summaryrefslogtreecommitdiffstats
path: root/Documentation/PCI/MSI-HOWTO.txt
Commit message (Collapse)AuthorAgeFilesLines
* PCI/MSI: Remove pci_enable_msi_{exact,range}()Christoph Hellwig2017-01-131-4/+2
| | | | | | | | All multi-MSI allocations are now done through pci_irq_alloc_vectors(), so remove the old pci_enable_msi_range() and pci_enable_msi_exact() interfaces. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* PCI: Use positive flags in pci_alloc_irq_vectors()Christoph Hellwig2016-08-161-14/+10
| | | | | | | | | | | | | | | | | | Instead of passing negative flags like PCI_IRQ_NOMSI to prevent use of certain interrupt types, pass positive flags like PCI_IRQ_LEGACY, PCI_IRQ_MSI, etc., to specify the acceptable interrupt types. This is based on a number of pending driver conversions that just happend to be a whole more obvious to read this way, and given that we have no users in the tree yet it can still easily be done. I've also added a PCI_IRQ_ALL_TYPES catchall to keep the case of accepting all interrupt types very simple. [bhelgaas: changelog, fix PCI_IRQ_AFFINITY doc typo, remove mention of PCI_IRQ_NOLEGACY] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alexander Gordeev <agordeev@redhat.com>
* PCI: Spread interrupt vectors in pci_alloc_irq_vectors()Christoph Hellwig2016-07-211-0/+4
| | | | | | | | | | | | | | | | | | Set the affinity_mask in the PCI device before allocating vectors so that the affinity can be propagated through the MSI descriptor structures to the core IRQ code. To facilitate this, new __pci_enable_msi_range() and __pci_enable_msix_range() helpers are factored out of their not prefixed variants which assigning the new IRQ affinity mask in the PCI device so that the low-level interrupt code can perform the interrupt affinity assignment and do node-local allocations. A new PCI_IRQ_NOAFFINITY flag is added to pci_alloc_irq_vectors() so that this function can also be used by drivers that don't wish to use the automatic affinity assignment. [bhelgaas: omit "else" after "return" consistently] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alexander Gordeev <agordeev@redhat.com>
* PCI: Provide sensible IRQ vector alloc/free routinesChristoph Hellwig2016-07-211-391/+76
| | | | | | | | | | | | | Add a function to allocate and free a range of interrupt vectors, using MSI-X, MSI or legacy vectors (in that order) based on the capabilities of the underlying device and PCIe complex. Additionally a new helper is provided to get the Linux IRQ number for given device-relative vector so that the drivers don't need to allocate their own arrays to keep track of the vectors for the multi vector MSI-X case. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alexander Gordeev <agordeev@redhat.com>
* doc:pci: Fix typo in Documentation/PCIMasanari Iida2015-03-201-3/+3
| | | | | | | This patch fix spelling typo in Documentation/PCI. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* MSI-HOWTO.txt: remove reference on IRQF_DISABLEDValentin Rothberg2015-03-201-12/+3
| | | | | | | | | | | | | | | | The IRQF_DISABLED is a NOOP and scheduled to be removed. According to Ingo Molnar in commit e58aa3d2d0cc01ad8d6f7f640a0670433f794922 (genirq: Run irq handlers with interrupts disabled), running IRQ handlers with interrupts enabled can cause stack overflows when the interrupt line of the issuing device is still active. This patch removes IRQF_DISABLED from this documentation. It was mentioned to be a solution to avoid deadlocks when a device uses multiple interrupts. As the flag is a NOOP this solution does not work anymore. Signed-off-by: Valentin Rothberg <Valentin.Rothberg@lip6.fr> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* doc: replace "practise" with "practice" in DocumentationJeremiah Mahler2014-06-191-1/+1
| | | | | | | | | | | | | | | | | | | | To keep the Documentation consistent either "practise" or "practice" should be used. Since there are 3 lines with "practise" ~/linux/Documentation$ grep -r practise * | wc -l 3 and 108 lines with "practice" ~/linux/Documentation$ grep -r practice * | wc -l 108 this patch converts "practise" to "practice". Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* PCI/MSI: Add pci_enable_msi_exact() and pci_enable_msix_exact()Alexander Gordeev2014-02-131-2/+84
| | | | | | | | | | | | | | The new functions are special cases for pci_enable_msi_range() and pci_enable_msix_range() when a particular number of MSI or MSI-X is needed. By contrast with pci_enable_msi_range() and pci_enable_msix_range() functions, pci_enable_msi_exact() and pci_enable_msix_exact() return zero in case of success, which indicates MSI or MSI-X interrupts have been successfully allocated. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* PCI/MSI: Fix cut-and-paste errors in documentationAlexander Gordeev2014-02-131-6/+6
| | | | | | | | | Function pci_enable_msi_range() is used in examples where pci_enable_msix_range() should have been used instead. Reported-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* PCI/MSI: Add pci_enable_msi() documentation backAlexander Gordeev2014-02-131-3/+20
| | | | | | | | | | | | | | | | | | | We deprecated pci_enable_msi() in 302a2523c277 ("PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()"). But we changed our minds after noticing that: - pci_enable_msi() doesn't have confusing return values like pci_enable_msi_block() and pci_enable_msix() did, and - pci_enable_msi() has a hundred or so callers that we don't want to change. This adds back the pci_enable_msi() documentation. [bhelgaas: changelog] Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()Alexander Gordeev2014-01-031-75/+186
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds pci_enable_msi_range(), which supersedes the pci_enable_msi() and pci_enable_msi_block() MSI interfaces. It also adds pci_enable_msix_range(), which supersedes the pci_enable_msix() MSI-X interface. The old interfaces have three categories of return values: negative: failure; caller should not retry positive: failure; value indicates number of interrupts that *could* have been allocated, and caller may retry with a smaller request zero: success; at least as many interrupts allocated as requested It is error-prone to handle these three cases correctly in drivers. The new functions return either a negative error code or a number of successfully allocated MSI/MSI-X interrupts, which is expected to lead to clearer device driver code. pci_enable_msi(), pci_enable_msi_block() and pci_enable_msix() still exist unchanged, but are deprecated and may be removed after callers are updated. [bhelgaas: tweak changelog] Suggested-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Tejun Heo <tj@kernel.org>
