iommu/amd: Modify clear_dte_entry() to avoid in-place update

By reusing the make_clear_dte() and update_dte256().

Also, there is no need to set TV bit for non-SNP system when clearing DTE
for blocked domain, and no longer need to apply erratum 63 in clear_dte()
since it is already stored in struct ivhd_dte_flags and apply in
set_dte_entry().

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20241118054937.5203-8-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index b7b5dce10813c8fede720ad1b457f4440edd3ee8..3ccad9fd0302d2dee35b8f92d9f9c885cfd13423 100644 (file)
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2103,19 +2103,16 @@ static void set_dte_entry(struct amd_iommu *iommu,
        }
 }
 
-static void clear_dte_entry(struct amd_iommu *iommu, u16 devid)
+/*
+ * Clear DMA-remap related flags to block all DMA (blockeded domain)
+ */
+static void clear_dte_entry(struct amd_iommu *iommu, struct iommu_dev_data *dev_data)
 {
-       struct dev_table_entry *dev_table = get_dev_table(iommu);
-
-       /* remove entry from the device table seen by the hardware */
-       dev_table[devid].data[0]  = DTE_FLAG_V;
-
-       if (!amd_iommu_snp_en)
-               dev_table[devid].data[0] |= DTE_FLAG_TV;
-
-       dev_table[devid].data[1] &= DTE_FLAG_MASK;
+       struct dev_table_entry new = {};
+       struct dev_table_entry *dte = &get_dev_table(iommu)[dev_data->devid];
 
-       amd_iommu_apply_erratum_63(iommu, devid);
+       make_clear_dte(dev_data, dte, &new);
+       update_dte256(iommu, dev_data, &new);
 }
 
 /* Update and flush DTE for the given device */
@@ -2126,7 +2123,7 @@ static void dev_update_dte(struct iommu_dev_data *dev_data, bool set)
        if (set)
                set_dte_entry(iommu, dev_data);
        else
-               clear_dte_entry(iommu, dev_data->devid);
+               clear_dte_entry(iommu, dev_data);
 
        clone_aliases(iommu, dev_data->dev);
        device_flush_dte(dev_data);