mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-08-05 16:54:27 +00:00
6141570c36
We always thought that 40bits of PA range would be the minimum people would actually build. Anything less is terrifyingly small. Turns out that we were both right and wrong. Nobody has ever built such a system, but the ARM Foundation Model has a PARange set to 36bits. Just because we can. Oh well. Now, the KVM API explicitely says that we offer a 40bit PA space to the VM, so we shouldn't run KVM on the Foundation Model at all. That being said, this patch offers a less agressive alternative, and loudly warns about the configuration being unsupported. You'll still be able to run VMs (at your own risks, though). This is just a workaround until we have a proper userspace API where we report the PARange to userspace. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
/*
|
|
* 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);
|
|
|
|
/*
|
|
* 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;
|
|
}
|