1 /*
2  * Copyright (c) 2013-2023, 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 void cm_prepare_el3_exit_ns(void);
38 
39 #ifdef __aarch64__
40 #if IMAGE_BL31
41 void cm_manage_extensions_el3(void);
42 void manage_extensions_nonsecure_per_world(void);
43 #endif
44 #if CTX_INCLUDE_EL2_REGS
45 void cm_el2_sysregs_context_save(uint32_t security_state);
46 void cm_el2_sysregs_context_restore(uint32_t security_state);
47 #endif
48 
49 void cm_el1_sysregs_context_save(uint32_t security_state);
50 void cm_el1_sysregs_context_restore(uint32_t security_state);
51 void cm_set_elr_el3(uint32_t security_state, uintptr_t entrypoint);
52 void cm_set_elr_spsr_el3(uint32_t security_state,
53 			uintptr_t entrypoint, uint32_t spsr);
54 void cm_write_scr_el3_bit(uint32_t security_state,
55 			  uint32_t bit_pos,
56 			  uint32_t value);
57 void cm_set_next_eret_context(uint32_t security_state);
58 u_register_t cm_get_scr_el3(uint32_t security_state);
59 
60 /* Inline definitions */
61 
62 /*******************************************************************************
63  * This function is used to program the context that's used for exception
64  * return. This initializes the SP_EL3 to a pointer to a 'cpu_context' set for
65  * the required security state
66  ******************************************************************************/
cm_set_next_context(void * context)67 static inline void cm_set_next_context(void *context)
68 {
69 #if ENABLE_ASSERTIONS
70 	uint64_t sp_mode;
71 
72 	/*
73 	 * Check that this function is called with SP_EL0 as the stack
74 	 * pointer
75 	 */
76 	__asm__ volatile("mrs	%0, SPSel\n"
77 			 : "=r" (sp_mode));
78 
79 	assert(sp_mode == MODE_SP_EL0);
80 #endif /* ENABLE_ASSERTIONS */
81 
82 	__asm__ volatile("msr	spsel, #1\n"
83 			 "mov	sp, %0\n"
84 			 "msr	spsel, #0\n"
85 			 : : "r" (context));
86 }
87 
88 #else
89 void *cm_get_next_context(void);
90 void cm_set_next_context(void *context);
cm_manage_extensions_el3(void)91 static inline void cm_manage_extensions_el3(void) {}
manage_extensions_nonsecure_per_world(void)92 static inline void manage_extensions_nonsecure_per_world(void) {}
93 #endif /* __aarch64__ */
94 
95 #endif /* CONTEXT_MGMT_H */
96