/* * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #include #include .global el1_sysregs_context_save .global el1_sysregs_context_restore #if CTX_INCLUDE_FPREGS .global fpregs_context_save .global fpregs_context_restore #endif .global save_gp_registers .global restore_gp_registers .global restore_gp_registers_eret .global el3_exit /* ----------------------------------------------------- * The following function strictly follows the AArch64 * PCS to use x9-x17 (temporary caller-saved registers) * to save EL1 system register context. It assumes that * 'x0' is pointing to a 'el1_sys_regs' structure where * the register context will be saved. * ----------------------------------------------------- */ func el1_sysregs_context_save mrs x9, spsr_el1 mrs x10, elr_el1 stp x9, x10, [x0, #CTX_SPSR_EL1] mrs x15, sctlr_el1 mrs x16, actlr_el1 stp x15, x16, [x0, #CTX_SCTLR_EL1] mrs x17, cpacr_el1 mrs x9, csselr_el1 stp x17, x9, [x0, #CTX_CPACR_EL1] mrs x10, sp_el1 mrs x11, esr_el1 stp x10, x11, [x0, #CTX_SP_EL1] mrs x12, ttbr0_el1 mrs x13, ttbr1_el1 stp x12, x13, [x0, #CTX_TTBR0_EL1] mrs x14, mair_el1 mrs x15, amair_el1 stp x14, x15, [x0, #CTX_MAIR_EL1] mrs x16, tcr_el1 mrs x17, tpidr_el1 stp x16, x17, [x0, #CTX_TCR_EL1] mrs x9, tpidr_el0 mrs x10, tpidrro_el0 stp x9, x10, [x0, #CTX_TPIDR_EL0] mrs x13, par_el1 mrs x14, far_el1 stp x13, x14, [x0, #CTX_PAR_EL1] mrs x15, afsr0_el1 mrs x16, afsr1_el1 stp x15, x16, [x0, #CTX_AFSR0_EL1] mrs x17, contextidr_el1 mrs x9, vbar_el1 stp x17, x9, [x0, #CTX_CONTEXTIDR_EL1] mrs x10, pmcr_el0 str x10, [x0, #CTX_PMCR_EL0] /* Save AArch32 system registers if the build has instructed so */ #if CTX_INCLUDE_AARCH32_REGS mrs x11, spsr_abt mrs x12, spsr_und stp x11, x12, [x0, #CTX_SPSR_ABT] mrs x13, spsr_irq mrs x14, spsr_fiq stp x13, x14, [x0, #CTX_SPSR_IRQ] mrs x15, dacr32_el2 mrs x16, ifsr32_el2 stp x15, x16, [x0, #CTX_DACR32_EL2] #endif /* Save NS timer registers if the build has instructed so */ #if NS_TIMER_SWITCH mrs x10, cntp_ctl_el0 mrs x11, cntp_cval_el0 stp x10, x11, [x0, #CTX_CNTP_CTL_EL0] mrs x12, cntv_ctl_el0 mrs x13, cntv_cval_el0 stp x12, x13, [x0, #CTX_CNTV_CTL_EL0] mrs x14, cntkctl_el1 str x14, [x0, #CTX_CNTKCTL_EL1] #endif ret endfunc el1_sysregs_context_save /* ----------------------------------------------------- * The following function strictly follows the AArch64 * PCS to use x9-x17 (temporary caller-saved registers) * to restore EL1 system register context. It assumes * that 'x0' is pointing to a 'el1_sys_regs' structure * from where the register context will be restored * ----------------------------------------------------- */ func el1_sysregs_context_restore ldp x9, x10, [x0, #CTX_SPSR_EL1] msr spsr_el1, x9 msr elr_el1, x10 ldp x15, x16, [x0, #CTX_SCTLR_EL1] msr sctlr_el1, x15 msr actlr_el1, x16 ldp x17, x9, [x0, #CTX_CPACR_EL1] msr cpacr_el1, x17 msr csselr_el1, x9 ldp x10, x11, [x0, #CTX_SP_EL1] msr sp_el1, x10 msr esr_el1, x11 ldp x12, x13, [x0, #CTX_TTBR0_EL1] msr ttbr0_el1, x12 msr ttbr1_el1, x13 ldp x14, x15, [x0, #CTX_MAIR_EL1] msr mair_el1, x14 msr amair_el1, x15 ldp x16, x17, [x0, #CTX_TCR_EL1] msr tcr_el1, x16 msr tpidr_el1, x17 ldp x9, x10, [x0, #CTX_TPIDR_EL0] msr tpidr_el0, x9 msr tpidrro_el0, x10 ldp x13, x14, [x0, #CTX_PAR_EL1] msr par_el1, x13 msr far_el1, x14 ldp x15, x16, [x0, #CTX_AFSR0_EL1] msr afsr0_el1, x15 msr afsr1_el1, x16 ldp x17, x9, [x0, #CTX_CONTEXTIDR_EL1] msr contextidr_el1, x17 msr vbar_el1, x9 ldr x10, [x0, #CTX_PMCR_EL0] msr pmcr_el0, x10 /* Restore AArch32 system registers if the build has instructed so */ #if CTX_INCLUDE_AARCH32_REGS ldp x11, x12, [x0, #CTX_SPSR_ABT] msr spsr_abt, x11 msr spsr_und, x12 ldp x13, x14, [x0, #CTX_SPSR_IRQ] msr spsr_irq, x13 msr spsr_fiq, x14 ldp x15, x16, [x0, #CTX_DACR32_EL2] msr dacr32_el2, x15 msr ifsr32_el2, x16 #endif /* Restore NS timer registers if the build has instructed so */ #if NS_TIMER_SWITCH ldp x10, x11, [x0, #CTX_CNTP_CTL_EL0] msr cntp_ctl_el0, x10 msr cntp_cval_el0, x11 ldp