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):
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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