linux/drivers/pci/search.c

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// SPDX-License-Identifier: GPL-2.0
/*
* PCI searching functions
*
* 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>
*/
#include <linux/pci.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include "pci.h"
DECLARE_RWSEM(pci_bus_sem);
/*
* 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.
*/
int pci_for_each_dma_alias(struct pci_dev *pdev,
int (*fn)(struct pci_dev *pdev,
u16 alias, void *data), void *data)
{
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.
*/
PCI: Add support for multiple DMA aliases Solve IOMMU support issues with PCIe non-transparent bridges that use Requester ID look-up tables (RID-LUT), e.g., the PEX8733. The NTB connects devices in two independent PCI domains. Devices separated by the NTB are not able to discover each other. A PCI packet being forwared from one domain to another has to have its RID modified so it appears on correct bus and completions are forwarded back to the original domain through the NTB. The RID is translated using a preprogrammed table (LUT) and the PCI packet propagates upstream away from the NTB. If the destination system has IOMMU enabled, the packet will be discarded because the new RID is unknown to the IOMMU. Adding a DMA alias for the new RID allows IOMMU to properly recognize the packet. Each device behind the NTB has a unique RID assigned in the RID-LUT. The current DMA alias implementation supports only a single alias, so it's not possible to support mutiple devices behind the NTB when IOMMU is enabled. Enable all possible aliases on a given bus (256) that are stored in a bitset. Alias devfn is directly translated to a bit number. The bitset is not allocated for devices that have no need for DMA aliases. More details can be found in the following article: http://www.plxtech.com/files/pdf/technical/expresslane/RTC_Enabling%20MulitHostSystemDesigns.pdf Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: David Woodhouse <David.Woodhouse@intel.com> Acked-by: Joerg Roedel <jroedel@suse.de>
2016-03-03 14:38:02 +00:00
if (unlikely(pdev->dma_alias_mask)) {
unsigned int devfn;
PCI: Add support for multiple DMA aliases Solve IOMMU support issues with PCIe non-transparent bridges that use Requester ID look-up tables (RID-LUT), e.g., the PEX8733. The NTB connects devices in two independent PCI domains. Devices separated by the NTB are not able to discover each other. A PCI packet being forwared from one domain to another has to have its RID modified so it appears on correct bus and completions are forwarded back to the original domain through the NTB. The RID is translated using a preprogrammed table (LUT) and the PCI packet propagates upstream away from the NTB. If the destination system has IOMMU enabled, the packet will be discarded because the new RID is unknown to the IOMMU. Adding a DMA alias for the new RID allows IOMMU to properly recognize the packet. Each device behind the NTB has a unique RID assigned in the RID-LUT. The current DMA alias implementation supports only a single alias, so it's not possible to support mutiple devices behind the NTB when IOMMU is enabled. Enable all possible aliases on a given bus (256) that are stored in a bitset. Alias devfn is directly translated to a bit number. The bitset is not allocated for devices that have no need for DMA aliases. More details can be found in the following article: http://www.plxtech.com/files/pdf/technical/expresslane/RTC_Enabling%20MulitHostSystemDesigns.pdf Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: David Woodhouse <David.Woodhouse@intel.com> Acked-by: Joerg Roedel <jroedel@suse.de>
2016-03-03 14:38:02 +00:00
for_each_set_bit(devfn, pdev->dma_alias_mask, MAX_NR_DEVFNS) {
PCI: Add support for multiple DMA aliases Solve IOMMU support issues with PCIe non-transparent bridges that use Requester ID look-up tables (RID-LUT), e.g., the PEX8733. The NTB connects devices in two independent PCI domains. Devices separated by the NTB are not able to discover each other. A PCI packet being forwared from one domain to another has to have its RID modified so it appears on correct bus and completions are forwarded back to the original domain through the NTB. The RID is translated using a preprogrammed table (LUT) and the PCI packet propagates upstream away from the NTB. If the destination system has IOMMU enabled, the packet will be discarded because the new RID is unknown to the