[PATCH v6 04/13] iommu/amd: Introduce helper function amd_iommu_update_dte()

Suravee Suthikulpanit
2026-01-15T06:09:02Z

Which includes DTE update, clone_aliases, DTE flush and completion-wait
commands to avoid code duplication when reuse to setup DTE for nested
translation.

Also, make amd_iommu_update_dte() non-static to reuse in
in a new nested.c file for nested translation.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
drivers/iommu/amd/amd_iommu.h | 4 ++++
drivers/iommu/amd/iommu.c | 24 ++++++++++++++++++------
2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 8eb5e9857079..d97b9b6d76d3 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -190,6 +190,10 @@ void amd_iommu_domain_set_pgtable(struct protection_domain *domain,
struct dev_table_entry *get_dev_table(struct amd_iommu *iommu);
struct iommu_dev_data *search_dev_data(struct amd_iommu *iommu, u16 devid);

+void amd_iommu_update_dte(struct amd_iommu *iommu,
+ struct iommu_dev_data *dev_data,
+ struct dev_table_entry *new);
+
static inline void
amd_iommu_make_clear_dte(struct iommu_dev_data *dev_data, struct dev_table_entry *new)
{
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index ded8d4ba86e3..6fea4ac97e3d 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -76,6 +76,8 @@ static void set_dte_entry(struct amd_iommu *iommu,
struct iommu_dev_data *dev_data,
phys_addr_t top_paddr, unsigned int top_level);

+static int device_flush_dte(struct iommu_dev_data *dev_data);
+
static void amd_iommu_change_top(struct pt_iommu *iommu_table,
phys_addr_t top_paddr, unsigned int top_level);

@@ -86,6 +88,10 @@ static bool amd_iommu_enforce_cache_coherency(struct iommu_domain *domain);
static int amd_iommu_set_dirty_tracking(struct iommu_domain *domain,
bool enable);

+static void clone_aliases(struct amd_iommu *iommu, struct device *dev);
+
+static int iommu_completion_wait(struct amd_iommu *iommu);
+
/****************************************************************************
*
* Helper functions
@@ -203,6 +209,16 @@ static void update_dte256(struct amd_iommu *iommu, struct iommu_dev_data *dev_da
spin_unlock_irqrestore(&dev_data->dte_lock, flags);
}

+void amd_iommu_update_dte(struct amd_iommu *iommu,
+ struct iommu_dev_data *dev_data,
+ struct dev_table_entry *new)
+{
+ update_dte256(iommu, dev_data, new);
+ clone_aliases(iommu, dev_data->dev);
+ device_flush_dte(dev_data);
+ iommu_completion_wait(iommu);
+}
+
static void get_dte256(struct amd_iommu *iommu, struct iommu_dev_data *dev_data,
struct dev_table_entry *dte)
{
@@ -2123,7 +2139,7 @@ static void set_dte_entry(struct amd_iommu *iommu,

set_dte_gcr3_table(iommu, dev_data, &new);

- update_dte256(iommu, dev_data, &new);
+ amd_iommu_update_dte(iommu, dev_data, &new);

/*
* A kdump kernel might be replacing a domain ID that was copied from
@@ -2143,7 +2159,7 @@ static void clear_dte_entry(struct amd_iommu *iommu, struct iommu_dev_data *dev_
struct dev_table_entry new = {};

amd_iommu_make_clear_dte(dev_data, &new);
- update_dte256(iommu, dev_data, &new);
+ amd_iommu_update_dte(iommu, dev_data, &new);
}

/* Update and flush DTE for the given device */
@@ -2155,10 +2171,6 @@ static void dev_update_dte(struct iommu_dev_data *dev_data, bool set)
set_dte_entry(iommu, dev_data, 0, 0);
else
clear_dte_entry(iommu, dev_data);
-
- clone_aliases(iommu, dev_data->dev);
- device_flush_dte(dev_data);
- iommu_completion_wait(iommu);
}

/*
--
2.34.1