1/* 2 * Copyright (c) 2017-2019, 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 191 192 /* -------------------------------------------------- 193 * Errata Workaround for Cortex A76 Errata #1130799. 194 * This applies only to revision <= r2p0 of Cortex A76. 195 * Inputs: 196 * x0: variant[4:7] and revision[0:3] of current cpu. 197 * Shall clobber: x0-x17 198 * -------------------------------------------------- 199 */ 200func errata_a76_1130799_wa 201 /* 202 * Compare x0 against revision r2p0 203 */ 204 mov x17, x30 205 bl check_errata_1130799 206 cbz x0, 1f 207 mrs x1, CORTEX_A76_CPUACTLR2_EL1 208 orr x1, x1 ,#(1 << 59) 209 msr CORTEX_A76_CPUACTLR2_EL1, x1 210 isb 2111: 212 ret x17 213endfunc errata_a76_1130799_wa 214 215func check_errata_1130799 216 mov x1, #0x20 217 b cpu_rev_var_ls 218endfunc check_errata_1130799 219 220func check_errata_cve_2018_3639 221#if WORKAROUND_CVE_2018_3639 222 mov x0, #ERRATA_APPLIES 223#else 224 mov x0, #ERRATA_MISSING 225#endif 226 ret 227endfunc check_errata_cve_2018_3639 228 229func cortex_a76_disable_wa_cve_2018_3639 230 mrs x0, CORTEX_A76_CPUACTLR2_EL1 231 bic x0, x0, #CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE 232 msr CORTEX_A76_CPUACTLR2_EL1, x0 233 isb 234 ret 235endfunc cortex_a76_disable_wa_cve_2018_3639 236 237 /* ------------------------------------------------- 238 * The CPU Ops reset function for Cortex-A76. 239 * Shall clobber: x0-x19 240 * ------------------------------------------------- 241 */ 242func cortex_a76_reset_func 243 mov x19, x30 244 bl cpu_get_rev_var 245 246#if ERRATA_A76_1130799 247 bl errata_a76_1130799_wa 248#endif 249 250#if WORKAROUND_CVE_2018_3639 251 /* If the PE implements SSBS, we don't need the dynamic workaround */ 252 mrs x0, id_aa64pfr1_el1 253 lsr x0, x0, #ID_AA64PFR1_EL1_SSBS_SHIFT 254 and x0, x0, #ID_AA64PFR1_EL1_SSBS_MASK 255 cbnz x0, 1f 256 257 mrs x0, CORTEX_A76_CPUACTLR2_EL1 258 orr x0, x0, #CORTEX_A76_CPUACTLR2_EL1_DISABLE_LOAD_PASS_STORE 259 msr CORTEX_A76_CPUACTLR2_EL1, x0 260 isb 261 262#ifdef IMAGE_BL31 263 /* 264 * The Cortex-A76 generic vectors are overwritten to use the vectors 265 * defined above. This is required in order to apply mitigation 266 * against CVE-2018-3639 on exception entry from lower ELs. 267 */ 268 adr x0, cortex_a76_wa_cve_2018_3639_a76_vbar 269 msr vbar_el3, x0 270 isb 271#endif 272 2731: 274#endif 275 276#if ERRATA_DSU_936184 277 bl errata_dsu_936184_wa 278#endif 279 ret x19 280endfunc cortex_a76_reset_func 281 282 /* --------------------------------------------- 283 * HW will do the cache maintenance while powering down 284 * --------------------------------------------- 285 */ 286func cortex_a76_core_pwr_dwn 287 /* --------------------------------------------- 288 * Enable CPU power down bit in power control register 289 * --------------------------------------------- 290 */ 291 mrs x0, CORTEX_A76_CPUPWRCTLR_EL1 292 orr x0, x0, #CORTEX_A76_CORE_PWRDN_EN_MASK 293 msr CORTEX_A76_CPUPWRCTLR_EL1, x0 294 isb 295 ret 296endfunc cortex_a76_core_pwr_dwn 297 298#if REPORT_ERRATA 299/* 300 * Errata printing function for Cortex Cortex A76. Must follow AAPCS. 301 */ 302func cortex_a76_errata_report 303 stp x8, x30, [sp, #-16]! 304 305 bl cpu_get_rev_var 306 mov x8, x0 307 308 /* 309 * Report all errata. The revision-variant information is passed to 310 * checking functions of each errata. 311 */ 312 report_errata ERRATA_A76_1130799, cortex_a76, 1130799 313 report_errata WORKAROUND_CVE_2018_3639, cortex_a76, cve_2018_3639 314 report_errata ERRATA_DSU_936184, cortex_a76, dsu_936184 315 316 ldp x8, x30, [sp], #16 317 ret 318endfunc cortex_a76_errata_report 319#endif 320 321 /* --------------------------------------------- 322 * This function provides cortex_a76 specific 323 * register information for crash reporting. 324 * It needs to return with x6 pointing to 325 * a list of register names in ascii and 326 * x8 - x15 having values of registers to be 327 * reported. 328 * --------------------------------------------- 329 */ 330.section .rodata.cortex_a76_regs, "aS" 331cortex_a76_regs: /* The ascii list of register names to be reported */ 332 .asciz "cpuectlr_el1", "" 333 334func cortex_a76_cpu_reg_dump 335 adr x6, cortex_a76_regs 336 mrs x8, CORTEX_A76_CPUECTLR_EL1 337 ret 338endfunc cortex_a76_cpu_reg_dump 339 340declare_cpu_ops_wa cortex_a76, CORTEX_A76_MIDR, \ 341 cortex_a76_reset_func, \ 342 CPU_NO_EXTRA1_FUNC, \ 343 cortex_a76_disable_wa_cve_2018_3639, \ 344 cortex_a76_core_pwr_dwn 345