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Subject[PATCH 1/2] ARM: Make PCI I/O space optional
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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 <bhelgaas@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;
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