 2 /* write TLS1 */
mcr p15, 0, r2, c13, c0, 3 /* write TLS2 */
mcr p15, 0, r3, c13, c0, 4 /* write TLS3 */
mcr p15, 0, r4, c1, c0, 2 /* write CPACR */
ldmia sp, {r0-r12} /* load vm's r0-r12 */
eret
_vm_to_host:
add r0, sp, #1*4
stmia r0, {r1-r12} /* save regs r1-r12 */
mov r1, #0
mcrr p15, 6, r1, r1, c2 /* write VTTBR */
mcr p15, 4, r1, c1, c1, 0 /* write HCR register */
mcr p15, 4, r1, c1, c1, 3 /* write HSTR register */
mcr p15, 0, r1, c1, c0, 2 /* write CPACR */
mrs r1, ELR_hyp /* read ip */
mrs r2, spsr /* read cpsr */
mrc p15, 0, r3, c1, c0, 0 /* read SCTRL */
mrc p15, 4, r4, c5, c2, 0 /* read HSR */
mrc p15, 4, r5, c6, c0, 4 /* read HPFAR */
mrc p15, 4, r6, c6, c0, 0 /* read HDFAR */
mrc p15, 4, r7, c6, c0, 2 /* read HIFAR */
mrc p15, 0, r8, c2, c0, 2 /* read TTBRC */
mrc p15, 0, r9, c2, c0, 0 /* read TTBR0 */
mrc p15, 0, r10, c2, c0, 1 /* read TTBR1 */
add r0, sp, #40*4 /* offset SCTRL */
stm r0!, {r3-r10}
add r0, r0, #3*4
mrc p15, 0, r3, c5, c0, 0 /* read DFSR */
mrc p15, 0, r4, c5, c0, 1 /* read IFSR */
mrc p15, 0, r5, c5, c1, 0 /* read ADFSR */
mrc p15, 0, r6, c5, c1, 1 /* read AIFSR */
mrc p15, 0, r7, c6, c0, 0 /* read DFAR */
mrc p15, 0, r8, c6, c0, 2 /* read IFAR */
mrc p15, 0, r9, c13, c0, 1 /* read CIDR */
mrc p15, 0, r10, c13, c0, 2 /* read TLS1 */
mrc p15, 0, r11, c13, c0, 3 /* read TLS2 */
mrc p15, 0, r12, c13, c0, 4 /* read TLS3 */
stm r0, {r3-r12}
add r0, sp, #13*4
ldr r3, _vt_host_context_ptr
_restore_kernel_sp r3, r4, r5
add r3, r3, #CIDR_OFFSET
ldmia r3, {r4-r9}
_switch_protection_domain r0, r4, r5
mcr p15, 0, r6, c1, c0, 0 /* write SCTRL */
mcr p15, 0, r7, c2, c0, 2 /* write TTBRC */
mcr p15, 0, r8, c10, c2, 0 /* write MAIR0 */
mcr p15, 0, r9, c3, c0, 0 /* write DACR */
cps #SVC_MODE
stmia r0, {r13-r14}^ /* save user regs sp,lr */
add r0, r0, #2*4
stmia r0!, {r1-r2} /* save ip, cpsr */
add r0, r0, #1*4
_save_bank UND_MODE /* save undefined banks */
_save_bank SVC_MODE /* save supervisor banks */
_save_bank ABT_MODE /* save abort banks */
_save_bank IRQ_MODE /* save irq banks */
_save_bank FIQ_MODE /* save fiq banks */
stmia r0!, {r8-r12} /* save fiq r8-r12 */
cps #SVC_MODE
ldr r0, _vt_host_context_ptr
_restore_kernel_sp r0, r1, r2 /* apply host kernel sp */
add r1, r0, #LR_OFFSET /* apply host kernel lr */
ldm r1, {lr, pc}
/* host kernel must jump to this point to switch to a vm */
.global _vt_vm_entry
_vt_vm_entry:
_get_client_context_ptr r0, lr, _vt_vm_context_ptr
add r0, r0, #SP_OFFSET
ldm r0, {r13 - r14}^
add r0, r0, #2*4
ldmia r0!, {r2 - r4}
_restore_bank UND_MODE
_restore_bank SVC_MODE
_restore_bank ABT_MODE
_restore_bank IRQ_MODE
_restore_bank FIQ_MODE
ldmia r0!, {r8 - r12}
cps #SVC_MODE
ldm r0!, {r5 - r12}
hvc #0
/*
* On virtualization exceptions the CPU has to jump to one of the following
* 7 entry vectors to switch to a kernel context.
*/
.p2align 5
.global _vt_host_entry
_vt_host_entry:
b _vt_rst_entry
b _vt_und_entry /* undefined instruction */
b _vt_svc_entry /* hypervisor call */
b _vt_pab_entry /* prefetch abort */
b _vt_dab_entry /* data abort */
b _vt_trp_entry /* hypervisor trap */
b _vt_irq_entry /* interrupt request */
_vm_exit 7 /* fast interrupt request */
_vt_rst_entry: _vm_exit 1
_vt_und_entry: _vm_exit 2
_vt_svc_entry: _vm_exit 3
_vt_pab_entry: _vm_exit 4
_vt_dab_entry: _vm_exit 5
_vt_irq_entry: _vm_exit 6
_vt_trp_entry: _vm_exit 8