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Diffstat (limited to 'arch/arm64/kvm/hyp-init.S')
| -rw-r--r-- | arch/arm64/kvm/hyp-init.S | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S new file mode 100644 index 000000000..178ba2248 --- /dev/null +++ b/arch/arm64/kvm/hyp-init.S @@ -0,0 +1,145 @@ +/* + * 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 <asm/assembler.h> +#include <asm/kvm_arm.h> +#include <asm/kvm_mmu.h> +#include <asm/pgtable-hwdef.h> + + .text + .pushsection .hyp.idmap.text, "ax" + + .align 11 + +ENTRY(__kvm_hyp_init) + ventry __invalid // Synchronous EL2t + ventry __invalid // IRQ EL2t + ventry __invalid // FIQ EL2t + ventry __invalid // Error EL2t + + ventry __invalid // Synchronous EL2h + ventry __invalid // IRQ EL2h + ventry __invalid // FIQ EL2h + ventry __invalid // Error EL2h + + ventry __do_hyp_init // Synchronous 64-bit EL1 + ventry __invalid // IRQ 64-bit EL1 + ventry __invalid // FIQ 64-bit EL1 + ventry __invalid // Error 64-bit EL1 + + ventry __invalid // Synchronous 32-bit EL1 + ventry __invalid // IRQ 32-bit EL1 + ventry __invalid // FIQ 32-bit EL1 + ventry __invalid // Error 32-bit EL1 + +__invalid: + b . + + /* + * x0: HYP boot pgd + * x1: HYP pgd + * x2: HYP stack + * x3: HYP vectors + */ +__do_hyp_init: + + msr ttbr0_el2, x0 + + mrs x4, tcr_el1 + ldr x5, =TCR_EL2_MASK + and x4, x4, x5 + ldr x5, =TCR_EL2_FLAGS + orr x4, x4, x5 + +#ifndef CONFIG_ARM64_VA_BITS_48 + /* + * If we are running with VA_BITS < 48, we may be running with an extra + * level of translation in the ID map. This is only the case if system + * RAM is out of range for the currently configured page size and number + * of translation levels, in which case we will also need the extra + * level for the HYP ID map, or we won't be able to enable the EL2 MMU. + * + * However, at EL2, there is only one TTBR register, and we can't switch + * between translation tables *and* update TCR_EL2.T0SZ at the same + * time. Bottom line: we need the extra level in *both* our translation + * tables. + * + * So use the same T0SZ value we use for the ID map. + */ + ldr_l x5, idmap_t0sz + bfi x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH +#endif + msr tcr_el2, x4 + + ldr x4, =VTCR_EL2_FLAGS + /* + * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in + * VTCR_EL2. + */ + mrs x5, ID_AA64MMFR0_EL1 + bfi x4, x5, #16, #3 + msr vtcr_el2, x4 + + mrs x4, mair_el1 + msr mair_el2, x4 + isb + + /* Invalidate the stale TLBs from Bootloader */ + tlbi alle2 + dsb sy + + mrs x4, sctlr_el2 + and x4, x4, #SCTLR_EL2_EE // preserve endianness of EL2 + ldr x5, =SCTLR_EL2_FLAGS + orr x4, x4, x5 + msr sctlr_el2, x4 + isb + + /* Skip the trampoline dance if we merged the boot and runtime PGDs */ + cmp x0, x1 + b.eq merged + + /* MMU is now enabled. Get ready for the trampoline dance */ + ldr x4, =TRAMPOLINE_VA + adr x5, target + bfi x4, x5, #0, #PAGE_SHIFT + br x4 + +target: /* We're now in the trampoline code, switch page tables */ + msr ttbr0_el2, x1 + isb + + /* Invalidate the old TLBs */ + tlbi alle2 + dsb sy + +merged: + /* Set the stack and new vectors */ + kern_hyp_va x2 + mov sp, x2 + kern_hyp_va x3 + msr vbar_el2, x3 + + /* Hello, World! */ + eret +ENDPROC(__kvm_hyp_init) + + .ltorg + + .popsection |