| /* |
| * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| #include <arch.h> |
| #include <asm_macros.S> |
| #include <context.h> |
| #include <cpu_data.h> |
| #include <interrupt_mgmt.h> |
| #include <platform_def.h> |
| #include <runtime_svc.h> |
| |
| .globl runtime_exceptions |
| |
| /* --------------------------------------------------------------------- |
| * This macro handles Synchronous exceptions. |
| * Only SMC exceptions are supported. |
| * --------------------------------------------------------------------- |
| */ |
| .macro handle_sync_exception |
| /* Enable the SError interrupt */ |
| msr daifclr, #DAIF_ABT_BIT |
| |
| str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] |
| |
| #if ENABLE_RUNTIME_INSTRUMENTATION |
| /* |
| * Read the timestamp value and store it in per-cpu data. The value |
| * will be extracted from per-cpu data by the C level SMC handler and |
| * saved to the PMF timestamp region. |
| */ |
| mrs x30, cntpct_el0 |
| str x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29] |
| mrs x29, tpidr_el3 |
| str x30, [x29, #CPU_DATA_PMF_TS0_OFFSET] |
| ldr x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29] |
| #endif |
| |
| mrs x30, esr_el3 |
| ubfx x30, x30, #ESR_EC_SHIFT, #ESR_EC_LENGTH |
| |
| /* Handle SMC exceptions separately from other synchronous exceptions */ |
| cmp x30, #EC_AARCH32_SMC |
| b.eq smc_handler32 |
| |
| cmp x30, #EC_AARCH64_SMC |
| b.eq smc_handler64 |
| |
| /* Other kinds of synchronous exceptions are not handled */ |
| no_ret report_unhandled_exception |
| .endm |
| |
| |
| /* --------------------------------------------------------------------- |
| * This macro handles FIQ or IRQ interrupts i.e. EL3, S-EL1 and NS |
| * interrupts. |
| * --------------------------------------------------------------------- |
| */ |
| .macro handle_interrupt_exception label |
| /* Enable the SError interrupt */ |
| msr daifclr, #DAIF_ABT_BIT |
| |
| str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] |
| bl save_gp_registers |
| |
| /* Save the EL3 system registers needed to return from this exception */ |
| mrs x0, spsr_el3 |
| mrs x1, elr_el3 |
| stp x0, x1, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3] |
| |
| /* Switch to the runtime stack i.e. SP_EL0 */ |
| ldr x2, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP] |
| mov x20, sp |
| msr spsel, #0 |
| mov sp, x2 |
| |
| /* |
| * Find out whether this is a valid interrupt type. |
| * If the interrupt controller reports a spurious interrupt then return |
| * to where we came from. |
| */ |
| bl plat_ic_get_pending_interrupt_type |
| cmp x0, #INTR_TYPE_INVAL |
| b.eq interrupt_exit_\label |
| |
| /* |
| * Get the registered handler for this interrupt type. |
| * A NULL return value could be 'cause of the following conditions: |
| * |
| * a. An interrupt of a type was routed correctly but a handler for its |
| * type was not registered. |
| * |
| * b. An interrupt of a type was not routed correctly so a handler for |
| * its type was not registered. |
| * |
| * c. An interrupt of a type was routed correctly to EL3, but was |
| * deasserted before its pending state could be read. Another |
| * interrupt of a different type pended at the same time and its |
| * type was reported as pending instead. However, a handler for this |
| * type was not registered. |
| * |
| * a. and b. can only happen due to a programming error. The |
| * occurrence of c. could be beyond the control of Trusted Firmware. |
| * It makes sense to return from this exception instead of reporting an |
| * error. |
| */ |
| bl get_interrupt_type_handler |
| cbz x0, interrupt_exit_\label |
| mov x21, x0 |
| |
| mov x0, #INTR_ID_UNAVAILABLE |
| |
| /* Set the current security state in the 'flags' parameter */ |
| mrs x2, scr_el3 |
| ubfx x1, x2, #0, #1 |
| |
| /* Restore the reference to the 'handle' i.e. SP_EL3 */ |
| mov x2, x20 |
| |
| /* x3 will point to a cookie (not used now) */ |
| mov x3, xzr |
| |
| /* Call the interrupt type handler */ |
| blr x21 |
| |
| interrupt_exit_\label: |
