1/* 2 * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7#include <arch.h> 8#include <asm_macros.S> 9#include <common/bl_common.h> 10#include <context.h> 11#include <cortex_a76.h> 12#include <cpu_macros.S> 13#include <plat_macros.S> 14#include <services/arm_arch_svc.h> 15 16#if !DYNAMIC_WORKAROUND_CVE_2018_3639 17#error Cortex A76 requires DYNAMIC_WORKAROUND_CVE_2018_3639=1 18#endif 19 20#define ESR_EL3_A64_SMC0 0x5e000000 21#define ESR_EL3_A32_SMC0 0x4e000000 22 23 /* 24 * This macro applies the mitigation for CVE-2018-3639. 25 * It implements a fash path where `SMCCC_ARCH_WORKAROUND_2` 26 * SMC calls from a lower EL running in AArch32 or AArch64 27 * will go through the fast and return early. 28 * 29 * The macro saves x2-x3 to the context. In the fast path 30 * x0-x3 registers do not need to be restored as the calling 31 * context will have saved them. 32 */ 33 .macro apply_cve_2018_3639_wa _is_sync_exception _esr_el3_val 34 stp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] 35 36 .if \_is_sync_exception 37 /* 38 * Ensure SMC is coming from A64/A32 state on #0 39 * with W0 = SMCCC_ARCH_WORKAROUND_2 40 * 41 * This sequence evaluates as: 42 * (W0==SMCCC_ARCH_WORKAROUND_2) ? (ESR_EL3==SMC#0) : (NE) 43 * allowing use of a single branch operation 44 */ 45 orr w2, wzr, #SMCCC_ARCH_WORKAROUND_2 46 cmp x0, x2 47 mrs x3, esr_el3 48 mov_imm w2, \_esr_el3_val 49 ccmp w2, w3, #0, eq 50 /* 51 * Static predictor will predict a fall-through, optimizing 52 * the `SMCCC_ARCH_WORKAROUND_2` fast path. 53 */ 54 bne 1f 55 56 /* 57 * The sequence below implements the `SMCCC_ARCH_WORKAROUND_2` 58 * fast path. 59 */ 60 cmp x1, xzr /* enable/disable check */ 61 62 /* 63 * When the calling context wants mitigation disabled, 64 * we program the mitigation disable function in the 65 * CPU context, which gets invoked on subsequent exits from 66 * EL3 via the `el3_exit` function. Otherwise NULL is 67 * programmed in the CPU context, which results in caller's 68 * inheriting the EL3 mitigation state (enabled) on subsequent 69 * `el3_exit`. 70 */ 71 mov x0, xzr 72 adr x1, cortex_a76_disable_wa_cve_2018_3639 73 csel x1, x1, x0, eq 74 str x1, [sp, #CTX_CVE_2018_3639_OFFSET + CTX_CVE_2018_3639_DISABLE] 75 76 mrs x2, CORTEX_A76_CPUACTLR2_EL1 77 orr x1, x2, #CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE 78 bic x3, x2, #CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE 79 csel x3, x3, x1, eq 80 msr CORTEX_A76_CPUACTLR2_EL1, x3 81 eret /* ERET implies ISB */ 82 .endif 831: 84 /* 85 * Always enable v4 mitigation during EL3 execution. This is not 86 * required for the fast path above because it does not perform any 87 * memory loads. 88 */ 89 mrs x2, CORTEX_A76_CPUACTLR2_EL1 90 orr x2, x2, #CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE 91 msr CORTEX_A76_CPUACTLR2_EL1, x2 92 isb 93 94 /* 95 * The caller may have passed arguments to EL3 via x2-x3. 96 * Restore these registers from the context before jumping to the 97 * main runtime vector table entry. 