xref: /openbmc/linux/arch/arm/include/asm/virt.h (revision 9cfc5c90)
1 /*
2  * Copyright (c) 2012 Linaro Limited.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
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 along
15  * with this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17  */
18 
19 #ifndef VIRT_H
20 #define VIRT_H
21 
22 #include <asm/ptrace.h>
23 
24 /*
25  * Flag indicating that the kernel was not entered in the same mode on every
26  * CPU.  The zImage loader stashes this value in an SPSR, so we need an
27  * architecturally defined flag bit here.
28  */
29 #define BOOT_CPU_MODE_MISMATCH	PSR_N_BIT
30 
31 #ifndef __ASSEMBLY__
32 #include <asm/cacheflush.h>
33 
34 #ifdef CONFIG_ARM_VIRT_EXT
35 /*
36  * __boot_cpu_mode records what mode the primary CPU was booted in.
37  * A correctly-implemented bootloader must start all CPUs in the same mode:
38  * if it fails to do this, the flag BOOT_CPU_MODE_MISMATCH is set to indicate
39  * that some CPU(s) were booted in a different mode.
40  *
41  * This allows the kernel to flag an error when the secondaries have come up.
42  */
43 extern int __boot_cpu_mode;
44 
45 static inline void sync_boot_mode(void)
46 {
47 	/*
48 	 * As secondaries write to __boot_cpu_mode with caches disabled, we
49 	 * must flush the corresponding cache entries to ensure the visibility
50 	 * of their writes.
51 	 */
52 	sync_cache_r(&__boot_cpu_mode);
53 }
54 
55 void __hyp_set_vectors(unsigned long phys_vector_base);
56 unsigned long __hyp_get_vectors(void);
57 #else
58 #define __boot_cpu_mode	(SVC_MODE)
59 #define sync_boot_mode()
60 #endif
61 
62 #ifndef ZIMAGE
63 void hyp_mode_check(void);
64 
65 /* Reports the availability of HYP mode */
66 static inline bool is_hyp_mode_available(void)
67 {
68 	return ((__boot_cpu_mode & MODE_MASK) == HYP_MODE &&
69 		!(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH));
70 }
71 
72 /* Check if the bootloader has booted CPUs in different modes */
73 static inline bool is_hyp_mode_mismatched(void)
74 {
75 	return !!(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH);
76 }
77 #endif
78 
79 #endif /* __ASSEMBLY__ */
80 
81 #endif /* ! VIRT_H */
82