mirror of https://gitee.com/openkylin/linux.git
217 lines
5.2 KiB
C
217 lines
5.2 KiB
C
/*
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* arch/xtensa/kernel/pci.c
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*
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* PCI bios-type initialisation for PCI machines
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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* Copyright (C) 2001-2005 Tensilica Inc.
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*
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* Based largely on work from Cort (ppc/kernel/pci.c)
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* IO functions copied from sparc.
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*
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* Chris Zankel <chris@zankel.net>
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*
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*/
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/delay.h>
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#include <linux/string.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/bootmem.h>
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#include <asm/pci-bridge.h>
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#include <asm/platform.h>
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/* PCI Controller */
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/*
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* pcibios_alloc_controller
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* pcibios_enable_device
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* pcibios_fixups
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* pcibios_align_resource
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* pcibios_fixup_bus
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* pci_bus_add_device
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*/
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static struct pci_controller *pci_ctrl_head;
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static struct pci_controller **pci_ctrl_tail = &pci_ctrl_head;
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static int pci_bus_count;
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/*
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* We need to avoid collisions with `mirrored' VGA ports
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* and other strange ISA hardware, so we always want the
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* addresses to be allocated in the 0x000-0x0ff region
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* modulo 0x400.
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*
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* Why? Because some silly external IO cards only decode
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* the low 10 bits of the IO address. The 0x00-0xff region
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* is reserved for motherboard devices that decode all 16
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* bits, so it's ok to allocate at, say, 0x2800-0x28ff,
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* but we want to try to avoid allocating at 0x2900-0x2bff
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* which might have be mirrored at 0x0100-0x03ff..
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*/
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resource_size_t
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pcibios_align_resource(void *data, const struct resource *res,
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resource_size_t size, resource_size_t align)
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{
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struct pci_dev *dev = data;
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resource_size_t start = res->start;
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if (res->flags & IORESOURCE_IO) {
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if (size > 0x100) {
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pr_err("PCI: I/O Region %s/%d too large (%u bytes)\n",
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pci_name(dev), dev->resource - res,
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size);
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}
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if (start & 0x300)
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start = (start + 0x3ff) & ~0x3ff;
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}
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return start;
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}
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static void __init pci_controller_apertures(struct pci_controller *pci_ctrl,
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struct list_head *resources)
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{
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struct resource *res;
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unsigned long io_offset;
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int i;
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io_offset = (unsigned long)pci_ctrl->io_space.base;
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res = &pci_ctrl->io_resource;
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if (!res->flags) {
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if (io_offset)
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pr_err("I/O resource not set for host bridge %d\n",
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pci_ctrl->index);
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res->start = 0;
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res->end = IO_SPACE_LIMIT;
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res->flags = IORESOURCE_IO;
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}
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res->start += io_offset;
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res->end += io_offset;
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pci_add_resource_offset(resources, res, io_offset);
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for (i = 0; i < 3; i++) {
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res = &pci_ctrl->mem_resources[i];
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if (!res->flags) {
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if (i > 0)
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continue;
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pr_err("Memory resource not set for host bridge %d\n",
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pci_ctrl->index);
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res->start = 0;
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res->end = ~0U;
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res->flags = IORESOURCE_MEM;
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}
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pci_add_resource(resources, res);
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}
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}
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static int __init pcibios_init(void)
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{
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struct pci_controller *pci_ctrl;
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struct list_head resources;
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struct pci_bus *bus;
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int next_busno = 0, ret;
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pr_info("PCI: Probing PCI hardware\n");
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/* Scan all of the recorded PCI controllers. */
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for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
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pci_ctrl->last_busno = 0xff;
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INIT_LIST_HEAD(&resources);
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pci_controller_apertures(pci_ctrl, &resources);
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bus = pci_scan_root_bus(NULL, pci_ctrl->first_busno,
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pci_ctrl->ops, pci_ctrl, &resources);
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if (!bus)
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continue;
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pci_ctrl->bus = bus;
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pci_ctrl->last_busno = bus->busn_res.end;
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if (next_busno <= pci_ctrl->last_busno)
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next_busno = pci_ctrl->last_busno+1;
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}
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pci_bus_count = next_busno;
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ret = platform_pcibios_fixup();
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if (ret)
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return ret;
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for (pci_ctrl = pci_ctrl_head; pci_ctrl; pci_ctrl = pci_ctrl->next) {
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if (pci_ctrl->bus)
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pci_bus_add_devices(pci_ctrl->bus);
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}
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return 0;
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}
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subsys_initcall(pcibios_init);
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void pcibios_fixup_bus(struct pci_bus *bus)
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{
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if (bus->parent) {
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/* This is a subordinate bridge */
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pci_read_bridge_bases(bus);
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}
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}
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void pcibios_set_master(struct pci_dev *dev)
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{
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/* No special bus mastering setup handling */
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}
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int pcibios_enable_device(struct pci_dev *dev, int mask)
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{
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u16 cmd, old_cmd;
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int idx;
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struct resource *r;
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pci_read_config_word(dev, PCI_COMMAND, &cmd);
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old_cmd = cmd;
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for (idx=0; idx<6; idx++) {
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r = &dev->resource[idx];
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if (!r->start && r->end) {
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pci_err(dev, "can't enable device: resource collisions\n");
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return -EINVAL;
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}
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if (r->flags & IORESOURCE_IO)
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cmd |= PCI_COMMAND_IO;
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if (r->flags & IORESOURCE_MEM)
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cmd |= PCI_COMMAND_MEMORY;
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}
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if (cmd != old_cmd) {
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pci_info(dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd);
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pci_write_config_word(dev, PCI_COMMAND, cmd);
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}
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return 0;
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}
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/*
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* Platform support for /proc/bus/pci/X/Y mmap()s.
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* -- paulus.
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*/
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int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
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{
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struct pci_controller *pci_ctrl = (struct pci_controller*) pdev->sysdata;
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resource_size_t ioaddr = pci_resource_start(pdev, bar);
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if (pci_ctrl == 0)
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return -EINVAL; /* should never happen */
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/* Convert to an offset within this PCI controller */
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ioaddr -= (unsigned long)pci_ctrl->io_space.base;
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vma->vm_pgoff += (ioaddr + pci_ctrl->io_space.start) >> PAGE_SHIFT;
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return 0;
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}
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