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SubjectRe: [PATCH v2 3/3] arm64: Add architecture support for PCI
From
On 27 February 2014 13:09, Liviu Dudau <Liviu.Dudau@arm.com> wrote:
> 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>
>
> 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..3edf9e0
> --- /dev/null
> +++ b/arch/arm64/include/asm/pci.h
> @@ -0,0 +1,47 @@
> +#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;
> +
> +static inline int pci_domain_nr(struct pci_bus *bus)
> +{
> + struct pci_host_bridge *bridge = to_pci_host_bridge(bus->bridge);
> +
> + if (bridge)
> + return bridge->domain_nr;
> +
> + return 0;
> +}
> +
> +static inline int pci_proc_domain(struct pci_bus *bus)
> +{
> + return pci_domain_nr(bus);
> +}
> +
> +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..496df41
> --- /dev/null
> +++ b/arch/arm64/kernel/pci.c
> @@ -0,1 +1,126 @@
> +/*
> + * 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)
> +{
> + 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 ALIGN(res->start, align);
> +}
> +EXPORT_SYMBOL(pcibios_align_resource);
> +
> +int pcibios_enable_device(struct pci_dev *dev, int mask)
> +{
> + return pci_enable_resources(dev, mask);
> +}

It looks like you will soon be able to remove this and rely on the
shinny new weak implementation of pcibios_enable_device now
(http://www.spinics.net/lists/linux-pci/msg29387.html)

Andrew Murray

> +
> +void pcibios_fixup_bridge_ranges(struct list_head *resources)
> +{
> +}
> +
> +#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
>
> --
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