On Mon, Jul 27, 2015 at 11:54:20AM +0100, Russell King - ARM Linux wrote:
> On Mon, Jul 27, 2015 at 10:40:46AM +0100, Lorenzo Pieralisi wrote:
> > On Sun, Jul 26, 2015 at 07:58:22PM +0100, Russell King - ARM Linux wrote:
> > > This doesn't seem to be a good approach. Maybe having a version of
> > > pci_scan_root_bus() which takes the MSI data as an argument would be
> > > better than selectively copying pci_scan_root_bus() into the ARM code?
> >
> > I understand your point, let's try to find a fast way forward, we are
> > stuck otherwise:
> >
> > 3) I patch pci_scan_root_bus() to pass the MSI pointer. I think that
> > pcibios_msi_controller was added to avoid doing this, that
> > function has already 5 parameters and it is a treewide change,
> > I suspect Bjorn won't be happy about this at all.
>
> Or you could use the suggestion I made in the paragraph you quoted above,
> which is a variation on your (3) without the down-sides of needing to
> change lots of callsites. Something like this (bios32.c is incomplete):
It is fine by me, I do not know if Bjorn is willing to accept the
PCI core change required below.
Bjorn, what do you think ? I will fold the diff below in the original
patch if we are all happy with the change.
Thanks !
Lorenzo
> arch/arm/kernel/bios32.c | 8 +++-----
> drivers/pci/probe.c | 15 +++++++++++++--
> include/linux/pci.h | 4 ++++
> 3 files changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index fcbbbb1b9e95..e4f7c0eb6c14 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -462,9 +462,6 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
> if (!sys)
> panic("PCI: unable to allocate sys data!");
>
> -#ifdef CONFIG_PCI_MSI
> - sys->msi_ctrl = hw->msi_ctrl;
> -#endif
> sys->busnr = busnr;
> sys->swizzle = hw->swizzle;
> sys->map_irq = hw->map_irq;
> @@ -486,8 +483,9 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
> if (hw->scan)
> sys->bus = hw->scan(nr, sys);
> else
> - sys->bus = pci_scan_root_bus(parent, sys->busnr,
> - hw->ops, sys, &sys->resources);
> + sys->bus = pci_scan_root_bus_msi(parent,
> + sys->busnr, hw->ops, sys,
> + &sys->resources, hw->msi_ctrl);
>
> if (!sys->bus)
> panic("PCI: unable to scan bus!");
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index cefd636681b6..4915c6d9c22d 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -2096,8 +2096,9 @@ void pci_bus_release_busn_res(struct pci_bus *b)
> res, ret ? "can not be" : "is");
> }
>
> -struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
> - struct pci_ops *ops, void *sysdata, struct list_head *resources)
> +struct pci_bus *pci_scan_root_bus_msi(struct device *parent, int bus,
> + struct pci_ops *ops, void *sysdata,
> + struct list_head *resources, struct msi_controller *msi)
> {
> struct resource_entry *window;
> bool found = false;
> @@ -2114,6 +2115,8 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
> if (!b)
> return NULL;
>
> + b->msi = msi;
> +
> if (!found) {
> dev_info(&b->dev,
> "No busn resource found for root bus, will use [bus %02x-ff]\n",
> @@ -2128,6 +2131,14 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
>
> return b;
> }
> +EXPORT_SYMBOL(pci_scan_root_bus_msi);
> +
> +struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
> + struct pci_ops *ops, void *sysdata, struct list_head *resources)
> +{
> + return pci_scan_root_bus_msi(parent, bus, ops, sysdata, resources,
> + NULL);
> +}
> EXPORT_SYMBOL(pci_scan_root_bus);
>
> struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 8a0321a8fb59..4d4f9d29fcc9 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -787,6 +787,10 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
> int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
> int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);
> void pci_bus_release_busn_res(struct pci_bus *b);
> +struct pci_bus *pci_scan_root_bus_msi(struct device *parent, int bus,
> + struct pci_ops *ops, void *sysdata,
> + struct list_head *resources,
> + struct msi_controller *msi);
> struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
> struct pci_ops *ops, void *sysdata,
> struct list_head *resources);
>
> And it's probably a good idea to kill off the ifdef around this:
>
> struct hw_pci {
> #ifdef CONFIG_PCI_MSI
> struct msi_controller *msi_ctrl;
> #endif
>
> so that we can avoid ifdefs in random places in arch/arm code (as is the
> decision in the rest of PCI for this.)
>
> --
> FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
> according to speedtest.net.
>
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