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authorVictor Kamensky <victor.kamensky@linaro.org>2014-06-12 09:30:10 -0700
committerChristoffer Dall <christoffer.dall@linaro.org>2014-07-11 04:57:42 -0700
commit9662fb4854e1319b4affda47f279c3f210316def (patch)
tree39a52d317829f60b035f683d835a6855c038e15a /virt/kvm
parentba083d20d8cfa9e999043cd89c4ebc964ccf8927 (diff)
downloadlinux-9662fb4854e1319b4affda47f279c3f210316def.tar.bz2
ARM64: KVM: fix vgic_bitmap_get_reg function for BE 64bit case
Fix vgic_bitmap_get_reg function to return 'right' word address of 'unsigned long' bitmap value in case of BE 64bit image. Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt/kvm')
-rw-r--r--virt/kvm/arm/vgic.c24
1 files changed, 22 insertions, 2 deletions
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index b0edc8c670f8..ede8f6466c95 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -98,14 +98,34 @@ static void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
static const struct vgic_ops *vgic_ops;
static const struct vgic_params *vgic;
+/*
+ * struct vgic_bitmap contains unions that provide two views of
+ * the same data. In one case it is an array of registers of
+ * u32's, and in the other case it is a bitmap of unsigned
+ * longs.
+ *
+ * This does not work on 64-bit BE systems, because the bitmap access
+ * will store two consecutive 32-bit words with the higher-addressed
+ * register's bits at the lower index and the lower-addressed register's
+ * bits at the higher index.
+ *
+ * Therefore, swizzle the register index when accessing the 32-bit word
+ * registers to access the right register's value.
+ */
+#if defined(CONFIG_CPU_BIG_ENDIAN) && BITS_PER_LONG == 64
+#define REG_OFFSET_SWIZZLE 1
+#else
+#define REG_OFFSET_SWIZZLE 0
+#endif
+
static u32 *vgic_bitmap_get_reg(struct vgic_bitmap *x,
int cpuid, u32 offset)
{
offset >>= 2;
if (!offset)
- return x->percpu[cpuid].reg;
+ return x->percpu[cpuid].reg + (offset ^ REG_OFFSET_SWIZZLE);
else
- return x->shared.reg + offset - 1;
+ return x->shared.reg + ((offset - 1) ^ REG_OFFSET_SWIZZLE);
}
static int vgic_bitmap_get_irq_val(struct vgic_bitmap *x,