Commit Graph

33 Commits

Author SHA1 Message Date
Masanari Iida 654d2e7cd1 doc:pci: Fix typo in Documentation/PCI
This patch fix spelling typo in Documentation/PCI.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-03-20 07:41:56 -06:00
Valentin Rothberg 2f9d7389b5 MSI-HOWTO.txt: remove reference on IRQF_DISABLED
The IRQF_DISABLED is a NOOP and scheduled to be removed.  According to Ingo
Molnar in commit e58aa3d2d0 (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>
2015-03-20 07:41:55 -06:00
Jeremiah Mahler 305af08c53 doc: replace "practise" with "practice" in Documentation
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>
2014-06-19 15:28:56 +02:00
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