xref: /openbmc/linux/arch/arm64/include/asm/virt.h (revision be709d48)
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 /*
22  * The arm64 hcall implementation uses x0 to specify the hcall
23  * number. A value less than HVC_STUB_HCALL_NR indicates a special
24  * hcall, such as set vector. Any other value is handled in a
25  * hypervisor specific way.
26  *
27  * The hypercall is allowed to clobber any of the caller-saved
28  * registers (x0-x18), so it is advisable to use it through the
29  * indirection of a function call (as implemented in hyp-stub.S).
30  */
31 
32 /*
33  * HVC_SET_VECTORS - Set the value of the vbar_el2 register.
34  *
35  * @x1: Physical address of the new vector table.
36  */
37 #define HVC_SET_VECTORS 0
38 
39 /*
40  * HVC_SOFT_RESTART - CPU soft reset, used by the cpu_soft_restart routine.
41  */
42 #define HVC_SOFT_RESTART 1
43 
44 /*
45  * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs
46  */
47 #define HVC_RESET_VECTORS 2
48 
49 /* Max number of HYP stub hypercalls */
50 #define HVC_STUB_HCALL_NR 3
51 
52 /* Error returned when an invalid stub number is passed into x0 */
53 #define HVC_STUB_ERR	0xbadca11
54 
55 #define BOOT_CPU_MODE_EL1	(0xe11)
56 #define BOOT_CPU_MODE_EL2	(0xe12)
57 
58 #ifndef __ASSEMBLY__
59 
60 #include <asm/ptrace.h>
61 #include <asm/sections.h>
62 #include <asm/sysreg.h>
63 #include <asm/cpufeature.h>
64 
65 /*
66  * __boot_cpu_mode records what mode CPUs were booted in.
67  * A correctly-implemented bootloader must start all CPUs in the same mode:
68  * In this case, both 32bit halves of __boot_cpu_mode will contain the
69  * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
70  *
71  * Should the bootloader fail to do this, the two values will be different.
72  * This allows the kernel to flag an error when the secondaries have come up.
73  */
74 extern u32 __boot_cpu_mode[2];
75 
76 void __hyp_set_vectors(phys_addr_t phys_vector_base);
77 void __hyp_reset_vectors(void);
78 
79 /* Reports the availability of HYP mode */
80 static inline bool is_hyp_mode_available(void)
81 {
82 	return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
83 		__boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
84 }
85 
86 /* Check if the bootloader has booted CPUs in different modes */
87 static inline bool is_hyp_mode_mismatched(void)
88 {
89 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
90 }
91 
92 static inline bool is_kernel_in_hyp_mode(void)
93 {
94 	return read_sysreg(CurrentEL) == CurrentEL_EL2;
95 }
96 
97 static inline bool has_vhe(void)
98 {
99 	if (cpus_have_const_cap(ARM64_HAS_VIRT_HOST_EXTN))
100 		return true;
101 
102 	return false;
103 }
104 
105 #endif /* __ASSEMBLY__ */
106 
107 #endif /* ! __ASM__VIRT_H */
108