svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
ahci(4)
AHCI(4) BSD Kernel Interfaces Manual AHCI(4)
NAME
ahci — Serial ATA Advanced Host Controller Interface driver
SYNOPSIS
To compile this driver into the kernel, place the following lines in your
kernel configuration file:
device pci
device scbus
device ahci
Alternatively, to load the driver as a module at boot time, place the
following line in loader.conf(5):
ahci_load="YES"
The following tunables are settable from the loader(8):
hint.ahci.X.msi
controls Message Signaled Interrupts (MSI) usage by the specified con‐
troller.
0 MSI disabled;
1 single MSI vector used, if supported;
2 multiple MSI vectors used, if supported (default);
hint.ahci.X.ccc
controls Command Completion Coalescing (CCC) usage by the specified con‐
troller. Non-zero value enables CCC and defines maximum time (in ms),
request can wait for interrupt, if there are some more requests present
on controller queue. CCC reduces number of context switches on systems
with many parallel requests, but it can decrease disk performance on some
workloads due to additional command latency.
hint.ahci.X.direct
controls whether the driver should use direct command completion from
interrupt thread(s), or queue them to CAM completion threads. Default
value depends on number of MSI interrupts supported and number of imple‐
mented SATA ports.
hint.ahcich.X.pm_level
controls SATA interface Power Management for the specified channel,
allowing some power to be saved at the cost of additional command
latency. Possible values:
0 interface Power Management is disabled (default);
1 device is allowed to initiate PM state change, host is pas‐
sive;
2 host initiates PARTIAL PM state transition every time port
becomes idle;
3 host initiates SLUMBER PM state transition every time port
becomes idle.
4 driver initiates PARTIAL PM state transition 1ms after port
becomes idle;
5 driver initiates SLUMBER PM state transition 125ms after port
becomes idle.
Some controllers, such as ICH8, do not implement modes 2 and 3 with NCQ
used. Because of artificial entering latency, performance degradation in
modes 4 and 5 is much smaller then in modes 2 and 3.
Note that interface Power Management complicates device presence detec‐
tion. A manual bus reset/rescan may be needed after device hot-plug,
unless hardware implements Cold Presence Detection.
hint.ahcich.X.sata_rev
setting to nonzero value limits maximum SATA revision (speed). Values 1,
2 and 3 are respectively 1.5, 3 and 6Gbps.
hw.ahci.force
setting to nonzero value forces driver attach to some known AHCI-capable
chips even if they are configured for legacy IDE emulation. Default is
1.
DESCRIPTION
This driver provides the CAM(4) subsystem with native access to the SATA
ports of AHCI-compatible controllers. Each SATA port found is repre‐
sented to CAM as a separate bus with one target, or, if HBA supports Port
Multipliers, 16 targets. Most of the bus-management details are handled
by the SATA-specific transport of CAM. Connected ATA disks are handled
by the ATA protocol disk peripheral driver ada(4). ATAPI devices are
handled by the SCSI protocol peripheral drivers cd(4), da(4), sa(4), etc.
Driver features include support for Serial ATA and ATAPI devices, Port
Multipliers (including FIS-based switching, when supported), hardware
command queues (up to 32 commands per port), Native Command Queuing, SATA
interface Power Management, device hot-plug and Message Signaled Inter‐
rupts.
Driver supports "LED" enclosure management messages, defined by the AHCI.
When supported by hardware, it allows to control per-port activity,
locate and fault LEDs via the led(4) API or emulated ses(4) device for
localization and status reporting purposes. Supporting AHCI controllers
may transmit that information to the backplane controllers via SGPIO
interface. Backplane controllers interpret received statuses in some way
(IBPI standard) to report them using present indicators.
HARDWARE
The ahci driver supports AHCI compatible controllers having PCI class 1
(mass storage), subclass 6 (SATA) and programming interface 1 (AHCI).
Also, in cooperation with atamarvell and atajmicron drivers of ata(4), it
supports AHCI part of legacy-PATA + AHCI-SATA combined controllers, such
as JMicron JMB36x and Marvell 88SE61xx.
FILES
/dev/led/ahci*.*.act activity LED device nodes
/dev/led/ahci*.*.fault fault LED device nodes
/dev/led/ahci*.*.locate locate LED device nodes
SEE ALSO
ada(4), ata(4), cam(4), cd(4), da(4), sa(4), ses(4)
HISTORY
The ahci driver first appeared in FreeBSD 8.0.
AUTHORS
Alexander Motin <mav@FreeBSD.org>
BSD October 22, 2013 BSD