xref: /openbmc/linux/arch/arm64/include/asm/el2_setup.h (revision 276e552e)
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
36 	mrs	x0, cnthctl_el2
37 	orr	x0, x0, #3			// Enable EL1 physical timers
38 	msr	cnthctl_el2, x0
39 	msr	cntvoff_el2, xzr		// Clear virtual offset
40 .endm
41 
42 .macro __init_el2_debug
43 	mrs	x1, id_aa64dfr0_el1
44 	sbfx	x0, x1, #ID_AA64DFR0_PMUVER_SHIFT, #4
45 	cmp	x0, #1
46 	b.lt	.Lskip_pmu_\@			// Skip if no PMU present
47 	mrs	x0, pmcr_el0			// Disable debug access traps
48 	ubfx	x0, x0, #11, #5			// to EL2 and allow access to
49 .Lskip_pmu_\@:
50 	csel	x2, xzr, x0, lt			// all PMU counters from EL1
51 
52 	/* Statistical profiling */
53 	ubfx	x0, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
54 	cbz	x0, .Lskip_spe_\@		// Skip if SPE not present
55 
56 	mrs_s	x0, SYS_PMBIDR_EL1              // If SPE available at EL2,
57 	and	x0, x0, #(1 << SYS_PMBIDR_EL1_P_SHIFT)
58 	cbnz	x0, .Lskip_spe_el2_\@		// then permit sampling of physical
59 	mov	x0, #(1 << SYS_PMSCR_EL2_PCT_SHIFT | \
60 		      1 << SYS_PMSCR_EL2_PA_SHIFT)
61 	msr_s	SYS_PMSCR_EL2, x0		// addresses and physical counter
62 .Lskip_spe_el2_\@:
63 	mov	x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
64 	orr	x2, x2, x0			// If we don't have VHE, then
65 						// use EL1&0 translation.
66 
67 .Lskip_spe_\@:
68 	/* Trace buffer */
69 	ubfx	x0, x1, #ID_AA64DFR0_TRBE_SHIFT, #4
70 	cbz	x0, .Lskip_trace_\@		// Skip if TraceBuffer is not present
71 
72 	mrs_s	x0, SYS_TRBIDR_EL1
73 	and	x0, x0, TRBIDR_PROG
74 	cbnz	x0, .Lskip_trace_\@		// If TRBE is available at EL2
75 
76 	mov	x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT)
77 	orr	x2, x2, x0			// allow the EL1&0 translation
78 						// to own it.
79 
80 .Lskip_trace_\@:
81 	msr	mdcr_el2, x2			// Configure debug traps
82 .endm
83 
84 /* LORegions */
85 .macro __init_el2_lor
86 	mrs	x1, id_aa64mmfr1_el1
87 	ubfx	x0, x1, #ID_AA64MMFR1_LOR_SHIFT, 4
88 	cbz	x0, .Lskip_lor_\@
89 	msr_s	SYS_LORC_EL1, xzr
90 .Lskip_lor_\@:
91 .endm
92 
93 /* Stage-2 translation */
94 .macro __init_el2_stage2
95 	msr	vttbr_el2, xzr
96 .endm
97 
98 /* GICv3 system register access */
99 .macro __init_el2_gicv3
100 	mrs	x0, id_aa64pfr0_el1
101 	ubfx	x0, x0, #ID_AA64PFR0_GIC_SHIFT, #4
102 	cbz	x0, .Lskip_gicv3_\@
103 
104 	mrs_s	x0, SYS_ICC_SRE_EL2
105 	orr	x0, x0, #ICC_SRE_EL2_SRE	// Set ICC_SRE_EL2.SRE==1
106 	orr	x0, x0, #ICC_SRE_EL2_ENABLE	// Set ICC_SRE_EL2.Enable==1
107 	msr_s	SYS_ICC_SRE_EL2, x0
108 	isb					// Make sure SRE is now set
109 	mrs_s	x0, SYS_ICC_SRE_EL2		// Read SRE back,
110 	tbz	x0, #0, 1f			// and check that it sticks
111 	msr_s	SYS_ICH_HCR_EL2, xzr		// Reset ICC_HCR_EL2 to defaults
112 .Lskip_gicv3_\@:
113 .endm
114 
115 .macro __init_el2_hstr
116 	msr	hstr_el2, xzr			// Disable CP15 traps to EL2
117 .endm
118 
119 /* Virtual CPU ID registers */
120 .macro __init_el2_nvhe_idregs
121 	mrs	x0, midr_el1
122 	mrs	x1, mpidr_el1
123 	msr	vpidr_el2, x0
124 	msr	vmpidr_el2, x1
125 .endm
126 
127 /* Coprocessor traps */
128 .macro __init_el2_nvhe_cptr
129 	mov	x0, #0x33ff
130 	msr	cptr_el2, x0			// Disable copro. traps to EL2
131 .endm
132 
133 /* SVE register access */
134 .macro __init_el2_nvhe_sve
135 	mrs	x1, id_aa64pfr0_el1
136 	ubfx	x1, x1, #ID_AA64PFR0_SVE_SHIFT, #4
137 	cbz	x1, .Lskip_sve_\@
138 
139 	bic	x0, x0, #CPTR_EL2_TZ		// Also disable SVE traps
140 	msr	cptr_el2, x0			// Disable copro. traps to EL2
141 	isb
142 	mov	x1, #ZCR_ELx_LEN_MASK		// SVE: Enable full vector
143 	msr_s	SYS_ZCR_EL2, x1			// length for EL1.
144 .Lskip_sve_\@:
145 .endm
146 
147 /* Disable any fine grained traps */
148 .macro __init_el2_fgt
149 	mrs	x1, id_aa64mmfr0_el1
150 	ubfx	x1, x1, #ID_AA64MMFR0_FGT_SHIFT, #4
151 	cbz	x1, .Lskip_fgt_\@
152 
153 	msr_s	SYS_HDFGRTR_EL2, xzr
154 	msr_s	SYS_HDFGWTR_EL2, xzr
155 	msr_s	SYS_HFGRTR_EL2, xzr
156 	msr_s	SYS_HFGWTR_EL2, xzr
157 	msr_s	SYS_HFGITR_EL2, xzr
158 
159 	mrs	x1, id_aa64pfr0_el1		// AMU traps UNDEF without AMU
160 	ubfx	x1, x1, #ID_AA64PFR0_AMU_SHIFT, #4
161 	cbz	x1, .Lskip_fgt_\@
162 
163 	msr_s	SYS_HAFGRTR_EL2, xzr
164 .Lskip_fgt_\@:
165 .endm
166 
167 .macro __init_el2_nvhe_prepare_eret
168 	mov	x0, #INIT_PSTATE_EL1
169 	msr	spsr_el2, x0
170 .endm
171 
172 /**
173  * Initialize EL2 registers to sane values. This should be called early on all
174  * cores that were booted in EL2. Note that everything gets initialised as
175  * if VHE was not evailable. The kernel context will be upgraded to VHE
176  * if possible later on in the boot process
177  *
178  * Regs: x0, x1 and x2 are clobbered.
179  */
180 .macro init_el2_state
181 	__init_el2_sctlr
182 	__init_el2_timers
183 	__init_el2_debug
184 	__init_el2_lor
185 	__init_el2_stage2
186 	__init_el2_gicv3
187 	__init_el2_hstr
188 	__init_el2_nvhe_idregs
189 	__init_el2_nvhe_cptr
190 	__init_el2_nvhe_sve
191 	__init_el2_fgt
192 	__init_el2_nvhe_prepare_eret
193 .endm
194 
195 #endif /* __ARM_KVM_INIT_H__ */
196