Use symbolic constants for edge/level values in irq_cfg, and
add comments about compressing/expanding configuration bits.
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/kvm/vgic.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
index 1cd6674..36a359e 100644
--- a/arch/arm/kvm/vgic.c
+++ b/arch/arm/kvm/vgic.c
@@ -175,9 +175,12 @@ static inline void vgic_bytemap_set_irq_val(struct vgic_bytemap *x,
*reg |= (val & 0xff) << shift;
}
-static inline int vgic_irq_is_edge(struct vgic_dist *dist, int irq)
+#define VGIC_CFG_LEVEL 0
+#define VGIC_CFG_EDGE 1
+
+static inline bool vgic_irq_is_edge(struct vgic_dist *dist, int irq)
{
- return vgic_bitmap_get_irq_val(&dist->irq_cfg, 0, irq);
+ return vgic_bitmap_get_irq_val(&dist->irq_cfg, 0, irq) == VGIC_CFG_EDGE;
}
static inline int vgic_irq_is_enabled(struct kvm_vcpu *vcpu, int irq)
@@ -484,8 +487,12 @@ static u32 vgic_cfg_expand(u16 val)
u32 res = 0;
int i;
+ /*
+ * Turn a 16bit value like abcd...mnop into a 32bit word
+ * a0b0c0d0...m0n0o0p0, which is what the HW cfg register is.
+ */
for (i = 0; i < 16; i++)
- res |= ((val >> i) & 1) << (2 * i + 1);
+ res |= ((val >> i) & VGIC_CFG_EDGE) << (2 * i + 1);
return res;
}
@@ -495,8 +502,12 @@ static u16 vgic_cfg_compress(u32 val)
u16 res = 0;
int i;
+ /*
+ * Turn a 32bit word a0b0c0d0...m0n0o0p0 into 16bit value like
+ * abcd...mnop which is what we really care about.
+ */
for (i = 0; i < 16; i++)
- res |= ((val >> (i * 2 + 1)) & 1) << i;
+ res |= ((val >> (i * 2 + 1)) & VGIC_CFG_EDGE) << i;
return res;
}
@@ -1186,7 +1197,7 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
vcpu->vcpu_id, i, 1);
if (i < VGIC_NR_PRIVATE_IRQS)
vgic_bitmap_set_irq_val(&dist->irq_cfg,
- vcpu->vcpu_id, i, 1);
+ vcpu->vcpu_id, i, VGIC_CFG_EDGE);
vgic_cpu->vgic_irq_lr_map[i] = LR_EMPTY;
}
--
1.8.0.1
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