[RFC PATCH v2 03/10] iommu/riscv: use data structure instead of individual values

[Zong Li]

The parameter will be increased when we need to set up more
bit fields in the device context. Use a data structure to
wrap them up.

Signed-off-by: Zong Li <zong.li at sifive.com>
---
 drivers/iommu/riscv/iommu.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index 1716b2251f38..9aeb4b20c145 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1045,7 +1045,7 @@ static void riscv_iommu_iotlb_inval(struct riscv_iommu_domain *domain,
  * interim translation faults.
  */
 static void riscv_iommu_iodir_update(struct riscv_iommu_device *iommu,
-				     struct device *dev, u64 fsc, u64 ta)
+				     struct device *dev, struct riscv_iommu_dc *new_dc)
 {
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 	struct riscv_iommu_dc *dc;
@@ -1079,10 +1079,10 @@ static void riscv_iommu_iodir_update(struct riscv_iommu_device *iommu,
 	for (i = 0; i < fwspec->num_ids; i++) {
 		dc = riscv_iommu_get_dc(iommu, fwspec->ids[i]);
 		tc = READ_ONCE(dc->tc);
-		tc |= ta & RISCV_IOMMU_DC_TC_V;
+		tc |= new_dc->ta & RISCV_IOMMU_DC_TC_V;
 
-		WRITE_ONCE(dc->fsc, fsc);
-		WRITE_ONCE(dc->ta, ta & RISCV_IOMMU_PC_TA_PSCID);
+		WRITE_ONCE(dc->fsc, new_dc->fsc);
+		WRITE_ONCE(dc->ta, new_dc->ta & RISCV_IOMMU_PC_TA_PSCID);
 		/* Update device context, write TC.V as the last step. */
 		dma_wmb();
 		WRITE_ONCE(dc->tc, tc);
@@ -1369,20 +1369,20 @@ static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
 	struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
 	struct riscv_iommu_device *iommu = dev_to_iommu(dev);
 	struct riscv_iommu_info *info = dev_iommu_priv_get(dev);
-	u64 fsc, ta;
+	struct riscv_iommu_dc dc = {0};
 
 	if (!riscv_iommu_pt_supported(iommu, domain->pgd_mode))
 		return -ENODEV;
 
-	fsc = FIELD_PREP(RISCV_IOMMU_PC_FSC_MODE, domain->pgd_mode) |
-	      FIELD_PREP(RISCV_IOMMU_PC_FSC_PPN, virt_to_pfn(domain->pgd_root));
-	ta = FIELD_PREP(RISCV_IOMMU_PC_TA_PSCID, domain->pscid) |
-	     RISCV_IOMMU_PC_TA_V;
+	dc.fsc = FIELD_PREP(RISCV_IOMMU_PC_FSC_MODE, domain->pgd_mode) |
+		 FIELD_PREP(RISCV_IOMMU_PC_FSC_PPN, virt_to_pfn(domain->pgd_root));
+	dc.ta = FIELD_PREP(RISCV_IOMMU_PC_TA_PSCID, domain->pscid) |
+			   RISCV_IOMMU_PC_TA_V;
 
 	if (riscv_iommu_bond_link(domain, dev))
 		return -ENOMEM;
 
-	riscv_iommu_iodir_update(iommu, dev, fsc, ta);
+	riscv_iommu_iodir_update(iommu, dev, &dc);
 	riscv_iommu_bond_unlink(info->domain, dev);
 	info->domain = domain;
 
@@ -1484,9 +1484,12 @@ static int riscv_iommu_attach_blocking_domain(struct iommu_domain *iommu_domain,
 {
 	struct riscv_iommu_device *iommu = dev_to_iommu(dev);
 	struct riscv_iommu_info *info = dev_iommu_priv_get(dev);
+	struct riscv_iommu_dc dc = {0};
+
+	dc.fsc = RISCV_IOMMU_FSC_BARE;
 
 	/* Make device context invalid, translation requests will fault w/ #258 */
-	riscv_iommu_iodir_update(iommu, dev, RISCV_IOMMU_FSC_BARE, 0);
+	riscv_iommu_iodir_update(iommu, dev, &dc);
 	riscv_iommu_bond_unlink(info->domain, dev);
 	info->domain = NULL;
 
@@ -1505,8 +1508,12 @@ static int riscv_iommu_attach_identity_domain(struct iommu_domain *iommu_domain,
 {
 	struct riscv_iommu_device *iommu = dev_to_iommu(dev);
 	struct riscv_iommu_info *info = dev_iommu_priv_get(dev);
+	struct riscv_iommu_dc dc = {0};
+
+	dc.fsc = RISCV_IOMMU_FSC_BARE;
+	dc.ta = RISCV_IOMMU_PC_TA_V;
 
-	riscv_iommu_iodir_update(iommu, dev, RISCV_IOMMU_FSC_BARE, RISCV_IOMMU_PC_TA_V);
+	riscv_iommu_iodir_update(iommu, dev, &dc);
 	riscv_iommu_bond_unlink(info->domain, dev);
 	info->domain = NULL;
 
-- 
2.17.1