Messages in this thread | | | Subject | Re: [PATCH v4 8/8] iommu/vt-d: Misc macro clean up for SVM | From | Joe Perches <> | Date | Mon, 02 Dec 2019 10:22:13 -0800 |
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On Mon, 2019-12-02 at 10:15 -0800, Jacob Pan wrote: > On Thu, 21 Nov 2019 13:37:10 -0800 > Joe Perches <joe@perches.com> wrote: > > > On Thu, 2019-11-21 at 13:26 -0800, Jacob Pan wrote: > > > Use combined macros for_each_svm_dev() to simplify SVM device > > > iteration and error checking. > > [] > > > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c > > [] > > > +#define for_each_svm_dev(sdev, svm, d) \ > > > + list_for_each_entry((sdev), &(svm)->devs, list) \ > > > + if ((d) != (sdev)->dev) {} else > > > + > > > int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, > > > struct svm_dev_ops *ops) { > > > struct intel_iommu *iommu = intel_svm_device_to_iommu(dev); > > > @@ -274,15 +278,13 @@ 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(sdev, svm, dev) { > > > + if (sdev->ops != ops) { > > > + ret = -EBUSY; > > > + goto out; > > > } > > > + sdev->users++; > > > + goto success; > > > } > > > > I think this does not read better as this is now a > > for_each loop that exits the loop on the first match. > > > I think one of the benefits is reduced indentation. What do you > recommend?
Making the code intelligible for a reader.
At least add a comment describing why there is only a single possible match.
Given the for_each name, it's odd code that only the first match has an action.
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