/* * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #include #include #include #include #include #include /* ------------------------------------------------- * CVE-2017-5715 mitigation * * Flush the indirect branch predictor and RSB on * entry to EL3 by issuing a newly added instruction * for Denver CPUs. * * To achieve this without performing any branch * instruction, a per-cpu vbar is installed which * executes the workaround and then branches off to * the corresponding vector entry in the main vector * table. * ------------------------------------------------- */ .globl workaround_bpflush_runtime_exceptions vector_base workaround_bpflush_runtime_exceptions .macro apply_workaround stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] /* ------------------------------------------------- * A new write-only system register where a write of * 1 to bit 0 will cause the indirect branch predictor * and RSB to be flushed. * * A write of 0 to bit 0 will be ignored. A write of * 1 to any other bit will cause an MCA. * ------------------------------------------------- */ mov x0, #1 msr s3_0_c15_c0_6, x0 isb ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] .endm /* --------------------------------------------------------------------- * Current EL with SP_EL0 : 0x0 - 0x200 * --------------------------------------------------------------------- */ vector_entry workaround_bpflush_sync_exception_sp_el0 b sync_exception_sp_el0 end_vector_entry workaround_bpflush_sync_exception_sp_el0 vector_entry workaround_bpflush_irq_sp_el0 b irq_sp_el0 end_vector_entry workaround_bpflush_irq_sp_el0 vector_entry workaround_bpflush_fiq_sp_el0 b fiq_sp_el0 end_vector_entry workaround_bpflush_fiq_sp_el0 vector_entry workaround_bpflush_serror_sp_el0 b serror_sp_el0 end_vector_entry workaround_bpflush_serror_sp_el0 /* --------------------------------------------------------------------- * Current EL with SP_ELx: 0x200 - 0x400 * --------------------------------------------------------------------- */ vector_entry workaround_bpflush_sync_exception_sp_elx b sync_exception_sp_elx end_vector_entry workaround_bpflush_sync_exception_sp_elx vector_entry workaround_bpflush_irq_sp_elx b irq_sp_elx end_vector_entry workaround_bpflush_irq_sp_elx vector_entry workaround_bpflush_fiq_sp_elx b fiq_sp_elx end_vector_entry workaround_bpflush_fiq_sp_elx vector_entry workaround_bpflush_serror_sp_elx b serror_sp_elx end_vector_entry workaround_bpflush_serror_sp_elx /* --------------------------------------------------------------------- * Lower EL using AArch64 : 0x400 - 0x600 * --------------------------------------------------------------------- */ vector_entry workaround_bpflush_sync_exception_aarch64 apply_workaround b sync_exception_aarch64 end_vector_entry workaround_bpflush_sync_exception_aarch64 vector_entry workaround_bpflush_irq_aarch64 apply_workaround b irq_aarch64 end_vector_entry workaround_bpflush_irq_aarch64 vector_entry workaround_bpflush_fiq_aarch64 apply_workaround b fiq_aarch64 end_vector_entry workaround_bpflush_fiq_aarch64 vector_entry workaround_bpflush_serror_aarch64 apply_workaround b serror_aarch64 end_vector_entry workaround_bpflush_serror_aarch64 /* --------------------------------------------------------------------- * Lower EL using AArch32 : 0x600 - 0x800 * --------------------------------------------------------------------- */ vector_entry workaround_bpflush_sync_exception_aarch32 apply_workaround b sync_exception_aarch32 end_vector_entry workaround_bpflush_sync_exception_aarch32 vector_entry workaround_bpflush_irq_aarch32 apply_workaround b irq_aarch32 end_vector_entry workaround_bpflush_irq_aarch32 vector_entry workaround_bpflush_fiq_aarch32 apply_workaround b fiq_aarch32 end_vector_entry