On Thursday 13 February 2014 17:57:41 Jingoo Han wrote:
> I want to use 'drivers/pci/host/pcie-designware.c' for both arm32
> and arm64, without any code changes. However, it looks impossible.
It is impossible at the moment, and I agree we have to fix that.
> I made 'drivers/pci/host/pcie-designware.c' based on 32bit arm PCI
> support. Then, with Liviu's patch, do I have to make new code for arm64,
> even though the same HW PCIe IP is used?
>
> - For arm32
> drivers/pci/host/pcie-designware.c
>
> - For arm64
> drivers/pci/host/pcie-designware-arm64.c
As a start, I'd suggest using "#ifdef CONFIG_ARM" in the driver,
but sharing as much code as you can. We should try to make the #else
section of the #ifdef architecture independent and get have the arm64
implementation shared with any architecture that doesn't have or want
its own pcibios32.c implementation.
> > > I am reviewing and compiling your patch.
> > > Would you consider adding 'struct pci_sys_data' and 'struct hw_pci'?
I would rather get rid of struct hw_pci for architecture independent
drivers and add a different registration method on arm32 that is
compatible with what we come up with on arm64. The main purpose of
hw_pci is to allow multiple PCI controllers to be initialized at
once, but we don't actually need that for any of the "modern" platforms
where we already have a probe function that gets called once for
each controller.
As a start, we could add a pci_host_bridge_register() function like
the one below to arm32 and migrate the drivers/pci/host/ drivers
over to use it with little effort. Instead of filling out hw_pci,
these drivers would allocate (by embedding in their device struct)
and fill out pci_sys_data directly. After that, we can gradually
move more code out of the arm32 implementation into common code, if
it doesn't already exist there, up to the point where a host driver
no longer has to call any function in bios32.c.
Arnd
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 317da88..12c2178 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -514,6 +514,26 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
}
}
+static void pci_common_bus_probe(struct pci_bus *bus)
+{
+ if (!pci_has_flag(PCI_PROBE_ONLY)) {
+ /*
+ * Size the bridge windows.
+ */
+ pci_bus_size_bridges(bus);
+
+ /*
+ * Assign resources.
+ */
+ pci_bus_assign_resources(bus);
+ }
+
+ /*
+ * Tell drivers about devices found.
+ */
+ pci_bus_add_devices(bus);
+}
+
void pci_common_init_dev(struct device *parent, struct hw_pci *hw)
{
struct pci_sys_data *sys;
@@ -528,27 +548,38 @@ void pci_common_init_dev(struct device *parent, struct hw_pci *hw)
pci_fixup_irqs(pcibios_swizzle, pcibios_map_irq);
- list_for_each_entry(sys, &head, node) {
- struct pci_bus *bus = sys->bus;
+ list_for_each_entry(sys, &head, node)
+ pci_common_bus_probe(sys->bus);
+}
- if (!pci_has_flag(PCI_PROBE_ONLY)) {
- /*
- * Size the bridge windows.
- */
- pci_bus_size_bridges(bus);
- /*
- * Assign resources.
- */
- pci_bus_assign_resources(bus);
- }
- /*
- * Tell drivers about devices found.
- */
- pci_bus_add_devices(bus);
- }
+
+int pci_host_bridge_register(struct device *parent, struct pci_sys_data *sys, struct pci_ops *ops, int (*setup)(int nr, struct pci_sys_data *))
+{
+ int ret;
+
+ pci_add_flags(PCI_REASSIGN_ALL_RSRC);
+ INIT_LIST_HEAD(&sys->resources);
+
+ ret = setup(0, sys);
+ if (ret)
+ return ret;
+
+ ret = pcibios_init_resources(0, sys);
+ if (ret)
+ return ret;
+
+ sys->bus = pci_scan_root_bus(parent, sys->busnr, ops, sys, &sys->resources);
+ if (!sys->bus)
+ return -ENODEV;
+
+ pci_fixup_irqs(pcibios_swizzle, pcibios_map_irq);
+
+ pci_common_bus_probe(sys->bus);
+ return ret;
}
+EXPORT_SYMBOL_GPL(pci_host_bridge_register);
#ifndef CONFIG_PCI_HOST_ITE8152
void pcibios_set_master(struct pci_dev *dev)
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