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| author | Vladimir Murzin <vladimir.murzin@arm.com> | 2016-09-12 17:49:20 +0300 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2016-09-22 14:21:59 +0300 |
| commit | d7d0a11e44a1c6c1e61db7f305115f33be900704 (patch) | |
| tree | ff8b15fe984d8c3f95cc7fca916979d955d45cf9 /virt/kvm/arm/vgic/vgic-mmio-v3.c | |
| parent | e533a37f7b5ee5eb8b102cf0823e84cd6a7deb57 (diff) | |
| download | linux-d7d0a11e44a1c6c1e61db7f305115f33be900704.tar.xz | |
KVM: arm: vgic: Support 64-bit data manipulation on 32-bit host systems
We have couple of 64-bit registers defined in GICv3 architecture, so
unsigned long accesses to these registers will only access a single
32-bit part of that regitser. On the other hand these registers can't
be accessed as 64-bit with a single instruction like ldrd/strd or
ldmia/stmia if we run a 32-bit host because KVM does not support
access to MMIO space done by these instructions.
It means that a 32-bit guest accesses these registers in 32-bit
chunks, so the only thing we need to do is to ensure that
extract_bytes() always takes 64-bit data.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-mmio-v3.c')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-mmio-v3.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c index 6385ed5814b4..0d3c76a4208b 100644 --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c @@ -23,7 +23,7 @@ #include "vgic-mmio.h" /* extract @num bytes at @offset bytes offset in data */ -unsigned long extract_bytes(unsigned long data, unsigned int offset, +unsigned long extract_bytes(u64 data, unsigned int offset, unsigned int num) { return (data >> (offset * 8)) & GENMASK_ULL(num * 8 - 1, 0); |