1.\" Copyright (c) 2009 Alexander Motin <mav@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. The name of the author may not be used to endorse or promote products 13.\" derived from this software without specific prior written permission. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd June 26, 2009 29.Dt AHCI 4 30.Os 31.Sh NAME 32.Nm ahci 33.Nd Serial ATA Advanced Host Controller Interface driver 34.Sh SYNOPSIS 35To compile this driver into the kernel, 36place the following lines in your 37kernel configuration file: 38.Bd -ragged -offset indent 39.Cd "device pci" 40.Cd "device scbus" 41.Cd "device ahci" 42.Ed 43.Pp 44Alternatively, to load the driver as a 45module at boot time, place the following line in 46.Xr loader.conf 5 : 47.Bd -literal -offset indent 48ahci_load="YES" 49.Ed 50.Pp 51The following tunables are settable from the loader: 52.Bl -ohang 53.It Va hint.ahci.X.msi 54controls Message Signaled Interrupts (MSI) usage by the specified controller 55.Bl -tag -compact 56.It 0 57MSI disabled; 58.It 1 59single MSI vector used, if supported (default); 60.It 2 61multiple MSI vectors used, if supported; 62.El 63.It Va hint.ahcich.X.pm_level 64controls SATA interface Power Management for specified channel, 65allowing some power to be saved at the cost of additional command 66latency. 67Possible values: 68.Bl -tag -compact 69.It 0 70interface Power Management is disabled (default); 71.It 1 72device is allowed to initiate PM state change, host is passive; 73.It 2 74host initiates PARTIAL PM state transition every time port becomes idle; 75.It 3 76host initiates SLUMBER PM state transition every time port becomes idle. 77.El 78Note that interface Power Management is not compatible with 79device presence detection. 80You will have to reset bus manually on device hot-plug. 81.It Va hint.ahcich.X.sata_rev 82setting to nonzero value limits maximum SATA revision (speed). 83Values 1, 2 and 3 are respectively 1.5, 3 and 6Gbps. 84.El 85.Sh DESCRIPTION 86This driver provides the CAM subsystem with native access to the 87.Tn SATA 88ports of AHCI-compatible controllers. 89Each SATA port found is represented to CAM as a separate bus with one 90target, or, if HBA supports Port Multipliers, 16 targets. 91Most of the bus-management details are handled by the SATA-specific 92transport of CAM. 93Connected ATA disks are handled by the ATA protocol disk peripheral driver 94.Xr ada 4 . 95ATAPI devices are handled by the SCSI protocol peripheral drivers 96.Xr cd 4 , 97.Xr da 4 , 98.Xr sa 4 , 99etc. 100.Pp 101Driver features include support for Serial ATA and ATAPI devices, 102Port Multipliers, hardware command queues (up to 32 commands per port), 103Native Command Queuing, SATA interface Power Management, device hot-plug 104and Message Signaled Interrupts. 105.Pp 106The Port Multiplier FIS Based Switching feature added in the AHCI 1.2 107specification, which is required for effective parallel operation of devices 108behind Port Multipliers, is not yet supported. 109.Pp 110AHCI hardware is also supported by ataahci driver from 111.Xr ata 4 112subsystem. If both drivers are loaded at the same time, this one will be 113given precedence as the more functional of the two. 114.Sh HARDWARE 115The 116.Nm 117driver supports AHCI compatible controllers having PCI class 1 (mass storage), 118subclass 6 (SATA) and programming interface 1 (AHCI). 119.Sh SEE ALSO 120.Xr ada 4 , 121.Xr cd 4 , 122.Xr da 4 , 123.Xr sa 4 , 124.Xr scsi 4 , 125.Xr ata 4 126.Sh HISTORY 127The 128.Nm 129driver first appeared in 130.Fx 8.0 . 131.Sh AUTHORS 132.An Alexander Motin Aq mav@FreeBSD.org . 133