98 */ 99 ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] 100 .endm 101 102vector_base cortex_a76_wa_cve_2018_3639_a76_vbar 103 104 /* --------------------------------------------------------------------- 105 * Current EL with SP_EL0 : 0x0 - 0x200 106 * --------------------------------------------------------------------- 107 */ 108vector_entry cortex_a76_sync_exception_sp_el0 109 b sync_exception_sp_el0 110end_vector_entry cortex_a76_sync_exception_sp_el0 111 112vector_entry cortex_a76_irq_sp_el0 113 b irq_sp_el0 114end_vector_entry cortex_a76_irq_sp_el0 115 116vector_entry cortex_a76_fiq_sp_el0 117 b fiq_sp_el0 118end_vector_entry cortex_a76_fiq_sp_el0 119 120vector_entry cortex_a76_serror_sp_el0 121 b serror_sp_el0 122end_vector_entry cortex_a76_serror_sp_el0 123 124 /* --------------------------------------------------------------------- 125 * Current EL with SP_ELx: 0x200 - 0x400 126 * --------------------------------------------------------------------- 127 */ 128vector_entry cortex_a76_sync_exception_sp_elx 129 b sync_exception_sp_elx 130end_vector_entry cortex_a76_sync_exception_sp_elx 131 132vector_entry cortex_a76_irq_sp_elx 133 b irq_sp_elx 134end_vector_entry cortex_a76_irq_sp_elx 135 136vector_entry cortex_a76_fiq_sp_elx 137 b fiq_sp_elx 138end_vector_entry cortex_a76_fiq_sp_elx 139 140vector_entry cortex_a76_serror_sp_elx 141 b serror_sp_elx 142end_vector_entry cortex_a76_serror_sp_elx 143 144 /* --------------------------------------------------------------------- 145 * Lower EL using AArch64 : 0x400 - 0x600 146 * --------------------------------------------------------------------- 147 */ 148vector_entry cortex_a76_sync_exception_aarch64 149 apply_cve_2018_3639_wa _is_sync_exception=1 _esr_el3_val=ESR_EL3_A64_SMC0 150 b sync_exception_aarch64 151end_vector_entry cortex_a76_sync_exception_aarch64 152 153vector_entry cortex_a76_irq_aarch64 154 apply_cve_2018_3639_wa _is_sync_exception=0 _esr_el3_val=ESR_EL3_A64_SMC0 155 b irq_aarch64 156end_vector_entry cortex_a76_irq_aarch64 157 158vector_entry cortex_a76_fiq_aarch64 159 apply_cve_2018_3639_wa _is_sync_exception=0 _esr_el3_val=ESR_EL3_A64_SMC0 160 b fiq_aarch64 161end_vector_entry cortex_a76_fiq_aarch64 162 163vector_entry cortex_a76_serror_aarch64 164 apply_cve_2018_3639_wa _is_sync_exception=0 _esr_el3_val=ESR_EL3_A64_SMC0 165 b serror_aarch64 166end_vector_entry cortex_a76_serror_aarch64 167 168 /* --------------------------------------------------------------------- 169 * Lower EL using AArch32 : 0x600 - 0x800 170 * --------------------------------------------------------------------- 171 */ 172vector_entry cortex_a76_sync_exception_aarch32 173 apply_cve_2018_3639_wa _is_sync_exception=1 _esr_el3_val=ESR_EL3_A32_SMC0 174 b sync_exception_aarch32 175end_vector_entry cortex_a76_sync_exception_aarch32 176 177vector_entry cortex_a76_irq_aarch32 178 apply_cve_2018_3639_wa _is_sync_exception=0 _esr_el3_val=ESR_EL3_A32_SMC0 179 b irq_aarch32 180end_vector_entry cortex_a76_irq_aarch32 181 182vector_entry cortex_a76_fiq_aarch32 183 apply_cve_2018_3639_wa _is_sync_exception=0 _esr_el3_val=ESR_EL3_A32_SMC0 184 b fiq_aarch32 185end_vector_entry cortex_a76_fiq_aarch32 186 187vector_entry cortex_a76_serror_aarch32 188 apply_cve_2018_3639_wa _is_sync_exception=0 _esr_el3_val=ESR_EL3_A32_SMC0 189 b serror_aarch32 190end_vector_entry cortex_a76_serror_aarch32 191 192func check_errata_cve_2018_3639 193#if WORKAROUND_CVE_2018_3639 194 mov