[PATCH v2 1/4] iommu/vt-d: Refactor device_to_iommu() helper

Lu Baolu
2020-07-06T00:30:16Z

It is refactored in two ways:

- Make it global so that it could be used in other files.

- Make bus/devfn optional so that callers could ignore these two returned
values when they only want to get the coresponding iommu pointer.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 55 +++++++++++--------------------------
drivers/iommu/intel/svm.c | 8 +++---
include/linux/intel-iommu.h | 3 +-
3 files changed, 21 insertions(+), 45 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index d759e7234e98..de17952ed133 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -778,16 +778,16 @@ is_downstream_to_pci_bridge(struct device *dev, struct device *bridge)
return false;
}

-static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)
+struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)
{
struct dmar_drhd_unit *drhd = NULL;
+ struct pci_dev *pdev = NULL;
struct intel_iommu *iommu;
struct device *tmp;
- struct pci_dev *pdev = NULL;
u16 segment = 0;
int i;

- if (iommu_dummy(dev))
+ if (!dev || iommu_dummy(dev))
return NULL;

if (dev_is_pci(dev)) {
@@ -818,8 +818,10 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf
if (pdev && pdev->is_virtfn)
goto got_pdev;

- *bus = drhd->devices[i].bus;
- *devfn = drhd->devices[i].devfn;
+ if (bus && devfn) {
+ *bus = drhd->devices[i].bus;
+ *devfn = drhd->devices[i].devfn;
+ }
goto out;
}

@@ -829,8 +831,10 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf

if (pdev && drhd->include_all) {
got_pdev:
- *bus = pdev->bus->number;
- *devfn = pdev->devfn;
+ if (bus && devfn) {
+ *bus = pdev->bus->number;
+ *devfn = pdev->devfn;
+ }
goto out;
}
}
@@ -5146,11 +5150,10 @@ static int aux_domain_add_dev(struct dmar_domain *domain,
struct device *dev)
{
int ret;
- u8 bus, devfn;
unsigned long flags;
struct intel_iommu *iommu;

- iommu = device_to_iommu(dev, &bus, &devfn);
+ iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu)
return -ENODEV;

@@ -5236,9 +5239,8 @@ static int prepare_domain_attach_device(struct iommu_domain *domain,
struct dmar_domain *dmar_domain = to_dmar_domain(domain);
struct intel_iommu *iommu;
int addr_width;
- u8 bus, devfn;

- iommu = device_to_iommu(dev, &bus, &devfn);
+ iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu)
return -ENODEV;

@@ -5658,9 +5660,8 @@ static bool intel_iommu_capable(enum iommu_cap cap)
static struct iommu_device *intel_iommu_probe_device(struct device *dev)
{
struct intel_iommu *iommu;
- u8 bus, devfn;

- iommu = device_to_iommu(dev, &bus, &devfn);
+ iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu)
return ERR_PTR(-ENODEV);

@@ -5673,9 +5674,8 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev)
static void intel_iommu_release_device(struct device *dev)
{
struct intel_iommu *iommu;
- u8 bus, devfn;

- iommu = device_to_iommu(dev, &bus, &devfn);
+ iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu)
return;

@@ -5825,37 +5825,14 @@ static struct iommu_group *intel_iommu_device_group(struct device *dev)
return generic_device_group(dev);
}

-#ifdef CONFIG_INTEL_IOMMU_SVM
-struct intel_iommu *intel_svm_device_to_iommu(struct device *dev)
-{
- struct intel_iommu *iommu;
- u8 bus, devfn;
-
- if (iommu_dummy(dev)) {
- dev_warn(dev,
- "No IOMMU translation for device; cannot enable SVM\n");
- return NULL;
- }
-
- iommu = device_to_iommu(dev, &bus, &devfn);
- if ((!iommu)) {
- dev_err(dev, "No IOMMU for device; cannot enable SVM\n");
- return NULL;
- }
-
- return iommu;
-}
-#endif /* CONFIG_INTEL_IOMMU_SVM */
-
static int intel_iommu_enable_auxd(struct device *dev)
{
struct device_domain_info *info;
struct intel_iommu *iommu;
unsigned long flags;
- u8 bus, devfn;
int ret;

- iommu = device_to_iommu(dev, &bus, &devfn);
+ iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu || dmar_disabled)
return -EINVAL;

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 6c87c807a0ab..25dd74f27252 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -231,7 +231,7 @@ static LIST_HEAD(global_svm_list);
int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
struct iommu_gpasid_bind_data *data)
{
- struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
+ struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct dmar_domain *dmar_domain;
struct intel_svm_dev *sdev;
struct intel_svm *svm;
@@ -373,7 +373,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,

int intel_svm_unbind_gpasid(struct device *dev, int pasid)
{
- struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
+ struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct intel_svm_dev *sdev;
struct intel_svm *svm;
int ret = -EINVAL;
@@ -430,7 +430,7 @@ static int
intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *ops,
struct mm_struct *mm, struct intel_svm_dev **sd)
{
- struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
+ struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct device_domain_info *info;
struct intel_svm_dev *sdev;
struct intel_svm *svm = NULL;
@@ -608,7 +608,7 @@ static int intel_svm_unbind_mm(struct device *dev, int pasid)
struct intel_svm *svm;
int ret = -EINVAL;

- iommu = intel_svm_device_to_iommu(dev);
+ iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu)
goto out;

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 3e8fa1c7a1e6..fc2cfc3db6e1 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -728,6 +728,7 @@ void iommu_flush_write_buffer(struct intel_iommu *iommu);
int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev);
struct dmar_domain *find_domain(struct device *dev);
struct device_domain_info *get_domain_info(struct device *dev);
+struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn);

#ifdef CONFIG_INTEL_IOMMU_SVM
extern void intel_svm_check(struct intel_iommu *iommu);
@@ -766,8 +767,6 @@ struct intel_svm {
struct list_head devs;
struct list_head list;
};
-
-extern struct intel_iommu *intel_svm_device_to_iommu(struct device *dev);
#else
static inline void intel_svm_check(struct intel_iommu *iommu) {}
#endif
--
2.17.1