| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | /* |
| 3 | * Copyright (C) 2012 - Virtual Open Systems and Columbia University |
| 4 | * Author: Christoffer Dall <c.dall@virtualopensystems.com> |
| 5 | */ |
| 6 | |
| 7 | #include <linux/linkage.h> |
| 8 | |
| 9 | .text |
| 10 | .arch_extension virt |
| 11 | |
| 12 | /******************************************************************** |
| 13 | * Call function in Hyp mode |
| 14 | * |
| 15 | * |
| 16 | * unsigned long kvm_call_hyp(void *hypfn, ...); |
| 17 | * |
| 18 | * This is not really a variadic function in the classic C-way and care must |
| 19 | * be taken when calling this to ensure parameters are passed in registers |
| 20 | * only, since the stack will change between the caller and the callee. |
| 21 | * |
| 22 | * Call the function with the first argument containing a pointer to the |
| 23 | * function you wish to call in Hyp mode, and subsequent arguments will be |
| 24 | * passed as r0, r1, and r2 (a maximum of 3 arguments in addition to the |
| 25 | * function pointer can be passed). The function being called must be mapped |
| 26 | * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are |
| 27 | * passed in r0 (strictly 32bit). |
| 28 | * |
| 29 | * The calling convention follows the standard AAPCS: |
| 30 | * r0 - r3: caller save |
| 31 | * r12: caller save |
| 32 | * rest: callee save |
| 33 | */ |
| 34 | ENTRY(__kvm_call_hyp) |
| 35 | hvc #0 |
| 36 | bx lr |
| 37 | ENDPROC(__kvm_call_hyp) |