xref: /openbmc/linux/arch/arm64/include/asm/el2_setup.h (revision b4e18b29)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012,2013 - ARM Ltd
4  * Author: Marc Zyngier <marc.zyngier@arm.com>
5  */
6 
7 #ifndef __ARM_KVM_INIT_H__
8 #define __ARM_KVM_INIT_H__
9 
10 #ifndef __ASSEMBLY__
11 #error Assembly-only header
12 #endif
13 
14 #include <asm/kvm_arm.h>
15 #include <asm/ptrace.h>
16 #include <asm/sysreg.h>
17 #include <linux/irqchip/arm-gic-v3.h>
18 
19 .macro __init_el2_sctlr
20 	mov_q	x0, INIT_SCTLR_EL2_MMU_OFF
21 	msr	sctlr_el2, x0
22 	isb
23 .endm
24 
25 /*
26  * Allow Non-secure EL1 and EL0 to access physical timer and counter.
27  * This is not necessary for VHE, since the host kernel runs in EL2,
28  * and EL0 accesses are configured in the later stage of boot process.
29  * Note that when HCR_EL2.E2H == 1, CNTHCTL_EL2 has the same bit layout
30  * as CNTKCTL_EL1, and CNTKCTL_EL1 accessing instructions are redefined
31  * to access CNTHCTL_EL2. This allows the kernel designed to run at EL1
32  * to transparently mess with the EL0 bits via CNTKCTL_EL1 access in
33  * EL2.
34  */
35 .macro __init_el2_timers mode
36 .ifeqs "\mode", "nvhe"
37 	mrs	x0, cnthctl_el2
38 	orr	x0, x0, #3			// Enable EL1 physical timers
39 	msr	cnthctl_el2, x0
40 .endif
41 	msr	cntvoff_el2, xzr		// Clear virtual offset
42 .endm
43 
44 .macro __init_el2_debug mode
45 	mrs	x1, id_aa64dfr0_el1
46 	sbfx	x0, x1, #ID_AA64DFR0_PMUVER_SHIFT, #4
47 	cmp	x0, #1
48 	b.lt	1f				// Skip if no PMU present
49 	mrs	x0, pmcr_el0			// Disable debug access traps
50 	ubfx	x0, x0, #11, #5			// to EL2 and allow access to
51 1:
52 	csel	x2, xzr, x0, lt			// all PMU counters from EL1
53 
54 	/* Statistical profiling */
55 	ubfx	x0, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
56 	cbz	x0, 3f				// Skip if SPE not present
57 
58 .ifeqs "\mode", "nvhe"
59 	mrs_s	x0, SYS_PMBIDR_EL1              // If SPE available at EL2,
60 	and	x0, x0, #(1 << SYS_PMBIDR_EL1_P_SHIFT)
61 	cbnz	x0, 2f				// then permit sampling of physical
62 	mov	x0, #(1 << SYS_PMSCR_EL2_PCT_SHIFT | \
63 		      1 << SYS_PMSCR_EL2_PA_SHIFT)
64 	msr_s	SYS_PMSCR_EL2, x0		// addresses and physical counter
65 2:
66 	mov	x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
67 	orr	x2, x2, x0			// If we don't have VHE, then
68 						// use EL1&0 translation.
