First cut at MI support for PCI Message Signalled Interrupts (MSI):

- Add 3 new functions to the pci_if interface along with suitable wrappers
  to provide the device driver visible API:
  - pci_alloc_msi(dev, int *count) backed by PCI_ALLOC_MSI().  '*count'
    here is an in and out parameter.  The driver stores the desired number
    of messages in '*count' before calling the function.  On success,
    '*count' holds the number of messages allocated to the device.  Also on
    success, the driver can access the messages as SYS_RES_IRQ resources
    starting at rid 1.  Note that the legacy INTx interrupt resource will
    not be available when using MSI.  Note that this function will allocate
    either MSI or MSI-X messages depending on the devices capabilities and
    the 'hw.pci.enable_msix' and 'hw.pci.enable_msi' tunables.  Also note
    that the driver should activate the memory resource that holds the
    MSI-X table and pending bit array (PBA) before calling this function
    if the device supports MSI-X.
  - pci_release_msi(dev) backed by PCI_RELEASE_MSI().  This function
    releases the messages allocated for this device.  All of the
    SYS_RES_IRQ resources need to be released for this function to succeed.
  - pci_msi_count(dev) backed by PCI_MSI_COUNT().  This function returns
    the maximum number of MSI or MSI-X messages supported by this device.
    MSI-X is preferred if present, but this function will honor the
    'hw.pci.enable_msix' and 'hw.pci.enable_msi' tunables.  This function
    should return the largest value that pci_alloc_msi() can return
    (assuming the MD code is able to allocate sufficient backing resources
    for all of the messages).
- Add default implementations for these 3 methods to the pci_driver generic
  PCI bus driver.  (The various other PCI bus drivers such as for ACPI and
  OFW will inherit these default implementations.)  This default
  implementation depends on 4 new pcib_if methods that bubble up through
  the PCI bridges to the MD code to allocate IRQ values and perform any
  needed MD setup code needed:
  - PCIB_ALLOC_MSI() attempts to allocate a group of MSI messages.
  - PCIB_RELEASE_MSI() releases a group of MSI messages.
  - PCIB_ALLOC_MSIX() attempts to allocate a single MSI-X message.
  - PCIB_RELEASE_MSIX() releases a single MSI-X message.
- Add default implementations for these 4 methods that just pass the
  request up to the parent bus's parent bridge driver and use the
  default implementation in the various MI PCI bridge drivers.
- Add MI functions for use by MD code when managing MSI and MSI-X
  interrupts:
  - pci_enable_msi(dev, address, data) programs the MSI capability address
    and data registers for a group of MSI messages
  - pci_enable_msix(dev, index, address, data) initializes a single MSI-X
    message in the MSI-X table
  - pci_mask_msix(dev, index) masks a single MSI-X message
  - pci_unmask_msix(dev, index) unmasks a single MSI-X message
  - pci_pending_msix(dev, index) returns true if the specified MSI-X
    message is currently pending
- Save the MSI capability address and data registers in the pci_cfgreg
  block in a PCI devices ivars and restore the values when a device is
  resumed.  Note that the MSI-X table is not currently restored during
  resume.
- Add constants for MSI-X register offsets and fields.
- Record interesting data about any MSI-X capability blocks we come
  across in the pci_cfgreg block in the ivars for PCI devices.

Tested on:	em (i386, MSI), bce (amd64/i386, MSI), mpt (amd64, MSI-X)
Reviewed by:	scottl, grehan, jfv
MFC after:	2 months

0 files changed, 0 insertions, 0 deletions