[PATCH RFC 7/9] iommu/hyperv: Split root IOMMU declarations

[Jacob Pan <jacob.pan@linux.microsoft.com>]

Move the root IOMMU shared domain type, page-size mask, and
geometry into a private Hyper-V IOMMU header so IOMMUFD support
can live outside the main root driver file.

Assisted-by: GPT-5.6 Sol
Signed-off-by: Jacob Pan <jacob.pan@linux.microsoft.com>
---
 drivers/iommu/hyperv/hv-iommu-root.c | 11 +----------
 drivers/iommu/hyperv/hv-iommu.h      | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+), 10 deletions(-)
 create mode 100644 drivers/iommu/hyperv/hv-iommu.h

diff --git a/drivers/iommu/hyperv/hv-iommu-root.c b/drivers/iommu/hyperv/hv-iommu-root.c
index a5268e0e52cc..3b82891c9cab 100644
--- a/drivers/iommu/hyperv/hv-iommu-root.c
+++ b/drivers/iommu/hyperv/hv-iommu-root.c
@@ -7,6 +7,7 @@
 #include <linux/dma-map-ops.h>
 #include <linux/interval_tree.h>
 #include <linux/hyperv.h>
+#include "hv-iommu.h"
 #include <asm/iommu.h>
 #include <asm/mshyperv.h>
 #include "../dma-iommu.h"
@@ -31,15 +32,6 @@ static struct iommu_domain_ops hv_paging_domain_ops;
 /* IOMMU device that we export to the world. HyperV supports max of one */
 static struct iommu_device hv_virt_iommu;
 
-struct hv_domain {
-	struct iommu_domain iommu_dom;
-	u32 domid_num;			      /* as opposed to domain_id.type */
-	spinlock_t mappings_lock;	      /* protects mappings_tree */
-	struct rb_root_cached mappings_tree;  /* iova to pa lookup tree */
-};
-
-#define to_hv_domain(d) container_of(d, struct hv_domain, iommu_dom)
-
 struct hv_iommu_mapping {
 	phys_addr_t paddr;
 	struct interval_tree_node iova;
@@ -67,7 +59,6 @@ static bool hv_special_domain(struct hv_domain *hvdom)
 	return hvdom == &hv_def_identity_dom || hvdom == &hv_def_blocked_dom;
 }
 
-#define HV_IOMMU_PGSIZES SZ_4K		/* for now, to be enhanced */
 static atomic_t hv_unique_id;		/* unique numeric id for a new domain */
 
 static bool hv_iommu_capable(struct device *dev, enum iommu_cap cap)
diff --git a/drivers/iommu/hyperv/hv-iommu.h b/drivers/iommu/hyperv/hv-iommu.h
new file mode 100644
index 000000000000..6895b4e7eb6d
--- /dev/null
+++ b/drivers/iommu/hyperv/hv-iommu.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Hyper-V root vIOMMU driver.
+ * Copyright (C) 2026, Microsoft, Inc.
+ */
+
+#ifndef __HYPERV_IOMMU_H
+#define __HYPERV_IOMMU_H
+
+#include <linux/interval_tree.h>
+#include <linux/iommu.h>
+#include <linux/sizes.h>
+#include <linux/spinlock.h>
+
+#define HV_IOMMU_PGSIZES SZ_4K  /* for now, to be enhanced */
+
+struct hv_domain {
+	struct iommu_domain iommu_dom;
+	u32 domid_num;			      /* as opposed to domain_id.type */
+	spinlock_t mappings_lock;	      /* protects mappings_tree */
+	struct rb_root_cached mappings_tree;  /* iova to pa lookup tree */
+};
+
+#define to_hv_domain(d) container_of(d, struct hv_domain, iommu_dom)
+
+#endif /* __HYPERV_IOMMU_H */
-- 
2.43.0