diff options
Diffstat (limited to 'arch/xtensa/kernel/pci.c')
-rw-r--r-- | arch/xtensa/kernel/pci.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c new file mode 100644 index 000000000..62c900e40 --- /dev/null +++ b/arch/xtensa/kernel/pci.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * arch/xtensa/kernel/pci.c + * + * PCI bios-type initialisation for PCI machines + * + * Copyright (C) 2001-2005 Tensilica Inc. + * + * Based largely on work from Cort (ppc/kernel/pci.c) + * IO functions copied from sparc. + * + * Chris Zankel <chris@zankel.net> + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/delay.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/errno.h> +#include <linux/memblock.h> + +#include <asm/pci-bridge.h> +#include <asm/platform.h> + +/* + * 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; + + if (res->flags & IORESOURCE_IO) { + if (size > 0x100) { + pr_err("PCI: I/O Region %s/%d too large (%u bytes)\n", + pci_name(dev), dev->resource - res, + size); + } + + if (start & 0x300) + start = (start + 0x3ff) & ~0x3ff; + } + + return start; +} + +void pcibios_fixup_bus(struct pci_bus *bus) +{ + if (bus->parent) { + /* This is a subordinate bridge */ + pci_read_bridge_bases(bus); + } +} + +/* + * Platform support for /proc/bus/pci/X/Y mmap()s. + * -- paulus. + */ + +int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma) +{ + struct pci_controller *pci_ctrl = (struct pci_controller*) pdev->sysdata; + resource_size_t ioaddr = pci_resource_start(pdev, bar); + + if (!pci_ctrl) + return -EINVAL; /* should never happen */ + + /* Convert to an offset within this PCI controller */ + ioaddr -= (unsigned long)pci_ctrl->io_space.base; + + vma->vm_pgoff += (ioaddr + pci_ctrl->io_space.start) >> PAGE_SHIFT; + return 0; +} |