1 /*
2 * Copyright (c) 2022-2026, Arm Limited. All rights reserved.
3 * Copyright (c) 2023, NVIDIA Corporation. All rights reserved.
4 *
5 * SPDX-License-Identifier: BSD-3-Clause
6 */
7
8 #ifndef TRAP_HANDLE_H
9 #define TRAP_HANDLE_H
10
11 #include <stdbool.h>
12 #include <context.h>
13
14 #define TRAP_RET_UNHANDLED -1
15 #define TRAP_RET_REPEAT 0
16 #define TRAP_RET_CONTINUE 1
17
18 #define XZR_REG_NUM 31
19
20 /**
21 * handle_sysreg_trap() - Handle AArch64 system register traps from lower ELs
22 * @esr_el3: The content of ESR_EL3, containing the trap syndrome information
23 * @ctx: Pointer to the lower EL context, containing saved registers
24 *
25 * Called by the exception handler when a synchronous trap identifies as a
26 * system register trap (EC=0x18). ESR contains the encoding of the op[x] and
27 * CRm/CRn fields, to identify the system register, and the target/source
28 * GPR plus the direction (MRS/MSR). The lower EL's context can be altered
29 * by the function, to inject back the result of the emulation.
30 *
31 * Return: indication how to proceed with the trap:
32 * TRAP_RET_UNHANDLED(-1): trap is unhandled, trigger panic
33 * TRAP_RET_REPEAT(0): trap was handled, return to the trapping instruction
34 * (repeating it)
35 * TRAP_RET_CONTINUE(1): trap was handled, return to the next instruction
36 * (continuing after it)
37 */
38 int handle_sysreg_trap(uint64_t esr_el3, cpu_context_t *ctx, u_register_t flags);
39
40 /* Handler for injecting UNDEF exception to lower EL */
41 void inject_undef64(cpu_context_t *ctx);
42
43 u_register_t create_spsr(u_register_t old_spsr, unsigned int target_el);
44
45 /* Prototypes for system register emulation handlers provided by platforms. */
46 int plat_handle_impdef_trap(uint64_t esr_el3, cpu_context_t *ctx);
47 #if ENABLE_FEAT_RNG_TRAP
48 int plat_handle_rng_trap(uint8_t rt, bool rndrrs, cpu_context_t *ctx);
49 #else
plat_handle_rng_trap(uint8_t rt,bool rndrrs,cpu_context_t * ctx)50 static inline int plat_handle_rng_trap(uint8_t rt, bool rndrrs, cpu_context_t *ctx)
51 {
52 return TRAP_RET_UNHANDLED;
53 }
54 #endif
55
56 #endif
57