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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <linux/arm-smccc.h>
#include <linux/linkage.h>
#include <asm/alternative.h>
#include <asm/assembler.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
#include <asm/pgtable-hwdef.h>
#include <asm/sysreg.h>
#include <asm/virt.h>
.text
.pushsection .hyp.idmap.text, "ax"
.align 11
SYM_CODE_START(__kvm_hyp_init)
ventry __invalid // Synchronous EL2t
ventry __invalid // IRQ EL2t
ventry __invalid // FIQ EL2t
ventry __invalid // Error EL2t
ventry __invalid // Synchronous EL2h
ventry __invalid // IRQ EL2h
ventry __invalid // FIQ EL2h
ventry __invalid // Error EL2h
ventry __do_hyp_init // Synchronous 64-bit EL1
ventry __invalid // IRQ 64-bit EL1
ventry __invalid // FIQ 64-bit EL1
ventry __invalid // Error 64-bit EL1
ventry __invalid // Synchronous 32-bit EL1
ventry __invalid // IRQ 32-bit EL1
ventry __invalid // FIQ 32-bit EL1
ventry __invalid // Error 32-bit EL1
__invalid:
b .
/*
* x0: SMCCC function ID
* x1: HYP pgd
* x2: per-CPU offset
* x3: HYP stack
* x4: HYP vectors
*/
__do_hyp_init:
/* Check for a stub HVC call */
cmp x0, #HVC_STUB_HCALL_NR
b.lo __kvm_handle_stub_hvc
// We only actively check bits [24:31], and everything
// else has to be zero, which we check at build time.
#if (KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) & 0xFFFFFFFF00FFFFFF)
#error Unexpected __KVM_HOST_SMCCC_FUNC___kvm_hyp_init value
#endif
ror x0, x0, #24
eor x0, x0, #((KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) >> 24) & 0xF)
ror x0, x0, #4
eor x0, x0, #((KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) >> 28) & 0xF)
cbz x0, 1f
mov x0, #SMCCC_RET_NOT_SUPPORTED
eret
1:
/* Set tpidr_el2 for use by HYP to free a register */
msr tpidr_el2, x2
phys_to_ttbr x0, x1
alternative_if ARM64_HAS_CNP
orr x0, x0, #TTBR_CNP_BIT
alternative_else_nop_endif
msr ttbr0_el2, x0
mrs x0, tcr_el1
mov_q x1, TCR_EL2_MASK
and x0, x0, x1
mov x1, #TCR_EL2_RES1
orr x0, x0, x1
/*
* The ID map may be configured to use an extended virtual address
* range. This is only the case if system RAM is out of range for the
* currently configured page size and VA_BITS, in which case we will
* also need the extended virtual range for the HYP ID map, or we won't
* be able to enable the EL2 MMU.
*
* However, at EL2, there is only one TTBR register, and we can't switch
* between translation tables *and* update TCR_EL2.T0SZ at the same
* time. Bottom line: we need to use the extended range with *both* our
* translation tables.
*
* So use the same T0SZ value we use for the ID map.
*/
ldr_l x1, idmap_t0sz
bfi x0, x1, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
/*
* Set the PS bits in TCR_EL2.
*/
tcr_compute_pa_size x0, #TCR_EL2_PS_SHIFT, x1, x2
msr tcr_el2, x0
mrs x0, mair_el1
msr mair_el2, x0
isb
/* Invalidate the stale TLBs from Bootloader */
tlbi alle2
dsb sy
/*
* Preserve all the RES1 bits while setting the default flags,
* as well as the EE bit on BE. Drop the A flag since the compiler
* is allowed to generate unaligned accesses.
*/
mov_q x0, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A))
CPU_BE( orr x0, x0, #SCTLR_ELx_EE)
alternative_if ARM64_HAS_ADDRESS_AUTH
mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \
SCTLR_ELx_ENDA | SCTLR_ELx_ENDB)
orr x0, x0, x1
alternative_else_nop_endif
msr sctlr_el2, x0
isb
/* Set the stack and new vectors */
mov sp, x3
msr vbar_el2, x4
/* Hello, World! */
mov x0, #SMCCC_RET_SUCCESS
eret
SYM_CODE_END(__kvm_hyp_init)
SYM_CODE_START(__kvm_handle_stub_hvc)
cmp x0, #HVC_SOFT_RESTART
b.ne 1f
/* This is where we're about to jump, staying at EL2 */
msr elr_el2, x1
mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h)
msr spsr_el2, x0
/* Shuffle the arguments, and don't come back */
mov x0, x2
mov x1, x3
mov x2, x4
b reset
1: cmp x0, #HVC_RESET_VECTORS
b.ne 1f
/*
* Set the HVC_RESET_VECTORS return code before entering the common
* path so that we do not clobber x0-x2 in case we are coming via
* HVC_SOFT_RESTART.
*/
mov x0, xzr
reset:
/* Reset kvm back to the hyp stub. */
mrs x5, sctlr_el2
mov_q x6, SCTLR_ELx_FLAGS
bic x5, x5, x6 // Clear SCTL_M and etc
pre_disable_mmu_workaround
msr sctlr_el2, x5
isb
/* Install stub vectors */
adr_l x5, __hyp_stub_vectors
msr vbar_el2, x5
eret
1: /* Bad stub call */
mov_q x0, HVC_STUB_ERR
eret
SYM_CODE_END(__kvm_handle_stub_hvc)
.popsection
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