On Fri, Jan 27, 2012 at 6:49 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> extend or shrink bus and parent buses top (subordinate)
>
> extended range is verified safe range, and stop at recorded parent_res.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> ---
> drivers/pci/probe.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 50 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 55404c3..3e62f45 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -624,6 +624,56 @@ static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
> }
> }
>
> +static void __devinit pci_bus_extend_top(struct pci_bus *parent,
> + resource_size_t size, struct resource *parent_res)
> +{
> + struct resource *res;
> +
> + if (!size)
> + return;
> +
> + while (parent) {
> + res = &parent->busn_res;
> + if (res == parent_res)
> + break;
> + res->end += size;
> + parent->subordinate += size;
This makes me nervous for the same reason as
pci_bus_update_busn_res_end() -- we're changing res->end for resources
already in a tree. How do we know the tree remains consistent?
> + pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS,
> + parent->subordinate);
> + dev_printk(KERN_DEBUG, &parent->dev,
> + "busn_res: extended %02llx to %06llx-%06llx\n",
> + (unsigned long long)size,
> + (unsigned long long)res->start,
> + (unsigned long long)res->end);
> + parent = parent->parent;
> + }
> +}
> +
> +static void __devinit pci_bus_shrink_top(struct pci_bus *parent,
> + resource_size_t size, struct resource *parent_res)
> +{
> + struct resource *res;
> +
> + if (!size)
> + return;
> +
> + while (parent) {
> + res = &parent->busn_res;
> + if (res == parent_res)
> + break;
> + res->end -= size;
> + parent->subordinate -= size;
> + pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS,
> + parent->subordinate);
> + dev_printk(KERN_DEBUG, &parent->dev,
> + "busn_res: shrunk %02llx to %06llx-%06llx\n",
> + (unsigned long long)size,
> + (unsigned long long)res->start,
> + (unsigned long long)res->end);
> + parent = parent->parent;
> + }
> +}
> +
> /*
> * If it's a bridge, configure it and scan the bus behind it.
> * For CardBus bridges, we don't scan behind as the devices will
> --
> 1.7.7
>
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