[PATCH v3 02/13] iommu/amd: Introduce get_amd_iommu_from_dev()

[Vasant Hegde <vasant.hegde@amd.com>]

From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

And replace rlookup_amd_iommu() with the new helper function where
applicable to avoid unnecessary loop to look up struct amd_iommu from
struct device.

Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
---
 drivers/iommu/amd/amd_iommu.h | 14 ++++++++++++++
 drivers/iommu/amd/iommu.c     | 20 ++++++++++----------
 include/linux/iommu.h         | 13 +++++++++++++
 3 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 38b3f4562f3b..b2071ebc73b5 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -150,6 +150,20 @@ static inline void *alloc_pgtable_page(int nid, gfp_t gfp)
 	return page ? page_address(page) : NULL;
 }
 
+/*
+ * This must be called after device probe completes. During probe
+ * use rlookup_amd_iommu() get the iommu.
+ */
+static inline struct amd_iommu *get_amd_iommu_from_dev(struct device *dev)
+{
+	struct iommu_device *iommu = iommu_get_iommu_dev(dev);
+
+	if (!iommu)
+		return NULL;
+
+	return container_of(iommu, struct amd_iommu, iommu);
+}
+
 bool translation_pre_enabled(struct amd_iommu *iommu);
 bool amd_iommu_is_attach_deferred(struct device *dev);
 int __init add_special_device(u8 type, u8 id, u32 *devid, bool cmd_line);
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 4f1b356adb8f..eedfa341085c 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1408,7 +1408,7 @@ static int device_flush_iotlb_range(struct iommu_dev_data *dev_data,
 	bool gn = is_pasid_valid(pasid);
 
 	qdep     = dev_data->ats_qdep;
-	iommu    = rlookup_amd_iommu(dev_data->dev);
+	iommu    = get_amd_iommu_from_dev(dev_data->dev);
 	if (!iommu)
 		return -EINVAL;
 
@@ -1436,7 +1436,7 @@ static int device_flush_dte(struct iommu_dev_data *dev_data)
 	u16 alias;
 	int ret;
 
-	iommu = rlookup_amd_iommu(dev_data->dev);
+	iommu = get_amd_iommu_from_dev(dev_data->dev);
 	if (!iommu)
 		return -EINVAL;
 
@@ -1644,7 +1644,7 @@ static void update_device_table(struct protection_domain *domain)
 	struct iommu_dev_data *dev_data;
 
 	list_for_each_entry(dev_data, &domain->dev_list, list) {
-		struct amd_iommu *iommu = rlookup_amd_iommu(dev_data->dev);
+		struct amd_iommu *iommu = get_amd_iommu_from_dev(dev_data->dev);
 
 		if (!iommu)
 			continue;
@@ -1676,7 +1676,7 @@ int amd_iommu_complete_ppr(struct pci_dev *pdev, u32 pasid,
 	struct iommu_cmd cmd;
 
 	dev_data = dev_iommu_priv_get(&pdev->dev);
-	iommu    = rlookup_amd_iommu(&pdev->dev);
+	iommu    = get_amd_iommu_from_dev(&pdev->dev);
 	if (!iommu)
 		return -ENODEV;
 
@@ -1902,7 +1902,7 @@ static void do_attach(struct iommu_dev_data *dev_data,
 {
 	struct amd_iommu *iommu;
 
-	iommu = rlookup_amd_iommu(dev_data->dev);
+	iommu = get_amd_iommu_from_dev(dev_data->dev);
 	if (!iommu)
 		return;
 
@@ -1930,7 +1930,7 @@ static void do_detach(struct iommu_dev_data *dev_data)
 	struct protection_domain *domain = dev_data->domain;
 	struct amd_iommu *iommu;
 
-	iommu = rlookup_amd_iommu(dev_data->dev);
+	iommu = get_amd_iommu_from_dev(dev_data->dev);
 	if (!iommu)
 		return;
 
@@ -2072,7 +2072,7 @@ static void amd_iommu_release_device(struct device *dev)
 	if (!check_device(dev))
 		return;
 
-	iommu = rlookup_amd_iommu(dev);
+	iommu = get_amd_iommu_from_dev(dev);
 	if (!iommu)
 		return;
 
@@ -2283,7 +2283,7 @@ static int amd_iommu_attach_device(struct iommu_domain *dom,
 {
 	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
 	struct protection_domain *domain = to_pdomain(dom);
-	struct amd_iommu *iommu = rlookup_amd_iommu(dev);
+	struct amd_iommu *iommu = get_amd_iommu_from_dev(dev);
 	int ret;
 
 	/*
@@ -2435,7 +2435,7 @@ static void amd_iommu_get_resv_regions(struct device *dev,
 		return;
 
 	devid = PCI_SBDF_TO_DEVID(sbdf);
-	iommu = rlookup_amd_iommu(dev);
+	iommu = get_amd_iommu_from_dev(dev);
 	if (!iommu)
 		return;
 	pci_seg = iommu->pci_seg;
@@ -2769,7 +2769,7 @@ static int set_remap_table_entry_alias(struct pci_dev *pdev, u16 alias,
 {
 	struct irq_remap_table *table = data;
 	struct amd_iommu_pci_seg *pci_seg;
-	struct amd_iommu *iommu = rlookup_amd_iommu(&pdev->dev);
+	struct amd_iommu *iommu = get_amd_iommu_from_dev(&pdev->dev);
 
 	if (!iommu)
 		return -EINVAL;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index d52d0826cae1..25d9e428797c 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -559,6 +559,19 @@ static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
 	return (struct iommu_device *)dev_get_drvdata(dev);
 }
 
+/**
+ * iommu_get_iommu_dev - Get iommu_device for a device
+ * @dev: an end-point device
+ *
+ * Note that this function must be called from the iommu_ops
+ * to retrieve the iommu_device for a device, which the core code
+ * guarentees it will not invoke the op without an attached iommu.
+ */
+static inline struct iommu_device *iommu_get_iommu_dev(struct device *dev)
+{
+	return dev->iommu->iommu_dev;
+}
+
 static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather)
 {
 	*gather = (struct iommu_iotlb_gather) {
-- 
2.31.1