KVM: arm/arm64: Helper to locate free rdist index

We introduce vgic_v3_rdist_free_slot to help identifying where we can place a new 2x64KB redistributor. Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

KVM: arm/arm64: Helper to locate free rdist index
We introduce vgic_v3_rdist_free_slot to help identifying where we can place a new 2x64KB redistributor. Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Eric Auger · Marc Zyngier
1 parent dbd9733ab6
Showing 3 changed files with 35 additions and 2 deletions Side-by-side Diff
virt/kvm/arm/vgic/vgic-mmio-v3.c
virt/kvm/arm/vgic/vgic-v3.c
virt/kvm/arm/vgic/vgic.h
@@ -593,8 +593,7 @@
 	 * function for all VCPUs when the base address is set.  Just return
 	 * without doing any work for now.
 	 */
-	rdreg = list_first_entry(&vgic->rd_regions,
-				 struct vgic_redist_region, list);
+	rdreg = vgic_v3_rdist_free_slot(&vgic->rd_regions);
 	if (!rdreg)
 		return 0;
  
@@ -453,6 +453,29 @@
 	return false;
 }
  
+/**
+ * vgic_v3_rdist_free_slot - Look up registered rdist regions and identify one
+ * which has free space to put a new rdist region.
+ *
+ * @rd_regions: redistributor region list head
+ *
+ * A redistributor regions maps n redistributors, n = region size / (2 x 64kB).
+ * Stride between redistributors is 0 and regions are filled in the index order.
+ *
+ * Return: the redist region handle, if any, that has space to map a new rdist
+ * region.
+ */
+struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rd_regions)
+{
+	struct vgic_redist_region *rdreg;
+
+	list_for_each_entry(rdreg, rd_regions, list) {
+		if (!vgic_v3_redist_region_full(rdreg))
+			return rdreg;
+	}
+	return NULL;
+}
+
 int vgic_v3_map_resources(struct kvm *kvm)
 {
 	int ret = 0;
@@ -265,6 +265,17 @@
 	}
 }
  
+static inline bool
+vgic_v3_redist_region_full(struct vgic_redist_region *region)
+{
+	if (!region->count)
+		return false;
+
+	return (region->free_index >= region->count);
+}
+
+struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rdregs);
+
 int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
 			 u32 devid, u32 eventid, struct vgic_irq **irq);
 struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
...	...	@@ -593,8 +593,7 @@
593	593	* function for all VCPUs when the base address is set. Just return
594	594	* without doing any work for now.
595	595	*/
596		- rdreg = list_first_entry(&vgic->rd_regions,
597		- struct vgic_redist_region, list);
	596	+ rdreg = vgic_v3_rdist_free_slot(&vgic->rd_regions);
598	597	if (!rdreg)
599	598	return 0;
600	599
...	...	@@ -453,6 +453,29 @@
453	453	return false;
454	454	}
455	455
	456	+/**
	457	+ * vgic_v3_rdist_free_slot - Look up registered rdist regions and identify one
	458	+ * which has free space to put a new rdist region.
	459	+ *
	460	+ * @rd_regions: redistributor region list head
	461	+ *
	462	+ * A redistributor regions maps n redistributors, n = region size / (2 x 64kB).
	463	+ * Stride between redistributors is 0 and regions are filled in the index order.
	464	+ *
	465	+ * Return: the redist region handle, if any, that has space to map a new rdist
	466	+ * region.
	467	+ */
	468	+struct vgic_redist_region vgic_v3_rdist_free_slot(struct list_head rd_regions)
	469	+{
	470	+ struct vgic_redist_region *rdreg;
	471	+
	472	+ list_for_each_entry(rdreg, rd_regions, list) {
	473	+ if (!vgic_v3_redist_region_full(rdreg))
	474	+ return rdreg;
	475	+ }
	476	+ return NULL;
	477	+}
	478	+
456	479	int vgic_v3_map_resources(struct kvm *kvm)
457	480	{
458	481	int ret = 0;
...	...	@@ -265,6 +265,17 @@
265	265	}
266	266	}
267	267
	268	+static inline bool
	269	+vgic_v3_redist_region_full(struct vgic_redist_region *region)
	270	+{
	271	+ if (!region->count)
	272	+ return false;
	273	+
	274	+ return (region->free_index >= region->count);
	275	+}
	276	+
	277	+struct vgic_redist_region vgic_v3_rdist_free_slot(struct list_head rdregs);
	278	+
268	279	int vgic_its_resolve_lpi(struct kvm kvm, struct vgic_its its,
269	280	u32 devid, u32 eventid, struct vgic_irq **irq);
270	281	struct vgic_its vgic_msi_to_its(struct kvm kvm, struct kvm_msi *msi);