1 /* SPDX-License-Identifier: GPL-2.0-only */
5 * Copyright (C) 2012 ARM Ltd.
6 * Author: Marc Zyngier <marc.zyngier@arm.com>
9 #include <linux/init.h>
10 #include <linux/linkage.h>
12 #include <asm/assembler.h>
13 #include <asm/el2_setup.h>
14 #include <asm/kvm_arm.h>
15 #include <asm/kvm_asm.h>
16 #include <asm/ptrace.h>
20 .pushsection .hyp.text, "ax"
24 SYM_CODE_START(__hyp_stub_vectors)
25 ventry el2_sync_invalid // Synchronous EL2t
26 ventry el2_irq_invalid // IRQ EL2t
27 ventry el2_fiq_invalid // FIQ EL2t
28 ventry el2_error_invalid // Error EL2t
30 ventry elx_sync // Synchronous EL2h
31 ventry el2_irq_invalid // IRQ EL2h
32 ventry el2_fiq_invalid // FIQ EL2h
33 ventry el2_error_invalid // Error EL2h
35 ventry elx_sync // Synchronous 64-bit EL1
36 ventry el1_irq_invalid // IRQ 64-bit EL1
37 ventry el1_fiq_invalid // FIQ 64-bit EL1
38 ventry el1_error_invalid // Error 64-bit EL1
40 ventry el1_sync_invalid // Synchronous 32-bit EL1
41 ventry el1_irq_invalid // IRQ 32-bit EL1
42 ventry el1_fiq_invalid // FIQ 32-bit EL1
43 ventry el1_error_invalid // Error 32-bit EL1
44 SYM_CODE_END(__hyp_stub_vectors)
48 SYM_CODE_START_LOCAL(elx_sync)
49 cmp x0, #HVC_SET_VECTORS
54 1: cmp x0, #HVC_VHE_RESTART
57 2: cmp x0, #HVC_SOFT_RESTART
65 3: cmp x0, #HVC_RESET_VECTORS
66 beq 9f // Nothing to reset!
68 /* Someone called kvm_call_hyp() against the hyp-stub... */
69 mov_q x0, HVC_STUB_ERR
74 SYM_CODE_END(elx_sync)
76 // nVHE? No way! Give me the real thing!
77 SYM_CODE_START_LOCAL(mutate_to_vhe)
78 // Sanity check: MMU *must* be off
82 // Needs to be VHE capable, obviously
83 mrs x1, id_aa64mmfr1_el1
84 ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4
87 // Check whether VHE is disabled from the command line
88 adr_l x1, id_aa64mmfr1_override
89 ldr x2, [x1, FTR_OVR_VAL_OFFSET]
90 ldr x1, [x1, FTR_OVR_MASK_OFFSET]
91 ubfx x2, x2, #ID_AA64MMFR1_VHE_SHIFT, #4
92 ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4
98 1: mov_q x0, HVC_STUB_ERR
101 // Engage the VHE magic!
102 mov_q x0, HCR_HOST_VHE_FLAGS
106 // Use the EL1 allocated stack, per-cpu offset
112 // FP configuration, vectors
113 mrs_s x0, SYS_CPACR_EL12
115 mrs_s x0, SYS_VBAR_EL12
118 // Use EL2 translations for SPE & TRBE and disable access from EL1
120 bic x0, x0, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
121 bic x0, x0, #(MDCR_EL2_E2TB_MASK << MDCR_EL2_E2TB_SHIFT)
124 // Transfer the MM state from EL1 to EL2
125 mrs_s x0, SYS_TCR_EL12
127 mrs_s x0, SYS_TTBR0_EL12
129 mrs_s x0, SYS_TTBR1_EL12
131 mrs_s x0, SYS_MAIR_EL12
135 // Hack the exception return to stay at EL2
137 and x0, x0, #~PSR_MODE_MASK
138 mov x1, #PSR_MODE_EL2h
143 SYM_CODE_END(mutate_to_vhe)
145 // At the point where we reach enter_vhe(), we run with
146 // the MMU off (which is enforced by mutate_to_vhe()).
147 // We thus need to be in the idmap, or everything will
148 // explode when enabling the MMU.
150 .pushsection .idmap.text, "ax"
152 SYM_CODE_START_LOCAL(enter_vhe)
153 // Invalidate TLBs before enabling the MMU
158 // Enable the EL2 S1 MMU, as set up from EL1
159 mrs_s x0, SYS_SCTLR_EL12
162 // Disable the EL1 S1 MMU for a good measure
163 mov_q x0, INIT_SCTLR_EL1_MMU_OFF
164 msr_s SYS_SCTLR_EL12, x0
169 SYM_CODE_END(enter_vhe)
173 .macro invalid_vector label
174 SYM_CODE_START_LOCAL(\label)
179 invalid_vector el2_sync_invalid
180 invalid_vector el2_irq_invalid
181 invalid_vector el2_fiq_invalid
182 invalid_vector el2_error_invalid
183 invalid_vector el1_sync_invalid
184 invalid_vector el1_irq_invalid
185 invalid_vector el1_fiq_invalid
186 invalid_vector el1_error_invalid
191 * __hyp_set_vectors: Call this after boot to set the initial hypervisor
192 * vectors as part of hypervisor installation. On an SMP system, this should
193 * be called on each CPU.
195 * x0 must be the physical address of the new vector table, and must be
198 * Before calling this, you must check that the stub hypervisor is installed
199 * everywhere, by waiting for any secondary CPUs to be brought up and then
200 * checking that is_hyp_mode_available() is true.
202 * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
203 * something else went wrong... in such cases, trying to install a new
204 * hypervisor is unlikely to work as desired.
206 * When you call into your shiny new hypervisor, sp_el2 will contain junk,
207 * so you will need to set that to something sensible at the new hypervisor's
208 * initialisation entry point.
211 SYM_FUNC_START(__hyp_set_vectors)
213 mov x0, #HVC_SET_VECTORS
216 SYM_FUNC_END(__hyp_set_vectors)
218 SYM_FUNC_START(__hyp_reset_vectors)
219 mov x0, #HVC_RESET_VECTORS
222 SYM_FUNC_END(__hyp_reset_vectors)
225 * Entry point to switch to VHE if deemed capable
227 SYM_FUNC_START(switch_to_vhe)
228 // Need to have booted at EL2
229 adr_l x1, __boot_cpu_mode
231 cmp w0, #BOOT_CPU_MODE_EL2
234 // and still be at EL1
236 cmp x0, #CurrentEL_EL1
239 // Turn the world upside down
240 mov x0, #HVC_VHE_RESTART
244 SYM_FUNC_END(switch_to_vhe)