x12, x13, [x0, #CTX_CNTV_CTL_EL0] msr cntv_ctl_el0, x12 msr cntv_cval_el0, x13 ldr x14, [x0, #CTX_CNTKCTL_EL1] msr cntkctl_el1, x14 #endif /* No explict ISB required here as ERET covers it */ ret endfunc el1_sysregs_context_restore /* ----------------------------------------------------- * The following function follows the aapcs_64 strictly * to use x9-x17 (temporary caller-saved registers * according to AArch64 PCS) to save floating point * register context. It assumes that 'x0' is pointing to * a 'fp_regs' structure where the register context will * be saved. * * Access to VFP registers will trap if CPTR_EL3.TFP is * set. However currently we don't use VFP registers * nor set traps in Trusted Firmware, and assume it's * cleared * * TODO: Revisit when VFP is used in secure world * ----------------------------------------------------- */ #if CTX_INCLUDE_FPREGS func fpregs_context_save stp q0, q1, [x0, #CTX_FP_Q0] stp q2, q3, [x0, #CTX_FP_Q2] stp q4, q5, [x0, #CTX_FP_Q4] stp q6, q7, [x0, #CTX_FP_Q6] stp q8, q9, [x0, #CTX_FP_Q8] stp q10, q11, [x0, #CTX_FP_Q10] stp q12, q13, [x0, #CTX_FP_Q12] stp q14, q15, [x0, #CTX_FP_Q14] stp q16, q17, [x0, #CTX_FP_Q16] stp q18, q19, [x0, #CTX_FP_Q18] stp q20, q21, [x0, #CTX_FP_Q20] stp q22, q23, [x0, #CTX_FP_Q22] stp q24, q25, [x0, #CTX_FP_Q24] stp q26, q27, [x0, #CTX_FP_Q26] stp q28, q29, [x0, #CTX_FP_Q28] stp q30, q31, [x0, #CTX_FP_Q30] mrs x9, fpsr str x9, [x0, #CTX_FP_FPSR] mrs x10, fpcr str x10, [x0, #CTX_FP_FPCR] #if CTX_INCLUDE_AARCH32_REGS mrs x11, fpexc32_el2 str x11, [x0, #CTX_FP_FPEXC32_EL2] #endif ret endfunc fpregs_context_save /* ----------------------------------------------------- * The following function follows the aapcs_64 strictly * to use x9-x17 (temporary caller-saved registers * according to AArch64 PCS) to restore floating point * register context. It assumes that 'x0' is pointing to * a 'fp_regs' structure from where the register context * will be restored. * * Access to VFP registers will trap if CPTR_EL3.TFP is * set. However currently we don't use VFP registers * nor set traps in Trusted Firmware, and assume it's * cleared * * TODO: Revisit when VFP is used in secure world * ----------------------------------------------------- */ func fpregs_context_restore ldp q0, q1, [x0, #CTX_FP_Q0] ldp q2, q3, [x0, #CTX_FP_Q2] ldp q4, q5, [x0, #CTX_FP_Q4] ldp q6, q7, [x0, #CTX_FP_Q6] ldp q8, q9, [x0, #CTX_FP_Q8] ldp q10, q11, [x0, #CTX_FP_Q10] ldp q12, q13, [x0, #CTX_FP_Q12] ldp q14, q15, [x0, #CTX_FP_Q14] ldp q16, q17, [x0, #CTX_FP_Q16] ldp q18, q19, [x0, #CTX_FP_Q18] ldp q20, q21, [x0, #CTX_FP_Q20] ldp q22, q23, [x0, #CTX_FP_Q22] ldp q24, q25, [x0, #CTX_FP_Q24] ldp q26, q27, [x0, #CTX_FP_Q26] ldp q28, q29, [x0, #CTX_FP_Q28] ldp q30, q31, [x0, #CTX_FP_Q30] ldr x9, [x0, #CTX_FP_FPSR] msr fpsr, x9 ldr x10, [x0, #CTX_FP_FPCR] msr fpcr, x10 #if CTX_INCLUDE_AARCH32_REGS ldr x11, [x0, #CTX_FP_FPEXC32_EL2] msr fpexc32_el2, x11 #endif /* * No explict ISB required here as ERET to * switch to secure EL1 or non-secure world * covers it */ ret endfunc fpregs_context_restore #endif /* CTX_INCLUDE_FPREGS */ /* ----------------------------------------------------- * The following functions are used to save and restore * all the general purpose registers. Ideally we would * only save and restore the callee saved registers when * a world switch occurs but that type of implementation * is more complex. So currently we will always save and * restore these registers on entry and exit of EL3. * These are not macros to ensure their invocation fits * within the 32 instructions per exception vector. * clobbers: x18 * ----------------------------------------------------- */ func save_gp_registers