1 /*
2 * Copyright (c) 2013-2023, Arm Limited and Contributors. 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 <lib/el3_runtime/context_mgmt.h>
13 #include <lib/utils.h>
14
15 #include "opteed_private.h"
16
17 /*******************************************************************************
18 * Given a OPTEE entrypoint info pointer, entry point PC, register width,
19 * cpu id & pointer to a context data structure, this function will
20 * initialize OPTEE context and entry point info for OPTEE.
21 ******************************************************************************/
opteed_init_optee_ep_state(struct entry_point_info * optee_entry_point,uint32_t rw,uint64_t pc,uint64_t arg0,uint64_t arg1,uint64_t arg2,uint64_t arg3,optee_context_t * optee_ctx)22 void opteed_init_optee_ep_state(struct entry_point_info *optee_entry_point,
23 uint32_t rw, uint64_t pc, uint64_t arg0,
24 uint64_t arg1, uint64_t arg2, uint64_t arg3,
25 optee_context_t *optee_ctx)
26 {
27 uint32_t ep_attr;
28
29 /* Passing a NULL context is a critical programming error */
30 assert(optee_ctx);
31 assert(optee_entry_point);
32 assert(pc);
33
34 /* Associate this context with the cpu specified */
35 optee_ctx->mpidr = read_mpidr_el1();
36 optee_ctx->state = 0;
37 set_optee_pstate(optee_ctx->state, OPTEE_PSTATE_OFF);
38
39 cm_set_context(&optee_ctx->cpu_ctx, SECURE);
40
41 /* initialise an entrypoint to set up the CPU context */
42 ep_attr = SECURE | EP_ST_ENABLE;
43 if ((read_sctlr_el3() & SCTLR_EE_BIT) != 0U) {
44 ep_attr |= EP_EE_BIG;
45 }
46 SET_PARAM_HEAD(optee_entry_point, PARAM_EP, VERSION_1, ep_attr);
47 optee_entry_point->pc = pc;
48 if (rw == OPTEE_AARCH64) {
49 optee_entry_point->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
50 DISABLE_ALL_EXCEPTIONS);
51 } else {
52 optee_entry_point->spsr = SPSR_MODE32(MODE32_svc, SPSR_T_ARM,
53 SPSR_E_LITTLE,
54 DAIF_FIQ_BIT |
55 DAIF_IRQ_BIT |
56 DAIF_ABT_BIT);
57 }
58
59 zeromem(&optee_entry_point->args, sizeof(optee_entry_point->args));
60 optee_entry_point->args.arg0 = arg0;
61 optee_entry_point->args.arg1 = arg1;
62 optee_entry_point->args.arg2 = arg2;
63 optee_entry_point->args.arg3 = arg3;
64 }
65
66 /*******************************************************************************
67 * This function takes an OPTEE context pointer and:
68 * 1. Applies the S-EL1 system register context from optee_ctx->cpu_ctx.
69 * 2. Saves the current C runtime state (callee saved registers) on the stack
70 * frame and saves a reference to this state.
71 * 3. Calls el3_exit() so that the EL3 system and general purpose registers
72 * from the optee_ctx->cpu_ctx are used to enter the OPTEE image.
73 ******************************************************************************/
opteed_synchronous_sp_entry(optee_context_t * optee_ctx)74 uint64_t opteed_synchronous_sp_entry(optee_context_t *optee_ctx)
75 {
76 uint64_t rc;
77
78 assert(optee_ctx != NULL);
79 assert(optee_ctx->c_rt_ctx == 0);
80
81 /* Apply the Secure EL1 system register context and switch to it */
82 assert(cm_get_context(SECURE) == &optee_ctx->cpu_ctx);
83 cm_el1_sysregs_context_restore(SECURE);
84 cm_set_next_eret_context(SECURE);
85
86 rc = opteed_enter_sp(&optee_ctx->c_rt_ctx);
87 #if ENABLE_ASSERTIONS
88 optee_ctx->c_rt_ctx = 0;
89 #endif
90
91 return rc;
92 }
93
94
95 /*******************************************************************************
96 * This function takes an OPTEE context pointer and:
97 * 1. Saves the S-EL1 system register context tp optee_ctx->cpu_ctx.
98 * 2. Restores the current C runtime state (callee saved registers) from the
99 * stack frame using the reference to this state saved in opteed_enter_sp().
100 * 3. It does not need to save any general purpose or EL3 system register state
101 * as the generic smc entry routine should have saved those.
102 ******************************************************************************/
opteed_synchronous_sp_exit(optee_context_t * optee_ctx,uint64_t ret)103 void opteed_synchronous_sp_exit(optee_context_t *optee_ctx, uint64_t ret)
104 {
105 assert(optee_ctx != NULL);
106 /* Save the Secure EL1 system register context */
107 assert(cm_get_context(SECURE) == &optee_ctx->cpu_ctx);
108 cm_el1_sysregs_context_save(SECURE);
109
110 assert(optee_ctx->c_rt_ctx != 0);
111 opteed_exit_sp(optee_ctx->c_rt_ctx, ret);
112
113 /* Should never reach here */
114 assert(0);
115 }
116