[PATCH 1/2] ARM: Make PCI I/O space optional

[Bjorn Helgaas]

For callers of pci_common_init_dev(), we previously always required a PCI
I/O port resource.  If the caller's ->setup() function had added an I/O
resource, we used that; otherwise, we added a default 64K I/O port space
for it.

There are PCI host bridges that do not support I/O port space, and we
should not add fictitious spaces for them.

If a caller sets struct hw_pci.io_optional, assume it is responsible for
adding any I/O port resource it desires, and do not add any default I/O
port space.

Signed-off-by: Bjorn Helgaas <bhelg...@google.com>
---
 arch/arm/include/asm/mach/pci.h |    1 +
 arch/arm/kernel/bios32.c        |   13 +++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
index 0070e85..2d88af5 100644
--- a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -22,6 +22,7 @@ struct hw_pci {
        struct msi_controller *msi_ctrl;
        struct pci_ops  *ops;
        int             nr_controllers;
+       unsigned int    io_optional:1;
        void            **private_data;
        int             (*setup)(int nr, struct pci_sys_data *);
        struct pci_bus *(*scan)(int nr, struct pci_sys_data *);
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 05e61a2..65f12ef 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -410,7 +410,8 @@ static int pcibios_map_irq(const struct pci_dev *dev, u8 
slot, u8 pin)
        return irq;
 }
 
-static int pcibios_init_resources(int busnr, struct pci_sys_data *sys)
+static int pcibios_init_resource(int busnr, struct pci_sys_data *sys,
+                                int io_optional)
 {
        int ret;
        struct resource_entry *window;
@@ -420,6 +421,14 @@ static int pcibios_init_resources(int busnr, struct 
pci_sys_data *sys)
                         &iomem_resource, sys->mem_offset);
        }
 
+       /*
+        * If a platform says I/O port support is optional, we don't add
+        * the default I/O space.  The platform is responsible for adding
+        * any I/O space it needs.
+        */
+       if (io_optional)
+               return 0;
+
        resource_list_for_each_entry(window, &sys->resources)
                if (resource_type(window->res) == IORESOURCE_IO)
                        return 0;
@@ -466,7 +475,7 @@ static void pcibios_init_hw(struct device *parent, struct 
hw_pci *hw,
                if (ret > 0) {
                        struct pci_host_bridge *host_bridge;
 
-                       ret = pcibios_init_resources(nr, sys);
+                       ret = pcibios_init_resource(nr, sys, hw->io_optional);
                        if (ret)  {
                                kfree(sys);
                                break;