diff options
Diffstat (limited to 'include/arch/aarch32/smccc_macros.S')
| -rw-r--r-- | include/arch/aarch32/smccc_macros.S | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/include/arch/aarch32/smccc_macros.S b/include/arch/aarch32/smccc_macros.S new file mode 100644 index 0000000..ea7835a --- /dev/null +++ b/include/arch/aarch32/smccc_macros.S @@ -0,0 +1,241 @@ +/* + * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ +#ifndef SMCCC_MACROS_S +#define SMCCC_MACROS_S + +#include <arch.h> + +/* + * Macro to save the General purpose registers (r0 - r12), the banked + * spsr, lr, sp registers and the `scr` register to the SMC context on entry + * due a SMC call. The `lr` of the current mode (monitor) is expected to be + * already saved. The `sp` must point to the `smc_ctx_t` to save to. + * Additionally, also save the 'pmcr' register as this is updated whilst + * executing in the secure world. + */ + .macro smccc_save_gp_mode_regs + /* Save r0 - r12 in the SMC context */ + stm sp, {r0-r12} + mov r0, sp + add r0, r0, #SMC_CTX_SP_USR + +#if ARM_ARCH_MAJOR == 7 && !defined(ARMV7_SUPPORTS_VIRTUALIZATION) + /* Must be in secure state to restore Monitor mode */ + ldcopr r4, SCR + bic r2, r4, #SCR_NS_BIT + stcopr r2, SCR + isb + + cps #MODE32_sys + stm r0!, {sp, lr} + + cps #MODE32_irq + mrs r2, spsr + stm r0!, {r2, sp, lr} + + cps #MODE32_fiq + mrs r2, spsr + stm r0!, {r2, sp, lr} + + cps #MODE32_svc + mrs r2, spsr + stm r0!, {r2, sp, lr} + + cps #MODE32_abt + mrs r2, spsr + stm r0!, {r2, sp, lr} + + cps #MODE32_und + mrs r2, spsr + stm r0!, {r2, sp, lr} + + /* lr_mon is already saved by caller */ + cps #MODE32_mon + mrs r2, spsr + stm r0!, {r2} + + stcopr r4, SCR +#else + /* Save the banked registers including the current SPSR and LR */ + mrs r4, sp_usr + mrs r5, lr_usr + mrs r6, spsr_irq + mrs r7, sp_irq + mrs r8, lr_irq + mrs r9, spsr_fiq + mrs r10, sp_fiq + mrs r11, lr_fiq + mrs r12, spsr_svc + stm r0!, {r4-r12} + + mrs r4, sp_svc + mrs r5, lr_svc + mrs r6, spsr_abt + mrs r7, sp_abt + mrs r8, lr_abt + mrs r9, spsr_und + mrs r10, sp_und + mrs r11, lr_und + mrs r12, spsr + stm r0!, {r4-r12} + /* lr_mon is already saved by caller */ + + ldcopr r4, SCR + +#if ARM_ARCH_MAJOR > 7 + /* + * Check if earlier initialization of SDCR.SCCD to 1 + * failed, meaning that ARMv8-PMU is not implemented, + * cycle counting is not disabled and PMCR should be + * saved in Non-secure context. + */ + ldcopr r5, SDCR + tst r5, #SDCR_SCCD_BIT + bne 1f +#endif + /* Secure Cycle Counter is not disabled */ +#endif + ldcopr r5, PMCR + + /* Check caller's security state */ + tst r4, #SCR_NS_BIT + beq 2f + + /* Save PMCR if called from Non-secure state */ + str r5, [sp, #SMC_CTX_PMCR] + + /* Disable cycle counter when event counting is prohibited */ +2: orr r5, r5, #PMCR_DP_BIT + stcopr r5, PMCR + isb +1: str r4, [sp, #SMC_CTX_SCR] + .endm + +/* + * Macro to restore the `smc_ctx_t`, which includes the General purpose + * registers and banked mode registers, and exit from the monitor mode. + * r0 must point to the `smc_ctx_t` to restore from. + */ + .macro monitor_exit + /* + * Save the current sp and restore the smc context + * pointer to sp which will be used for handling the + * next SMC. + */ + str sp, [r0, #SMC_CTX_SP_MON] + mov sp, r0 + + /* + * Restore SCR first so that we access the right banked register + * when the other mode registers are restored. + */ + ldr r1, [r0, #SMC_CTX_SCR] + stcopr r1, SCR + isb + + /* + * Restore PMCR when returning to Non-secure state + */ + tst r1, #SCR_NS_BIT + beq 2f + + /* + * Back to Non-secure state + */ +#if ARM_ARCH_MAJOR > 7 + /* + * Check if earlier initialization SDCR.SCCD to 1 + * failed, meaning that ARMv8-PMU is not implemented and + * PMCR should be restored from Non-secure context. + */ + ldcopr r1, SDCR + tst r1, #SDCR_SCCD_BIT + bne 2f +#endif + /* + * Restore the PMCR register. + */ + ldr r1, [r0, #SMC_CTX_PMCR] + stcopr r1, PMCR +2: + /* Restore the banked registers including the current SPSR */ + add r1, r0, #SMC_CTX_SP_USR + +#if ARM_ARCH_MAJOR == 7 && !defined(ARMV7_SUPPORTS_VIRTUALIZATION) + /* Must be in secure state to restore Monitor mode */ + ldcopr r4, SCR + bic r2, r4, #SCR_NS_BIT + stcopr r2, SCR + isb + + cps #MODE32_sys + ldm r1!, {sp, lr} + + cps #MODE32_irq + ldm r1!, {r2, sp, lr} + msr spsr_fsxc, r2 + + cps #MODE32_fiq + ldm r1!, {r2, sp, lr} + msr spsr_fsxc, r2 + + cps #MODE32_svc + ldm r1!, {r2, sp, lr} + msr spsr_fsxc, r2 + + cps #MODE32_abt + ldm r1!, {r2, sp, lr} + msr spsr_fsxc, r2 + + cps #MODE32_und + ldm r1!, {r2, sp, lr} + msr spsr_fsxc, r2 + + cps #MODE32_mon + ldm r1!, {r2} + msr spsr_fsxc, r2 + + stcopr r4, SCR + isb +#else + ldm r1!, {r4-r12} + msr sp_usr, r4 + msr lr_usr, r5 + msr spsr_irq, r6 + msr sp_irq, r7 + msr lr_irq, r8 + msr spsr_fiq, r9 + msr sp_fiq, r10 + msr lr_fiq, r11 + msr spsr_svc, r12 + + ldm r1!, {r4-r12} + msr sp_svc, r4 + msr lr_svc, r5 + msr spsr_abt, r6 + msr sp_abt, r7 + msr lr_abt, r8 + msr spsr_und, r9 + msr sp_und, r10 + msr lr_und, r11 + /* + * Use the `_fsxc` suffix explicitly to instruct the assembler + * to update all the 32 bits of SPSR. Else, by default, the + * assembler assumes `_fc` suffix which only modifies + * f->[31:24] and c->[7:0] bits of SPSR. + */ + msr spsr_fsxc, r12 +#endif + + /* Restore the LR */ + ldr lr, [r0, #SMC_CTX_LR_MON] + + /* Restore the rest of the general purpose registers */ + ldm r0, {r0-r12} + exception_return + .endm + +#endif /* SMCCC_MACROS_S */ |