1/* 2 * Copyright (c) 2015-2018, 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 <assert_macros.S> 10#include <context.h> 11#include <denver.h> 12#include <cpu_macros.S> 13#include <plat_macros.S> 14 15 /* ------------------------------------------------- 16 * CVE-2017-5715 mitigation 17 * 18 * Flush the indirect branch predictor and RSB on 19 * entry to EL3 by issuing a newly added instruction 20 * for Denver CPUs. 21 * 22 * To achieve this without performing any branch 23 * instruction, a per-cpu vbar is installed which 24 * executes the workaround and then branches off to 25 * the corresponding vector entry in the main vector 26 * table. 27 * ------------------------------------------------- 28 */ 29 .globl workaround_bpflush_runtime_exceptions 30 31vector_base workaround_bpflush_runtime_exceptions 32 33 .macro apply_workaround 34 stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] 35 36 /* ------------------------------------------------- 37 * A new write-only system register where a write of 38 * 1 to bit 0 will cause the indirect branch predictor 39 * and RSB to be flushed. 40 * 41 * A write of 0 to bit 0 will be ignored. A write of 42 * 1 to any other bit will cause an MCA. 43 * ------------------------------------------------- 44 */ 45 mov x0, #1 46 msr s3_0_c15_c0_6, x0 47 isb 48 49 ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] 50 .endm 51 52 /* --------------------------------------------------------------------- 53 * Current EL with SP_EL0 : 0x0 - 0x200 54 * --------------------------------------------------------------------- 55 */ 56vector_entry workaround_bpflush_sync_exception_sp_el0 57 b sync_exception_sp_el0 58end_vector_entry workaround_bpflush_sync_exception_sp_el0 59 60vector_entry workaround_bpflush_irq_sp_el0 61 b irq_sp_el0 62end_vector_entry workaround_bpflush_irq_sp_el0 63 64vector_entry workaround_bpflush_fiq_sp_el0 65 b fiq_sp_el0 66end_vector_entry workaround_bpflush_fiq_sp_el0 67 68vector_entry workaround_bpflush_serror_sp_el0 69 b serror_sp_el0 70end_vector_entry workaround_bpflush_serror_sp_el0 71 72 /* --------------------------------------------------------------------- 73 * Current EL with SP_ELx: 0x200 - 0x400 74 * --------------------------------------------------------------------- 75 */ 76vector_entry workaround_bpflush_sync_exception_sp_elx 77 b sync_exception_sp_elx 78end_vector_entry workaround_bpflush_sync_exception_sp_elx 79 80vector_entry workaround_bpflush_irq_sp_elx 81 b irq_sp_elx 82end_vector_entry workaround_bpflush_irq_sp_elx 83 84vector_entry workaround_bpflush_fiq_sp_elx 85 b fiq_sp_elx 86end_vector_entry workaround_bpflush_fiq_sp_elx 87 88vector_entry workaround_bpflush_serror_sp_elx 89 b serror_sp_elx 90end_vector_entry workaround_bpflush_serror_sp_elx 91 92 /* --------------------------------------------------------------------- 93 * Lower EL using AArch64 : 0x400 - 0x600 94 * --------------------------------------------------------------------- 95 */ 96vector_entry workaround_bpflush_sync_exception_aarch64 97 apply_workaround 98 b sync_exception_aarch64 99end_vector_entry workaround_bpflush_sync_exception_aarch64 100 101vector_entry workaround_bpflush_irq_aarch64 102 apply_workaround 103 b irq_aarch64 104end_vector_entry workaround_bpflush_irq_aarch64 105 106vector_entry