Commit e93e4a63 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommu/riscv: Disable SADE 



In terms of the iommu subystem the SADE/GADE feature "3.4. IOMMU updating
of PTE accessed (A) and dirty (D) updates" is called dirty tracking.

There is no reason to enable HW support for this, and the HW cost
associated with it, unless dirty tracking is actually enabled through
iommufd. It should be a dynamic feature linked to user request.

Further, without implementing the read dirty ops the whole thing is
pointless.

Do not set DC.tc.SADE just because the HW has support for dirty tracking.

Tested-by: default avatarVincent Chen <vincent.chen@sifive.com>
Acked-by: Paul Walmsley <pjw@kernel.org> # arch/riscv
Reviewed-by: default avatarTomasz Jeznach <tjeznach@rivosinc.com>
Tested-by: default avatarTomasz Jeznach <tjeznach@rivosinc.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent e71e0012

drivers/iommu/riscv/iommu.c

+0 −6
Original line number Diff line number Diff line
@@ -810,7 +810,6 @@ struct riscv_iommu_domain { 
	struct list_head bonds;

	spinlock_t lock;		/* protect bonds list updates. */

	int pscid;

	bool amo_enabled;

	int numa_node;

	unsigned int pgd_mode;

	unsigned long *pgd_root;
@@ -1201,8 +1200,6 @@ static int riscv_iommu_map_pages(struct iommu_domain *iommu_domain, 


	if (!(prot & IOMMU_WRITE))

		pte_prot = _PAGE_BASE | _PAGE_READ;

	else if (domain->amo_enabled)

		pte_prot = _PAGE_BASE | _PAGE_READ | _PAGE_WRITE;

	else

		pte_prot = _PAGE_BASE | _PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY;
@@ -1387,7 +1384,6 @@ static struct iommu_domain *riscv_iommu_alloc_paging_domain(struct device *dev) 
	INIT_LIST_HEAD_RCU(&domain->bonds);

	spin_lock_init(&domain->lock);

	domain->numa_node = dev_to_node(iommu->dev);

	domain->amo_enabled = !!(iommu->caps & RISCV_IOMMU_CAPABILITIES_AMO_HWAD);

	domain->pgd_mode = pgd_mode;

	domain->pgd_root = iommu_alloc_pages_node_sz(domain->numa_node,

						     GFP_KERNEL_ACCOUNT, SZ_4K);
@@ -1512,8 +1508,6 @@ static struct iommu_device *riscv_iommu_probe_device(struct device *dev) 
	 * the device directory. Do not mark the context valid yet.

	 */

	tc = 0;

	if (iommu->caps & RISCV_IOMMU_CAPABILITIES_AMO_HWAD)

		tc |= RISCV_IOMMU_DC_TC_SADE;

	for (i = 0; i < fwspec->num_ids; i++) {

		dc = riscv_iommu_get_dc(iommu, fwspec->ids[i]);

		if (!dc) {