xref: /openbmc/linux/arch/arm64/include/asm/el2_setup.h (revision 0bf49ffb)
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 	msr	mdcr_el2, x2			// Configure debug traps
69 .endm
70 
71 /* LORegions */
72 .macro __init_el2_lor
73 	mrs	x1, id_aa64mmfr1_el1
74 	ubfx	x0, x1, #ID_AA64MMFR1_LOR_SHIFT, 4
75 	cbz	x0, .Lskip_lor_\@
76 	msr_s	SYS_LORC_EL1, xzr
77 .Lskip_lor_\@:
78 .endm
79 
80 /* Stage-2 translation */
81 .macro __init_el2_stage2
82 	msr	vttbr_el2, xzr
83 .endm
84 
85 /* GICv3 system register access */
86 .macro __init_el2_gicv3
87 	mrs	x0, id_aa64pfr0_el1
88 	ubfx	x0, x0, #ID_AA64PFR0_GIC_SHIFT, #4
89 	cbz	x0, .Lskip_gicv3_\@
90 
91 	mrs_s	x0, SYS_ICC_SRE_EL2
92 	orr	x0, x0, #ICC_SRE_EL2_SRE	// Set ICC_SRE_EL2.SRE==1
93 	orr	x0, x0, #ICC_SRE_EL2_ENABLE	// Set ICC_SRE_EL2.Enable==1
94 	msr_s	SYS_ICC_SRE_EL2, x0
95 	isb					// Make sure SRE is now set
96 	mrs_s	x0, SYS_ICC_SRE_EL2		// Read SRE back,
97 	tbz	x0, #0, 1f			// and check that it sticks
98 	msr_s	SYS_ICH_HCR_EL2, xzr		// Reset ICC_HCR_EL2 to defaults
99 .Lskip_gicv3_\@:
100 .endm
101 
102 .macro __init_el2_hstr
103 	msr	hstr_el2, xzr			// Disable CP15 traps to EL2
104 .endm
105 
106 /* Virtual CPU ID registers */
107 .macro __init_el2_nvhe_idregs
108 	mrs	x0, midr_el1
109 	mrs	x1, mpidr_el1
110 	msr	vpidr_el2, x0
111 	msr	vmpidr_el2, x1
112 .endm
113 
114 /* Coprocessor traps */
115 .macro __init_el2_nvhe_cptr
116 	mov	x0, #0x33ff
117 	msr	cptr_el2, x0			// Disable copro. traps to EL2
118 .endm
119 
120 /* SVE register access */
121 .macro __init_el2_nvhe_sve
122 	mrs	x1, id_aa64pfr0_el1
123 	ubfx	x1, x1, #ID_AA64PFR0_SVE_SHIFT, #4
124 	cbz	x1, .Lskip_sve_\@
125 
126 	bic	x0, x0, #CPTR_EL2_TZ		// Also disable SVE traps
127 	msr	cptr_el2, x0			// Disable copro. traps to EL2
128 	isb
129 	mov	x1, #ZCR_ELx_LEN_MASK		// SVE: Enable full vector
130 	msr_s	SYS_ZCR_EL2, x1			// length for EL1.
131 .Lskip_sve_\@:
132 .endm
133 
134 .macro __init_el2_nvhe_prepare_eret
135 	mov	x0, #INIT_PSTATE_EL1
136 	msr	spsr_el2, x0
137 .endm
138 
139 /**
140  * Initialize EL2 registers to sane values. This should be called early on all
141  * cores that were booted in EL2. Note that everything gets initialised as
142  * if VHE was not evailable. The kernel context will be upgraded to VHE
143  * if possible later on in the boot process
144  *
145  * Regs: x0, x1 and x2 are clobbered.
146  */
147 .macro init_el2_state
148 	__init_el2_sctlr
149 	__init_el2_timers
150 	__init_el2_debug
151 	__init_el2_lor
152 	__init_el2_stage2
153 	__init_el2_gicv3
154 	__init_el2_hstr
155 	__init_el2_nvhe_idregs
156 	__init_el2_nvhe_cptr
157 	__init_el2_nvhe_sve
158 	__init_el2_nvhe_prepare_eret
159 .endm
160 
161 #endif /* __ARM_KVM_INIT_H__ */
162