workaround_bpflush_fiq_aarch64 107 apply_workaround 108 b fiq_aarch64 109end_vector_entry workaround_bpflush_fiq_aarch64 110 111vector_entry workaround_bpflush_serror_aarch64 112 apply_workaround 113 b serror_aarch64 114end_vector_entry workaround_bpflush_serror_aarch64 115 116 /* --------------------------------------------------------------------- 117 * Lower EL using AArch32 : 0x600 - 0x800 118 * --------------------------------------------------------------------- 119 */ 120vector_entry workaround_bpflush_sync_exception_aarch32 121 apply_workaround 122 b sync_exception_aarch32 123end_vector_entry workaround_bpflush_sync_exception_aarch32 124 125vector_entry workaround_bpflush_irq_aarch32 126 apply_workaround 127 b irq_aarch32 128end_vector_entry workaround_bpflush_irq_aarch32 129 130vector_entry workaround_bpflush_fiq_aarch32 131 apply_workaround 132 b fiq_aarch32 133end_vector_entry workaround_bpflush_fiq_aarch32 134 135vector_entry workaround_bpflush_serror_aarch32 136 apply_workaround 137 b serror_aarch32 138end_vector_entry workaround_bpflush_serror_aarch32 139 140 .global denver_disable_dco 141 142 /* --------------------------------------------- 143 * Disable debug interfaces 144 * --------------------------------------------- 145 */ 146func denver_disable_ext_debug 147 mov x0, #1 148 msr osdlr_el1, x0 149 isb 150 dsb sy 151 ret 152endfunc denver_disable_ext_debug 153 154 /* ---------------------------------------------------- 155 * Enable dynamic code optimizer (DCO) 156 * ---------------------------------------------------- 157 */ 158func denver_enable_dco 159 mov x3, x30 160 bl plat_my_core_pos 161 mov x1, #1 162 lsl x1, x1, x0 163 msr s3_0_c15_c0_2, x1 164 mov x30, x3 165 ret 166endfunc denver_enable_dco 167 168 /* ---------------------------------------------------- 169 * Disable dynamic code optimizer (DCO) 170 * ---------------------------------------------------- 171 */ 172func denver_disable_dco 173 174 mov x3, x30 175 176 /* turn off background work */ 177 bl plat_my_core_pos 178 mov x1, #1 179 lsl x1, x1, x0 180 lsl x2, x1, #16 181 msr s3_0_c15_c0_2, x2 182 isb 183 184 /* wait till the background work turns off */ 1851: mrs x2, s3_0_c15_c0_2 186 lsr x2, x2, #32 187 and w2, w2, 0xFFFF 188 and x2, x2, x1 189 cbnz x2, 1b 190 191 mov x30, x3 192 ret 193endfunc denver_disable_dco 194 195func check_errata_cve_2017_5715 196 mov x0, #ERRATA_MISSING 197#if WORKAROUND_CVE_2017_5715 198 /* 199 * Check if the CPU supports the special instruction 200 * required to flush the indirect branch predictor and 201 * RSB. Support for this operation can be determined by 202 * comparing bits 19:16 of ID_AFR0_EL1 with 0b0001. 203 */ 204 mrs x1, id_afr0_el1 205 mov x2, #0x10000 206 and x1, x1, x2 207 cbz x1, 1f 208 mov x0, #ERRATA_APPLIES 2091: 210#endif 211 ret 212endfunc check_errata_cve_2017_5715 213 214 /* ------------------------------------------------- 215 * The CPU Ops reset function for Denver. 216 * ------------------------------------------------- 217 */ 218func denver_reset_func 219 220 mov x19, x30 221 222#if IMAGE_BL31 && WORKAROUND_CVE_2017_5715 223 /* 224 * Check if the CPU supports the special instruction 225 * required to flush the indirect branch predictor and 226 * RSB. Support for this operation can be determined by 227 * comparing bits 19:16 of ID_AFR0_EL1 with 0b0001. 