[RFC PATCH v3 08/10] iommu/riscv: Pre-enable GADE for second-stage domains
| Newsgroups | org.infradead.lists.linux-riscv,dev.linux.lists.iommu,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
From: Fangyu Yu <[email protected]> Pre-enable RISCV_IOMMU_DC_TC_GADE in the device context when attaching a second-stage domain, if the IOMMU supports AMO_HWAD. Software pre-populates second-stage page tables with D set, so enabling GADE by default does not change normal behavior. When dirty tracking is enabled, iommufd clears the pre-set D bits and GADE becomes necessary for hardware to update the dirty bit on write access. This avoids toggling GADE dynamically and keeps device context setup consistent with second-stage domain attachment. Signed-off-by: Fangyu Yu <[email protected]> --- drivers/iommu/riscv/iommu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c index 16779877351b..f01fd4e2f840 100644 --- a/drivers/iommu/riscv/iommu.c +++ b/drivers/iommu/riscv/iommu.c @@ -1330,6 +1330,8 @@ static int riscv_iommu_attach_paging_domain(struct iommu_domain *iommu_domain, 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); + if (iommu->caps & RISCV_IOMMU_CAPABILITIES_AMO_HWAD) + dc.tc |= RISCV_IOMMU_DC_TC_GADE; } else { if (!riscv_iommu_fsc_supported(iommu, pt_info.fsc_iosatp_mode)) return -ENODEV; -- 2.50.1 _______________________________________________ linux-riscv mailing list [email protected] http://lists.infradead.org/mailman/listinfo/linux-riscv