| /* |
| * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| |
| #include <asm_macros.S> |
| #include <assert_macros.S> |
| #include <context.h> |
| #include <ea_handle.h> |
| #include <ras_arch.h> |
| |
| |
| .globl handle_lower_el_ea_esb |
| .globl enter_lower_el_sync_ea |
| .globl enter_lower_el_async_ea |
| |
| |
| /* |
| * Function to delegate External Aborts synchronized by ESB instruction at EL3 |
| * vector entry. This function assumes GP registers x0-x29 have been saved, and |
| * are available for use. It delegates the handling of the EA to platform |
| * handler, and returns only upon successfully handling the EA; otherwise |
| * panics. On return from this function, the original exception handler is |
| * expected to resume. |
| */ |
| func handle_lower_el_ea_esb |
| mov x0, #ERROR_EA_ESB |
| mrs x1, DISR_EL1 |
| b ea_proceed |
| endfunc handle_lower_el_ea_esb |
| |
| |
| /* |
| * This function forms the tail end of Synchronous Exception entry from lower |
| * EL, and expects to handle only Synchronous External Aborts from lower EL. If |
| * any other kind of exception is detected, then this function reports unhandled |
| * exception. |
| * |
| * Since it's part of exception vector, this function doesn't expect any GP |
| * registers to have been saved. It delegates the handling of the EA to platform |
| * handler, and upon successfully handling the EA, exits EL3; otherwise panics. |
| */ |
| func enter_lower_el_sync_ea |
| /* |
| * Explicitly save x30 so as to free up a register and to enable |
| * branching. |
| */ |
| str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] |
| |
| mrs x30, esr_el3 |
| ubfx x30, x30, #ESR_EC_SHIFT, #ESR_EC_LENGTH |
| |
| /* Check for I/D aborts from lower EL */ |
| cmp x30, #EC_IABORT_LOWER_EL |
| b.eq 1f |
| |
| cmp x30, #EC_DABORT_LOWER_EL |
| b.ne 2f |
| |
| 1: |
| /* Test for EA bit in the instruction syndrome */ |
| mrs x30, esr_el3 |
| tbz x30, #ESR_ISS_EABORT_EA_BIT, 2f |
| |
| /* Save GP registers */ |
| bl save_gp_registers |
| |
| /* Setup exception class and syndrome arguments for platform handler */ |
| mov x0, #ERROR_EA_SYNC |
| mrs x1, esr_el3 |
| adr x30, el3_exit |
| b delegate_sync_ea |
| |
| 2: |
| /* Synchronous exceptions other than the above are assumed to be EA */ |
| ldr x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] |
| no_ret report_unhandled_exception |
| endfunc enter_lower_el_sync_ea |
| |
| |
| /* |
| * This function handles SErrors from lower ELs. |
| * |
| * Since it's part of exception vector, this function doesn't expect any GP |
| * registers to have been saved. It delegates the handling of the EA to platform |
| * handler, and upon successfully handling the EA, exits EL3; otherwise panics. |
| */ |
| func enter_lower_el_async_ea |
| /* |
| * Explicitly save x30 so as to free up a register and to enable |
| * branching |
| */ |
| str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] |
| |
| /* Save GP registers */ |
| bl save_gp_registers |
| |
| /* Setup exception class and syndrome arguments for platform handler */ |
| mov x0, #ERROR_EA_ASYNC |
| mrs x1, esr_el3 |
| adr x30, el3_exit |
| b delegate_async_ea |
| endfunc enter_lower_el_async_ea |
| |
| |
| /* |
| * Prelude for Synchronous External Abort handling. This function assumes that |
| * all GP registers have been saved by the caller. |
| * |
| * x0: EA reason |
