[PATCH 4/7] iommu/vt-d: Remove domain_update_iommu_cap()

From: Lu Baolu
Date: Fri Oct 11 2024 - 00:33:01 EST


The attributes of a paging domain are initialized during the allocation
process, and any attempt to attach a domain that is not compatible will
result in a failure. Therefore, there is no need to update the domain
attributes at the time of domain attachment.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel/iommu.h | 1 -
drivers/iommu/intel/iommu.c | 83 -------------------------------------
2 files changed, 84 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 1497f3112b12..a4bff90c2d07 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1232,7 +1232,6 @@ void domain_detach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu);
void device_block_translation(struct device *dev);
int prepare_domain_attach_device(struct iommu_domain *domain,
struct device *dev);
-void domain_update_iommu_cap(struct dmar_domain *domain);

int dmar_ir_support(void);

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index f6a3266b17d4..ada271e7be50 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -352,36 +352,6 @@ static bool iommu_paging_structure_coherency(struct intel_iommu *iommu)
ecap_smpwc(iommu->ecap) : ecap_coherent(iommu->ecap);
}

-static void domain_update_iommu_coherency(struct dmar_domain *domain)
-{
- struct iommu_domain_info *info;
- struct dmar_drhd_unit *drhd;
- struct intel_iommu *iommu;
- bool found = false;
- unsigned long i;
-
- domain->iommu_coherency = true;
- xa_for_each(&domain->iommu_array, i, info) {
- found = true;
- if (!iommu_paging_structure_coherency(info->iommu)) {
- domain->iommu_coherency = false;
- break;
- }
- }
- if (found)
- return;
-
- /* No hardware attached; use lowest common denominator */
- rcu_read_lock();
- for_each_active_iommu(iommu, drhd) {
- if (!iommu_paging_structure_coherency(iommu)) {
- domain->iommu_coherency = false;
- break;
- }
- }
- rcu_read_unlock();
-}
-
static int domain_update_iommu_superpage(struct dmar_domain *domain,
struct intel_iommu *skip)
{
@@ -412,29 +382,6 @@ static int domain_update_iommu_superpage(struct dmar_domain *domain,
return fls(mask);
}

-static int domain_update_device_node(struct dmar_domain *domain)
-{
- struct device_domain_info *info;
- int nid = NUMA_NO_NODE;
- unsigned long flags;
-
- spin_lock_irqsave(&domain->lock, flags);
- list_for_each_entry(info, &domain->devices, link) {
- /*
- * There could possibly be multiple device numa nodes as devices
- * within the same domain may sit behind different IOMMUs. There
- * isn't perfect answer in such situation, so we select first
- * come first served policy.
- */
- nid = dev_to_node(info->dev);
- if (nid != NUMA_NO_NODE)
- break;
- }
- spin_unlock_irqrestore(&domain->lock, flags);
-
- return nid;
-}
-
/* Return the super pagesize bitmap if supported. */
static unsigned long domain_super_pgsize_bitmap(struct dmar_domain *domain)
{
@@ -452,34 +399,6 @@ static unsigned long domain_super_pgsize_bitmap(struct dmar_domain *domain)
return bitmap;
}

-/* Some capabilities may be different across iommus */
-void domain_update_iommu_cap(struct dmar_domain *domain)
-{
- domain_update_iommu_coherency(domain);
- domain->iommu_superpage = domain_update_iommu_superpage(domain, NULL);
-
- /*
- * If RHSA is missing, we should default to the device numa domain
- * as fall back.
- */
- if (domain->nid == NUMA_NO_NODE)
- domain->nid = domain_update_device_node(domain);
-
- /*
- * First-level translation restricts the input-address to a
- * canonical address (i.e., address bits 63:N have the same
- * value as address bit [N-1], where N is 48-bits with 4-level
- * paging and 57-bits with 5-level paging). Hence, skip bit
- * [N-1].
- */
- if (domain->use_first_level)
- domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw - 1);
- else
- domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw);
-
- domain->domain.pgsize_bitmap |= domain_super_pgsize_bitmap(domain);
-}
-
struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
u8 devfn, int alloc)
{
@@ -1493,7 +1412,6 @@ int domain_attach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu)
ret = xa_err(curr) ? : -EBUSY;
goto err_clear;
}
- domain_update_iommu_cap(domain);

spin_unlock(&iommu->lock);
return 0;
@@ -1519,7 +1437,6 @@ void domain_detach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu)
clear_bit(info->did, iommu->domain_ids);
xa_erase(&domain->iommu_array, iommu->seq_id);
domain->nid = NUMA_NO_NODE;
- domain_update_iommu_cap(domain);
kfree(info);
}
spin_unlock(&iommu->lock);
--
2.43.0