xref: /openbmc/linux/arch/arm64/include/asm/el2_setup.h (revision 77423a62)
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 	mov	x0, #3				// Enable EL1 physical timers
37 	msr	cnthctl_el2, x0
38 	msr	cntvoff_el2, xzr		// Clear virtual offset
39 .endm
40 
41 .macro __init_el2_debug
42 	mrs	x1, id_aa64dfr0_el1
43 	sbfx	x0, x1, #ID_AA64DFR0_PMUVER_SHIFT, #4
44 	cmp	x0, #1
45 	b.lt	.Lskip_pmu_\@			// Skip if no PMU present
46 	mrs	x0, pmcr_el0			// Disable debug access traps
47 	ubfx	x0, x0, #11, #5			// to EL2 and allow access to
48 .Lskip_pmu_\@:
49 	csel	x2, xzr, x0, lt			// all PMU counters from EL1
50 
51 	/* Statistical profiling */
52 	ubfx	x0, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
53 	cbz	x0, .Lskip_spe_\@		// Skip if SPE not present
54 
55 	mrs_s	x0, SYS_PMBIDR_EL1              // If SPE available at EL2,
56 	and	x0, x0, #(1 << SYS_PMBIDR_EL1_P_SHIFT)
57 	cbnz	x0, .Lskip_spe_el2_\@		// then permit sampling of physical
58 	mov	x0, #(1 << SYS_PMSCR_EL2_PCT_SHIFT | \
59 		      1 << SYS_PMSCR_EL2_PA_SHIFT)
60 	msr_s	SYS_PMSCR_EL2, x0		// addresses and physical counter
61 .Lskip_spe_el2_\@:
62 	mov	x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
63 	orr	x2, x2, x0			// If we don't have VHE, then
64 						// use EL1&0 translation.
65 
66 .Lskip_spe_\@:
67 	/* Trace buffer */
68 	ubfx	x0, x1, #ID_AA64DFR0_TRBE_SHIFT, #4
69 	cbz	x0, .Lskip_trace_\@		// Skip if TraceBuffer is not present
70 
71 	mrs_s	x0, SYS_TRBIDR_EL1
72 	and	x0, x0, TRBIDR_PROG
73 	cbnz	x0, .Lskip_trace_\@		// If TRBE is available at EL2
74 
75 	mov	x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT)
76 	orr	x2, x2, x0			// allow the EL1&0 translation
77 						// to own it.
78 
79 .Lskip_trace_\@:
80 	msr	mdcr_el2, x2			// Configure debug traps
81 .endm
82 
83 /* LORegions */
84 .macro __init_el2_lor
85 	mrs	x1, id_aa64mmfr1_el1
86 	ubfx	x0, x1, #ID_AA64MMFR1_LOR_SHIFT, 4
87 	cbz	x0, .Lskip_lor_\@
88 	msr_s	SYS_LORC_EL1, xzr
89 .Lskip_lor_\@:
90 .endm
91 
92 /* Stage-2 translation */
93 .macro __init_el2_stage2
94 	msr	vttbr_el2, xzr
95 .endm
96 
97 /* GICv3 system register access */
98 .macro __init_el2_gicv3
99 	mrs	x0, id_aa64pfr0_el1
100 	ubfx	x0, x0, #ID_AA64PFR0_GIC_SHIFT, #4
101 	cbz	x0, .Lskip_gicv3_\@
102 
103 	mrs_s	x0, SYS_ICC_SRE_EL2
104 	orr	x0, x0, #ICC_SRE_EL2_SRE	// Set ICC_SRE_EL2.SRE==1
105 	orr	x0, x0, #ICC_SRE_EL2_ENABLE	// Set ICC_SRE_EL2.Enable==1
106 	msr_s	SYS_ICC_SRE_EL2, x0
107 	isb					// Make sure SRE is now set
