From 9662fb4854e1319b4affda47f279c3f210316def Mon Sep 17 00:00:00 2001 From: Victor Kamensky Date: Thu, 12 Jun 2014 09:30:10 -0700 Subject: [PATCH] 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 Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier --- virt/kvm/arm/vgic.c | 24 ++++++++++++++++++++++-- 1 file 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, -- 2.39.5