1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * Copyright (C) 2012,2013 - ARM Ltd 4 * Author: Marc Zyngier <marc.zyngier@arm.com> 5 */ 6 7#include <linux/linkage.h> 8 9#include <asm/alternative.h> 10#include <asm/assembler.h> 11#include <asm/kvm_arm.h> 12#include <asm/kvm_mmu.h> 13#include <asm/pgtable-hwdef.h> 14#include <asm/sysreg.h> 15#include <asm/virt.h> 16 17 .text 18 .pushsection .hyp.idmap.text, "ax" 19 20 .align 11 21 22SYM_CODE_START(__kvm_hyp_init) 23 ventry __invalid // Synchronous EL2t 24 ventry __invalid // IRQ EL2t 25 ventry __invalid // FIQ EL2t 26 ventry __invalid // Error EL2t 27 28 ventry __invalid // Synchronous EL2h 29 ventry __invalid // IRQ EL2h 30 ventry __invalid // FIQ EL2h 31 ventry __invalid // Error EL2h 32 33 ventry __do_hyp_init // Synchronous 64-bit EL1 34 ventry __invalid // IRQ 64-bit EL1 35 ventry __invalid // FIQ 64-bit EL1 36 ventry __invalid // Error 64-bit EL1 37 38 ventry __invalid // Synchronous 32-bit EL1 39 ventry __invalid // IRQ 32-bit EL1 40 ventry __invalid // FIQ 32-bit EL1 41 ventry __invalid // Error 32-bit EL1 42 43__invalid: 44 b . 45 46 /* 47 * x0: HYP pgd 48 * x1: HYP stack 49 * x2: HYP vectors 50 * x3: per-CPU offset 51 */ 52__do_hyp_init: 53 /* Check for a stub HVC call */ 54 cmp x0, #HVC_STUB_HCALL_NR 55 b.lo __kvm_handle_stub_hvc 56 57 phys_to_ttbr x4, x0 58alternative_if ARM64_HAS_CNP 59 orr x4, x4, #TTBR_CNP_BIT 60alternative_else_nop_endif 61 msr ttbr0_el2, x4 62 63 mrs x4, tcr_el1 64 mov_q x5, TCR_EL2_MASK 65 and x4, x4, x5 66 mov x5, #TCR_EL2_RES1 67 orr x4, x4, x5 68 69 /* 70 * The ID map may be configured to use an extended virtual address 71 * range. This is only the case if system RAM is out of range for the 72 * currently configured page size and VA_BITS, in which case we will 73 * also need the extended virtual range for the HYP ID map, or we won't 74 * be able to enable the EL2 MMU. 75 * 76 * However, at EL2, there is only one TTBR register, and we can't switch 77 * between translation tables *and* update TCR_EL2.T0SZ at the same 78 * time. Bottom line: we need to use the extended range with *both* our 79 * translation tables. 80 * 81 * So use the same T0SZ value we use for the ID map. 82 */ 83 ldr_l x5, idmap_t0sz 84 bfi x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH 85 86 /* 87 * Set the PS bits in TCR_EL2. 88 */ 89 tcr_compute_pa_size x4, #TCR_EL2_PS_SHIFT, x5, x6 90 91 msr tcr_el2, x4 92 93 mrs x4, mair_el1 94 msr mair_el2, x4 95 isb 96 97 /* Invalidate the stale TLBs from Bootloader */ 98 tlbi alle2 99 dsb sy 100 101 /* 102 * Preserve all the RES1 bits while setting the default flags, 103 * as well as the EE bit on BE. Drop the A flag since the compiler 104 * is allowed to generate unaligned accesses. 105 */ 106 mov_q x4, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) 107CPU_BE( orr x4, x4, #SCTLR_ELx_EE) 108alternative_if ARM64_HAS_ADDRESS_AUTH 109 mov_q x5, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ 110 SCTLR_ELx_ENDA | SCTLR_ELx_ENDB) 111 orr x4, x4, x5 112alternative_else_nop_endif 113 msr sctlr_el2, x4 114 isb 115 116 /* Set the stack and new vectors */ 117 kern_hyp_va x1 118 mov sp, x1 119 msr vbar_el2, x2 120 121 /* Set tpidr_el2 for use by HYP */ 122 msr tpidr_el2, x3 123 124 /* Hello, World! */ 125 eret 126SYM_CODE_END(__kvm_hyp_init) 127 128SYM_CODE_START(__kvm_handle_stub_hvc) 129 cmp x0, #HVC_SOFT_RESTART 130 b.ne 1f 131 132 /* This is where we're about to jump, staying at EL2 */ 133 msr elr_el2, x1 134 mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h) 135 msr spsr_el2, x0 136 137 /* Shuffle the arguments, and don't come back */ 138 mov x0, x2 139 mov x1, x3 140 mov x2, x4 141 b reset 142 1431: cmp x0, #HVC_RESET_VECTORS 144 b.ne 1f 145 146 /* 147 * Set the HVC_RESET_VECTORS return code before entering the common 148 * path so that we do not clobber x0-x2 in case we are coming via 149 * HVC_SOFT_RESTART. 150 */ 151 mov x0, xzr 152reset: 153 /* Reset kvm back to the hyp stub. */ 154 mrs x5, sctlr_el2 155 mov_q x6, SCTLR_ELx_FLAGS 156 bic x5, x5, x6 // Clear SCTL_M and etc 157 pre_disable_mmu_workaround 158 msr sctlr_el2, x5 159 isb 160 161 /* Install stub vectors */ 162 adr_l x5, __hyp_stub_vectors 163 msr vbar_el2, x5 164 eret 165 1661: /* Bad stub call */ 167 mov_q x0, HVC_STUB_ERR 168 eret 169 170SYM_CODE_END(__kvm_handle_stub_hvc) 171 172 .popsection 173