| * x1: EA syndrome |
| */ |
| func delegate_sync_ea |
| #if RAS_EXTENSION |
| /* |
| * Check for Uncontainable error type. If so, route to the platform |
| * fatal error handler rather than the generic EA one. |
| */ |
| ubfx x2, x1, #EABORT_SET_SHIFT, #EABORT_SET_WIDTH |
| cmp x2, #ERROR_STATUS_SET_UC |
| b.ne 1f |
| |
| /* Check fault status code */ |
| ubfx x3, x1, #EABORT_DFSC_SHIFT, #EABORT_DFSC_WIDTH |
| cmp x3, #SYNC_EA_FSC |
| b.ne 1f |
| |
| no_ret plat_handle_uncontainable_ea |
| 1: |
| #endif |
| |
| b ea_proceed |
| endfunc delegate_sync_ea |
| |
| |
| /* |
| * Prelude for Asynchronous External Abort handling. This function assumes that |
| * all GP registers have been saved by the caller. |
| * |
| * x0: EA reason |
| * x1: EA syndrome |
| */ |
| func delegate_async_ea |
| #if RAS_EXTENSION |
| /* |
| * Check for Implementation Defined Syndrome. If so, skip checking |
| * Uncontainable error type from the syndrome as the format is unknown. |
| */ |
| tbnz x1, #SERROR_IDS_BIT, 1f |
| |
| /* |
| * Check for Uncontainable error type. If so, route to the platform |
| * fatal error handler rather than the generic EA one. |
| */ |
| ubfx x2, x1, #EABORT_AET_SHIFT, #EABORT_AET_WIDTH |
| cmp x2, #ERROR_STATUS_UET_UC |
| b.ne 1f |
| |
| /* Check DFSC for SError type */ |
| ubfx x3, x1, #EABORT_DFSC_SHIFT, #EABORT_DFSC_WIDTH |
| cmp x3, #DFSC_SERROR |
| b.ne 1f |
| |
| no_ret plat_handle_uncontainable_ea |
| 1: |
| #endif |
| |
| b ea_proceed |
| endfunc delegate_async_ea |
| |
| |
| /* |
| * Delegate External Abort handling to platform's EA handler. This function |
| * assumes that all GP registers have been saved by the caller. |
| * |
| * x0: EA reason |
| * x1: EA syndrome |
| */ |
| func ea_proceed |
| /* Save EL3 state */ |
| mrs x2, spsr_el3 |
| mrs x3, elr_el3 |
| stp x2, x3, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3] |
| |
| /* |
| * Save ESR as handling might involve lower ELs, and returning back to |
| * EL3 from there would trample the original ESR. |
| */ |
| mrs x4, scr_el3 |
| mrs x5, esr_el3 |
| stp x4, x5, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3] |
| |
| /* |
| * Setup rest of arguments, and call platform External Abort handler. |
| * |
| * x0: EA reason (already in place) |
| * x1: Exception syndrome (already in place). |
| * x2: Cookie (unused for now). |
| * x3: Context pointer. |
| * x4: Flags (security state from SCR for now). |
| */ |
| mov x2, xzr |
| mov x3, sp |
| ubfx x4, x4, #0, #1 |
| |
| /* Switch to runtime stack */ |
| ldr x5, [sp, #CTX_EL3STATE_OFFSET + CTX_RUNTIME_SP] |
| msr spsel, #0 |
| mov sp, x5 |
| |
| mov x29, x30 |
| #if ENABLE_ASSERTIONS |
| /* Stash the stack pointer */ |
| mov x28, sp |
| #endif |
| bl plat_ea_handler |
| mov x30, x29 |
| |
| #if ENABLE_ASSERTIONS |
| /* |
| * Error handling flows might involve long jumps; so upon returning from |
| * the platform error handler, validate that the we've completely |
| * unwound the stack. |
| */ |
| mov x27, sp |
| cmp x28, x27 |
| ASM_ASSERT(eq) |
| #endif |
| |
| /* Make SP point to context */ |
| msr spsel, #1 |
| |
| /* Restore EL3 state */ |
| ldp x1, x2, [sp, #CTX_EL3STATE_OFFSET + CTX_SPSR_EL3] |
| msr spsr_el3, x1 |
| msr elr_el3, x2 |
| |
| /* Restore ESR_EL3 and SCR_EL3 */ |
| ldp x3, x4, [sp, #CTX_EL3STATE_OFFSET + CTX_SCR_EL3] |
| msr scr_el3, x3 |
| msr esr_el3, x4 |
| |
| ret |
| endfunc ea_proceed |