On Wed, 2011-05-25 at 16:42 +0200, Ingo Molnar wrote: > * Sasha Levin <[email protected]> wrote: > > > void virtio_console__init(struct kvm *kvm) > > { > > u8 dev, line, pin; > > + u16 console_base_addr; > > > > if (irq__register_device(VIRTIO_ID_CONSOLE, &dev, &pin, &line) < 0) > > return; > > > > virtio_console_pci_device.irq_pin = pin; > > virtio_console_pci_device.irq_line = line; > > + console_base_addr = ioport__find_free_range(); > > + virtio_console_pci_device.bar[0] = console_base_addr | > > PCI_BASE_ADDRESS_SPACE_IO; > > + cdev.base_addr = console_base_addr; > > pci__register(&virtio_console_pci_device, dev); > > - ioport__register(IOPORT_VIRTIO_CONSOLE, &virtio_console_io_ops, > > IOPORT_VIRTIO_CONSOLE_SIZE); > > + ioport__register(console_base_addr, &virtio_console_io_ops, > > IOPORT_SIZE); > > Why is the ioport registration done in two steps? > > Wouldnt a better sequence be something like: > > > + console_base_addr = > > ioport__register(&virtio_console_io_ops, IOPORT_SIZE); > > > > + virtio_console_pci_device.bar[0] = console_base_addr | > > PCI_BASE_ADDRESS_SPACE_IO; > > + cdev.base_addr = console_base_addr; > > pci__register(&virtio_console_pci_device, dev); > > I.e. first register the ioport range - this would also get a free > range for you, and then register the PCI driver? > > Or something even more compact could be done i suspect - all of the > drivers seem to be using the same registration sequence.
Some drivers need explicit IO ports, such as the serial driver. It was a question of whether I create another registration function (which may be as simple as calling 'ioport__find_free_range()' before calling the real registration) but it would lead to two 'registration' functions behaving very differently - one returning a new port and one that just does nothing except registering. -- Sasha. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
