[PATCH 02/12] iommu/vt-d: Remove for_each_device_domain()

Lu Baolu
2022-05-27T06:34:08Z

The per-device device_domain_info data could be retrieved from the
device itself. There's no need to search a global list.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel/iommu.h | 2 --
drivers/iommu/intel/iommu.c | 25 -------------------------
drivers/iommu/intel/pasid.c | 37 +++++++++++--------------------------
3 files changed, 11 insertions(+), 53 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 8a6d64d726c0..2f4a5b9509c0 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -727,8 +727,6 @@ extern int dmar_ir_support(void);
void *alloc_pgtable_page(int node);
void free_pgtable_page(void *vaddr);
struct intel_iommu *domain_get_iommu(struct dmar_domain *domain);
-int for_each_device_domain(int (*fn)(struct device_domain_info *info,
- void *data), void *data);
void iommu_flush_write_buffer(struct intel_iommu *iommu);
int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev);
struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn);
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cacae8bdaa65..6549b09d7f32 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -316,31 +316,6 @@ static int iommu_skip_te_disable;

static DEFINE_SPINLOCK(device_domain_lock);
static LIST_HEAD(device_domain_list);
-
-/*
- * Iterate over elements in device_domain_list and call the specified
- * callback @fn against each element.
- */
-int for_each_device_domain(int (*fn)(struct device_domain_info *info,
- void *data), void *data)
-{
- int ret = 0;
- unsigned long flags;
- struct device_domain_info *info;
-
- spin_lock_irqsave(&device_domain_lock, flags);
- list_for_each_entry(info, &device_domain_list, global) {
- ret = fn(info, data);
- if (ret) {
- spin_unlock_irqrestore(&device_domain_lock, flags);
- return ret;
- }
- }
- spin_unlock_irqrestore(&device_domain_lock, flags);
-
- return 0;
-}
-
const struct iommu_ops intel_iommu_ops;

static bool translation_pre_enabled(struct intel_iommu *iommu)
diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index b2ac5869286f..0627d6465f25 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -103,36 +103,20 @@ device_detach_pasid_table(struct device_domain_info *info,
}

struct pasid_table_opaque {
- struct pasid_table **pasid_table;
- int segment;
- int bus;
- int devfn;
+ struct pasid_table *pasid_table;
};

-static int search_pasid_table(struct device_domain_info *info, void *opaque)
-{
- struct pasid_table_opaque *data = opaque;
-
- if (info->iommu->segment == data->segment &&
- info->bus == data->bus &&
- info->devfn == data->devfn &&
- info->pasid_table) {
- *data->pasid_table = info->pasid_table;
- return 1;
- }
-
- return 0;
-}
-
static int get_alias_pasid_table(struct pci_dev *pdev, u16 alias, void *opaque)
{
struct pasid_table_opaque *data = opaque;
+ struct device_domain_info *info;

- data->segment = pci_domain_nr(pdev->bus);
- data->bus = PCI_BUS_NUM(alias);
- data->devfn = alias & 0xff;
+ info = dev_iommu_priv_get(&pdev->dev);
+ if (!info || !info->pasid_table)
+ return 0;

- return for_each_device_domain(&search_pasid_table, data);
+ data->pasid_table = info->pasid_table;
+ return 1;
}

/*
@@ -141,9 +125,9 @@ static int get_alias_pasid_table(struct pci_dev *pdev, u16 alias, void *opaque)
*/
int intel_pasid_alloc_table(struct device *dev)
{
+ struct pasid_table_opaque data = { NULL };
struct device_domain_info *info;
struct pasid_table *pasid_table;
- struct pasid_table_opaque data;
struct page *pages;
u32 max_pasid = 0;
int ret, order;
@@ -155,11 +139,12 @@ int intel_pasid_alloc_table(struct device *dev)
return -EINVAL;

/* DMA alias device already has a pasid table, use it: */
- data.pasid_table = &pasid_table;
ret = pci_for_each_dma_alias(to_pci_dev(dev),
&get_alias_pasid_table, &data);
- if (ret)
+ if (ret) {
+ pasid_table = data.pasid_table;
goto attach_out;
+ }

pasid_table = kzalloc(sizeof(*pasid_table), GFP_KERNEL);
if (!pasid_table)
--
2.25.1