iommu/amd: Introduce get_amd_iommu_from_dev()

Introduce get_amd_iommu_from_dev() and get_amd_iommu_from_dev_data().
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>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240205115615.6053-4-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 7464222ad8af..4e1f9a444a1a 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -138,6 +138,21 @@ 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)
+{
+	return iommu_get_iommu_dev(dev, struct amd_iommu, iommu);
+}
+
+/* This must be called after device probe completes. */
+static inline struct amd_iommu *get_amd_iommu_from_dev_data(struct iommu_dev_data *dev_data)
+{
+	return iommu_get_iommu_dev(dev_data->dev, 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);