lkml.org 
[lkml]   [2015]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 02/10] PCI, x86: clip firmware assigned resource under parent bridge's
From
On Wed, Jan 14, 2015 at 8:52 AM, Bjorn Helgaas <bhelgaas@google.com> wrote:
> On Mon, Jan 12, 2015 at 11:23:12AM -0800, Yinghai Lu wrote:

> There's a lot of duplicated code in these patches. Is it possible to
> factor this out a bit, e.g., something like this?
>
> int pci_claim_bridge_resource(struct pci_dev *dev, int i)
> {
> if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
> return 0;
>
> if (pci_claim_resource(dev, i) == 0)
> return 0; /* claimed the window */
>
> if (!pci_bus_clip_resource(dev, i))
> return -EINVAL; /* clipping didn't change anything */
>
> if (dev->subordinate)
> pci_setup_bridge(dev->subordinate);
> if (pci_claim_resource(dev, i) == 0)
> return 0; /* claimed a smaller window */
>
> return -EINVAL;
> }

ok. will have one in setup_bus.c

>
>> }
>>
>> static void pcibios_allocate_bus_resources(struct pci_bus *bus)
>> @@ -234,8 +251,12 @@ static void pcibios_allocate_bus_resources(struct pci_bus *bus)
>> struct pci_bus *child;
>>
>> /* Depth-First Search on bus tree */
>> - if (bus->self)
>> - pcibios_allocate_bridge_resources(bus->self);
>> + if (bus->self) {
>> + bool changed = pcibios_allocate_bridge_resources(bus->self);
>> +
>> + if (changed)
>> + pci_setup_bridge(bus);
>> + }
>> list_for_each_entry(child, &bus->children, node)
>> pcibios_allocate_bus_resources(child);
>> }
>> @@ -274,18 +295,27 @@ static void pcibios_allocate_dev_resources(struct pci_dev *dev, int pass)
>> dev_dbg(&dev->dev,
>> "BAR %d: reserving %pr (d=%d, p=%d)\n",
>> idx, r, disabled, pass);
>> - if (pci_claim_resource(dev, idx) < 0) {
>> - if (r->flags & IORESOURCE_PCI_FIXED) {
>> - dev_info(&dev->dev, "BAR %d %pR is immovable\n",
>> +
>> + if (pci_claim_resource(dev, idx) >= 0)
>> + continue;
>> +
>> + if (r->flags & IORESOURCE_PCI_FIXED) {
>> + dev_info(&dev->dev, "BAR %d %pR is immovable\n",
>> idx, r);
>> - } else {
>> - /* We'll assign a new address later */
>> - pcibios_save_fw_addr(dev,
>> - idx, r->start);
>> - r->end -= r->start;
>> - r->start = 0;
>> - }
>> + continue;
>> + }
>> +
>> + /* try again with clip */
>> + if (pci_bus_clip_resource(dev, r)) {
>> + pci_update_resource(dev, idx);
>> + if (pci_claim_resource(dev, idx) >= 0)
>> + continue;
>
> This hunk doesn't make sense to me. This only deals with standard BARs and
> IOV BARS. It doesn't deal with bridge windows at all. The sizes of these
> BARs and IOV BARs are fixed and there's no point in trying to clip them
> because we can't tell the hardware that the BAR is now smaller.
>
> It's different for bridge windows because we can adjust their size.

ok, will drop that.


\
 
 \ /
  Last update: 2015-01-14 20:41    [W:0.049 / U:0.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site