IOMMU. Adding a DMA alias for the new RID allows IOMMU to properly recognize the packet. Each device behind the NTB has a unique RID assigned in the RID-LUT. The current DMA alias implementation supports only a single alias, so it's not possible to support mutiple devices behind the NTB when IOMMU is enabled. Enable all possible aliases on a given bus (256) that are stored in a bitset. Alias devfn is directly translated to a bit number. The bitset is not allocated for devices that have no need for DMA aliases. More details can be found in the following article: http://www.plxtech.com/files/pdf/technical/expresslane/RTC_Enabling%20MulitHostSystemDesigns.pdf Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: David Woodhouse <David.Woodhouse@intel.com> Acked-by: Joerg Roedel <jroedel@suse.de>
2016-03-03 14:38:02 +00:00
ret = fn(pdev, PCI_DEVID(pdev->bus->number, devfn),
data);
if (ret)
return ret;
}
}
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 ret;
}
pci: do not mark exported functions as __devinit Functions marked __devinit will be removed after kernel init. But being exported they are potentially called by a module much later. So the safer choice seems to be to keep the function even in the non CONFIG_HOTPLUG case. This silence the follwoing section mismatch warnings: WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_device from __ksymtab_gpl between '__ksymtab_pci_bus_add_device' (at offset 0x20) and '__ksymtab_pci_walk_bus' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_create_bus from __ksymtab_gpl between '__ksymtab_pci_create_bus' (at offset 0x40) and '__ksymtab_pci_stop_bus_device' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_max_busnr from __ksymtab_gpl between '__ksymtab_pci_bus_max_busnr' (at offset 0xc0) and '__ksymtab_pci_assign_resource_fixed' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_claim_resource from __ksymtab_gpl between '__ksymtab_pci_claim_resource' (at offset 0xe0) and '__ksymtab_pcie_port_bus_type' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_devices from __ksymtab between '__ksymtab_pci_bus_add_devices' (at offset 0x70) and '__ksymtab_pci_bus_alloc_resource' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_scan_bus_parented from __ksymtab between '__ksymtab_pci_scan_bus_parented' (at offset 0x90) and '__ksymtab_pci_root_buses' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_assign_resources from __ksymtab between '__ksymtab_pci_bus_assign_resources' (at offset 0x4d0) and '__ksymtab_pci_bus_size_bridges' WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_size_bridges from __ksymtab between '__ksymtab_pci_bus_size_bridges' (at offset 0x4e0) and '__ksymtab_pci_setup_cardbus' Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-27 05:53:30 +00:00
static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr)
{
struct pci_bus *child;
struct pci_bus *tmp;
if (bus->number == busnr)
return bus;
list_for_each_entry(tmp, &bus->children, node) {
child = pci_do_find_bus(tmp, busnr);
if (child)
return child;
}
return NULL;
}
/**
* pci_find_bus - locate PCI bus from a given domain and bus number
* @domain: number of PCI domain to search
* @busnr: number of desired PCI bus
*
* Given a PCI bus number and domain number, the desired PCI bus is located
* 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 *bus = NULL;
struct pci_bus *tmp_bus;
while ((bus = pci_find_next_bus(bus)) != NULL) {
if (pci_domain_nr(bus) != domain)
continue;
tmp_bus = pci_do_find_bus(bus, busnr);
if (tmp_bus)
return tmp_bus;
}
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 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 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 = 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
* in case of multi-function devices.
*
* 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
* decrement the reference count by calling pci_dev_put().
* If no device is found, %NULL is returned.
*/
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) {
if (dev->devfn == devfn)
goto out;
}
dev = NULL;
out:
pci_dev_get(dev);
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
* @domain: PCI domain/segment on which the PCI device resides.
* @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 in case of
* multi-function devices.
*
* Given a PCI domain, 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 decrement the
* reference count by calling pci_dev_put(). If no device is found,
* %NULL is returned.
