diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 0e187f6ae3..7bbe3889a2 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -25,10 +25,10 @@
 unsigned int __read_mostly iommu_dev_iotlb_timeout = 1000;
 integer_param("iommu_dev_iotlb_timeout", iommu_dev_iotlb_timeout);
 
-bool_t __initdata iommu_enable = 1;
-bool_t __read_mostly iommu_enabled;
-bool_t __read_mostly force_iommu;
-bool_t __read_mostly iommu_verbose;
+bool __initdata iommu_enable = 1;
+bool __read_mostly iommu_enabled;
+bool __read_mostly force_iommu;
+bool __read_mostly iommu_verbose;
 static bool_t __read_mostly iommu_crash_disable;
 
 #define IOMMU_quarantine_none         0 /* aka false */
@@ -57,7 +57,7 @@ int8_t __hwdom_initdata iommu_hwdom_reserved = -1;
 bool __read_mostly iommu_hap_pt_share = true;
 #endif
 
-bool_t __read_mostly iommu_debug;
+bool __read_mostly iommu_debug;
 
 DEFINE_PER_CPU(bool_t, iommu_dont_flush_iotlb);
 
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 405db59971..8c0818cd01 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -52,7 +52,7 @@ static inline bool_t dfn_eq(dfn_t x, dfn_t y)
 }
 
 #ifdef CONFIG_HAS_PASSTHROUGH
-extern bool_t iommu_enable, iommu_enabled;
+extern bool iommu_enable, iommu_enabled;
 extern bool force_iommu, iommu_verbose;
 /* Boolean except for the specific purposes of drivers/passthrough/iommu.c. */
 extern uint8_t iommu_quarantine;
@@ -108,8 +108,8 @@ static inline void clear_iommu_hap_pt_share(void)
 #endif
 }
 
-extern bool_t iommu_debug;
-extern bool_t amd_iommu_perdev_intremap;
+extern bool iommu_debug;
+extern bool amd_iommu_perdev_intremap;
 
 extern bool iommu_hwdom_strict, iommu_hwdom_passthrough, iommu_hwdom_inclusive;
 extern int8_t iommu_hwdom_reserved;
@@ -165,10 +165,10 @@ enum
  * values indicate partial completion, which is possible only with
  * IOMMUF_preempt passed in.
  */
-long __must_check iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn,
+long __must_check iommu_map(struct domain *d, dfn_t dfn0, mfn_t mfn0,
                             unsigned long page_count, unsigned int flags,
                             unsigned int *flush_flags);
-long __must_check iommu_unmap(struct domain *d, dfn_t dfn,
+long __must_check iommu_unmap(struct domain *d, dfn_t dfn0,
                               unsigned long page_count, unsigned int flags,
                               unsigned int *flush_flags);
 
@@ -197,11 +197,13 @@ bool_t iommu_has_feature(struct domain *d, enum iommu_feature feature);
 
 #ifdef CONFIG_HAS_PCI
 struct pirq;
-int hvm_do_IRQ_dpci(struct domain *, struct pirq *);
-int pt_irq_create_bind(struct domain *, const struct xen_domctl_bind_pt_irq *);
-int pt_irq_destroy_bind(struct domain *, const struct xen_domctl_bind_pt_irq *);
+int hvm_do_IRQ_dpci(struct domain *d, struct pirq *pirq);
+int pt_irq_create_bind(struct domain *d,
+                       const struct xen_domctl_bind_pt_irq *pt_irq_bind);
+int pt_irq_destroy_bind(struct domain *d,
+                        const struct xen_domctl_bind_pt_irq *pt_irq_bind);
 
-struct hvm_irq_dpci *domain_get_irq_dpci(const struct domain *);
+struct hvm_irq_dpci *domain_get_irq_dpci(const struct domain *d);
 void free_hvm_irq_dpci(struct hvm_irq_dpci *dpci);
 
 struct msi_desc;
@@ -229,8 +231,8 @@ int iommu_release_dt_devices(struct domain *d);
  */
 int iommu_add_dt_device(struct dt_device_node *np);
 
-int iommu_do_dt_domctl(struct xen_domctl *, struct domain *,
-                       XEN_GUEST_HANDLE_PARAM(xen_domctl_t));
+int iommu_do_dt_domctl(struct xen_domctl *domctl, struct domain *d,
+                       XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl);
 
 #endif /* HAS_DEVICE_TREE */
 
@@ -386,12 +388,12 @@ static inline int iommu_do_domctl(struct xen_domctl *domctl, struct domain *d,
 int __must_check iommu_suspend(void);
 void iommu_resume(void);
 void iommu_crash_shutdown(void);
-int iommu_get_reserved_device_memory(iommu_grdm_t *, void *);
+int iommu_get_reserved_device_memory(iommu_grdm_t *func, void *ctxt);
 int iommu_quarantine_dev_init(device_t *dev);
 
 #ifdef CONFIG_HAS_PCI
-int iommu_do_pci_domctl(struct xen_domctl *, struct domain *d,
-                        XEN_GUEST_HANDLE_PARAM(xen_domctl_t));
+int iommu_do_pci_domctl(struct xen_domctl *domctl, struct domain *d,
+                        XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl);
 #endif
 
 void iommu_dev_iotlb_flush_timeout(struct domain *d, struct pci_dev *pdev);