workaround_bpflush_fiq_aarch32 vector_entry workaround_bpflush_serror_aarch32 apply_workaround b serror_aarch32 end_vector_entry workaround_bpflush_serror_aarch32 .global denver_disable_dco /* --------------------------------------------- * Disable debug interfaces * --------------------------------------------- */ func denver_disable_ext_debug mov x0, #1 msr osdlr_el1, x0 isb dsb sy ret endfunc denver_disable_ext_debug /* ---------------------------------------------------- * Enable dynamic code optimizer (DCO) * ---------------------------------------------------- */ func denver_enable_dco mrs x0, mpidr_el1 and x0, x0, #0xF mov x1, #1 lsl x1, x1, x0 msr s3_0_c15_c0_2, x1 ret endfunc denver_enable_dco /* ---------------------------------------------------- * Disable dynamic code optimizer (DCO) * ---------------------------------------------------- */ func denver_disable_dco /* turn off background work */ mrs x0, mpidr_el1 and x0, x0, #0xF mov x1, #1 lsl x1, x1, x0 lsl x2, x1, #16 msr s3_0_c15_c0_2, x2 isb /* wait till the background work turns off */ 1: mrs x2, s3_0_c15_c0_2 lsr x2, x2, #32 and w2, w2, 0xFFFF and x2, x2, x1 cbnz x2, 1b ret endfunc denver_disable_dco /* ------------------------------------------------- * The CPU Ops reset function for Denver. * ------------------------------------------------- */ func denver_reset_func mov x19, x30 #if IMAGE_BL31 && WORKAROUND_CVE_2017_5715 /* * Check if the CPU supports the special instruction * required to flush the indirect branch predictor and * RSB. Support for this operation can be determined by * comparing bits 19:16 of ID_AFR0_EL1 with 0b0001. */ mrs x0, id_afr0_el1 mov x1, #0x10000 and x0, x0, x1 cmp x0, #0 adr x1, workaround_bpflush_runtime_exceptions mrs x2, vbar_el3 csel x0, x1, x2, ne msr vbar_el3, x0 #endif /* ---------------------------------------------------- * Enable dynamic code optimizer (DCO) * ---------------------------------------------------- */ bl denver_enable_dco ret x19 endfunc denver_reset_func /* ---------------------------------------------------- * The CPU Ops core power down function for Denver. * ---------------------------------------------------- */ func denver_core_pwr_dwn mov x19, x30 /* --------------------------------------------- * Force the debug interfaces to be quiescent * --------------------------------------------- */ bl denver_disable_ext_debug ret x19 endfunc denver_core_pwr_dwn /* ------------------------------------------------------- * The CPU Ops cluster power down function for Denver. * ------------------------------------------------------- */ func denver_cluster_pwr_dwn ret endfunc denver_cluster_pwr_dwn /* --------------------------------------------- * This function provides Denver specific * register information for crash reporting. * It needs to return with x6 pointing to * a list of register names in ascii and * x8 - x15 having values of registers to be * reported. * --------------------------------------------- */ .section .rodata.denver_regs, "aS" denver_regs: /* The ascii list of register names to be reported */ .asciz "actlr_el1", "" func denver_cpu_reg_dump adr x6, denver_regs mrs x8, ACTLR_EL1 ret endfunc denver_cpu_reg_dump declare_cpu_ops denver, DENVER_MIDR_PN0, \ denver_reset_func, \ denver_core_pwr_dwn, \ denver_cluster_pwr_dwn declare_cpu_ops denver, DENVER_MIDR_PN1, \ denver_reset_func, \ denver_core_pwr_dwn, \ denver_cluster_pwr_dwn declare_cpu_ops denver, DENVER_MIDR_PN2, \ denver_reset_func, \ denver_core_pwr_dwn, \ denver_cluster_pwr_dwn declare_cpu_ops denver, DENVER_MIDR_PN3, \ denver_reset_func, \ denver_core_pwr_dwn, \ denver_cluster_pwr_dwn declare_cpu_ops denver, DENVER_MIDR_PN4, \ denver_reset_func, \ denver_core_pwr_dwn, \ denver_cluster_pwr_dwn