[PATCH 07/10] xen/arm: vgic-v2: Correctly set GICD_TYPER.CPUNumber

[Julien Grall <julien.grall@linaro.org>]

The number of implemented CPU interfaces is one more than the value of
this field.

Also avoid to hardcode the shift and remove unuseful mask.

Signed-off-by: Julien Grall <julien.grall@linaro.org>

---
    This patch should be backported to Xen 4.4 and Xen 4.5.

    Although this patch won't apply directly for Xen 4.4 and may require
    to define GICD_TYPE_CPUS_SHIFT if "xen/arm: vgic-v3: Correctly set
    GICD_TYPER.CPUNumber" is not backported.
---
 xen/arch/arm/vgic-v2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index 4dc2267..a34a0c7 100644
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -55,7 +55,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         if ( dabt.size != DABT_WORD ) goto bad_width;
         /* No secure world support for guests. */
         vgic_lock(v);
-        *r = ( (v->domain->max_vcpus << 5) & GICD_TYPE_CPUS )
+        *r = ( ((v->domain->max_vcpus - 1) << GICD_TYPE_CPUS_SHIFT) )
             |( ((v->domain->arch.vgic.nr_lines / 32)) & GICD_TYPE_LINES );
         vgic_unlock(v);
         return 1;
-- 
2.1.4