| /* Return from exception, possibly in a different security state */ |
| b el3_exit |
| |
| .endm |
| |
| |
| .macro save_x18_to_x29_sp_el0 |
| 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] |
| .endm |
| |
| |
| vector_base runtime_exceptions |
| |
| /* --------------------------------------------------------------------- |
| * Current EL with SP_EL0 : 0x0 - 0x200 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry sync_exception_sp_el0 |
| /* We don't expect any synchronous exceptions from EL3 */ |
| no_ret report_unhandled_exception |
| check_vector_size sync_exception_sp_el0 |
| |
| vector_entry irq_sp_el0 |
| /* |
| * EL3 code is non-reentrant. Any asynchronous exception is a serious |
| * error. Loop infinitely. |
| */ |
| no_ret report_unhandled_interrupt |
| check_vector_size irq_sp_el0 |
| |
| |
| vector_entry fiq_sp_el0 |
| no_ret report_unhandled_interrupt |
| check_vector_size fiq_sp_el0 |
| |
| |
| vector_entry serror_sp_el0 |
| no_ret report_unhandled_exception |
| check_vector_size serror_sp_el0 |
| |
| /* --------------------------------------------------------------------- |
| * Current EL with SP_ELx: 0x200 - 0x400 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry sync_exception_sp_elx |
| /* |
| * This exception will trigger if anything went wrong during a previous |
| * exception entry or exit or while handling an earlier unexpected |
| * synchronous exception. There is a high probability that SP_EL3 is |
| * corrupted. |
| */ |
| no_ret report_unhandled_exception |
| check_vector_size sync_exception_sp_elx |
| |
| vector_entry irq_sp_elx |
| no_ret report_unhandled_interrupt |
| check_vector_size irq_sp_elx |
| |
| vector_entry fiq_sp_elx |
| no_ret report_unhandled_interrupt |
| check_vector_size fiq_sp_elx |
| |
| vector_entry serror_sp_elx |
| no_ret report_unhandled_exception |
| check_vector_size serror_sp_elx |
| |
| /* --------------------------------------------------------------------- |
| * Lower EL using AArch64 : 0x400 - 0x600 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry sync_exception_aarch64 |
| /* |
| * This exception vector will be the entry point for SMCs and traps |
| * that are unhandled at lower ELs most commonly. SP_EL3 should point |
| * to a valid cpu context where the general purpose and system register |
| * state can be saved. |
| */ |
| handle_sync_exception |
| check_vector_size sync_exception_aarch64 |
| |
| vector_entry irq_aarch64 |
| handle_interrupt_exception irq_aarch64 |
| check_vector_size irq_aarch64 |
| |
| vector_entry fiq_aarch64 |
| handle_interrupt_exception fiq_aarch64 |
| check_vector_size fiq_aarch64 |
| |
| vector_entry serror_aarch64 |
| /* |
| * SError exceptions from lower ELs are not currently supported. |
| * Report their occurrence. |
| */ |
| no_ret report_unhandled_exception |
| check_vector_size serror_aarch64 |
| |
| /* --------------------------------------------------------------------- |
| * Lower EL using AArch32 : 0x600 - 0x800 |
| * --------------------------------------------------------------------- |
| */ |
| vector_entry sync_exception_aarch32 |
| /* |
| * This exception vector will be the entry point for SMCs and traps |
| * that are unhandled at lower ELs most commonly. SP_EL3 should point |
| * to a valid cpu context where the general purpose and system register |
| * state can be saved. |
| */ |
| handle_sync_exception |
| check_vector_size sync_exception_aarch32 |
| |
| vector_entry irq_aarch32 |
| handle_interrupt_exception irq_aarch32 |
| check_vector_size irq_aarch32 |
| |
| vector_entry fiq_aarch32 |
| handle_interrupt_exception fiq_aarch32 |
| check_vector_size fiq_aarch32 |
| |
| vector_entry serror_aarch32 |
| /* |
| * SError exceptions from lower ELs are not currently supported. |
| * Report their occurrence. |
| */ |
| no_ret report_unhandled_exception |
| check_vector_size serror_aarch32 |
| |
| |
| /* --------------------------------------------------------------------- |
| * The following code handles secure monitor calls. |
| * Depending upon the execution state from where the SMC has been |
