diff options
Diffstat (limited to 'drivers/pci/search.c')
| -rw-r--r-- | drivers/pci/search.c | 273 |
1 files changed, 201 insertions, 72 deletions
diff --git a/drivers/pci/search.c b/drivers/pci/search.c index d0627fa9f368..e6e84dc62e82 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -1,13 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 /* - * PCI searching functions. + * PCI searching functions * - * Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter, + * Copyright (C) 1993 -- 1997 Drew Eckhardt, Frederic Potter, * David Mosberger-Tang - * Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz> - * Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com> + * Copyright (C) 1997 -- 2000 Martin Mares <mj@ucw.cz> + * Copyright (C) 2003 -- 2004 Greg Kroah-Hartman <greg@kroah.com> */ -#include <linux/init.h> #include <linux/pci.h> #include <linux/slab.h> #include <linux/module.h> @@ -15,54 +15,115 @@ #include "pci.h" DECLARE_RWSEM(pci_bus_sem); -EXPORT_SYMBOL_GPL(pci_bus_sem); /* - * find the upstream PCIe-to-PCI bridge of a PCI device - * if the device is PCIE, return NULL - * if the device isn't connected to a PCIe bridge (that is its parent is a - * legacy PCI bridge and the bridge is directly connected to bus 0), return its - * parent + * pci_for_each_dma_alias - Iterate over DMA aliases for a device + * @pdev: starting downstream device + * @fn: function to call for each alias + * @data: opaque data to pass to @fn + * + * Starting @pdev, walk up the bus calling @fn for each possible alias + * of @pdev at the root bus. */ -struct pci_dev * -pci_find_upstream_pcie_bridge(struct pci_dev *pdev) +int pci_for_each_dma_alias(struct pci_dev *pdev, + int (*fn)(struct pci_dev *pdev, + u16 alias, void *data), void *data) { - struct pci_dev *tmp = NULL; - - if (pci_is_pcie(pdev)) - return NULL; - while (1) { - if (pci_is_root_bus(pdev->bus)) - break; - pdev = pdev->bus->self; - /* a p2p bridge */ - if (!pci_is_pcie(pdev)) { - tmp = pdev; - continue; + struct pci_bus *bus; + int ret; + + /* + * The device may have an explicit alias requester ID for DMA where the + * requester is on another PCI bus. + */ + pdev = pci_real_dma_dev(pdev); + + ret = fn(pdev, pci_dev_id(pdev), data); + if (ret) + return ret; + + /* + * If the device is broken and uses an alias requester ID for + * DMA, iterate over that too. + */ + if (unlikely(pdev->dma_alias_mask)) { + unsigned int devfn; + + for_each_set_bit(devfn, pdev->dma_alias_mask, MAX_NR_DEVFNS) { + ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn), + data); + if (ret) + return ret; } - /* PCI device should connect to a PCIe bridge */ - if (pci_pcie_type(pdev) != PCI_EXP_TYPE_PCI_BRIDGE) { - /* Busted hardware? */ - WARN_ON_ONCE(1); - return NULL; + } + + for (bus = pdev->bus; !pci_is_root_bus(bus); bus = bus->parent) { + struct pci_dev *tmp; + + /* Skip virtual buses */ + if (!bus->self) + continue; + + tmp = bus->self; + + /* stop at bridge where translation unit is associated */ + if (tmp->dev_flags & PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT) + return ret; + + /* + * PCIe-to-PCI/X bridges alias transactions from downstream + * devices using the subordinate bus number (PCI Express to + * PCI/PCI-X Bridge Spec, rev 1.0, sec 2.3). For all cases + * where the upstream bus is PCI/X we alias to the bridge + * (there are various conditions in the previous reference + * where the bridge may take ownership of transactions, even + * when the secondary interface is PCI-X). + */ + if (pci_is_pcie(tmp)) { + switch (pci_pcie_type(tmp)) { + case PCI_EXP_TYPE_ROOT_PORT: + case PCI_EXP_TYPE_UPSTREAM: + case PCI_EXP_TYPE_DOWNSTREAM: + continue; + case PCI_EXP_TYPE_PCI_BRIDGE: + ret = fn(tmp, + PCI_DEVID(tmp->subordinate->number, + PCI_DEVFN(0, 0)), data); + if (ret) + return ret; + continue; + case PCI_EXP_TYPE_PCIE_BRIDGE: + ret = fn(tmp, pci_dev_id(tmp), data); + if (ret) + return ret; + continue; + } + } else { + if (tmp->dev_flags & PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS) + ret = fn(tmp, + PCI_DEVID(tmp->subordinate->number, + PCI_DEVFN(0, 0)), data); + else + ret = fn(tmp, pci_dev_id(tmp), data); + if (ret) + return