xref: /openbmc/linux/arch/arm64/include/asm/virt.h (revision 12eb4683)
1 /*
2  * Copyright (C) 2012 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 #ifndef __ASM__VIRT_H
19 #define __ASM__VIRT_H
20 
21 #define BOOT_CPU_MODE_EL1	(0xe11)
22 #define BOOT_CPU_MODE_EL2	(0xe12)
23 
24 #ifndef __ASSEMBLY__
25 #include <asm/cacheflush.h>
26 
27 /*
28  * __boot_cpu_mode records what mode CPUs were booted in.
29  * A correctly-implemented bootloader must start all CPUs in the same mode:
30  * In this case, both 32bit halves of __boot_cpu_mode will contain the
31  * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
32  *
33  * Should the bootloader fail to do this, the two values will be different.
34  * This allows the kernel to flag an error when the secondaries have come up.
35  */
36 extern u32 __boot_cpu_mode[2];
37 
38 void __hyp_set_vectors(phys_addr_t phys_vector_base);
39 phys_addr_t __hyp_get_vectors(void);
40 
41 static inline void sync_boot_mode(void)
42 {
43 	/*
44 	 * As secondaries write to __boot_cpu_mode with caches disabled, we
45 	 * must flush the corresponding cache entries to ensure the visibility
46 	 * of their writes.
47 	 */
48 	__flush_dcache_area(__boot_cpu_mode, sizeof(__boot_cpu_mode));
49 }
50 
51 /* Reports the availability of HYP mode */
52 static inline bool is_hyp_mode_available(void)
53 {
54 	sync_boot_mode();
55 	return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
56 		__boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
57 }
58 
59 /* Check if the bootloader has booted CPUs in different modes */
60 static inline bool is_hyp_mode_mismatched(void)
61 {
62 	sync_boot_mode();
63 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
64 }
65 
66 #endif /* __ASSEMBLY__ */
67 
68 #endif /* ! __ASM__VIRT_H */
69