linux-toradex.git/Documentation/PCI, branch v3.14.3

PCI/MSI: Add pci_enable_msi_exact() and pci_enable_msix_exact()

2014-02-13T17:48:02+00:00

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 
Signed-off-by: Bjorn Helgaas

PCI/MSI: Fix cut-and-paste errors in documentation

2014-02-13T17:47:56+00:00

Function pci_enable_msi_range() is used in examples where
pci_enable_msix_range() should have been used instead.

Reported-by: Bjorn Helgaas 
Signed-off-by: Alexander Gordeev 
Signed-off-by: Bjorn Helgaas

PCI/MSI: Add pci_enable_msi() documentation back

2014-02-13T17:47:51+00:00

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 
Signed-off-by: Bjorn Helgaas

Merge branch 'pci/msi' into next

2014-01-08T00:34:39+00:00

* pci/msi:
  PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()
  PCI/MSI: Add pci_msix_vec_count()
  PCI/MSI: Remove pci_enable_msi_block_auto()
  PCI/MSI: Add pci_msi_vec_count()

Merge branch 'pci/misc' into next

2014-01-08T00:34:33+00:00

* pci/misc:
  PCI: Update documentation 00-INDEX file
  PCI: Convert ioapic to be builtin only, not modular

PCI: Update documentation 00-INDEX file

2014-01-07T23:37:15+00:00

The PCI-DMA-mapping.txt moved to general docs and became DMA-API-HOWTO.txt
in 5e07c2c7301b ("Documentation: rename PCI/PCI-DMA-mapping.txt to
DMA-API-HOWTO.txt").  Add new file about PCI Express I/O Virtualization.

Signed-off-by: Erik Ekman 
Signed-off-by: Bjorn Helgaas

PCI/MSI: Add pci_enable_msi_range() and pci_enable_msix_range()

2014-01-04T00:17:55+00:00

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 
Signed-off-by: Alexander Gordeev 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Tejun Heo

PCI/MSI: Add pci_msix_vec_count()

2014-01-04T00:17:55+00:00

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 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Tejun Heo

PCI/MSI: Remove pci_enable_msi_block_auto()

2014-01-04T00:17:55+00:00

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 
Signed-off-by: Bjorn Helgaas 
Acked-by: Tejun Heo

PCI/MSI: Add pci_msi_vec_count()

2014-01-04T00:17:55+00:00

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 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Tejun Heo