From 87dd9a4de421f052fd9be58c7da08a453f340d5e Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Wed, 5 Oct 2016 18:18:13 +0100 Subject: MIPS: PCI: Support generic drivers Introduce support for PCI drivers using only functionality provided generically by the PCI subsystem, by adding the minimum arch-provided functions required. The driver this has been developed for & tested with the xilinx-pcie on a MIPS Boston development board. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14346/ Signed-off-by: Ralf Baechle --- arch/mips/pci/Makefile | 1 + arch/mips/pci/pci-generic.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+) create mode 100644 arch/mips/pci/pci-generic.c (limited to 'arch/mips/pci') diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile index 847821040cd9..4b821481dd44 100644 --- a/arch/mips/pci/Makefile +++ b/arch/mips/pci/Makefile @@ -4,6 +4,7 @@ obj-y += pci.o obj-$(CONFIG_PCI_DRIVERS_LEGACY)+= pci-legacy.o +obj-$(CONFIG_PCI_DRIVERS_GENERIC)+= pci-generic.o # # PCI bus host bridge specific code diff --git a/arch/mips/pci/pci-generic.c b/arch/mips/pci/pci-generic.c new file mode 100644 index 000000000000..dce304dc3d62 --- /dev/null +++ b/arch/mips/pci/pci-generic.c @@ -0,0 +1,52 @@ +/* + * Copyright (C) 2016 Imagination Technologies + * Author: Paul Burton + * + * pcibios_align_resource taken from arch/arm/kernel/bios32.c. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include + +/* + * We need to avoid collisions with `mirrored' VGA ports + * and other strange ISA hardware, so we always want the + * addresses to be allocated in the 0x000-0x0ff region + * modulo 0x400. + * + * Why? Because some silly external IO cards only decode + * the low 10 bits of the IO address. The 0x00-0xff region + * is reserved for motherboard devices that decode all 16 + * bits, so it's ok to allocate at, say, 0x2800-0x28ff, + * but we want to try to avoid allocating at 0x2900-0x2bff + * which might have be mirrored at 0x0100-0x03ff.. + */ +resource_size_t pcibios_align_resource(void *data, const struct resource *res, + resource_size_t size, resource_size_t align) +{ + struct pci_dev *dev = data; + resource_size_t start = res->start; + struct pci_host_bridge *host_bridge; + + if (res->flags & IORESOURCE_IO && start & 0x300) + start = (start + 0x3ff) & ~0x3ff; + + start = (start + align - 1) & ~(align - 1); + + host_bridge = pci_find_host_bridge(dev->bus); + + if (host_bridge->align_resource) + return host_bridge->align_resource(dev, res, + start, size, align); + + return start; +} + +void pcibios_fixup_bus(struct pci_bus *bus) +{ + pci_read_bridge_bases(bus); +} -- cgit v1.2.3