Linux kernel PCI Domains Support for ARM

Linux kernel 支援不同 domain 的 PCI, 看起來是 ACPI 的功能之一.
其他平台看起來也有支援, 像是 sparc or mips 都有.

但是在 ARM 上並沒有這樣的支援

我的平台有 2 個 PCIe Host Controller , 而且都要設定在 PCIe bus 0 上面.
這時就拿 PCI domain 的 code 來用最快,
以下就是 Sample Code 和 ARM 部份的 Patch Code (不含我目前使用平台的 Patch)

Seems ARM don’s support PCI Domains function now.
Here is a tiny patch for PCI Domains support

It’s work on my platform,
There are two PCIe host controller on my platform, and both bus number
should be 0
So, use PCI Domain to control both PCIe host controller is better choice.

Here is platform PCIe sample code,
static struct hw_pci cxxxxxx_pcie0 __initdata = {
.swizzle = pci_std_swizzle,
.map_irq = cxxxxxx_pcie0_map_irq,
.nr_controllers = 1,
.nr_domains = 0,
.setup = cxxxxxx_pci_setup,
.scan = cxxxxxx_pci_scan_bus,
.preinit = cxxxxxx_pci_preinit,
.postinit = cxxxxxx_pcie0_postinit,
};
static struct hw_pci cxxxxxx_pcie1 __initdata = {
.swizzle = pci_std_swizzle,
.map_irq = cxxxxxx_pcie1_map_irq,
.nr_controllers = 1,
.nr_domains = 1,
.setup = cxxxxxx_pci_setup,
.scan = cxxxxxx_pci_scan_bus,
.postinit = cxxxxxx_pcie1_postinit,
};

static int __init cxxxxxx_pci_init(void)
{
pci_common_init(&cxxxxxx_pcie0);
pci_common_init(&cxxxxxx_pcie1);
return 0;
}

—
diff –git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 79a3074..33a49ba 100644
— a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -865,6 +865,10 @@ config PCI
your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
VESA. If you have PCI, say Y, otherwise N.

+config PCI_DOMAINS
+ def_bool y
+ depends on PCI
+
config PCI_SYSCALL
def_bool PCI

diff –git a/arch/arm/include/asm/mach/pci.h
b/arch/arm/include/asm/mach/pci.h
index a38bdc7..f099067 100644
— a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -20,6 +20,9 @@ struct hw_pci {
void (*postinit)(void);
u8 (*swizzle)(struct pci_dev *dev, u8 *pin);
int (*map_irq)(struct pci_dev *dev, u8 slot, u8 pin);
+#ifdef CONFIG_PCI_DOMAINS
+ int nr_domains;
+#endif
};

/*
@@ -37,8 +40,12 @@ struct pci_sys_data {
/* IRQ mapping */
int (*map_irq)(struct pci_dev *, u8, u8);
struct hw_pci *hw;
+#ifdef CONFIG_PCI_DOMAINS
+ int domain;
+#endif
};

+
/*
* This is the standard PCI-PCI bridge swizzling algorithm.
*/
diff –git a/arch/arm/include/asm/pci.h b/arch/arm/include/asm/pci.h
index 0abf386..57ce5bd 100644
— a/arch/arm/include/asm/pci.h
+++ b/arch/arm/include/asm/pci.h
@@ -25,6 +25,11 @@ static inline void pcibios_penalize_isa_irq(int irq,
int active)
/* We don’t do dynamic PCI IRQ allocation */
}

+#ifdef CONFIG_PCI_DOMAINS
+int pci_domain_nr(struct pci_bus *bus);
+int pci_proc_domain(struct pci_bus *bus);
+#endif
+
/*
* The PCI address space does equal the physical memory address space.
* The networking and block device layers use this boolean for bounce
diff –git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 8096819..b364ca8 100644
— a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -531,6 +531,7 @@ static void __init pcibios_init_hw(struct hw_pci *hw)
sys->busnr = busnr;
sys->swizzle = hw->swizzle;
sys->map_irq = hw->map_irq;
+ sys->domain = hw->nr_domains;
sys->resource[0] = &ioport_resource;
sys->resource[1] = &iomem_resource;

@@ -694,3 +695,20 @@ int pci_mmap_page_range(struct pci_dev *dev, struct
vm_area_struct *vma,

return 0;
}
+#ifdef CONFIG_PCI_DOMAINS
+int pci_domain_nr(struct pci_bus *bus)
+{
+
+ //struct pci_sysdata *sd = bus->sysdata;
+ struct pci_sys_data *sd = bus->sysdata;
+ return sd->domain;
+
+}
+EXPORT_SYMBOL(pci_domain_nr);
+
+int pci_proc_domain(struct pci_bus *bus)
+{
+ return pci_domain_nr(bus);
+}
+EXPORT_SYMBOL(pci_proc_domain);
+#endif

Ref
x86/x86-64 PCI domain support