1/* 2 * Copyright (C) 2012,2013 - 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/linkage.h> 19 20#include <asm/assembler.h> 21#include <asm/kvm_arm.h> 22#include <asm/kvm_mmu.h> 23#include <asm/pgtable-hwdef.h> 24#include <asm/sysreg.h> 25 26 .text 27 .pushsection .hyp.idmap.text, "ax" 28 29 .align 11 30 31ENTRY(__kvm_hyp_init) 32 ventry __invalid // Synchronous EL2t 33 ventry __invalid // IRQ EL2t 34 ventry __invalid // FIQ EL2t 35 ventry __invalid // Error EL2t 36 37 ventry __invalid // Synchronous EL2h 38 ventry __invalid // IRQ EL2h 39 ventry __invalid // FIQ EL2h 40 ventry __invalid // Error EL2h 41 42 ventry __do_hyp_init // Synchronous 64-bit EL1 43 ventry __invalid // IRQ 64-bit EL1 44 ventry __invalid // FIQ 64-bit EL1 45 ventry __invalid // Error 64-bit EL1 46 47 ventry __invalid // Synchronous 32-bit EL1 48 ventry __invalid // IRQ 32-bit EL1 49 ventry __invalid // FIQ 32-bit EL1 50 ventry __invalid // Error 32-bit EL1 51 52__invalid: 53 b . 54 55 /* 56 * x0: HYP pgd 57 * x1: HYP stack 58 * x2: HYP vectors 59 */ 60__do_hyp_init: 61 62 msr ttbr0_el2, x0 63 64 mrs x4, tcr_el1 65 ldr x5, =TCR_EL2_MASK 66 and x4, x4, x5 67 mov x5, #TCR_EL2_RES1 68 orr x4, x4, x5 69 70#ifndef CONFIG_ARM64_VA_BITS_48 71 /* 72 * If we are running with VA_BITS < 48, we may be running with an extra 73 * level of translation in the ID map. This is only the case if system 74 * RAM is out of range for the currently configured page size and number 75 * of translation levels, in which case we will also need the extra 76 * level for the HYP ID map, or we won't be able to enable the EL2 MMU. 77 * 78 * However, at EL2, there is only one TTBR register, and we can't switch 79 * between translation tables *and* update TCR_EL2.T0SZ at the same 80 * time. Bottom line: we need the extra level in *both* our translation 81 * tables. 82 * 83 * So use the same T0SZ value we use for the ID map. 84 */ 85 ldr_l x5, idmap_t0sz 86 bfi x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH 87#endif 88 /* 89 * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in 90 * TCR_EL2. 91 */ 92 mrs x5, ID_AA64MMFR0_EL1 93 bfi x4, x5, #16, #3 94 95 msr tcr_el2, x4 96 97 mrs x4, mair_el1 98 msr mair_el2, x4 99 isb 100 101 /* Invalidate the stale TLBs from Bootloader */ 102 tlbi alle2 103 dsb sy 104 105 /* 106 * Preserve all the RES1 bits while setting the default flags, 107 * as well as the EE bit on BE. Drop the A flag since the compiler 108 * is allowed to generate unaligned accesses. 109 */ 110 ldr x4, =(SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) 111CPU_BE( orr x4, x4, #SCTLR_ELx_EE) 112 msr sctlr_el2, x4 113 isb 114 115 /* Set the stack and new vectors */ 116 kern_hyp_va x1 117 mov sp, x1 118 kern_hyp_va x2 119 msr vbar_el2, x2 120 121 /* Hello, World! */ 122 eret 123ENDPROC(__kvm_hyp_init) 124 125 /* 126 * Reset kvm back to the hyp stub. 127 */ 128ENTRY(__kvm_hyp_reset) 129 /* We're now in idmap, disable MMU */ 130 mrs x0, sctlr_el2 131 ldr x1, =SCTLR_ELx_FLAGS 132 bic x0, x0, x1 // Clear SCTL_M and etc 133 msr sctlr_el2, x0 134 isb 135 136 /* Install stub vectors */ 137 adr_l x0, __hyp_stub_vectors 138 msr vbar_el2, x0 139 140 eret 141ENDPROC(__kvm_hyp_reset) 142 143 .ltorg 144 145 .popsection 146