[PATCH 1/2] ARM: Make PCI I/O space optional
From: bhelgaas@google.com (Bjorn Helgaas)
Date: 2016-06-21 17:14:00
Also in:
linux-pci, linux-renesas-soc, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
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;