[RFC PATCH v3 06/14] iommu/riscv: Cache the programmed device context

[Andrew Jones]

Interrupt-remapping state needs to update the MSI fields of an existing
device context without rebuilding its translation fields. Keep the
software copy in the per-device information.

Signed-off-by: Andrew Jones <andrew.jones@xxxxxxxxxxxxxxxx>
---
 drivers/iommu/riscv/iommu.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index 2cee87ffc122..86d5795a12dd 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -872,6 +872,7 @@ PT_IOMMU_CHECK_DOMAIN(struct riscv_iommu_domain, riscvpt.iommu, domain);
 /* Private IOMMU data for managed devices, dev_iommu_priv_* */
 struct riscv_iommu_info {
 	struct riscv_iommu_domain *domain;
+	struct riscv_iommu_dc dc;
 	unsigned int nr_forwarded_irqs;
 };
 
@@ -1513,8 +1514,9 @@ static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
 		kfree(bond);
 		return -EBUSY;
 	}
+	info->dc = dc;
 	riscv_iommu_bond_link(domain, bond);
-	riscv_iommu_iodir_update(dev, &dc);
+	riscv_iommu_iodir_update(dev, &info->dc);
 	riscv_iommu_bond_unlink(info->domain, dev);
 	info->domain = domain;
 	riscv_iommu_msi_tables_unlock(old, iommu_domain, flags);
@@ -1668,7 +1670,8 @@ static int riscv_iommu_attach_blocking_domain(struct iommu_domain *iommu_domain,
 
 	/* Make device context invalid, translation requests will fault w/ #258 */
 	flags = riscv_iommu_msi_tables_lock(old, NULL);
-	riscv_iommu_iodir_update(dev, &dc);
+	info->dc = dc;
+	riscv_iommu_iodir_update(dev, &info->dc);
 	riscv_iommu_bond_unlink(info->domain, dev);
 	info->domain = NULL;
 	riscv_iommu_msi_tables_unlock(old, NULL, flags);
@@ -1695,7 +1698,8 @@ static int riscv_iommu_attach_identity_domain(struct iommu_domain *iommu_domain,
 	dc.ta = RISCV_IOMMU_PC_TA_V;
 
 	flags = riscv_iommu_msi_tables_lock(old, NULL);
-	riscv_iommu_iodir_update(dev, &dc);
+	info->dc = dc;
+	riscv_iommu_iodir_update(dev, &info->dc);
 	riscv_iommu_bond_unlink(info->domain, dev);
 	info->domain = NULL;
 	riscv_iommu_msi_tables_unlock(old, NULL, flags);
-- 
2.43.0