Hi Christoph,
On 2/14/22 3:38 PM, Christoph Hellwig wrote:
const struct iommu_ops intel_iommu_ops;
@@ -903,7 +905,8 @@ static void pgtable_walk(struct intel_iommu *iommu,
unsigned long pfn, u8 bus, u
struct dmar_domain *domain;
int offset, level;
- info = dmar_search_domain_by_dev_info(iommu->segment, bus, devfn);
+ info = xa_load(&device_domain_array,
+ devi_idx(iommu->segment, bus, devfn));
if (!info || !info->domain) {
pr_info("device [%02x:%02x.%d] not probed\n",
bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
@@ -1742,14 +1745,14 @@ static int iommu_init_domains(struct intel_iommu *iommu)
Don't we need a rcu critical section here?
- list_for_each_entry_safe(info, tmp, &device_domain_list, global) {
+ rcu_read_lock();
+ xa_for_each(&device_domain_array, index, info) {
if (info->iommu != iommu)
continue;
@@ -1758,7 +1761,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
__dmar_remove_one_dev_info(info);
}
- spin_unlock_irqrestore(&device_domain_lock, flags);
+ rcu_read_unlock();
__dmar_remove_one_dev_info asserts that device_domain_lock is held,
which these two hunks remove.
spin_lock_irqsave(&device_domain_lock, flags);
dev_iommu_priv_set(dev, NULL);
- list_del(&info->global);
+ xa_erase(&device_domain_array,
+ devi_idx(info->segment, info->bus, info->devfn));
spin_unlock_irqrestore(&device_domain_lock, flags);
kfree(info);
Do we need a kfree_rcu here to allow rcu based access?
Thanks for your time and very appreciated for your comments. As replied
to Jason, I will stop 10/11 and 11/11 for now. From the current usage
scenario, the value of such refactoring is limited.
Best regards,
baolu
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