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2014-02-13PCI/MSI: Add pci_enable_msi_exact() and pci_enable_msix_exact()Alexander Gordeev
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>
2014-02-13PCI/MSI: Fix cut-and-paste errors in documentationAlexander Gordeev
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>
2014-02-13PCI/MSI: Add pci_enable_msi() documentation backAlexander Gordeev
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>
2014-01-03PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()Alexander Gordeev
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>
2014-01-03PCI/MSI: Add pci_msix_vec_count()Alexander Gordeev
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>
2014-01-03PCI/MSI: Remove pci_enable_msi_block_auto()Alexander Gordeev
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>
2014-01-03PCI/MSI: Add pci_msi_vec_count()Alexander Gordeev
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>
2013-12-20PCI/MSI: Make pci_enable_msi/msix() 'nvec' argument type as intAlexander Gordeev
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>
2013-01-24PCI/MSI: Enable multiple MSIs with pci_enable_msi_block_auto()Alexander Gordeev
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>
2011-08-02Docs: MSI-HOWTO: MSI -> MSIsMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: Insert a commaMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: can -> couldMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: Use `unknown ...' rather than `... know about.'Michael Witten
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>
2011-08-02Docs: MSI-HOWTO: may -> mightMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: Insert a commaMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: API -> functionMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: , -> ;Michael Witten
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>
2011-08-02Docs: MSI-HOWTO: Move a sentence to another paragraphMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: Insert `that'Michael Witten
... 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>
2011-08-02Docs: MSI-HOWTO: Offset modifier with a comma, and insert `yet' for emphasisMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: Put the `because' subordinate clause firstMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: Streamline some wordingMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: `asked for' -> `requested'Michael Witten
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>
2011-08-02Docs: MSI-HOWTO: Use present tense and streamline some wordingMichael Witten
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>
2011-08-02Docs: MSI-HOWTO: Use the subjunctive, and change `can' to `may'Michael Witten
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>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2009-03-20PCI MSI: Add example request loop to MSI-HOWTO.txtMichael Ellerman
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>
2009-03-20PCI MSI: Add support for multiple MSIMatthew Wilcox
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>
2009-03-20Rewrite MSI-HOWTOMatthew Wilcox
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>
2008-11-14Create/use more directory structure in the Documentation/ tree.Randy Dunlap
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>
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