Messages in this thread | | | Date | Wed, 23 Feb 2022 12:00:56 -0600 | From | Bjorn Helgaas <> | Subject | Re: [PATCH v5 07/14] PCI: Add driver dma ownership management |
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In subject,
s/dma/DMA/ to match the other patches
On Tue, Jan 04, 2022 at 09:56:37AM +0800, Lu Baolu wrote: > Multiple PCI devices may be placed in the same IOMMU group because > they cannot be isolated from each other. These devices must either be > entirely under kernel control or userspace control, never a mixture. This > checks and sets DMA ownership during driver binding, and release the > ownership during driver unbinding. > > The device driver may set a new flag (no_kernel_api_dma) to skip calling > iommu_device_use_dma_api() during the binding process. For instance, the > userspace framework drivers (vfio etc.) which need to manually claim > their own dma ownership when assigning the device to userspace.
s/vfio/VFIO/ when used as an acronym (occurs in several patches)
> + * @no_kernel_api_dma: Device driver doesn't use kernel DMA API for DMA. > + * Drivers which don't require DMA or want to manually claim the > + * owner type (e.g. userspace driver frameworks) could set this > + * flag.
s/Drivers which/Drivers that/
> static int pci_dma_configure(struct device *dev) > { > + struct pci_driver *driver = to_pci_driver(dev->driver); > struct device *bridge; > int ret = 0; > > + if (!driver->no_kernel_api_dma) {
Ugh. Double negative, totally agree this needs a better name that reverses the sense. Every place you use it, you negate it again.
> + if (ret && !driver->no_kernel_api_dma) > + iommu_device_unuse_dma_api(dev);
> +static void pci_dma_cleanup(struct device *dev) > +{ > + struct pci_driver *driver = to_pci_driver(dev->driver); > + > + if (!driver->no_kernel_api_dma) > + iommu_device_unuse_dma_api(dev);
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