On Sun, 9 Jun 2019 06:44:19 -0700 Jacob Pan <jacob.jun....@linux.intel.com> wrote:
> Use combined macro for_each_svm_dev() to simplify SVM device iteration. > > Suggested-by: Andy Shevchenko <andriy.shevche...@linux.intel.com> > Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> > Reviewed-by: Eric Auger <eric.au...@redhat.com> > --- > drivers/iommu/intel-svm.c | 79 > +++++++++++++++++++++++------------------------ > 1 file changed, 39 insertions(+), 40 deletions(-) > > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c > index 9cbcc1f..66d98e1 100644 > --- a/drivers/iommu/intel-svm.c > +++ b/drivers/iommu/intel-svm.c > @@ -225,6 +225,9 @@ static const struct mmu_notifier_ops intel_mmuops = { > > static DEFINE_MUTEX(pasid_mutex); > static LIST_HEAD(global_svm_list); > +#define for_each_svm_dev() \ > + list_for_each_entry(sdev, &svm->devs, list) \ > + if (dev == sdev->dev) \ Could we make this macro less opaque and have it take the svm and dev as arguments? > > int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct > svm_dev_ops *ops) > { > @@ -271,15 +274,13 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, > int flags, struct svm_dev_ > goto out; > } > > - list_for_each_entry(sdev, &svm->devs, list) { > - if (dev == sdev->dev) { > - if (sdev->ops != ops) { > - ret = -EBUSY; > - goto out; > - } > - sdev->users++; > - goto success; > + for_each_svm_dev() { > + if (sdev->ops != ops) { > + ret = -EBUSY; > + goto out; > } > + sdev->users++; > + goto success; > } > > break; > @@ -409,40 +410,38 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) > if (!svm) > goto out; > > - list_for_each_entry(sdev, &svm->devs, list) { > - if (dev == sdev->dev) { > - ret = 0; > - sdev->users--; > - if (!sdev->users) { > - list_del_rcu(&sdev->list); > - /* Flush the PASID cache and IOTLB for this > device. > - * Note that we do depend on the hardware *not* > using > - * the PASID any more. Just as we depend on > other > - * devices never using PASIDs that they have no > right > - * to use. We have a *shared* PASID table, > because it's > - * large and has to be physically contiguous. > So it's > - * hard to be as defensive as we might like. */ > - intel_pasid_tear_down_entry(iommu, dev, > svm->pasid); > - intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, > !svm->mm); > - kfree_rcu(sdev, rcu); > - > - if (list_empty(&svm->devs)) { > - ioasid_free(svm->pasid); > - if (svm->mm) > - > mmu_notifier_unregister(&svm->notifier, svm->mm); > - > - list_del(&svm->list); > - > - /* We mandate that no page faults may > be outstanding > - * for the PASID when > intel_svm_unbind_mm() is called. > - * If that is not obeyed, subtle errors > will happen. > - * Let's make them less subtle... */ > - memset(svm, 0x6b, sizeof(*svm)); > - kfree(svm); > - } > + for_each_svm_dev() { > + ret = 0; > + sdev->users--; > + if (!sdev->users) { > + list_del_rcu(&sdev->list); > + /* Flush the PASID cache and IOTLB for this device. > + * Note that we do depend on the hardware *not* using > + * the PASID any more. Just as we depend on other > + * devices never using PASIDs that they have no right > + * to use. We have a *shared* PASID table, because it's > + * large and has to be physically contiguous. So it's > + * hard to be as defensive as we might like. */ > + intel_pasid_tear_down_entry(iommu, dev, svm->pasid); > + intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, > !svm->mm); > + kfree_rcu(sdev, rcu); > + > + if (list_empty(&svm->devs)) { > + ioasid_free(svm->pasid); > + if (svm->mm) > + mmu_notifier_unregister(&svm->notifier, > svm->mm); > + > + list_del(&svm->list); > + > + /* We mandate that no page faults may be > outstanding > + * for the PASID when intel_svm_unbind_mm() is > called. > + * If that is not obeyed, subtle errors will > happen. > + * Let's make them less subtle... */ > + memset(svm, 0x6b, sizeof(*svm)); > + kfree(svm); > } > - break; > } > + break; > } > out: > mutex_unlock(&pasid_mutex);