[PATCH v7 3/3] arm64: Add architecture support for PCI

Liviu Dudau
2014-03-14T15:35:08Z

Use the generic host bridge functions to provide support for
PCI Express on arm64. There is no support for ISA memory.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Tested-by: Tanmay Inamdar <tinamdar@apm.com>
---
arch/arm64/Kconfig | 19 +++-
arch/arm64/include/asm/Kbuild | 1 +
arch/arm64/include/asm/io.h | 3 +-
arch/arm64/include/asm/pci.h | 51 ++++++++++
arch/arm64/kernel/Makefile | 1 +
arch/arm64/kernel/pci.c | 173 ++++++++++++++++++++++++++++++++
6 files changed, 246 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 27bbcfc..d1c8568 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -62,7 +62,7 @@ config MMU
def_bool y

config NO_IOPORT
- def_bool y
+ def_bool y if !PCI

config STACKTRACE_SUPPORT
def_bool y
@@ -134,6 +134,23 @@ 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_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 71c53ec..46924bc 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -26,6 +26,7 @@ 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 += posix_types.h
generic-y += resource.h
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 7846a6b..67463a5 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -120,7 +120,8 @@ 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..d93576f
--- /dev/null
+++ b/arch/arm64/include/asm/pci.h
@@ -0,0 +1,51 @@
+#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
+
+struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus);
+
+/*
+ * 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_domain_nr(struct pci_bus *bus)
+{
+ struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
+
+ if (bridge)
+ return bridge->domain_nr;
+
+ return 0;
+}
+
+static inline int pci_proc_domain(struct pci_bus *bus)
+{
+ return 1;
+}
+#endif
+
+extern unsigned long pci_ioremap_io(const struct resource *res, phys_addr_t phys_addr);
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_PCI_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 2d4554b..64fc479 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -20,6 +20,7 @@ arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o
arm64-obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o suspend.o
arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.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..9f29c9a
--- /dev/null
+++ b/arch/arm64/kernel/pci.c
@@ -0,0 +1,173 @@
+/*
+ * 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>
+
+struct ioresource {
+ struct list_head list;
+ phys_addr_t start;
+ resource_size_t size;
+};
+
+static LIST_HEAD(io_list);
+
+int pci_register_io_range(phys_addr_t address, resource_size_t size)
+{
+ struct ioresource *res;
+ resource_size_t allocated_size = 0;
+
+ /* find if the range has not been already allocated */
+ list_for_each_entry(res, &io_list, list) {
+ if (address >= res->start &&
+ address + size <= res->start + size)
+ return 0;
+ allocated_size += res->size;
+ }
+
+ /* range not already registered, check for space */
+ if (allocated_size + size > IO_SPACE_LIMIT)
+ return -E2BIG;
+
+ /* add the range in the list */
+ res = kzalloc(sizeof(*res), GFP_KERNEL);
+ if (!res)
+ return -ENOMEM;
+ res->start = address;
+ res->size = size;
+
+ list_add_tail(&res->list, &io_list);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_register_io_range);
+
+unsigned long pci_address_to_pio(phys_addr_t address)
+{
+ struct ioresource *res;
+
+ list_for_each_entry(res, &io_list, list) {
+ if (address >= res->start &&
+ address < res->start + res->size) {
+ return res->start - address;
+ }
+ }
+
+ return (unsigned long)-1;
+}
+EXPORT_SYMBOL_GPL(pci_address_to_pio);
+
+/*
+ * Called after each bus is probed, but before its children are examined
+ */
+void pcibios_fixup_bus(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+ struct resource *res;
+ int i;
+
+ if (!pci_is_root_bus(bus)) {
+ pci_read_bridge_bases(bus);
+
+ pci_bus_for_each_resource(bus, res, i) {
+ if (!res || !res->flags || res->parent)
+ continue;
+
+ /*
+ * If we are going to reassign everything, we can
+ * shrink the P2P resource to have zero size to
+ * save space
+ */
+ if (pci_has_flag(PCI_REASSIGN_ALL_RSRC)) {
+ res->flags |= IORESOURCE_UNSET;
+ res->start = 0;
+ res->end = -1;
+ continue;
+ }
+ }
+ }
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ /* Ignore fully discovered devices */
+ if (dev->is_added)
+ continue;
+
+ set_dev_node(&dev->dev, pcibus_to_node(dev->bus));
+
+ /* Read default IRQs and fixup if necessary */
+ dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
+ }
+}
+EXPORT_SYMBOL(pcibios_fixup_bus);
+
+/*
+ * 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;
+}
+
+int pcibios_enable_device(struct pci_dev *dev, int mask)
+{
+ return pci_enable_resources(dev, mask);
+}
+
+#define IO_SPACE_PAGES ((IO_SPACE_LIMIT + 1) / PAGE_SIZE)
+static DECLARE_BITMAP(pci_iospace, IO_SPACE_PAGES);
+
+unsigned long pci_ioremap_io(const struct resource *res, phys_addr_t phys_addr)
+{
+ unsigned long start, len, virt_start;
+ int err;
+
+ if (res->end > IO_SPACE_LIMIT)
+ return -EINVAL;
+
+ /*
+ * try finding free space for the whole size first,
+ * fall back to 64K if not available
+ */
+ len = resource_size(res);
+ start = bitmap_find_next_zero_area(pci_iospace, IO_SPACE_PAGES,
+ res->start / PAGE_SIZE, len / PAGE_SIZE, 0);
+ if (start == IO_SPACE_PAGES && len > SZ_64K) {
+ len = SZ_64K;
+ start = 0;
+ start = bitmap_find_next_zero_area(pci_iospace, IO_SPACE_PAGES,
+ start, len / PAGE_SIZE, 0);
+ }
+
+ /* no 64K area found */
+ if (start == IO_SPACE_PAGES)
+ return -ENOMEM;
+
+ /* ioremap physical aperture to virtual aperture */
+ virt_start = start * PAGE_SIZE + (unsigned long)PCI_IOBASE;
+ err = ioremap_page_range(virt_start, virt_start + len,
+ phys_addr, __pgprot(PROT_DEVICE_nGnRE));
+ if (err)
+ return err;
+
+ bitmap_set(pci_iospace, start, len / PAGE_SIZE);
+
+ /* return io_offset */
+ return start * PAGE_SIZE - res->start;
+}
--
1.9.0