69 .else
70 	orr	x2, x2, #MDCR_EL2_TPMS		// For VHE, use EL2 translation
71 						// and disable access from EL1
72 .endif
73 
74 3:
75 	msr	mdcr_el2, x2			// Configure debug traps
76 .endm
77 
78 /* LORegions */
79 .macro __init_el2_lor
80 	mrs	x1, id_aa64mmfr1_el1
81 	ubfx	x0, x1, #ID_AA64MMFR1_LOR_SHIFT, 4
82 	cbz	x0, 1f
83 	msr_s	SYS_LORC_EL1, xzr
84 1:
85 .endm
86 
87 /* Stage-2 translation */
88 .macro __init_el2_stage2
89 	msr	vttbr_el2, xzr
90 .endm
91 
92 /* GICv3 system register access */
93 .macro __init_el2_gicv3
94 	mrs	x0, id_aa64pfr0_el1
95 	ubfx	x0, x0, #ID_AA64PFR0_GIC_SHIFT, #4
96 	cbz	x0, 1f
97 
98 	mrs_s	x0, SYS_ICC_SRE_EL2
99 	orr	x0, x0, #ICC_SRE_EL2_SRE	// Set ICC_SRE_EL2.SRE==1
100 	orr	x0, x0, #ICC_SRE_EL2_ENABLE	// Set ICC_SRE_EL2.Enable==1
101 	msr_s	SYS_ICC_SRE_EL2, x0
102 	isb					// Make sure SRE is now set
103 	mrs_s	x0, SYS_ICC_SRE_EL2		// Read SRE back,
104 	tbz	x0, #0, 1f			// and check that it sticks
105 	msr_s	SYS_ICH_HCR_EL2, xzr		// Reset ICC_HCR_EL2 to defaults
106 1:
107 .endm
108 
109 .macro __init_el2_hstr
110 	msr	hstr_el2, xzr			// Disable CP15 traps to EL2
111 .endm
112 
113 /* Virtual CPU ID registers */
114 .macro __init_el2_nvhe_idregs
115 	mrs	x0, midr_el1
116 	mrs	x1, mpidr_el1
117 	msr	vpidr_el2, x0
118 	msr	vmpidr_el2, x1
119 .endm
120 
121 /* Coprocessor traps */
122 .macro __init_el2_nvhe_cptr
123 	mov	x0, #0x33ff
124 	msr	cptr_el2, x0			// Disable copro. traps to EL2
125 .endm
126 
127 /* SVE register access */
128 .macro __init_el2_nvhe_sve
129 	mrs	x1, id_aa64pfr0_el1
130 	ubfx	x1, x1, #ID_AA64PFR0_SVE_SHIFT, #4
131 	cbz	x1, 1f
132 
133 	bic	x0, x0, #CPTR_EL2_TZ		// Also disable SVE traps
134 	msr	cptr_el2, x0			// Disable copro. traps to EL2
135 	isb
136 	mov	x1, #ZCR_ELx_LEN_MASK		// SVE: Enable full vector
137 	msr_s	SYS_ZCR_EL2, x1			// length for EL1.
138 1:
139 .endm
140 
141 .macro __init_el2_nvhe_prepare_eret
142 	mov	x0, #INIT_PSTATE_EL1
143 	msr	spsr_el2, x0
144 .endm
145 
146 /**
147  * Initialize EL2 registers to sane values. This should be called early on all
148  * cores that were booted in EL2.
149  *
150  * Regs: x0, x1 and x2 are clobbered.
151  */
152 .macro init_el2_state mode
153 .ifnes "\mode", "vhe"
154 .ifnes "\mode", "nvhe"
155 .error "Invalid 'mode' argument"
156 .endif
157 .endif
158 
159 	__init_el2_sctlr
160 	__init_el2_timers \mode
161 	__init_el2_debug \mode
162 	__init_el2_lor
163 	__init_el2_stage2
164 	__init_el2_gicv3
165 	__init_el2_hstr
166 
167 	/*
168 	 * When VHE is not in use, early init of EL2 needs to be done here.
169 	 * When VHE _is_ in use, EL1 will not be used in the host and
170 	 * requires no configuration, and all non-hyp-specific EL2 setup
171 	 * will be done via the _EL1 system register aliases in __cpu_setup.
172 	 */
173 .ifeqs "\mode", "nvhe"
174 	__init_el2_nvhe_idregs
175 	__init_el2_nvhe_cptr
176 	__init_el2_nvhe_sve
177 	__init_el2_nvhe_prepare_eret
178 .endif
179 .endm
180 
181 #endif /* __ARM_KVM_INIT_H__ */
182