1 /* 2 * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <arch_helpers.h> 32 #include <assert.h> 33 #include <bl_common.h> 34 #include <context_mgmt.h> 35 #include <string.h> 36 #include "tlkd_private.h" 37 38 /******************************************************************************* 39 * Given a secure payload entrypoint, register width, cpu id & pointer to a 40 * context data structure, this function will create a secure context ready for 41 * programming an entry into the secure payload. 42 ******************************************************************************/ 43 void tlkd_init_tlk_ep_state(struct entry_point_info *tlk_entry_point, 44 uint32_t rw, 45 uint64_t pc, 46 tlk_context_t *tlk_ctx) 47 { 48 uint32_t ep_attr, spsr; 49 50 /* Passing a NULL context is a critical programming error */ 51 assert(tlk_ctx); 52 assert(tlk_entry_point); 53 assert(pc); 54 55 /* Associate this context with the cpu specified */ 56 tlk_ctx->mpidr = read_mpidr_el1(); 57 clr_std_smc_active_flag(tlk_ctx->state); 58 cm_set_context(&tlk_ctx->cpu_ctx, SECURE); 59 60 if (rw == SP_AARCH64) 61 spsr = SPSR_64(MODE_EL1, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS); 62 else 63 spsr = SPSR_MODE32(MODE32_svc, 64 SPSR_T_ARM, 65 read_sctlr_el3() & SCTLR_EE_BIT, 66 DISABLE_ALL_EXCEPTIONS); 67 68 /* initialise an entrypoint to set up the CPU context */ 69 ep_attr = SECURE | EP_ST_ENABLE; 70 if (read_sctlr_el3() & SCTLR_EE_BIT) 71 ep_attr |= EP_EE_BIG; 72 SET_PARAM_HEAD(tlk_entry_point, PARAM_EP, VERSION_1, ep_attr); 73 74 tlk_entry_point->pc = pc; 75 tlk_entry_point->spsr = spsr; 76 } 77 78 /******************************************************************************* 79 * This function takes a TLK context pointer and: 80 * 1. Applies the S-EL1 system register context from tlk_ctx->cpu_ctx. 81 * 2. Saves the current C runtime state (callee saved registers) on the stack 82 * frame and saves a reference to this state. 83 * 3. Calls el3_exit() so that the EL3 system and general purpose registers 84 * from the tlk_ctx->cpu_ctx are used to enter the secure payload image. 85 ******************************************************************************/ 86 uint64_t tlkd_synchronous_sp_entry(tlk_context_t *tlk_ctx) 87 { 88 uint64_t rc; 89 90 /* Passing a NULL context is a critical programming error */ 91 assert(tlk_ctx); 92 assert(tlk_ctx->c_rt_ctx == 0); 93 94 /* Apply the Secure EL1 system register context and switch to it */ 95 assert(cm_get_context(SECURE) == &tlk_ctx->cpu_ctx); 96 cm_el1_sysregs_context_restore(SECURE); 97 cm_set_next_eret_context(SECURE); 98 99 rc = tlkd_enter_sp(&tlk_ctx->c_rt_ctx); 100 #if DEBUG 101 tlk_ctx->c_rt_ctx = 0; 102 #endif 103 104 return rc; 105 } 106 107 /******************************************************************************* 108 * This function takes a TLK context pointer and: 109 * 1. Saves the S-EL1 system register context to tlk_ctx->cpu_ctx. 110 * 2. Restores the current C runtime state (callee saved registers) from the 111 * stack frame using reference to this state saved in tlkd_enter_sp(). 112 * 3. It does not need to save any general purpose or EL3 system register state 113 * as the generic smc entry routine should have saved those. 114 ******************************************************************************/ 115 void tlkd_synchronous_sp_exit(tlk_context_t *tlk_ctx, uint64_t ret) 116 { 117 /* Passing a NULL context is a critical programming error */ 118 assert(tlk_ctx); 119 120 /* Save the Secure EL1 system register context */ 121 assert(cm_get_context(SECURE) == &tlk_ctx->cpu_ctx); 122 cm_el1_sysregs_context_save(SECURE); 123 124 assert(tlk_ctx->c_rt_ctx != 0); 125 tlkd_exit_sp(tlk_ctx->c_rt_ctx, ret); 126 127 /* Should never reach here */ 128 assert(0); 129 } 130