392 lines
12 KiB
C
392 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* PCI searching functions
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*
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* Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter,
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* David Mosberger-Tang
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* Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz>
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* Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com>
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*/
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#include <linux/pci.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include "pci.h"
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DECLARE_RWSEM(pci_bus_sem);
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EXPORT_SYMBOL_GPL(pci_bus_sem);
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/*
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* pci_for_each_dma_alias - Iterate over DMA aliases for a device
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* @pdev: starting downstream device
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* @fn: function to call for each alias
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* @data: opaque data to pass to @fn
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*
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* Starting @pdev, walk up the bus calling @fn for each possible alias
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* of @pdev at the root bus.
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*/
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int pci_for_each_dma_alias(struct pci_dev *pdev,
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int (*fn)(struct pci_dev *pdev,
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u16 alias, void *data), void *data)
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{
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struct pci_bus *bus;
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int ret;
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ret = fn(pdev, pci_dev_id(pdev), data);
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if (ret)
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return ret;
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/*
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* If the device is broken and uses an alias requester ID for
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* DMA, iterate over that too.
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*/
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if (unlikely(pdev->dma_alias_mask)) {
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u8 devfn;
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for_each_set_bit(devfn, pdev->dma_alias_mask, U8_MAX) {
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ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn),
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data);
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if (ret)
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return ret;
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}
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}
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for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) {
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struct pci_dev *tmp;
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/* Skip virtual buses */
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if (!bus->self)
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continue;
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tmp = bus->self;
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/* stop at bridge where translation unit is associated */
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if (tmp->dev_flags & PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT)
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return ret;
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/*
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* PCIe-to-PCI/X bridges alias transactions from downstream
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* devices using the subordinate bus number (PCI Express to
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* PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases
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* where the upstream bus is PCI/X we alias to the bridge
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* (there are various conditions in the previous reference
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* where the bridge may take ownership of transactions, even
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* when the secondary interface is PCI-X).
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*/
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if (pci_is_pcie(tmp)) {
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switch (pci_pcie_type(tmp)) {
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case PCI_EXP_TYPE_ROOT_PORT:
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case PCI_EXP_TYPE_UPSTREAM:
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case PCI_EXP_TYPE_DOWNSTREAM:
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continue;
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case PCI_EXP_TYPE_PCI_BRIDGE:
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ret = fn(tmp,
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PCI_DEVID(tmp->subordinate->number,
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PCI_DEVFN(0, 0)), data);
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if (ret)
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return ret;
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continue;
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case PCI_EXP_TYPE_PCIE_BRIDGE:
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ret = fn(tmp, pci_dev_id(tmp), data);
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if (ret)
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return ret;
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continue;
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}
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} else {
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if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS)
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ret = fn(tmp,
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PCI_DEVID(tmp->subordinate->number,
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PCI_DEVFN(0, 0)), data);
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else
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ret = fn(tmp, pci_dev_id(tmp), data);
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if (ret)
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return ret;
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}
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}
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return ret;
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}
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static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
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{
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struct pci_bus *child;
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struct pci_bus *tmp;
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if (bus->number == busnr)
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return bus;
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list_for_each_entry(tmp, &bus->children, node) {
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child = pci_do_find_bus(tmp, busnr);
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if (child)
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return child;
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}
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return NULL;
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}
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/**
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* pci_find_bus - locate PCI bus from a given domain and bus number
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* @domain: number of PCI domain to search
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* @busnr: number of desired PCI bus
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*
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* Given a PCI bus number and domain number, the desired PCI bus is located
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* in the global list of PCI buses. If the bus is found, a pointer to its
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* data structure is returned. If no bus is found, %NULL is returned.
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*/
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struct pci_bus *pci_find_bus(int domain, int busnr)
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{
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struct pci_bus *bus = NULL;
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struct pci_bus *tmp_bus;
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while ((bus = pci_find_next_bus(bus)) != NULL) {
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if (pci_domain_nr(bus) != domain)
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continue;
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tmp_bus = pci_do_find_bus(bus, busnr);
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if (tmp_bus)
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return tmp_bus;
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}
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return NULL;
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}
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EXPORT_SYMBOL(pci_find_bus);
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/**
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* pci_find_next_bus - begin or continue searching for a PCI bus
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* @from: Previous PCI bus found, or %NULL for new search.
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*
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* Iterates through the list of known PCI buses. A new search is
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* initiated by passing %NULL as the @from argument. Otherwise if
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* @from is not %NULL, searches continue from next device on the
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* global list.
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*/
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struct pci_bus *pci_find_next_bus(const struct pci_bus *from)
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{
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struct list_head *n;
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struct pci_bus *b = NULL;
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WARN_ON(in_interrupt());
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down_read(&pci_bus_sem);
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n = from ? from->node.next : pci_root_buses.next;
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if (n != &pci_root_buses)
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b = list_entry(n, struct pci_bus, node);
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up_read(&pci_bus_sem);
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return b;
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}
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EXPORT_SYMBOL(pci_find_next_bus);
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/**
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* pci_get_slot - locate PCI device for a given PCI slot
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* @bus: PCI bus on which desired PCI device resides
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* @devfn: encodes number of PCI slot in which the desired PCI
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* device resides and the logical device number within that slot
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* in case of multi-function devices.
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*
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* Given a PCI bus and slot/function number, the desired PCI device
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* is located in the list of PCI devices.
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* If the device is found, its reference count is increased and this
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* function returns a pointer to its data structure. The caller must
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* decrement the reference count by calling pci_dev_put().
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* If no device is found, %NULL is returned.