x0, #ERRATA_APPLIES 195#else 196 mov x0, #ERRATA_MISSING 197#endif 198 ret 199endfunc check_errata_cve_2018_3639 200 201func cortex_a76_disable_wa_cve_2018_3639 202 mrs x0, CORTEX_A76_CPUACTLR2_EL1 203 bic x0, x0, #CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE 204 msr CORTEX_A76_CPUACTLR2_EL1, x0 205 isb 206 ret 207endfunc cortex_a76_disable_wa_cve_2018_3639 208 209func cortex_a76_reset_func 210 mov x19, x30 211 212#if WORKAROUND_CVE_2018_3639 213 /* If the PE implements SSBS, we don't need the dynamic workaround */ 214 mrs x0, id_aa64pfr1_el1 215 lsr x0, x0, #ID_AA64PFR1_EL1_SSBS_SHIFT 216 and x0, x0, #ID_AA64PFR1_EL1_SSBS_MASK 217 cbnz x0, 1f 218 219 mrs x0, CORTEX_A76_CPUACTLR2_EL1 220 orr x0, x0, #CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE 221 msr CORTEX_A76_CPUACTLR2_EL1, x0 222 isb 223 224#ifdef IMAGE_BL31 225 /* 226 * The Cortex-A76 generic vectors are overwritten to use the vectors 227 * defined above. This is required in order to apply mitigation 228 * against CVE-2018-3639 on exception entry from lower ELs. 229 */ 230 adr x0, cortex_a76_wa_cve_2018_3639_a76_vbar 231 msr vbar_el3, x0 232 isb 233#endif 234 2351: 236#endif 237 238#if ERRATA_DSU_936184 239 bl errata_dsu_936184_wa 240#endif 241 ret x19 242endfunc cortex_a76_reset_func 243 244 /* --------------------------------------------- 245 * HW will do the cache maintenance while powering down 246 * --------------------------------------------- 247 */ 248func cortex_a76_core_pwr_dwn 249 /* --------------------------------------------- 250 * Enable CPU power down bit in power control register 251 * --------------------------------------------- 252 */ 253 mrs x0, CORTEX_A76_CPUPWRCTLR_EL1 254 orr x0, x0, #CORTEX_A76_CORE_PWRDN_EN_MASK 255 msr CORTEX_A76_CPUPWRCTLR_EL1, x0 256 isb 257 ret 258endfunc cortex_a76_core_pwr_dwn 259 260#if REPORT_ERRATA 261/* 262 * Errata printing function for Cortex Cortex A76. Must follow AAPCS. 263 */ 264func cortex_a76_errata_report 265 stp x8, x30, [sp, #-16]! 266 267 bl cpu_get_rev_var 268 mov x8, x0 269 270 /* 271 * Report all errata. The revision-variant information is passed to 272 * checking functions of each errata. 273 */ 274 report_errata WORKAROUND_CVE_2018_3639, cortex_a76, cve_2018_3639 275 report_errata ERRATA_DSU_936184, cortex_a76, dsu_936184 276 277 ldp x8, x30, [sp], #16 278 ret 279endfunc cortex_a76_errata_report 280#endif 281 282 /* --------------------------------------------- 283 * This function provides cortex_a76 specific 284 * register information for crash reporting. 285 * It needs to return with x6 pointing to 286 * a list of register names in ascii and 287 * x8 - x15 having values of registers to be 288 * reported. 289 * --------------------------------------------- 290 */ 291.section .rodata.cortex_a76_regs, "aS" 292cortex_a76_regs: /* The ascii list of register names to be reported */ 293 .asciz "cpuectlr_el1", "" 294 295func cortex_a76_cpu_reg_dump 296 adr x6, cortex_a76_regs 297 mrs x8, CORTEX_A76_CPUECTLR_EL1 298 ret 299endfunc cortex_a76_cpu_reg_dump 300 301declare_cpu_ops_wa cortex_a76, CORTEX_A76_MIDR, \ 302 cortex_a76_reset_func, \ 303 CPU_NO_EXTRA1_FUNC, \ 304 cortex_a76_disable_wa_cve_2018_3639, \ 305 cortex_a76_core_pwr_dwn 306