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From:   Matthew Rosato <mjrosato@linux.ibm.com>
To:     linux-s390@vger.kernel.org
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Subject: [PATCH v4 14/32] iommu: introduce iommu_domain_alloc_type and the KVM type
Date:   Mon, 14 Mar 2022 15:44:33 -0400
Message-Id: <20220314194451.58266-15-mjrosato@linux.ibm.com>
In-Reply-To: <20220314194451.58266-1-mjrosato@linux.ibm.com>
References: <20220314194451.58266-1-mjrosato@linux.ibm.com>
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s390x will introduce an additional domain type that is used for
managing IOMMU owned by KVM.  Define the type here and add an
interface for allocating a specified type vs the default type.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
---
 drivers/iommu/iommu.c |  7 +++++++
 include/linux/iommu.h | 12 ++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f2c45b85b9fc..8bb57e0e3945 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1976,6 +1976,13 @@ void iommu_domain_free(struct iommu_domain *domain)
 }
 EXPORT_SYMBOL_GPL(iommu_domain_free);
 
+struct iommu_domain *iommu_domain_alloc_type(struct bus_type *bus,
+					     unsigned int t)
+{
+	return __iommu_domain_alloc(bus, t);
+}
+EXPORT_SYMBOL_GPL(iommu_domain_alloc_type);
+
 static int __iommu_attach_device(struct iommu_domain *domain,
 				 struct device *dev)
 {
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9208eca4b0d1..b427bbb9f387 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -63,6 +63,7 @@ struct iommu_domain_geometry {
 					      implementation              */
 #define __IOMMU_DOMAIN_PT	(1U << 2)  /* Domain is identity mapped   */
 #define __IOMMU_DOMAIN_DMA_FQ	(1U << 3)  /* DMA-API uses flush queue    */
+#define __IOMMU_DOMAIN_KVM	(1U << 4)  /* Domain is controlled by KVM */
 
 /*
  * This are the possible domain-types
@@ -77,6 +78,7 @@ struct iommu_domain_geometry {
  *				  certain optimizations for these domains
  *	IOMMU_DOMAIN_DMA_FQ	- As above, but definitely using batched TLB
  *				  invalidation.
+ *	IOMMU_DOMAIN_KVM	- DMA mappings managed by KVM, used for VMs
  */
 #define IOMMU_DOMAIN_BLOCKED	(0U)
 #define IOMMU_DOMAIN_IDENTITY	(__IOMMU_DOMAIN_PT)
@@ -86,6 +88,8 @@ struct iommu_domain_geometry {
 #define IOMMU_DOMAIN_DMA_FQ	(__IOMMU_DOMAIN_PAGING |	\
 				 __IOMMU_DOMAIN_DMA_API |	\
 				 __IOMMU_DOMAIN_DMA_FQ)
+#define IOMMU_DOMAIN_KVM	(__IOMMU_DOMAIN_PAGING |	\
+				 __IOMMU_DOMAIN_KVM)
 
 struct iommu_domain {
 	unsigned type;
@@ -421,6 +425,8 @@ extern bool iommu_capable(struct bus_type *bus, enum iommu_cap cap);
 extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);
 extern struct iommu_group *iommu_group_get_by_id(int id);
 extern void iommu_domain_free(struct iommu_domain *domain);
+extern struct iommu_domain *iommu_domain_alloc_type(struct bus_type *bus,
+						    unsigned int t);
 extern int iommu_attach_device(struct iommu_domain *domain,
 			       struct device *dev);
 extern void iommu_detach_device(struct iommu_domain *domain,
@@ -708,6 +714,12 @@ static inline void iommu_domain_free(struct iommu_domain *domain)
 {
 }
 
+static inline struct iommu_domain *iommu_domain_alloc_type(struct bus_type *bus,
+							   unsigned int t)
+{
+	return NULL;
+}
+
 static inline int iommu_attach_device(struct iommu_domain *domain,
 				      struct device *dev)
 {
-- 
2.27.0