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/*
* Copyright (C) 2016 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/types.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_hyp.h>
u32 __hyp_text __init_stage2_translation(void)
{
u64 val = VTCR_EL2_FLAGS;
u64 parange;
u64 tmp;
/*
* Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS
* bits in VTCR_EL2. Amusingly, the PARange is 4 bits, while
* PS is only 3. Fortunately, bit 19 is RES0 in VTCR_EL2...
*/
parange = read_sysreg(id_aa64mmfr0_el1) & 7;
val |= parange << 16;
/* Compute the actual PARange... */
switch (parange) {
case 0:
parange = 32;
break;
case 1:
parange = 36;
break;
case 2:
parange = 40;
break;
case 3:
parange = 42;
break;
case 4:
parange = 44;
break;
case 5:
default:
parange = 48;
break;
}
/*
* ... and clamp it to 40 bits, unless we have some braindead
* HW that implements less than that. In all cases, we'll
* return that value for the rest of the kernel to decide what
* to do.
*/
val |= 64 - (parange > 40 ? 40 : parange);
/*
* Check the availability of Hardware Access Flag / Dirty Bit
* Management in ID_AA64MMFR1_EL1 and enable the feature in VTCR_EL2.
*/
tmp = (read_sysreg(id_aa64mmfr1_el1) >> ID_AA64MMFR1_HADBS_SHIFT) & 0xf;
if (tmp)
val |= VTCR_EL2_HA;
/*
* Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS
* bit in VTCR_EL2.
*/
tmp = (read_sysreg(id_aa64mmfr1_el1) >> ID_AA64MMFR1_VMIDBITS_SHIFT) & 0xf;
val |= (tmp == ID_AA64MMFR1_VMIDBITS_16) ?
VTCR_EL2_VS_16BIT :
VTCR_EL2_VS_8BIT;
write_sysreg(val, vtcr_el2);
return parange;
}
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