108 	mrs_s	x0, SYS_ICC_SRE_EL2		// Read SRE back,
109 	tbz	x0, #0, .Lskip_gicv3_\@		// and check that it sticks
110 	msr_s	SYS_ICH_HCR_EL2, xzr		// Reset ICH_HCR_EL2 to defaults
111 .Lskip_gicv3_\@:
112 .endm
113 
114 .macro __init_el2_hstr
115 	msr	hstr_el2, xzr			// Disable CP15 traps to EL2
116 .endm
117 
118 /* Virtual CPU ID registers */
119 .macro __init_el2_nvhe_idregs
120 	mrs	x0, midr_el1
121 	mrs	x1, mpidr_el1
122 	msr	vpidr_el2, x0
123 	msr	vmpidr_el2, x1
124 .endm
125 
126 /* Coprocessor traps */
127 .macro __init_el2_nvhe_cptr
128 	mov	x0, #0x33ff
129 	msr	cptr_el2, x0			// Disable copro. traps to EL2
130 .endm
131 
132 /* Disable any fine grained traps */
133 .macro __init_el2_fgt
134 	mrs	x1, id_aa64mmfr0_el1
135 	ubfx	x1, x1, #ID_AA64MMFR0_FGT_SHIFT, #4
136 	cbz	x1, .Lskip_fgt_\@
137 
138 	mov	x0, xzr
139 	mrs	x1, id_aa64dfr0_el1
140 	ubfx	x1, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
141 	cmp	x1, #3
142 	b.lt	.Lset_debug_fgt_\@
143 	/* Disable PMSNEVFR_EL1 read and write traps */
144 	orr	x0, x0, #(1 << 62)
145 
146 .Lset_debug_fgt_\@:
147 	msr_s	SYS_HDFGRTR_EL2, x0
148 	msr_s	SYS_HDFGWTR_EL2, x0
149 
150 	mov	x0, xzr
151 	mrs	x1, id_aa64pfr1_el1
152 	ubfx	x1, x1, #ID_AA64PFR1_SME_SHIFT, #4
153 	cbz	x1, .Lset_fgt_\@
154 
155 	/* Disable nVHE traps of TPIDR2 and SMPRI */
156 	orr	x0, x0, #HFGxTR_EL2_nSMPRI_EL1_MASK
157 	orr	x0, x0, #HFGxTR_EL2_nTPIDR2_EL0_MASK
158 
159 .Lset_fgt_\@:
160 	msr_s	SYS_HFGRTR_EL2, x0
161 	msr_s	SYS_HFGWTR_EL2, x0
162 	msr_s	SYS_HFGITR_EL2, xzr
163 
164 	mrs	x1, id_aa64pfr0_el1		// AMU traps UNDEF without AMU
165 	ubfx	x1, x1, #ID_AA64PFR0_AMU_SHIFT, #4
166 	cbz	x1, .Lskip_fgt_\@
167 
168 	msr_s	SYS_HAFGRTR_EL2, xzr
169 .Lskip_fgt_\@:
170 .endm
171 
172 .macro __init_el2_nvhe_prepare_eret
173 	mov	x0, #INIT_PSTATE_EL1
174 	msr	spsr_el2, x0
175 .endm
176 
177 /**
178  * Initialize EL2 registers to sane values. This should be called early on all
179  * cores that were booted in EL2. Note that everything gets initialised as
180  * if VHE was not evailable. The kernel context will be upgraded to VHE
181  * if possible later on in the boot process
182  *
183  * Regs: x0, x1 and x2 are clobbered.
184  */
185 .macro init_el2_state
186 	__init_el2_sctlr
187 	__init_el2_timers
188 	__init_el2_debug
189 	__init_el2_lor
190 	__init_el2_stage2
191 	__init_el2_gicv3
192 	__init_el2_hstr
193 	__init_el2_nvhe_idregs
194 	__init_el2_nvhe_cptr
195 	__init_el2_fgt
196 	__init_el2_nvhe_prepare_eret
197 .endm
198 
199 #endif /* __ARM_KVM_INIT_H__ */
200