Re: [PATCH v3 5/7] PCI: Do not use IORESOURCE_STARTALIGN to identify bridge resources

From: Gavin Shan
Date: Thu Jun 30 2016 - 22:34:37 EST


On Thu, Jun 30, 2016 at 06:53:11PM +0800, Yongji Xie wrote:
>Now we use the IORESOURCE_STARTALIGN to identify bridge resources
>in __assign_resources_sorted(). That's quite fragile. We may also
>set flag IORESOURCE_STARTALIGN for SR-IOV resources in some cases,
>for example, using the option "noresize" of parameter
>"pci=resource_alignment".
>
>In this patch, we try to use a more robust way to identify
>bridge resources.
>
>Signed-off-by: Yongji Xie <xyjxie@xxxxxxxxxxxxxxxxxx>

Reviewed-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>

Yongji, I think this doesn't have to be part of this series, meaning
it can be sent or merged separately.

>---
> drivers/pci/setup-bus.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
>index 55641a3..216ddbc 100644
>--- a/drivers/pci/setup-bus.c
>+++ b/drivers/pci/setup-bus.c
>@@ -390,6 +390,7 @@ static void __assign_resources_sorted(struct list_head *head,
> struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
> unsigned long fail_type;
> resource_size_t add_align, align;
>+ int index;
>
> /* Check if optional add_size is there */
> if (!realloc_head || list_empty(realloc_head))
>@@ -410,11 +411,13 @@ static void __assign_resources_sorted(struct list_head *head,
>
> /*
> * There are two kinds of additional resources in the list:
>- * 1. bridge resource -- IORESOURCE_STARTALIGN
>- * 2. SR-IOV resource -- IORESOURCE_SIZEALIGN
>+ * 1. bridge resource
>+ * 2. SR-IOV resource
> * Here just fix the additional alignment for bridge
> */
>- if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
>+ index = dev_res->res - dev_res->dev->resource;
>+ if (index < PCI_BRIDGE_RESOURCES ||
>+ index > PCI_BRIDGE_RESOURCE_END)
> continue;
>
> add_align = get_res_add_align(realloc_head, dev_res->res);

Thanks,
Gavin