[PATCH v9] arm64: Add architectural support for PCIe

Liviu Dudau
2014-08-12T16:26:00Z

Use the generic PCI domain and host bridge functions
to provide support for PCI Express on arm64.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
[Generic PCI domain support]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/Kconfig | 22 +++++++++++++++++++-
arch/arm64/include/asm/Kbuild | 1 +
arch/arm64/include/asm/io.h | 3 ++-
arch/arm64/include/asm/pci.h | 37 +++++++++++++++++++++++++++++++++
arch/arm64/kernel/Makefile | 1 +
arch/arm64/kernel/pci.c | 48 +++++++++++++++++++++++++++++++++++++++++++
6 files changed, 110 insertions(+), 2 deletions(-)
create mode 100644 arch/arm64/include/asm/pci.h
create mode 100644 arch/arm64/kernel/pci.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 839f48c..30832d9 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -76,7 +76,7 @@ config MMU
def_bool y

config NO_IOPORT_MAP
- def_bool y
+ def_bool y if !PCI

config STACKTRACE_SUPPORT
def_bool y
@@ -151,6 +151,26 @@ menu "Bus support"
config ARM_AMBA
bool

+config PCI
+ bool "PCI support"
+ help
+ This feature enables support for PCIe bus system. If you say Y
+ here, the kernel will include drivers and infrastructure code
+ to support PCIe bus devices.
+
+config PCI_DOMAINS
+ def_bool PCI
+
+config PCI_DOMAINS_GENERIC
+ def_bool PCI
+
+config PCI_SYSCALL
+ def_bool PCI
+
+source "drivers/pci/Kconfig"
+source "drivers/pci/pcie/Kconfig"
+source "drivers/pci/hotplug/Kconfig"
+
endmenu

menu "Kernel Features"
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index 0b3fcf8..07cb417 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -29,6 +29,7 @@ generic-y += mman.h
generic-y += msgbuf.h
generic-y += mutex.h
generic-y += pci.h
+generic-y += pci-bridge.h
generic-y += poll.h
generic-y += preempt.h
generic-y += resource.h
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index e0ecdcf..dc34039 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -121,7 +121,8 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
/*
* I/O port access primitives.
*/
-#define IO_SPACE_LIMIT 0xffff
+#define arch_has_dev_port() (1)
+#define IO_SPACE_LIMIT 0x1ffffff
#define PCI_IOBASE ((void __iomem *)(MODULES_VADDR - SZ_32M))

static inline u8 inb(unsigned long addr)
diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
new file mode 100644
index 0000000..872ba93
--- /dev/null
+++ b/arch/arm64/include/asm/pci.h
@@ -0,0 +1,37 @@
+#ifndef __ASM_PCI_H
+#define __ASM_PCI_H
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/io.h>
+#include <asm-generic/pci-bridge.h>
+#include <asm-generic/pci-dma-compat.h>
+
+#define PCIBIOS_MIN_IO 0x1000
+#define PCIBIOS_MIN_MEM 0
+
+/*
+ * Set to 1 if the kernel should re-assign all PCI bus numbers
+ */
+#define pcibios_assign_all_busses() \
+ (pci_has_flag(PCI_REASSIGN_ALL_BUS))
+
+/*
+ * PCI address space differs from physical memory address space
+ */
+#define PCI_DMA_BUS_IS_PHYS (0)
+
+extern int isa_dma_bridge_buggy;
+
+#ifdef CONFIG_PCI
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+ return 1;
+}
+#endif /* CONFIG_PCI */
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_PCI_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index cdaedad..36b117a 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -29,6 +29,7 @@ arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o suspend.o
arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o
arm64-obj-$(CONFIG_KGDB) += kgdb.o
arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o
+arm64-obj-$(CONFIG_PCI) += pci.o

obj-y += $(arm64-obj-y) vdso/
obj-m += $(arm64-obj-m)
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
new file mode 100644
index 0000000..fe99049
--- /dev/null
+++ b/arch/arm64/kernel/pci.c
@@ -0,0 +1,48 @@
+/*
+ * Code borrowed from powerpc/kernel/pci-common.c
+ *
+ * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Copyright (C) 2014 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+#include <asm/pci-bridge.h>
+
+/*
+ * Called after each bus is probed, but before its children are examined
+ */
+void pcibios_fixup_bus(struct pci_bus *bus)
+{
+ /* nothing to do, expected to be removed in the future */
+}
+
+/*
+ * We don't have to worry about legacy ISA devices, so nothing to do here
+ */
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+ resource_size_t size, resource_size_t align)
+{
+ return res->start;
+}
+
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+{
+ int domain = of_pci_get_domain_nr(parent->of_node, true);
+
+ if (domain >= 0)
+ bus->domain_nr = domain;
+}
+#endif
--
2.0.4