* PCI/MSI: Add pci_msix_vec_count()Alexander Gordeev2014-01-031-0/+13
| | | | | | | | | | | | | | | | | This creates an MSI-X counterpart for pci_msi_vec_count(). Device drivers can use this function to obtain maximum number of MSI-X interrupts the device supports and use that number in a subsequent call to pci_enable_msix(). pci_msix_vec_count() supersedes pci_msix_table_size() and returns a negative errno if device does not support MSI-X interrupts. After this update, callers must always check the returned value. The only user of pci_msix_table_size() was the PCI-Express port driver, which is also updated by this change. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Tejun Heo <tj@kernel.org>
* PCI/MSI: Remove pci_enable_msi_block_auto()Alexander Gordeev2014-01-031-33/+6
| | | | | | | | | | | | | | The new pci_msi_vec_count() interface makes pci_enable_msi_block_auto() superfluous. Drivers can use pci_msi_vec_count() to learn the maximum number of MSIs supported by the device, and then call pci_enable_msi_block(). pci_enable_msi_block_auto() was introduced recently, and its only user is the AHCI driver, which is also updated by this change. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Tejun Heo <tj@kernel.org>
* PCI/MSI: Add pci_msi_vec_count()Alexander Gordeev2014-01-031-0/+15
| | | | | | | | | Device drivers can use this interface to obtain the maximum number of MSI interrupts the device supports and use that number, e.g., in a subsequent call to pci_enable_msi_block(). Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Tejun Heo <tj@kernel.org>
* PCI/MSI: Make pci_enable_msi/msix() 'nvec' argument type as intAlexander Gordeev2013-12-201-1/+1
| | | | | | | | Make pci_enable_msi_block(), pci_enable_msi_block_auto() and pci_enable_msix() consistent with regard to the type of 'nvec' argument. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Tejun Heo <tj@kernel.org>
* PCI/MSI: Enable multiple MSIs with pci_enable_msi_block_auto()Alexander Gordeev2013-01-241-5/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | The new function pci_enable_msi_block_auto() tries to allocate maximum possible number of MSIs up to the number the device supports. It generalizes a pattern when pci_enable_msi_block() is contiguously called until it succeeds or fails. Opposite to pci_enable_msi_block() which takes the number of MSIs to allocate as a input parameter, pci_enable_msi_block_auto() could be used by device drivers to obtain the number of assigned MSIs and the number of MSIs the device supports. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c3de2419df94a0f95ca1a6f755afc421486455e6.1353324359.git.agordeev@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Docs: MSI-HOWTO: MSI -> MSIsMichael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Insert a commaMichael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: can -> couldMichael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Use `unknown ...' rather than `... know about.'Michael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: may -> mightMichael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Insert a commaMichael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: API -> functionMichael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: , -> ;Michael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Move a sentence to another paragraphMichael Witten2011-08-021-4/+3
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Insert `that'Michael Witten2011-08-021-1/+1
| | | | | | | | | ... as per Randy Dunlap's wishes :-P Message-Id: <20110717114023.2b4cce91.rdunlap@xenotime.net> Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Offset modifier with a comma, and insert `yet' for emphasisMichael Witten2011-08-021-3/+3
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Put the `because' subordinate clause firstMichael Witten2011-08-021-4/+4
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Streamline some wordingMichael Witten2011-08-021-2/+2
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: `asked for' -> `requested'Michael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Use present tense and streamline some wordingMichael Witten2011-08-021-22/+22
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Docs: MSI-HOWTO: Use the subjunctive, and change `can' to `may'Michael Witten2011-08-021-1/+1
| | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Acked-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
* Fix common misspellingsLucas De Marchi2011-03-311-2/+2
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* PCI MSI: Add example request loop to MSI-HOWTO.txtMichael Ellerman2009-03-201-1/+22
| | | | | | | | | | Encourage driver writers to think about supporting a variable number of MSI-X interrupts, and give an example of how to do such a request. Acked-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* PCI MSI: Add support for multiple MSIMatthew Wilcox2009-03-201-6/+39
| | | | | | | | | | Add the new API pci_enable_msi_block() to allow drivers to request multiple MSI and reimplement pci_enable_msi in terms of pci_enable_msi_block. Ensure that the architecture back ends don't have to know about multiple MSI. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* Rewrite MSI-HOWTOMatthew Wilcox2009-03-201-481/+277
| | | | | | | | | I didn't find the previous version very useful, so I rewrote it. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com> Reviewed-by: Grant Grundler <grundler@parisc-linunx.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* Create/use more directory structure in the Documentation/ tree.Randy Dunlap2008-11-141-0/+509
Create Documentation/blockdev/ sub-directory and populate it. Populate the Documentation/serial/ sub-directory. Move MSI-HOWTO.txt to Documentation/PCI/. Move ioctl-number.txt to Documentation/ioctl/. Update all relevant 00-INDEX files. Update all relevant Kconfig files and source files. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-05 00:30:56 +0000