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

On Fri, Mar 14, 2014 at 03:34:18PM +0000, Liviu Dudau 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 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;
  

• 	}
  

• }
  

• }

Is there any other place we can put this? I'm trying to nuke pcibios_fixup_bus() because things like hotplug work better if we can do them in a per-device way rather than a per-bus way.

• 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));
  

Do you really need this? pci_device_add() already contains the same line.

• /* Read default IRQs and fixup if necessary */
  

• dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
  

Could this be done in pcibios_add_device() or someplace similar?

• }

+} +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);

+}

There is already a weak default implementation of pcibios_enable_device() that does this, so you should be able to just drop this.

+#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