Hi Suravee,
On Fri, May 15, 2015 at 03:09:03AM +0100, Suravee Suthikulanit wrote:
> On 5/14/2015 9:42 AM, Lorenzo Pieralisi wrote:
> > When a device is scanned and added to the PCI bus, its resources
> > should be claimed to validate the BARs configuration and to assign
> > them a parent resource so that the resource hierarchy can be sanity
> > checked.
> >
> > This patch adds code that carries out PCI device resources claiming to
> > the ARM64 pcibios_add_device implementation so that device resources
> > are claimed by the core PCI layer upon PCI device initialization on
> > ARM64 systems.
> >
> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: Will Deacon <will.deacon@xxxxxxx>
> > Cc: Liviu Dudau <liviu.dudau@xxxxxxx>
> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > ---
> > arch/arm64/kernel/pci.c | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> > index 4095379..c0a88ca 100644
> > --- a/arch/arm64/kernel/pci.c
> > +++ b/arch/arm64/kernel/pci.c
> > @@ -43,8 +43,18 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
> > */
> > int pcibios_add_device(struct pci_dev *dev)
> > {
> > + struct resource *res;
> > + int i;
> > +
> > dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
> >
> > + for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> > + res = &dev->resource[i];
> > + if (res->parent || !res->flags)
> > + continue;
> > + pci_claim_resource(dev, i);
> > + }
> > +
> > return 0;
> > }
> >
> >
>
> Lorenzo/Bjorn,
>
> I have tested this patch on top of Jayachandran's V2 patch series
> (http://www.spinics.net/lists/linux-pci/msg40811.html) on AMD Seattle
> (w/ PROBE_ONLY and non-PROBE_ONLY mode), and your changes here works
> with additional changes below.
>
> It seems that when booting w/ PROBE_ONLY case, we need to call
> pci_read_bridge_bases() at some point before claiming the resources of
> devices underneath the bridge. This is needed to determine the bridge
> bases (i.e. bridge io, mmio and mmio_pref bases), and update bridge
> resources accordingly.
Thanks for testing, I will give it a go on Seattle, if you can drop
the log you get on PROBE_ONLY (without your patch below) that would be
great so that I can have a look at the issue.
Thanks,
Lorenzo
> ---- BEGIN PATCH -----
> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> index c0a88ca..57be6aa 100644
> --- a/arch/arm64/kernel/pci.c
> +++ b/arch/arm64/kernel/pci.c
> @@ -48,6 +48,11 @@ int pcibios_add_device(struct pci_dev *dev)
>
> dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
>
> + if (pci_has_flag(PCI_PROBE_ONLY) &&
> + !pci_is_root_bus(dev->bus) &&
> + !pci_bridge_bases_is_read(dev->bus))
> + pci_read_bridge_bases(dev->bus);
> +
> for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> res = &dev->resource[i];
> if (res->parent || !res->flags)
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 6675a7a..6cab8be 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -447,6 +447,13 @@ static void pci_read_bridge_mmio_pref(struct
> pci_bus *child)
> }
> }
>
> +bool pci_bridge_bases_is_read(struct pci_bus *bus)
> +{
> + return (bus->resource[0]->start ||
> + bus->resource[1]->start ||
> + bus->resource[2]->start);
> +}
> +
> void pci_read_bridge_bases(struct pci_bus *child)
> {
> struct pci_dev *dev = child->self;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 353db8d..11c674d 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -798,6 +798,7 @@ void pci_device_add(struct pci_dev *dev, struct
> pci_bus *bus);
> unsigned int pci_scan_child_bus(struct pci_bus *bus);
> void pci_bus_add_device(struct pci_dev *dev);
> void pci_read_bridge_bases(struct pci_bus *child);
> +bool pci_bridge_bases_is_read(struct pci_bus *bus);
> struct resource *pci_find_parent_resource(const struct pci_dev *dev,
> struct resource *res);
> u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin);
> ---- END PATCH -----
>
> I'm not sure if this is the best place to be reading the bridge bases.
> I guess we should be able to do this when adding bridge devices.
>
> Thanks,
>
> Suravee
>
>
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