228 */ 229 mrs x0, id_afr0_el1 230 mov x1, #0x10000 231 and x0, x0, x1 232 cmp x0, #0 233 adr x1, workaround_bpflush_runtime_exceptions 234 mrs x2, vbar_el3 235 csel x0, x1, x2, ne 236 msr vbar_el3, x0 237#endif 238 239 /* ---------------------------------------------------- 240 * Enable dynamic code optimizer (DCO) 241 * ---------------------------------------------------- 242 */ 243 bl denver_enable_dco 244 245 ret x19 246endfunc denver_reset_func 247 248 /* ---------------------------------------------------- 249 * The CPU Ops core power down function for Denver. 250 * ---------------------------------------------------- 251 */ 252func denver_core_pwr_dwn 253 254 mov x19, x30 255 256 /* --------------------------------------------- 257 * Force the debug interfaces to be quiescent 258 * --------------------------------------------- 259 */ 260 bl denver_disable_ext_debug 261 262 ret x19 263endfunc denver_core_pwr_dwn 264 265 /* ------------------------------------------------------- 266 * The CPU Ops cluster power down function for Denver. 267 * ------------------------------------------------------- 268 */ 269func denver_cluster_pwr_dwn 270 ret 271endfunc denver_cluster_pwr_dwn 272 273#if REPORT_ERRATA 274 /* 275 * Errata printing function for Denver. Must follow AAPCS. 276 */ 277func denver_errata_report 278 stp x8, x30, [sp, #-16]! 279 280 bl cpu_get_rev_var 281 mov x8, x0 282 283 /* 284 * Report all errata. The revision-variant information is passed to 285 * checking functions of each errata. 286 */ 287 report_errata WORKAROUND_CVE_2017_5715, denver, cve_2017_5715 288 289 ldp x8, x30, [sp], #16 290 ret 291endfunc denver_errata_report 292#endif 293 294 /* --------------------------------------------- 295 * This function provides Denver specific 296 * register information for crash reporting. 297 * It needs to return with x6 pointing to 298 * a list of register names in ascii and 299 * x8 - x15 having values of registers to be 300 * reported. 301 * --------------------------------------------- 302 */ 303.section .rodata.denver_regs, "aS" 304denver_regs: /* The ascii list of register names to be reported */ 305 .asciz "actlr_el1", "" 306 307func denver_cpu_reg_dump 308 adr x6, denver_regs 309 mrs x8, ACTLR_EL1 310 ret 311endfunc denver_cpu_reg_dump 312 313declare_cpu_ops_wa denver, DENVER_MIDR_PN0, \ 314 denver_reset_func, \ 315 check_errata_cve_2017_5715, \ 316 CPU_NO_EXTRA2_FUNC, \ 317 denver_core_pwr_dwn, \ 318 denver_cluster_pwr_dwn 319 320declare_cpu_ops_wa denver, DENVER_MIDR_PN1, \ 321 denver_reset_func, \ 322 check_errata_cve_2017_5715, \ 323 CPU_NO_EXTRA2_FUNC, \ 324 denver_core_pwr_dwn, \ 325 denver_cluster_pwr_dwn 326 327declare_cpu_ops_wa denver, DENVER_MIDR_PN2, \ 328 denver_reset_func, \ 329 check_errata_cve_2017_5715, \ 330 CPU_NO_EXTRA2_FUNC, \ 331 denver_core_pwr_dwn, \ 332 denver_cluster_pwr_dwn 333 334declare_cpu_ops_wa denver, DENVER_MIDR_PN3, \ 335 denver_reset_func, \ 336 check_errata_cve_2017_5715, \ 337 CPU_NO_EXTRA2_FUNC, \ 338 denver_core_pwr_dwn, \ 339 denver_cluster_pwr_dwn 340 341declare_cpu_ops_wa denver, DENVER_MIDR_PN4, \ 342 denver_reset_func, \ 343 check_errata_cve_2017_5715, \ 344 CPU_NO_EXTRA2_FUNC, \ 345 denver_core_pwr_dwn, \ 346 denver_cluster_pwr_dwn 347