1 /*
2  * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #ifndef CONTEXT_MGMT_H
8 #define CONTEXT_MGMT_H
9 
10 #include <assert.h>
11 #include <context.h>
12 #include <stdint.h>
13 
14 #include <arch.h>
15 
16 /*******************************************************************************
17  * Forward declarations
18  ******************************************************************************/
19 struct entry_point_info;
20 
21 /*******************************************************************************
22  * Function & variable prototypes
23  ******************************************************************************/
24 void cm_init(void);
25 void *cm_get_context_by_index(unsigned int cpu_idx,
26 			      unsigned int security_state);
27 void cm_set_context_by_index(unsigned int cpu_idx,
28 			     void *context,
29 			     unsigned int security_state);
30 void *cm_get_context(uint32_t security_state);
31 void cm_set_context(void *context, uint32_t security_state);
32 void cm_init_my_context(const struct entry_point_info *ep);
33 void cm_init_context_by_index(unsigned int cpu_idx,
34 			      const struct entry_point_info *ep);
35 void cm_setup_context(cpu_context_t *ctx, const struct entry_point_info *ep);
36 void cm_prepare_el3_exit(uint32_t security_state);
37 
38 #ifdef __aarch64__
39 #if CTX_INCLUDE_EL2_REGS
40 void cm_el2_sysregs_context_save(uint32_t security_state);
41 void cm_el2_sysregs_context_restore(uint32_t security_state);
42 #endif
43 
44 void cm_el1_sysregs_context_save(uint32_t security_state);
45 void cm_el1_sysregs_context_restore(uint32_t security_state);
46 void cm_set_elr_el3(uint32_t security_state, uintptr_t entrypoint);
47 void cm_set_elr_spsr_el3(uint32_t security_state,
48 			uintptr_t entrypoint, uint32_t spsr);
49 void cm_write_scr_el3_bit(uint32_t security_state,
50 			  uint32_t bit_pos,
51 			  uint32_t value);
52 void cm_set_next_eret_context(uint32_t security_state);
53 u_register_t cm_get_scr_el3(uint32_t security_state);
54 
55 /* Inline definitions */
56 
57 /*******************************************************************************
58  * This function is used to program the context that's used for exception
59  * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
60  * the required security state
61  ******************************************************************************/
cm_set_next_context(void * context)62 static inline void cm_set_next_context(void *context)
63 {
64 #if ENABLE_ASSERTIONS
65 	uint64_t sp_mode;
66 
67 	/*
68 	 * Check that this function is called with SP_EL0 as the stack
69 	 * pointer
70 	 */
71 	__asm__ volatile("mrs	%0, SPSel\n"
72 			 : "=r" (sp_mode));
73 
74 	assert(sp_mode == MODE_SP_EL0);
75 #endif /* ENABLE_ASSERTIONS */
76 
77 	__asm__ volatile("msr	spsel, #1\n"
78 			 "mov	sp, %0\n"
79 			 "msr	spsel, #0\n"
80 			 : : "r" (context));
81 }
82 
83 #else
84 void *cm_get_next_context(void);
85 void cm_set_next_context(void *context);
86 #endif /* __aarch64__ */
87 
88 #endif /* CONTEXT_MGMT_H */
89