diff options
Diffstat (limited to 'common/aarch64/context.S')
-rw-r--r-- | common/aarch64/context.S | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/common/aarch64/context.S b/common/aarch64/context.S new file mode 100644 index 0000000000..3d13a8027d --- /dev/null +++ b/common/aarch64/context.S @@ -0,0 +1,401 @@ +/* + * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of ARM nor the names of its contributors may be used + * to endorse or promote products derived from this software without specific + * prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <arch.h> +#include <asm_macros.S> +#include <context.h> + + .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_eret + .global restore_gp_registers_callee_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 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, 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 x11, dacr32_el2 + mrs x12, ifsr32_el2 + stp x11, x12, [x0, #CTX_DACR32_EL2] + + 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] + + /* 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 + + mrs x15, fpexc32_el2 + str x15, [x0, #CTX_FP_FPEXC32_EL2] + + 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 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_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 x11, x12, [x0, #CTX_DACR32_EL2] + msr dacr32_el2, x11 + msr ifsr32_el2, x12 + + 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 + + /* 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 + + ldr x15, [x0, #CTX_FP_FPEXC32_EL2] + msr fpexc32_el2, x15 + + /* 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] + + 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 + + /* + * No explict ISB required here as ERET to + * swtich 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 + +func restore_gp_registers_eret + ldp x0, x1, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X0] + ldp x2, x3, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2] + b restore_gp_registers_callee_eret +endfunc restore_gp_registers_eret + +func restore_gp_registers_callee_eret + 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 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] + ldp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28] + ldp x30, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] + msr sp_el0, x17 + ldp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16] + eret +endfunc restore_gp_registers_callee_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 + + /* Restore saved general purpose registers and return */ + b restore_gp_registers_eret +endfunc el3_exit |