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392 lines
12 KiB
392 lines
12 KiB
// 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 <[email protected]> |
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* Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <[email protected]> |
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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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/* |
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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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/* |
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* The device may have an explicit alias requester ID for DMA where the |
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* requester is on another PCI bus. |
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*/ |
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pdev = pci_real_dma_dev(pdev); |
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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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unsigned int devfn; |
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for_each_set_bit(devfn, pdev->dma_alias_mask, MAX_NR_DEVFNS) { |
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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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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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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, const void *data) |
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{ |
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struct pci_dev *pdev = to_pci_dev(dev); |
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const 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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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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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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