freebsd-nq/sys/dev/pci/pcib_if.m

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#-
# 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>
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#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 {
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device_t pcib;
device_t dev;
int pin;
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} DEFAULT null_route_interrupt;
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
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#
# 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;
};
Expand the MSI/MSI-X API to address some deficiencies in the MSI-X support. - First off, device drivers really do need to know if they are allocating MSI or MSI-X messages. MSI requires allocating powerof2() messages for example where MSI-X does not. To address this, split out the MSI-X support from pci_msi_count() and pci_alloc_msi() into new driver-visible functions pci_msix_count() and pci_alloc_msix(). As a result, pci_msi_count() now just returns a count of the max supported MSI messages for the device, and pci_alloc_msi() only tries to allocate MSI messages. To get a count of the max supported MSI-X messages, use pci_msix_count(). To allocate MSI-X messages, use pci_alloc_msix(). pci_release_msi() still handles both MSI and MSI-X messages, however. As a result of this change, drivers using the existing API will only use MSI messages and will no longer try to use MSI-X messages. - Because MSI-X allows for each message to have its own data and address values (and thus does not require all of the messages to have their MD vectors allocated as a group), some devices allow for "sparse" use of MSI-X message slots. For example, if a device supports 8 messages but the OS is only able to allocate 2 messages, the device may make the best use of 2 IRQs if it enables the messages at slots 1 and 4 rather than default of using the first N slots (or indicies) at 1 and 2. To support this, add a new pci_remap_msix() function that a driver may call after a successful pci_alloc_msix() (but before allocating any of the SYS_RES_IRQ resources) to allow the allocated IRQ resources to be assigned to different message indices. For example, from the earlier example, after pci_alloc_msix() returned a value of 2, the driver would call pci_remap_msix() passing in array of integers { 1, 4 } as the new message indices to use. The rid's for the SYS_RES_IRQ resources will always match the message indices. Thus, after the call to pci_remap_msix() the driver would be able to access the first message in slot 1 at SYS_RES_IRQ rid 1, and the second message at slot 4 at SYS_RES_IRQ rid 4. Note that the message slots/indices are 1-based rather than 0-based so that they will always correspond to the rid values (SYS_RES_IRQ rid 0 is reserved for the legacy INTx interrupt). To support this API, a new PCIB_REMAP_MSIX() method was added to the pcib interface to change the message index for a single IRQ. Tested by: scottl
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#
# Remap a single MSI-X message to a different index.
#
METHOD int remap_msix {
device_t pcib;
device_t dev;
int index;
int irq;
};
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
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#
# Release a single MSI-X message mapped onto 'irq'.
#
METHOD int release_msix {
device_t pcib;
device_t dev;
int irq;
};