stp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] stp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] stp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4] stp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6] stp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8] stp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10] stp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12] stp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14] stp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16] stp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18] stp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20] stp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22] stp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24] stp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26] stp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28] mrs x18, sp_el0 str x18, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_SP_EL0] ret endfunc save_gp_registers /* ----------------------------------------------------- * This function restores all general purpose registers except x30 from the * CPU context. x30 register must be explicitly restored by the caller. * ----------------------------------------------------- */ func restore_gp_registers ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] ldp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4] ldp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6] ldp x8, x9, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X8] ldp x10, x11, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X10] ldp x12, x13, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X12] ldp x14, x15, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X14] ldp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16] ldp x18, x19, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X18] ldp x20, x21, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X20] ldp x22, x23, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X22] ldp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24] ldp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26] ldr x28, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_SP_EL0] msr sp_el0, x28 ldp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28] ret endfunc restore_gp_registers /* ----------------------------------------------------- * Restore general purpose registers (including x30), and exit EL3 via. ERET to * a lower exception level. * ----------------------------------------------------- */ func restore_gp_registers_eret bl restore_gp_registers ldr x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] #if IMAGE_BL31 && RAS_EXTENSION /* * Issue Error Synchronization Barrier to synchronize SErrors before * exiting EL3. We're running with EAs unmasked, so any synchronized * errors would be taken immediately; therefore no need to inspect * DISR_EL1 register. */ esb #endif eret endfunc restore_gp_registers_eret /* ----------------------------------------------------- * This routine assumes that the SP_EL3 is pointing to * a valid context structure from where the gp regs and * other special registers can be retrieved. * ----------------------------------------------------- */ func el3_exit /* ----------------------------------------------------- * Save the current SP_EL0 i.e. the EL3 runtime stack * which will be used for handling the next SMC. Then * switch to SP_EL3 * ----------------------------------------------------- */ mov x17, sp msr spsel, #1 str x17, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP] /* ----------------------------------------------------- * Restore SPSR_EL3, ELR_EL3 and SCR_EL3 prior to ERET * ----------------------------------------------------- */ ldr x18, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3] ldp x16, x17, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3] msr scr_el3, x18 msr spsr_el3, x16 msr elr_el3, x17 #if IMAGE_BL31 && DYNAMIC_WORKAROUND_CVE_2018_3639 /* Restore mitigation state as it was on entry to EL3 */ ldr x17, [sp, #CTX_CVE_2018_3639_OFFSET + CTX_CVE_2018_3639_DISABLE] cmp x17, xzr beq 1f blr x17 1: #endif /* Restore saved general purpose registers and return */ b restore_gp_registers_eret endfunc el3_exit