Re: [RFC PATCH v2 05/10] iommu/riscv: support GSCID and GVMA invalidation command

On Thu, May 07, 2026 at 07:37:01PM +0800, [email protected] wrote:
> @@ -1212,8 +1225,15 @@ static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
>  	if (!riscv_iommu_pt_supported(iommu, pt_info.fsc_iosatp_mode))
>  		return -ENODEV;

This needs something like the below diff squashed in.

Thanks,
drew

>  
> -	dc.fsc = FIELD_PREP(RISCV_IOMMU_PC_FSC_MODE, pt_info.fsc_iosatp_mode) |
> -	      FIELD_PREP(RISCV_IOMMU_PC_FSC_PPN, pt_info.ppn);
> +	if (domain->gscid) {
> +		dc.iohgatp = FIELD_PREP(RISCV_IOMMU_DC_IOHGATP_MODE, pt_info.iohgatp_mode) |
> +			     FIELD_PREP(RISCV_IOMMU_DC_IOHGATP_GSCID, domain->gscid) |
> +			     FIELD_PREP(RISCV_IOMMU_DC_IOHGATP_PPN, pt_info.ppn);
> +	} else {
> +		dc.fsc = FIELD_PREP(RISCV_IOMMU_PC_FSC_MODE, pt_info.fsc_iosatp_mode) |
> +		      FIELD_PREP(RISCV_IOMMU_PC_FSC_PPN, pt_info.ppn);
> +	}
> +
>  	dc.ta = FIELD_PREP(RISCV_IOMMU_PC_TA_PSCID, domain->pscid) |
>  	     RISCV_IOMMU_PC_TA_V;
>

diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index 307baf33c646..434d2d4f26f5 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1262,9 +1262,9 @@ static void riscv_iommu_free_paging_domain(struct iommu_domain *iommu_domain)
 	kfree(domain);
 }
 
-static bool riscv_iommu_pt_supported(struct riscv_iommu_device *iommu, int pgd_mode)
+static bool riscv_iommu_fsc_supported(struct riscv_iommu_device *iommu, int mode)
 {
-	switch (pgd_mode) {
+	switch (mode) {
 	case RISCV_IOMMU_DC_FSC_IOSATP_MODE_SV39:
 		return iommu->caps & RISCV_IOMMU_CAPABILITIES_SV39;
 
@@ -1277,6 +1277,21 @@ static bool riscv_iommu_pt_supported(struct riscv_iommu_device *iommu, int pgd_m
 	return false;
 }
 
+static bool riscv_iommu_iohgatp_supported(struct riscv_iommu_device *iommu, int mode)
+{
+	switch (mode) {
+	case RISCV_IOMMU_DC_IOHGATP_MODE_SV39X4:
+		return iommu->caps & RISCV_IOMMU_CAPABILITIES_SV39X4;
+
+	case RISCV_IOMMU_DC_IOHGATP_MODE_SV48X4:
+		return iommu->caps & RISCV_IOMMU_CAPABILITIES_SV48X4;
+
+	case RISCV_IOMMU_DC_IOHGATP_MODE_SV57X4:
+		return iommu->caps & RISCV_IOMMU_CAPABILITIES_SV57X4;
+	}
+	return false;
+}
+
 static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
 					    struct device *dev,
 					    struct iommu_domain *old)
@@ -1294,14 +1309,17 @@ static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain,
 
 	pt_iommu_riscv_64_hw_info(&domain->riscvpt, &pt_info);
 
-	if (!riscv_iommu_pt_supported(iommu, pt_info.fsc_iosatp_mode))
-		return -ENODEV;
-
 	if (domain->gscid) {
+		if (!riscv_iommu_iohgatp_supported(iommu, pt_info.iohgatp_mode))
+			return -ENODEV;
+
 		dc.iohgatp = FIELD_PREP(RISCV_IOMMU_DC_IOHGATP_MODE, pt_info.iohgatp_mode) |
 			     FIELD_PREP(RISCV_IOMMU_DC_IOHGATP_GSCID, domain->gscid) |
 			     FIELD_PREP(RISCV_IOMMU_DC_IOHGATP_PPN, pt_info.ppn);
 	} else {
+		if (!riscv_iommu_fsc_supported(iommu, pt_info.fsc_iosatp_mode))
+			return -ENODEV;
+
 		dc.fsc = FIELD_PREP(RISCV_IOMMU_PC_FSC_MODE, pt_info.fsc_iosatp_mode) |
 			 FIELD_PREP(RISCV_IOMMU_PC_FSC_PPN, pt_info.ppn);
 	}