1 /* 2 * Copyright (c) 2021-2022, ProvenRun S.A.S. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <string.h> 9 10 #include <arch_helpers.h> 11 #include <common/bl_common.h> 12 #include <common/debug.h> 13 #include <lib/el3_runtime/context_mgmt.h> 14 #include <lib/utils.h> 15 #include <plat/common/platform.h> 16 17 #include "pncd_private.h" 18 19 /******************************************************************************* 20 * Given a secure payload entrypoint info pointer, entry point PC & pointer to a 21 * context data structure, this function will initialize pnc context and entry 22 * point info for the secure payload 23 ******************************************************************************/ 24 void pncd_init_pnc_ep_state(struct entry_point_info *pnc_entry_point, 25 uint64_t pc, 26 pnc_context_t *pnc_ctx) 27 { 28 uint32_t ep_attr; 29 30 /* Passing a NULL context is a critical programming error */ 31 assert(pnc_ctx); 32 assert(pnc_entry_point); 33 assert(pc); 34 35 /* Associate this context with the current cpu */ 36 pnc_ctx->mpidr = read_mpidr(); 37 38 cm_set_context(&pnc_ctx->cpu_ctx, SECURE); 39 40 /* initialise an entrypoint to set up the CPU context */ 41 ep_attr = SECURE | EP_ST_ENABLE; 42 if (read_sctlr_el3() & SCTLR_EE_BIT) { 43 ep_attr |= EP_EE_BIG; 44 } 45 SET_PARAM_HEAD(pnc_entry_point, PARAM_EP, VERSION_1, ep_attr); 46 47 pnc_entry_point->pc = pc; 48 pnc_entry_point->spsr = SPSR_64(MODE_EL1, 49 MODE_SP_ELX, 50 DISABLE_ALL_EXCEPTIONS); 51 memset(&pnc_entry_point->args, 0, sizeof(pnc_entry_point->args)); 52 } 53 54 /******************************************************************************* 55 * This function takes an SP context pointer and: 56 * 1. Applies the S-EL1 system register context from pnc_ctx->cpu_ctx. 57 * 2. Saves the current C runtime state (callee saved registers) on the stack 58 * frame and saves a reference to this state. 59 * 3. Calls el3_exit() so that the EL3 system and general purpose registers 60 * from the pnc_ctx->cpu_ctx are used to enter the secure payload image. 61 ******************************************************************************/ 62 uint64_t pncd_synchronous_sp_entry(pnc_context_t *pnc_ctx) 63 { 64 assert(pnc_ctx != NULL); 65 assert(pnc_ctx->c_rt_ctx == 0U); 66 67 /* Apply the Secure EL1 system register context and switch to it */ 68 assert(cm_get_context(SECURE) == &pnc_ctx->cpu_ctx); 69 cm_el1_sysregs_context_restore(SECURE); 70 71 #if CTX_INCLUDE_FPREGS 72 simd_ctx_restore(SECURE); 73 #endif 74 cm_set_next_eret_context(SECURE); 75 76 return pncd_enter_sp(&pnc_ctx->c_rt_ctx); 77 } 78 79 80 /******************************************************************************* 81 * This function takes an SP context pointer and: 82 * 1. Saves the S-EL1 system register context tp pnc_ctx->cpu_ctx. 83 * 2. Restores the current C runtime state (callee saved registers) from the 84 * stack frame using the reference to this state saved in pncd_enter_sp(). 85 * 3. It does not need to save any general purpose or EL3 system register state 86 * as the generic smc entry routine should have saved those. 87 ******************************************************************************/ 88 void pncd_synchronous_sp_exit(pnc_context_t *pnc_ctx, uint64_t ret) 89 { 90 assert(pnc_ctx != NULL); 91 /* Save the Secure EL1 system register context */ 92 assert(cm_get_context(SECURE) == &pnc_ctx->cpu_ctx); 93 cm_el1_sysregs_context_save(SECURE); 94 95 #if CTX_INCLUDE_FPREGS 96 simd_ctx_save(SECURE, false); 97 #endif 98 99 assert(pnc_ctx->c_rt_ctx != 0); 100 pncd_exit_sp(pnc_ctx->c_rt_ctx, ret); 101 102 /* Should never reach here */ 103 panic(); 104 } 105