xref: /openbmc/linux/arch/arm64/include/asm/virt.h (revision 15e3ae36)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  * Author: Marc Zyngier <marc.zyngier@arm.com>
5  */
6 
7 #ifndef __ASM__VIRT_H
8 #define __ASM__VIRT_H
9 
10 /*
11  * The arm64 hcall implementation uses x0 to specify the hcall
12  * number. A value less than HVC_STUB_HCALL_NR indicates a special
13  * hcall, such as set vector. Any other value is handled in a
14  * hypervisor specific way.
15  *
16  * The hypercall is allowed to clobber any of the caller-saved
17  * registers (x0-x18), so it is advisable to use it through the
18  * indirection of a function call (as implemented in hyp-stub.S).
19  */
20 
21 /*
22  * HVC_SET_VECTORS - Set the value of the vbar_el2 register.
23  *
24  * @x1: Physical address of the new vector table.
25  */
26 #define HVC_SET_VECTORS 0
27 
28 /*
29  * HVC_SOFT_RESTART - CPU soft reset, used by the cpu_soft_restart routine.
30  */
31 #define HVC_SOFT_RESTART 1
32 
33 /*
34  * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs
35  */
36 #define HVC_RESET_VECTORS 2
37 
38 /* Max number of HYP stub hypercalls */
39 #define HVC_STUB_HCALL_NR 3
40 
41 /* Error returned when an invalid stub number is passed into x0 */
42 #define HVC_STUB_ERR	0xbadca11
43 
44 #define BOOT_CPU_MODE_EL1	(0xe11)
45 #define BOOT_CPU_MODE_EL2	(0xe12)
46 
47 #ifndef __ASSEMBLY__
48 
49 #include <asm/ptrace.h>
50 #include <asm/sections.h>
51 #include <asm/sysreg.h>
52 #include <asm/cpufeature.h>
53 
54 /*
55  * __boot_cpu_mode records what mode CPUs were booted in.
56  * A correctly-implemented bootloader must start all CPUs in the same mode:
57  * In this case, both 32bit halves of __boot_cpu_mode will contain the
58  * same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
59  *
60  * Should the bootloader fail to do this, the two values will be different.
61  * This allows the kernel to flag an error when the secondaries have come up.
62  */
63 extern u32 __boot_cpu_mode[2];
64 
65 void __hyp_set_vectors(phys_addr_t phys_vector_base);
66 void __hyp_reset_vectors(void);
67 
68 /* Reports the availability of HYP mode */
69 static inline bool is_hyp_mode_available(void)
70 {
71 	return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
72 		__boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
73 }
74 
75 /* Check if the bootloader has booted CPUs in different modes */
76 static inline bool is_hyp_mode_mismatched(void)
77 {
78 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
79 }
80 
81 static inline bool is_kernel_in_hyp_mode(void)
82 {
83 	return read_sysreg(CurrentEL) == CurrentEL_EL2;
84 }
85 
86 static __always_inline bool has_vhe(void)
87 {
88 	if (cpus_have_const_cap(ARM64_HAS_VIRT_HOST_EXTN))
89 		return true;
90 
91 	return false;
92 }
93 
94 #endif /* __ASSEMBLY__ */
95 
96 #endif /* ! __ASM__VIRT_H */
97