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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAlexander Gordeev <agordeev@redhat.com>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAlexander Gordeev <agordeev@redhat.com>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAlexander Gordeev <agordeev@redhat.com>

This patch fix spelling typo in Documentation/PCI.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The IRQF_DISABLED is a NOOP and scheduled to be removed.  According to Ingo
Molnar in commit e58aa3d2 (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: NValentin Rothberg <Valentin.Rothberg@lip6.fr>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

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: NJeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Function pci_enable_msi_range() is used in examples where
pci_enable_msix_range() should have been used instead.
Reported-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

We deprecated pci_enable_msi() in 302a2523 ("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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Function pci_enable_msi_range() is used in examples where
pci_enable_msix_range() should have been used instead.
Reported-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

We deprecated pci_enable_msi() in 302a2523 ("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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

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: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NTejun Heo <tj@kernel.org>

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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NTejun Heo <tj@kernel.org>

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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NTejun Heo <tj@kernel.org>

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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NTejun Heo <tj@kernel.org>

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: NAlexander Gordeev <agordeev@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NTejun Heo <tj@kernel.org>

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: NAlexander Gordeev <agordeev@redhat.com>
Acked-by: NBjorn 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.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

... as per Randy Dunlap's wishes :-P
Message-Id: <20110717114023.2b4cce91.rdunlap@xenotime.net>
Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Signed-off-by: NMichael Witten <mfwitten@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

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: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

I didn't find the previous version very useful, so I rewrote it.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Reviewed-by: NRandy Dunlap <randy.dunlap@oracle.com>
Reviewed-by: NGrant Grundler <grundler@parisc-linunx.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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: NRandy Dunlap <randy.dunlap@oracle.com>

The current MSI-HOWTO.txt says that device drivers should not request the
memory space that contains MSI-X tables.  This is because the original
MSI-X implementation did a request_mem_region() on this space, but that
code was removed long ago (in the pre-git era, in fact).  Years after the
code was changed, we might as well clean up the documention to avoid a
confusing mention of requesting regions: drivers using MSI-X can just use
pci_request_regions() just like any other driver, and so there's no need
for MSI-HOWTO.txt to talk about this at all.
Signed-off-by: NRoland Dreier <roland@digitalvampire.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>