On Thu, May 4, 2017 at 12:31 PM, Christian König
<deathsimple@xxxxxxxxxxx> wrote:
> From: Christian König <christian.koenig@xxxxxxx>
>
> This allows device drivers to request resizing their BARs.
>
> The function only tries to reprogram the windows of the bridge directly above
> the requesting device and only the BAR of the same type (usually mem, 64bit,
> prefetchable). This is done to make sure not to disturb other drivers by
> changing the BARs of their devices.
>
> If reprogramming the bridge BAR fails the old status is restored and -ENOSPC
> returned to the calling device driver.
My comments below.
> +int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
> +{
> + struct pci_dev_resource *dev_res;
> + LIST_HEAD(saved);
> + LIST_HEAD(added);
> + LIST_HEAD(failed);
> + unsigned int i;
> + int ret;
> +
> + /* Walk to the root BUS, releasing bridge BARs when possible */
> + while (1) {
> + for (i = PCI_BRIDGE_RESOURCES; i < PCI_BRIDGE_RESOURCE_END;
> + i++) {
> + struct resource *res = &bridge->resource[i];
> +
> + if ((res->flags ^ type) & PCI_RES_TYPE_MASK)
> + continue;
> +
> + /* Ignore BARs which are still in use */
> + if (res->child)
> + continue;
> +
> + ret = add_to_list(&saved, bridge, res, 0, 0);
> + if (ret)
> + goto cleanup;
> +
> + dev_info(&bridge->dev, "BAR %d: releasing %pR\n",
> + i, res);
> +
> + if (res->parent)
> + release_resource(res);
> + res->start = 0;
> + res->end = 0;
> + break;
> + }
> + if (i == PCI_BRIDGE_RESOURCE_END)
> + break;
> +
> + if (!bridge->bus || !bridge->bus->self)
> + break;
> +
> + bridge = bridge->bus->self;
> + }
> +
Please, consider to refactor as I proposed the other day.
> +}
> +int pci_resize_resource(struct pci_dev *dev, int resno, int size)
> +{
> + struct resource *res = dev->resource + resno;
> + int old, ret = 0;
Redundant assignment.
> + u32 sizes;
> + u16 cmd;
> +
> + ret = pci_rbar_set_size(dev, resno, size);
> + if (ret)
> + goto error_reassign;
> +
> + return 0;
> +
> +error_resize:
> + pci_rbar_set_size(dev, resno, old);
> + res->end = res->start + pci_rbar_size_to_bytes(old) - 1;
> +
> +error_reassign:
> + pci_assign_unassigned_bus_resources(dev->bus);
> + return ret;
> +}
--
With Best Regards,
Andy Shevchenko