*/
struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
unsigned int devfn)
{
struct pci_dev *dev = NULL;
for_each_pci_dev(dev) {
if (pci_domain_nr(dev->bus) == domain &&
(dev->bus->number == bus && dev->devfn == devfn))
return dev;
}
return NULL;
}
EXPORT_SYMBOL(pci_get_domain_bus_and_slot);
bus_find_device: Unify the match callback with class_find_device There is an arbitrary difference between the prototypes of bus_find_device() and class_find_device() preventing their callers from passing the same pair of data and match() arguments to both of them, which is the const qualifier used in the prototype of class_find_device(). If that qualifier is also used in the bus_find_device() prototype, it will be possible to pass the same match() callback function to both bus_find_device() and class_find_device(), which will allow some optimizations to be made in order to avoid code duplication going forward. Also with that, constify the "data" parameter as it is passed as a const to the match function. For this reason, change the prototype of bus_find_device() to match the prototype of class_find_device() and adjust its callers to use the const qualifier in accordance with the new prototype of it. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Corey Minyard <minyard@acm.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Kershner <david.kershner@unisys.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: David Airlie <airlied@linux.ie> Cc: Felipe Balbi <balbi@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonathan Cameron <jic23@kernel.org> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: Len Brown <lenb@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Jamet <michael.jamet@intel.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Sebastian Ott <sebott@linux.ibm.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Cc: rafael@kernel.org Acked-by: Corey Minyard <minyard@acm.org> Acked-by: David Kershner <david.kershner@unisys.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-14 17:53:59 +00:00
static int match_pci_dev_by_id(struct device *dev, const void *data)
{
struct pci_dev *pdev = to_pci_dev(dev);
bus_find_device: Unify the match callback with class_find_device There is an arbitrary difference between the prototypes of bus_find_device() and class_find_device() preventing their callers from passing the same pair of data and match() arguments to both of them, which is the const qualifier used in the prototype of class_find_device(). If that qualifier is also used in the bus_find_device() prototype, it will be possible to pass the same match() callback function to both bus_find_device() and class_find_device(), which will allow some optimizations to be made in order to avoid code duplication going forward. Also with that, constify the "data" parameter as it is passed as a const to the match function. For this reason, change the prototype of bus_find_device() to match the prototype of class_find_device() and adjust its callers to use the const qualifier in accordance with the new prototype of it. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Corey Minyard <minyard@acm.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Kershner <david.kershner@unisys.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: David Airlie <airlied@linux.ie> Cc: Felipe Balbi <balbi@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonathan Cameron <jic23@kernel.org> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: Len Brown <lenb@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Jamet <michael.jamet@intel.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Sebastian Ott <sebott@linux.ibm.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Cc: rafael@kernel.org Acked-by: Corey Minyard <minyard@acm.org> Acked-by: David Kershner <david.kershner@unisys.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-14 17:53:59 +00:00
const struct pci_device_id *id = data;
if (pci_match_one_device(id, pdev))
return 1;
return 0;
}
/*
* pci_get_dev_by_id - begin or continue searching for a PCI device by id
* @id: pointer to struct pci_device_id to match for the device
* @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 id a pointer to its device structure is returned, and the
* reference count to the device is incremented. Otherwise, %NULL is returned.
* 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.
*
* This is an internal function for use by the other search functions in
* this file.
*/
static struct pci_dev *pci_get_dev_by_id(const struct pci_device_id *id,
struct pci_dev *from)
{
struct device *dev;
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;
}
/**
* 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
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
* @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 @vendor, @device, @ss_vendor and @ss_device, a pointer to its
* device structure is returned, and the reference count to the device is
* incremented. Otherwise, %NULL is returned. 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.
*/
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);
}
EXPORT_SYMBOL(pci_get_subsys);
/**
* pci_get_device - begin or continue searching for a PCI device by vendor/device id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @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 @vendor and @device, the reference count to the
* device is incremented and a pointer to its device structure is returned.
* Otherwise, %NULL is returned. 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.
*/
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);
/**
* pci_get_class - begin or continue searching for a PCI device by class
* @class: search for a PCI device with this class designation
* @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 @class, the reference count to the device is
* incremented and a pointer to its device structure is returned.
* Otherwise, %NULL is returned.
* 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.
*/
struct pci_dev *pci_get_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 = PCI_ANY_ID,
.class = class,
};
return pci_get_dev_by_id(&id, from);
}
EXPORT_SYMBOL(pci_get_class);
/**
* pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
* @ids: A pointer to a null terminated list of struct pci_device_id structures
* that describe the type of PCI device the caller is trying to find.
*
* Obvious fact: You do not have a reference to any device that might be found
* by this function, so if that device is removed from the system right after
* this function is finished, the value will be stale. Use this function to
* find devices that are usually built into a system, or for a general hint as
* to if another device happens to be present at this specific moment in time.
*/
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) {
pci_dev_put(found);
return 1;
}
ids++;
}
return 0;
}
EXPORT_SYMBOL(pci_dev_present);