Re: [PATCH 10/10] PCI, sparc: clip firmware assigned resource under parent bridge's

From: Kjetil Oftedal
Date: Mon Jan 12 2015 - 17:31:18 EST


Hi,

Am I missing something or is this just code to get the the resource
subsystem to accept the bus resources, not caring if the resources are
actually usable? PCI BARs usually have a given size for a reason?

-
Kjetil Oftedal


On 12/01/2015, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> Some bios put range that is not fully coverred by root bus resources.
> Try to clip them and update them in pci bridge bars.
>
> We'd like to fix other arches instead of just x86.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=85491
> Reported-by: Marek Kordik <kordikmarek@xxxxxxxxx>
> Fixes: 5b28541552ef ("PCI: Restrict 64-bit prefetchable bridge windows to
> 64-bit resources")
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
> Cc: Yijing Wang <wangyijing@xxxxxxxxxx>
> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Cc: sparclinux@xxxxxxxxxxxxxxx
> ---
> arch/sparc/kernel/pci.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
> index b36365f..0e391e5 100644
> --- a/arch/sparc/kernel/pci.c
> +++ b/arch/sparc/kernel/pci.c
> @@ -623,6 +623,7 @@ static void pci_claim_bus_resources(struct pci_bus
> *bus)
> struct pci_dev *dev;
>
> list_for_each_entry(dev, &bus->devices, bus_list) {
> + bool changed = false;
> int i;
>
> for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> @@ -639,8 +640,25 @@ static void pci_claim_bus_resources(struct pci_bus
> *bus)
> (unsigned long long)r->end,
> (unsigned int)r->flags);
>
> - pci_claim_resource(dev, i);
> + if (pci_claim_resource(dev, i) >= 0)
> + continue;
> +
> + if (dev->subordinate &&
> + i >= PCI_BRIDGE_RESOURCES &&
> + i < PCI_NUM_RESOURCES &&
> + (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI &&
> + pci_bus_clip_resource(dev, r)) {
> + changed = true;
> + pci_claim_resource(dev, i);
> + } else if (i < PCI_BRIDGE_RESOURCES &&
> + i != PCI_ROM_RESOURCE &&
> + pci_bus_clip_resource(dev, r)) {
> + pci_update_resource(dev, i);
> + pci_claim_resource(dev, i);
> + }
> }
> + if (changed)
> + pci_setup_bridge(dev->subordinate);
> }
>
> list_for_each_entry(child_bus, &bus->children, node)
> --
> 1.8.4.5
>
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