projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 55c7401d MZ |
1 | /* |
| 2 | * Copyright (C) 2012,2013 - ARM Ltd | |
| 3 | * Author: Marc Zyngier <marc.zyngier@arm.com> | |
| 4 | * | |
| 5 | * This program is free software; you can redistribute it and/or modify | |
| 6 | * it under the terms of the GNU General Public License version 2 as | |
| 7 | * published by the Free Software Foundation. | |
| 8 | * | |
| 9 | * This program is distributed in the hope that it will be useful, | |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 12 | * GNU General Public License for more details. | |
| 13 | * | |
| 14 | * You should have received a copy of the GNU General Public License | |
| 15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
| 16 | */ | |
| 17 | ||
| 18 | #include <linux/linkage.h> | |
| 55c7401d | 19 | |
| b81125c7 | 20 | #include <asm/alternative.h> |
| c6d01a94 | 21 | #include <asm/assembler.h> |
| b81125c7 | 22 | #include <asm/cpufeature.h> |
| 55c7401d | 23 | |
| b20c9f29 | 24 | /* |
| a0bf9776 | 25 | * u64 __kvm_call_hyp(void *hypfn, ...); |
| b20c9f29 MZ |
26 | * |
| 27 | * This is not really a variadic function in the classic C-way and care must | |
| 28 | * be taken when calling this to ensure parameters are passed in registers | |
| 29 | * only, since the stack will change between the caller and the callee. | |
| 30 | * | |
| 31 | * Call the function with the first argument containing a pointer to the | |
| 32 | * function you wish to call in Hyp mode, and subsequent arguments will be | |
| 33 | * passed as x0, x1, and x2 (a maximum of 3 arguments in addition to the | |
| 34 | * function pointer can be passed). The function being called must be mapped | |
| 35 | * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are | |
| 1ea66d27 | 36 | * passed in x0. |
| b20c9f29 | 37 | * |
| ad72e59f GL |
38 | * A function pointer with a value less than 0xfff has a special meaning, |
| 39 | * and is used to implement __hyp_get_vectors in the same way as in | |
| b20c9f29 | 40 | * arch/arm64/kernel/hyp_stub.S. |
| 00a44cda | 41 | * HVC behaves as a 'bl' call and will clobber lr. |
| b20c9f29 | 42 | */ |
| a0bf9776 | 43 | ENTRY(__kvm_call_hyp) |
| 00a44cda JM |
44 | alternative_if_not ARM64_HAS_VIRT_HOST_EXTN |
| 45 | str lr, [sp, #-16]! | |
| 55c7401d | 46 | hvc #0 |
| 00a44cda | 47 | ldr lr, [sp], #16 |
| 55c7401d | 48 | ret |
| e506236a | 49 | alternative_else_nop_endif |
| b81125c7 | 50 | b __vhe_hyp_call |
| a0bf9776 | 51 | ENDPROC(__kvm_call_hyp) |