freebsd-skq/sys/dev/pci/pcib_if.m
John Baldwin 9bf4c9c1b0 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
2006-11-13 21:47:30 +00:00

136 lines
3.6 KiB
Objective-C

#-
# Copyright (c) 2000 Doug Rabson
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
#
#include <sys/bus.h>
#include <dev/pci/pcivar.h>
INTERFACE pcib;
CODE {
static int
null_route_interrupt(device_t pcib, device_t dev, int pin)
{
return (PCI_INVALID_IRQ);
}
};
#
# Return the number of slots on the attached PCI bus.
#
METHOD int maxslots {
device_t dev;
};
#
# Read configuration space on the PCI bus. The bus, slot and func
# arguments determine the device which is being read and the reg
# argument is a byte offset into configuration space for that
# device. The width argument (which should be 1, 2 or 4) specifies how
# many byte of configuration space to read from that offset.
#
METHOD u_int32_t read_config {
device_t dev;
u_int bus;
u_int slot;
u_int func;
u_int reg;
int width;
};
#
# Write configuration space on the PCI bus. The bus, slot and func
# arguments determine the device which is being written and the reg
# argument is a byte offset into configuration space for that
# device. The value field is written to the configuration space, with
# the number of bytes written depending on the width argument.
#
METHOD void write_config {
device_t dev;
u_int bus;
u_int slot;
u_int func;
u_int reg;
u_int32_t value;
int width;
};
#
# Route an interrupt. Returns a value suitable for stuffing into
# a device's interrupt register.
#
METHOD int route_interrupt {
device_t pcib;
device_t dev;
int pin;
} DEFAULT null_route_interrupt;
#
# Allocate 'count' MSI messsages mapped onto 'count' IRQs. 'irq' points
# to an array of at least 'count' ints. The max number of messages this
# device supports is included so that the MD code can take that into
# account when assigning resources so that the proper number of low bits
# are clear in the resulting message data value.
#
METHOD int alloc_msi {
device_t pcib;
device_t dev;
int count;
int maxcount;
int *irqs;
};
#
# Release 'count' MSI message mapped onto 'count' IRQs stored in the
# array pointed to by 'irq'.
#
METHOD int release_msi {
device_t pcib;
device_t dev;
int count;
int *irqs;
};
#
# Allocate a single MSI-X message mapped onto '*irq'.
#
METHOD int alloc_msix {
device_t pcib;
device_t dev;
int index;
int *irq;
};
#
# Release a single MSI-X message mapped onto 'irq'.
#
METHOD int release_msix {
device_t pcib;
device_t dev;
int irq;
};