ret; } - return pdev; } - return tmp; + return ret; } static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr) { - struct pci_bus* child; - struct list_head *tmp; + struct pci_bus *child; + struct pci_bus *tmp; - if(bus->number == busnr) + if (bus->number == busnr) return bus; - list_for_each(tmp, &bus->children) { - child = pci_do_find_bus(pci_bus_b(tmp), busnr); - if(child) + list_for_each_entry(tmp, &bus->children, node) { + child = pci_do_find_bus(tmp, busnr); + if (child) return child; } return NULL; @@ -77,7 +138,7 @@ static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr) * in the global list of PCI buses. If the bus is found, a pointer to its * data structure is returned. If no bus is found, %NULL is returned. */ -struct pci_bus * pci_find_bus(int domain, int busnr) +struct pci_bus *pci_find_bus(int domain, int busnr) { struct pci_bus *bus = NULL; struct pci_bus *tmp_bus; @@ -91,39 +152,39 @@ struct pci_bus * pci_find_bus(int domain, int busnr) } return NULL; } +EXPORT_SYMBOL(pci_find_bus); /** * pci_find_next_bus - begin or continue searching for a PCI bus * @from: Previous PCI bus found, or %NULL for new search. * - * Iterates through the list of known PCI busses. A new search is + * Iterates through the list of known PCI buses. A new search is * initiated by passing %NULL as the @from argument. Otherwise if * @from is not %NULL, searches continue from next device on the * global list. */ -struct pci_bus * -pci_find_next_bus(const struct pci_bus *from) +struct pci_bus *pci_find_next_bus(const struct pci_bus *from) { struct list_head *n; struct pci_bus *b = NULL; - WARN_ON(in_interrupt()); down_read(&pci_bus_sem); n = from ? from->node.next : pci_root_buses.next; if (n != &pci_root_buses) - b = pci_bus_b(n); + b = list_entry(n, struct pci_bus, node); up_read(&pci_bus_sem); return b; } +EXPORT_SYMBOL(pci_find_next_bus); /** * pci_get_slot - locate PCI device for a given PCI slot * @bus: PCI bus on which desired PCI device resides - * @devfn: encodes number of PCI slot in which the desired PCI - * device resides and the logical device number within that slot + * @devfn: encodes number of PCI slot in which the desired PCI + * device resides and the logical device number within that slot * in case of multi-function devices. * - * Given a PCI bus and slot/function number, the desired PCI device + * Given a PCI bus and slot/function number, the desired PCI device * is located in the list of PCI devices. * If the device is found, its reference count is increased and this * function returns a pointer to its data structure. The caller must @@ -134,7 +195,6 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn) { struct pci_dev *dev; - WARN_ON(in_interrupt()); down_read(&pci_bus_sem); list_for_each_entry(dev, &bus->devices, bus_list) { @@ -148,6 +208,7 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn) up_read(&pci_bus_sem); return dev; } +EXPORT_SYMBOL(pci_get_slot); /** * pci_get_domain_bus_and_slot - locate PCI device for a given PCI domain (segment), bus, and slot @@ -178,10 +239,10 @@ struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus, } EXPORT_SYMBOL(pci_get_domain_bus_and_slot); -static int match_pci_dev_by_id(struct device *dev, void *data) +static int match_pci_dev_by_id(struct device *dev, const void *data) { struct pci_dev *pdev = to_pci_dev(dev); - struct pci_device_id *id = data; + const struct pci_device_id *id = data; if (pci_match_one_device(id, pdev)) return 1; @@ -211,18 +272,55 @@ static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id, struct device *dev_start = NULL; struct pci_dev *pdev = NULL; - WARN_ON(in_interrupt()); if (from) dev_start = &from->dev; dev = bus_find_device(&pci_bus_type, dev_start, (void *)id, match_pci_dev_by_id); if (dev) pdev = to_pci_dev(dev); + pci_dev_put(from); + return pdev; +} + +static struct pci_dev *pci_get_dev_by_id_reverse(const struct pci_device_id *id, + struct pci_dev *from) +{ + struct device *dev; + struct device *dev_start = NULL; + struct pci_dev *pdev = NULL; + if (from) - pci_dev_put(from); + dev_start = &from->dev; + dev = bus_find_device_reverse(&pci_bus_type, dev_start, (void *)id, + match_pci_dev_by_id); + if (dev) + pdev = to_pci_dev(dev); + pci_dev_put(from); return pdev; } +enum pci_search_direction { + PCI_SEARCH_FORWARD, + PCI_SEARCH_REVERSE, +}; + +static struct pci_dev *__pci_get_subsys(unsigned int vendor, unsigned int device, + unsigned int ss_vendor, unsigned int ss_device, + struct pci_dev *from, enum pci_search_direction dir) +{ + struct pci_device_id id = { + .vendor = vendor, + .device = device, + .subvendor = ss_vendor, + .subdevice = ss_device, + }; + + if (dir == PCI_SEARCH_FORWARD) + return pci_get_dev_by_id(&id, from); + else + return pci_get_dev_by_id_reverse(&id, from); +} + /** * pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id * @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids @@ -243,15 +341,10 @@ struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, unsigned int ss_vendor, unsigned int ss_device, struct pci_dev *from) { - struct pci_device_id id = { - .vendor = vendor, - .device = device, - .subvendor = ss_vendor, - .subdevice = ss_device, - }; - - return pci_get_dev_by_id(&id, from); + return __pci_get_subsys(vendor, device, ss_vendor, ss_device, from, + PCI_SEARCH_FORWARD); } +EXPORT_SYMBOL(pci_get_subsys); /** * pci_get_device - begin or continue searching for a PCI device by vendor/device id @@ -267,11 +360,25 @@ struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, * from next device on the global list. The reference count for @from is * always decremented if it is not %NULL. */ -struct pci_dev * -pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from) +struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device, + struct pci_dev *from) { return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from); } +EXPORT_SYMBOL(pci_get_device); + +/* + * Same semantics as pci_get_device(), except walks the PCI device list + * in reverse discovery order. + */ +struct pci_dev *pci_get_device_reverse(unsigned int vendor, + unsigned int device, + struct pci_dev *from) +{ + return __pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from, + PCI_SEARCH_REVERSE); +} +EXPORT_SYMBOL(pci_get_device_reverse); /** * pci_get_class - begin or continue searching for a PCI device by class @@ -300,6 +407,38 @@ struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from) return pci_get_dev_by_id(&id, from); } +EXPORT_SYMBOL(pci_get_class); + +/** + * pci_get_base_class - searching for a PCI device by matching against the base class code only + * @class: search for a PCI device with this base class code + * @from: Previous PCI device found in search, or %NULL for new search. + * + * Iterates through the list of known PCI devices. If a PCI device is found + * with a matching base class code, the reference count to the device is + * incremented. See pci_match_one_device() to figure out how does this works. + * A new search is initiated by passing %NULL as the @from argument. + * Otherwise if @from is not %NULL, searches continue from next device on the + * global list. The reference count for @from is always decremented if it is + * not %NULL. + * + * Returns: + * A pointer to a matched PCI device, %NULL Otherwise. + */ +struct pci_dev *pci_get_base_class(unsigned int class, struct pci_dev *from) +{ + struct pci_device_id id = { + .vendor = PCI_ANY_ID, + .device = PCI_ANY_ID, + .subvendor = PCI_ANY_ID, + .subdevice = PCI_ANY_ID, + .class_mask = 0xFF0000, + .class = class << 16, + }; + + return pci_get_dev_by_id(&id, from); +} +EXPORT_SYMBOL(pci_get_base_class); /** * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not. @@ -316,7 +455,6 @@ int pci_dev_present(const struct pci_device_id *ids) { struct pci_dev *found = NULL; - WARN_ON(in_interrupt()); while (ids->vendor || ids->subvendor || ids->class_mask) { found = pci_get_dev_by_id(ids, NULL); if (found) { @@ -329,12 +467,3 @@ int pci_dev_present(const struct pci_device_id *ids) return 0; } EXPORT_SYMBOL(pci_dev_present); - -/* For boot time work */ -EXPORT_SYMBOL(pci_find_bus); -EXPORT_SYMBOL(pci_find_next_bus); -/* For everyone */ -EXPORT_SYMBOL(pci_get_device); -EXPORT_SYMBOL(pci_get_subsys); -EXPORT_SYMBOL(pci_get_slot); -EXPORT_SYMBOL(pci_get_class); |