RE: [PATCH 04/12] iommu/vt-d: Use pci_get_domain_bus_and_slot() in pgtable_walk()

Tian, Kevin
2022-06-01T08:56:37Z

> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Friday, May 27, 2022 2:30 PM
>
> Use pci_get_domain_bus_and_slot() instead of searching the global list
> to retrieve the pci device pointer. This removes device_domain_list
> global list as there are no consumers anymore.
>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

> ---
> drivers/iommu/intel/iommu.h | 1 -
> drivers/iommu/intel/iommu.c | 33 ++++++---------------------------
> 2 files changed, 6 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
> index 2f4a5b9509c0..6724703d573b 100644
> --- a/drivers/iommu/intel/iommu.h
> +++ b/drivers/iommu/intel/iommu.h
> @@ -609,7 +609,6 @@ struct intel_iommu {
> /* PCI domain-device relationship */
> struct device_domain_info {
> struct list_head link; /* link to domain siblings */
> - struct list_head global; /* link to global list */
> struct list_head table; /* link to pasid table */
> u32 segment; /* PCI segment number */
> u8 bus; /* PCI bus number */
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 25d4c5200526..bbdd3417a1b1 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -131,8 +131,6 @@ static struct intel_iommu **g_iommus;
>
> static void __init check_tylersburg_isoch(void);
> static int rwbf_quirk;
> -static inline struct device_domain_info *
> -dmar_search_domain_by_dev_info(int segment, int bus, int devfn);
>
> /*
> * set to 1 to panic kernel if can't successfully enable VT-d
> @@ -315,7 +313,6 @@ static int iommu_skip_te_disable;
> #define IDENTMAP_AZALIA 4
>
> static DEFINE_SPINLOCK(device_domain_lock);
> -static LIST_HEAD(device_domain_list);
> const struct iommu_ops intel_iommu_ops;
>
> static bool translation_pre_enabled(struct intel_iommu *iommu)
> @@ -845,9 +842,14 @@ static void pgtable_walk(struct intel_iommu
> *iommu, unsigned long pfn, u8 bus, u
> struct device_domain_info *info;
> struct dma_pte *parent, *pte;
> struct dmar_domain *domain;
> + struct pci_dev *pdev;
> int offset, level;
>
> - info = dmar_search_domain_by_dev_info(iommu->segment, bus,
> devfn);
> + pdev = pci_get_domain_bus_and_slot(iommu->segment, bus, devfn);
> + if (!pdev)
> + return;
> +
> + info = dev_iommu_priv_get(&pdev->dev);
> if (!info || !info->domain) {
> pr_info("device [%02x:%02x.%d] not probed\n",
> bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
> @@ -2348,19 +2350,6 @@ static void domain_remove_dev_info(struct
> dmar_domain *domain)
> spin_unlock_irqrestore(&device_domain_lock, flags);
> }
>
> -static inline struct device_domain_info *
> -dmar_search_domain_by_dev_info(int segment, int bus, int devfn)
> -{
> - struct device_domain_info *info;
> -
> - list_for_each_entry(info, &device_domain_list, global)
> - if (info->segment == segment && info->bus == bus &&
> - info->devfn == devfn)
> - return info;
> -
> - return NULL;
> -}
> -
> static int domain_setup_first_level(struct intel_iommu *iommu,
> struct dmar_domain *domain,
> struct device *dev,
> @@ -4564,7 +4553,6 @@ static struct iommu_device
> *intel_iommu_probe_device(struct device *dev)
> struct pci_dev *pdev = dev_is_pci(dev) ? to_pci_dev(dev) : NULL;
> struct device_domain_info *info;
> struct intel_iommu *iommu;
> - unsigned long flags;
> u8 bus, devfn;
>
> iommu = device_to_iommu(dev, &bus, &devfn);
> @@ -4607,10 +4595,7 @@ static struct iommu_device
> *intel_iommu_probe_device(struct device *dev)
> }
> }
>
> - spin_lock_irqsave(&device_domain_lock, flags);
> - list_add(&info->global, &device_domain_list);
> dev_iommu_priv_set(dev, info);
> - spin_unlock_irqrestore(&device_domain_lock, flags);
>
> return &iommu->iommu;
> }
> @@ -4618,15 +4603,9 @@ static struct iommu_device
> *intel_iommu_probe_device(struct device *dev)
> static void intel_iommu_release_device(struct device *dev)
> {
> struct device_domain_info *info = dev_iommu_priv_get(dev);
> - unsigned long flags;
>
> dmar_remove_one_dev_info(dev);
> -
> - spin_lock_irqsave(&device_domain_lock, flags);
> dev_iommu_priv_set(dev, NULL);
> - list_del(&info->global);
> - spin_unlock_irqrestore(&device_domain_lock, flags);
> -
> kfree(info);
> set_dma_ops(dev, NULL);
> }
> --
> 2.25.1