arch/arm64/kvm/hyp/s2-setup.c

   1 /*
   2  * Copyright (C) 2016 - ARM Ltd
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/types.h>
  19 #include <asm/kvm_arm.h>
  20 #include <asm/kvm_asm.h>
  21 #include <asm/kvm_hyp.h>
  22
  23 void __hyp_text __init_stage2_translation(void)
  24 {
  25         u64 val = VTCR_EL2_FLAGS;
  26         u64 tmp;
  27
  28         /*
  29          * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS
  30          * bits in VTCR_EL2. Amusingly, the PARange is 4 bits, while
  31          * PS is only 3. Fortunately, bit 19 is RES0 in VTCR_EL2...
  32          */
  33         val |= (read_sysreg(id_aa64mmfr0_el1) & 7) << 16;
  34
  35         /*
  36          * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS
  37          * bit in VTCR_EL2.
  38          */
  39         tmp = (read_sysreg(id_aa64mmfr1_el1) >> 4) & 0xf;
  40         val |= (tmp == 2) ? VTCR_EL2_VS : 0;
  41
  42         write_sysreg(val, vtcr_el2);
  43 }