| * invoked, it frees some general purpose registers to perform the |
| * remaining tasks. They involve finding the runtime service handler |
| * that is the target of the SMC & switching to runtime stacks (SP_EL0) |
| * before calling the handler. |
| * |
| * Note that x30 has been explicitly saved and can be used here |
| * --------------------------------------------------------------------- |
| */ |
| func smc_handler |
| smc_handler32: |
| /* Check whether aarch32 issued an SMC64 */ |
| tbnz x0, #FUNCID_CC_SHIFT, smc_prohibited |
| |
| /* |
| * Since we're are coming from aarch32, x8-x18 need to be saved as per |
| * SMC32 calling convention. If a lower EL in aarch64 is making an |
| * SMC32 call then it must have saved x8-x17 already therein. |
| */ |
| 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] |
| |
| /* x4-x7, x18, sp_el0 are saved below */ |
| |
| smc_handler64: |
| /* |
| * Populate the parameters for the SMC handler. |
| * We already have x0-x4 in place. x5 will point to a cookie (not used |
| * now). x6 will point to the context structure (SP_EL3) and x7 will |
| * contain flags we need to pass to the handler Hence save x5-x7. |
| * |
| * Note: x4 only needs to be preserved for AArch32 callers but we do it |
| * for AArch64 callers as well for convenience |
| */ |
| stp x4, x5, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X4] |
| stp x6, x7, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X6] |
| |
| /* Save rest of the gpregs and sp_el0*/ |
| save_x18_to_x29_sp_el0 |
| |
| mov x5, xzr |
| mov x6, sp |
| |
| /* Get the unique owning entity number */ |
| ubfx x16, x0, #FUNCID_OEN_SHIFT, #FUNCID_OEN_WIDTH |
| ubfx x15, x0, #FUNCID_TYPE_SHIFT, #FUNCID_TYPE_WIDTH |
| orr x16, x16, x15, lsl #FUNCID_OEN_WIDTH |
| |
| adr x11, (__RT_SVC_DESCS_START__ + RT_SVC_DESC_HANDLE) |
| |
| /* Load descriptor index from array of indices */ |
| adr x14, rt_svc_descs_indices |
| ldrb w15, [x14, x16] |
| |
| /* |
| * Restore the saved C runtime stack value which will become the new |
| * SP_EL0 i.e. EL3 runtime stack. It was saved in the 'cpu_context' |
| * structure prior to the last ERET from EL3. |
| */ |
| ldr x12, [x6, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP] |
| |
| /* |
| * Any index greater than 127 is invalid. Check bit 7 for |
| * a valid index |
| */ |
| tbnz w15, 7, smc_unknown |
| |
| /* Switch to SP_EL0 */ |
| msr spsel, #0 |
| |
| /* |
| * Get the descriptor using the index |
| * x11 = (base + off), x15 = index |
| * |
| * handler = (base + off) + (index << log2(size)) |
| */ |
| lsl w10, w15, #RT_SVC_SIZE_LOG2 |
| ldr x15, [x11, w10, uxtw] |
| |
| /* |
| * Save the SPSR_EL3, ELR_EL3, & SCR_EL3 in case there is a world |
| * switch during SMC handling. |
| * TODO: Revisit if all system registers can be saved later. |
| */ |
| mrs x16, spsr_el3 |
| mrs x17, elr_el3 |
| mrs x18, scr_el3 |
| stp x16, x17, [x6, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3] |
| str x18, [x6, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3] |
| |
| /* Copy SCR_EL3.NS bit to the flag to indicate caller's security */ |
| bfi x7, x18, #0, #1 |
| |
| mov sp, x12 |
| |
| /* |
| * Call the Secure Monitor Call handler and then drop directly into |
| * el3_exit() which will program any remaining architectural state |
| * prior to issuing the ERET to the desired lower EL. |
| */ |
| #if DEBUG |
| cbz x15, rt_svc_fw_critical_error |
| #endif |
| blr x15 |
| |
| b el3_exit |
| |
| smc_unknown: |
| /* |
| * Here we restore x4-x18 regardless of where we came from. AArch32 |
| * callers will find the registers contents unchanged, but AArch64 |
| * callers will find the registers modified (with stale earlier NS |
| * content). Either way, we aren't leaking any secure information |
| * through them. |
| */ |
| mov w0, #SMC_UNK |
| b restore_gp_registers_callee_eret |
| |
| smc_prohibited: |
| ldr x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] |
| mov w0, #SMC_UNK |
| eret |
| |
| rt_svc_fw_critical_error: |
| /* Switch to SP_ELx */ |
| msr spsel, #1 |
| no_ret report_unhandled_exception |
| endfunc smc_handler |
