iommu: Drop sw_msi from iommu_domain

There are only two sw_msi implementations in the entire system, thus it's
not very necessary to have an sw_msi pointer.

Instead, check domain->cookie_type to call the two sw_msi implementations
directly from the core code.

Link: https://patch.msgid.link/r/7ded87c871afcbaac665b71354de0a335087bf0f.1742871535.git.nicolinc@nvidia.com
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: nicolinc

drivers/iommu/dma-iommu.c

@@ -94,9 +94,6 @@ static int __init iommu_dma_forcedac_setup(char *str)
 }
 early_param("iommu.forcedac", iommu_dma_forcedac_setup);
 
-static int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
-			    phys_addr_t msi_addr);
-
 /* Number of entries per flush queue */
 #define IOVA_DEFAULT_FQ_SIZE	256
 #define IOVA_SINGLE_FQ_SIZE	32768
@@ -377,7 +374,6 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
 
 	mutex_init(&cookie->mutex);
 	INIT_LIST_HEAD(&cookie->msi_page_list);
-	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
 	domain->cookie_type = IOMMU_COOKIE_DMA_IOVA;
 	domain->iova_cookie = cookie;
 	return 0;
@@ -411,7 +407,6 @@ int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
 
 	cookie->msi_iova = base;
 	INIT_LIST_HEAD(&cookie->msi_page_list);
-	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
 	domain->cookie_type = IOMMU_COOKIE_DMA_MSI;
 	domain->msi_cookie = cookie;
 	return 0;
@@ -427,11 +422,6 @@ void iommu_put_dma_cookie(struct iommu_domain *domain)
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	struct iommu_dma_msi_page *msi, *tmp;
 
-#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
-	if (domain->sw_msi != iommu_dma_sw_msi)
-		return;
-#endif
-
 	if (cookie->iovad.granule) {
 		iommu_dma_free_fq(cookie);
 		put_iova_domain(&cookie->iovad);
@@ -1826,8 +1816,8 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	return NULL;
 }
 
-static int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
-			    phys_addr_t msi_addr)
+int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+		     phys_addr_t msi_addr)
 {
 	struct device *dev = msi_desc_to_dev(desc);
 	const struct iommu_dma_msi_page *msi_page;

drivers/iommu/dma-iommu.h

@@ -19,6 +19,9 @@ int iommu_dma_init_fq(struct iommu_domain *domain);
 
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
+int iommu_dma_sw_msi(struct iommu_domain *domain, struct msi_desc *desc,
+		     phys_addr_t msi_addr);
+
 extern bool iommu_dma_forcedac;
 
 #else /* CONFIG_IOMMU_DMA */
@@ -49,5 +52,11 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he
 {
 }
 
+static inline int iommu_dma_sw_msi(struct iommu_domain *domain,
+				   struct msi_desc *desc, phys_addr_t msi_addr)
+{
+	return -ENODEV;
+}
+
 #endif	/* CONFIG_IOMMU_DMA */
 #endif	/* __DMA_IOMMU_H */

drivers/iommu/iommu.c

@@ -18,6 +18,7 @@
 #include <linux/errno.h>
 #include <linux/host1x_context_bus.h>
 #include <linux/iommu.h>
+#include <linux/iommufd.h>
 #include <linux/idr.h>
 #include <linux/err.h>
 #include <linux/pci.h>
@@ -3650,8 +3651,21 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
 		return 0;
 
 	mutex_lock(&group->mutex);
-	if (group->domain && group->domain->sw_msi)
-		ret = group->domain->sw_msi(group->domain, desc, msi_addr);
+	/* An IDENTITY domain must pass through */
+	if (group->domain && group->domain->type != IOMMU_DOMAIN_IDENTITY) {
+		switch (group->domain->cookie_type) {
+		case IOMMU_COOKIE_DMA_MSI:
+		case IOMMU_COOKIE_DMA_IOVA:
+			ret = iommu_dma_sw_msi(group->domain, desc, msi_addr);
+			break;
+		case IOMMU_COOKIE_IOMMUFD:
+			ret = iommufd_sw_msi(group->domain, desc, msi_addr);
+			break;
+		default:
+			ret = -EOPNOTSUPP;
+			break;
+		}
+	}
 	mutex_unlock(&group->mutex);
 	return ret;
 }

drivers/iommu/iommufd/hw_pagetable.c

@@ -161,7 +161,6 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 	}
 	hwpt->domain->iommufd_hwpt = hwpt;
 	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
-	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	/*
 	 * Set the coherency mode before we do iopt_table_add_domain() as some
@@ -259,7 +258,6 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
 	hwpt->domain->owner = ops;
 	hwpt->domain->iommufd_hwpt = hwpt;
 	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
-	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
 		rc = -EINVAL;
@@ -318,7 +316,6 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
 	hwpt->domain->iommufd_hwpt = hwpt;
 	hwpt->domain->owner = viommu->iommu_dev->ops;
 	hwpt->domain->cookie_type = IOMMU_COOKIE_IOMMUFD;
-	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
 		rc = -EINVAL;

include/linux/iommu.h

@@ -229,11 +229,6 @@ struct iommu_domain {
 	struct iommu_domain_geometry geometry;
 	int (*iopf_handler)(struct iopf_group *group);
 
-#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
-	int (*sw_msi)(struct iommu_domain *domain, struct msi_desc *desc,
-		      phys_addr_t msi_addr);
-#endif
-
 	union { /* cookie */
 		struct iommu_dma_cookie *iova_cookie;
 		struct iommu_dma_msi_cookie *msi_cookie;
@@ -254,16 +249,6 @@ struct iommu_domain {
 	};
 };
 
-static inline void iommu_domain_set_sw_msi(
-	struct iommu_domain *domain,
-	int (*sw_msi)(struct iommu_domain *domain, struct msi_desc *desc,
-		      phys_addr_t msi_addr))
-{
-#if IS_ENABLED(CONFIG_IRQ_MSI_IOMMU)
-	domain->sw_msi = sw_msi;
-#endif
-}
-
 static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
 {
 	return domain->type & __IOMMU_DOMAIN_DMA_API;