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*/
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struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn)
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{
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struct pci_dev *dev;
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WARN_ON(in_interrupt());
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down_read(&pci_bus_sem);
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list_for_each_entry(dev, &bus->devices, bus_list) {
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if (dev->devfn == devfn)
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goto out;
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}
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dev = NULL;
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out:
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pci_dev_get(dev);
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up_read(&pci_bus_sem);
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return dev;
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}
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EXPORT_SYMBOL(pci_get_slot);
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/**
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* pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot
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* @domain: PCI domain/segment on which the PCI device resides.
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* @bus: PCI bus on which desired PCI device resides
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* @devfn: encodes number of PCI slot in which the desired PCI device
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* resides and the logical device number within that slot in case of
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* multi-function devices.
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*
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* Given a PCI domain, bus, and slot/function number, the desired PCI
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* device is located in the list of PCI devices. If the device is
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* found, its reference count is increased and this function returns a
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* pointer to its data structure. The caller must decrement the
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* reference count by calling pci_dev_put(). If no device is found,
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* %NULL is returned.
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*/
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struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
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unsigned int devfn)
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{
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struct pci_dev *dev = NULL;
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for_each_pci_dev(dev) {
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if (pci_domain_nr(dev->bus) == domain &&
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(dev->bus->number == bus && dev->devfn == devfn))
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return dev;
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}
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return NULL;
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}
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EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
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static int match_pci_dev_by_id(struct device *dev, void *data)
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{
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struct pci_dev *pdev = to_pci_dev(dev);
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struct pci_device_id *id = data;
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if (pci_match_one_device(id, pdev))
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return 1;
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return 0;
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}
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/*
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* pci_get_dev_by_id - begin or continue searching for a PCI device by id
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* @id: pointer to struct pci_device_id to match for the device
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is found
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* with a matching id a pointer to its device structure is returned, and the
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* reference count to the device is incremented. Otherwise, %NULL is returned.
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* A new search is initiated by passing %NULL as the @from argument. Otherwise
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* if @from is not %NULL, searches continue from next device on the global
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* list. The reference count for @from is always decremented if it is not
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* %NULL.
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*
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* This is an internal function for use by the other search functions in
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* this file.
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*/
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static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
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struct pci_dev *from)
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{
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struct device *dev;
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struct device *dev_start = NULL;
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struct pci_dev *pdev = NULL;
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WARN_ON(in_interrupt());
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if (from)
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dev_start = &from->dev;
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dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
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match_pci_dev_by_id);
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if (dev)
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pdev = to_pci_dev(dev);
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pci_dev_put(from);
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return pdev;
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}
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/**
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* pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
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* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
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* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is found
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* with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
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* device structure is returned, and the reference count to the device is
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* incremented. Otherwise, %NULL is returned. A new search is initiated by
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* passing %NULL as the @from argument. Otherwise if @from is not %NULL,
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* searches continue from next device on the global list.
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* The reference count for @from is always decremented if it is not %NULL.
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*/
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struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device,
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unsigned int ss_vendor, unsigned int ss_device,
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struct pci_dev *from)
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{
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struct pci_device_id id = {
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.vendor = vendor,
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.device = device,
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.subvendor = ss_vendor,
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.subdevice = ss_device,
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};
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return pci_get_dev_by_id(&id, from);
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}
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EXPORT_SYMBOL(pci_get_subsys);
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/**
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* pci_get_device - begin or continue searching for a PCI device by vendor/device id
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* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
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* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is
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* found with a matching @vendor and @device, the reference count to the
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* device is incremented and a pointer to its device structure is returned.
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* Otherwise, %NULL is returned. A new search is initiated by passing %NULL
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* as the @from argument. Otherwise if @from is not %NULL, searches continue
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* from next device on the global list. The reference count for @from is
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* always decremented if it is not %NULL.
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*/
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struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device,
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struct pci_dev *from)
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{
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return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
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}
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EXPORT_SYMBOL(pci_get_device);
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/**
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* pci_get_class - begin or continue searching for a PCI device by class
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* @class: search for a PCI device with this class designation
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* @from: Previous PCI device found in search, or %NULL for new search.
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*
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* Iterates through the list of known PCI devices. If a PCI device is
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* found with a matching @class, the reference count to the device is
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* incremented and a pointer to its device structure is returned.
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* Otherwise, %NULL is returned.
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* A new search is initiated by passing %NULL as the @from argument.
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* Otherwise if @from is not %NULL, searches continue from next device
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* on the global list. The reference count for @from is always decremented
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* if it is not %NULL.
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*/
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struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from)
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{
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struct pci_device_id id = {
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.vendor = PCI_ANY_ID,
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.device = PCI_ANY_ID,
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.subvendor = PCI_ANY_ID,
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.subdevice = PCI_ANY_ID,
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.class_mask = PCI_ANY_ID,
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.class = class,
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};
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return pci_get_dev_by_id(&id, from);
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}
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EXPORT_SYMBOL(pci_get_class);
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/**
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* pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
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* @ids: A pointer to a null terminated list of struct pci_device_id structures
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* that describe the type of PCI device the caller is trying to find.
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*
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* Obvious fact: You do not have a reference to any device that might be found
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* by this function, so if that device is removed from the system right after
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* this function is finished, the value will be stale. Use this function to
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* find devices that are usually built into a system, or for a general hint as
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* to if another device happens to be present at this specific moment in time.
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*/
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int pci_dev_present(const struct pci_device_id *ids)
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{
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struct pci_dev *found = NULL;
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WARN_ON(in_interrupt());
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while (ids->vendor || ids->subvendor || ids->class_mask) {
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found = pci_get_dev_by_id(ids, NULL);
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if (found) {
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pci_dev_put(found);
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return 1;
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}
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ids++;
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}
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return 0;
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}
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EXPORT_SYMBOL(pci_dev_present);
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