Commit Graph

30 Commits

Author SHA1 Message Date
Alexander Gordeev 3ce4e860e5 PCI/MSI: Add pci_enable_msi_exact() and pci_enable_msix_exact()
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>
2014-02-13 10:48:02 -07:00
Alexander Gordeev 13f9653dab PCI/MSI: Fix cut-and-paste errors in documentation
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>
2014-02-13 10:47:56 -07:00
Alexander Gordeev 7918b2dc66 PCI/MSI: Add pci_enable_msi() documentation back
We deprecated pci_enable_msi() in 302a2523c2 ("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>
2014-02-13 10:47:51 -07:00
Alexander Gordeev 302a2523c2 PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()
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>
2014-01-03 17:17:55 -07:00
Alexander Gordeev ff1aa430a2 PCI/MSI: Add pci_msix_vec_count()
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>
2014-01-03 17:17:55 -07:00
Alexander Gordeev 7b92b4f61e PCI/MSI: Remove pci_enable_msi_block_auto()
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>
2014-01-03 17:17:55 -07:00
Alexander Gordeev d1ac1d2622 PCI/MSI: Add pci_msi_vec_count()
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>
2014-01-03 17:17:55 -07:00
Alexander Gordeev 52179dc9ed PCI/MSI: Make pci_enable_msi/msix() 'nvec' argument type as int
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>
2013-12-20 09:45:05 -07:00
Alexander Gordeev 08261d87f7 PCI/MSI: Enable multiple MSIs with pci_enable_msi_block_auto()
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>
2013-01-24 17:25:13 +01:00
Michael Witten 798c794df8 Docs: MSI-HOWTO: MSI -> MSIs
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>
2011-08-02 21:34:41 +00:00
Michael Witten c2b65e181a Docs: MSI-HOWTO: Insert a comma
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>
2011-08-02 21:34:40 +00:00
Michael Witten 1b8386f612 Docs: MSI-HOWTO: can -> could
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>
2011-08-02 21:34:39 +00:00
Michael Witten e6b85a1f8a Docs: MSI-HOWTO: Use `unknown ...' rather than `... know about.'
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>
2011-08-02 21:34:39 +00:00
Michael Witten 952df55b5a Docs: MSI-HOWTO: may -> might
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>
2011-08-02 21:34:37 +00:00
Michael Witten e14bd7e614 Docs: MSI-HOWTO: Insert a comma
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>
2011-08-02 21:34:37 +00:00
Michael Witten e6ffceb0de Docs: MSI-HOWTO: API -> function
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>
2011-08-02 21:34:36 +00:00
Michael Witten 5a84fc3162 Docs: MSI-HOWTO: , -> ;
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>
2011-08-02 21:34:36 +00:00
Michael Witten 6457d9b350 Docs: MSI-HOWTO: Move a sentence to another paragraph
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>
2011-08-02 21:34:35 +00:00
Michael Witten ed737c1882 Docs: MSI-HOWTO: Insert `that'
... 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>
2011-08-02 21:34:34 +00:00
Michael Witten e4439236ef Docs: MSI-HOWTO: Offset modifier with a comma, and insert `yet' for emphasis
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>
2011-08-02 21:34:33 +00:00
Michael Witten 263d8d57b3 Docs: MSI-HOWTO: Put the `because' subordinate clause first
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>
2011-08-02 21:34:32 +00:00
Michael Witten 1d15afcc73 Docs: MSI-HOWTO: Streamline some wording
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>
2011-08-02 21:34:32 +00:00
Michael Witten a2d4d50128 Docs: MSI-HOWTO: `asked for' -> `requested'
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>
2011-08-02 21:34:31 +00:00
Michael Witten 4979de6efb Docs: MSI-HOWTO: Use present tense and streamline some wording
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>
2011-08-02 21:34:31 +00:00
Michael Witten 891f692533 Docs: MSI-HOWTO: Use the subjunctive, and change `can' to `may'
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>
2011-08-02 21:34:30 +00:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Michael Ellerman fafad5bf06 PCI MSI: Add example request loop to MSI-HOWTO.txt
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>
2009-03-20 11:35:04 -07:00
Matthew Wilcox 1c8d7b0a56 PCI MSI: Add support for multiple MSI
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>
2009-03-20 10:48:14 -07:00
Matthew Wilcox c41ade2ee1 Rewrite MSI-HOWTO
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>
2009-03-20 10:48:11 -07:00
Randy Dunlap 31c00fc15e Create/use more directory structure in the Documentation/ tree.
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>
2008-11-14 17:28:53 +00:00