MVS(4)

💖 MVS(4) 💖

okay bestie, sit DOWN, because today we're talking about mvs — the Marvell Serial ATA Host Controller driver — and she is lowkey iconic. this is the Kernel Interfaces Manual page, and i'm gonna walk you through every single crumb of it. no skips. periodt. ✨

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🌸 NAME 🌸

mvs — Marvell Serial ATA Host Controller driver

like. that's her. that's the whole name. short, sweet, runs your SATA ports. 💅

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🎀 SYNOPSIS 🎀

so if you wanna bake this driver into the kernel, you drop these lines into your kernel configuration file:

device pci
device scbus
device mvs

OR — and this is the fun lil alternative — you can load it as a module at boot time by putting this line in loader.conf(5):

mvs_load="YES"

and then there's the tunables, which you can set from loader(8). here's the whole roster, bestie, no gatekeeping:

• hint.mvs.X.msi — controls Message Signaled Interrupts (MSI) usage by the specified controller.
• hint.mvs.X.ccc — controls Command Completion Coalescing (CCC) usage by the specified controller. a non-zero value enables CCC and defines the maximum time (in us) that a request can wait for an interrupt. CCC reduces the number of context switches on systems with many parallel requests, but heads up — it can decrease disk performance on some workloads due to additional command latency. 😭
• hint.mvs.X.cccc — defines the number of completed commands for CCC that trigger an interrupt without waiting for the specified coalescing timeout.
• hint.mvsch.X.pm_level — controls SATA interface Power Management for the specified channel, letting you save a lil power at the cost of additional command latency. possible values, and yes i'm listing all of them:
  • 0 — interface Power Management is disabled (default);
  • 1 — device is allowed to initiate PM state change, host is passive;
  • 4 — driver initiates PARTIAL PM state transition 1ms after port becomes idle;
  • 5 — driver initiates SLUMBER PM state transition 125ms after port becomes idle.

⚠️ important, bestie: interface Power Management is not compatible with device presence detection. a manual bus reset is needed on device hot-plug. don't forget it or you'll be confused and sad. 🙈

• hint.mvsch.X.sata_rev — setting this to a nonzero value limits maximum SATA revision (speed). the values 1, 2 and 3 are respectively 1.5, 3 and 6Gbps.

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🦋 DESCRIPTION 🦋

so what does she actually DO? this driver gives the CAM(4) subsystem native access to the SATA ports of several generations — Gen-I/II/IIe — of Marvell SATA controllers. 🌈

every SATA port it finds is represented to CAM as a separate bus with one target, or — if the HBA supports Port Multipliers (Gen-II/IIe) — 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, and this is her resume, and it EATS:

• support for Serial ATA and ATAPI devices
• Port Multipliers (including FIS-based switching, when supported)
• hardware command queues (up to 31 command per port)
• Native Command Queuing
• SATA interface Power Management
• device hot-plug
• Message Signaled Interrupts

main character energy, honestly. 👑

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👑 HARDWARE 👑

the mvs driver supports the following controllers:

Gen-I (SATA 1.5Gbps):

• 88SX5040
• 88SX5041
• 88SX5080
• 88SX5081

Gen-II (SATA 3Gbps, NCQ, PMP):

• 88SX6040
• 88SX6041 (including Adaptec 1420SA)
• 88SX6080
• 88SX6081

Gen-IIe (SATA 3Gbps, NCQ, PMP with FBS):

• 88SX6042
• 88SX7042 (including Adaptec 1430SA)
• 88F5182 SoC
• 88F6281 SoC
• MV78100 SoC

🫶 note, that this hardware supports command queueing and FIS-based switching only for ATA DMA commands. ATAPI and non-DMA ATA commands are executed one by one for each port. that's just how it is, no cap.

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⭐ SEE ALSO ⭐

ada(4), ata(4), cam(4), cd(4), da(4), sa(4)

go read them, they're all friends of hers, iykyk 💜

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🌟 HISTORY 🌟

the mvs driver first appeared in FreeBSD 8.1. a whole era. a whole vibe. 🎀

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💕 AUTHORS 💕

Alexander Motin <mav@FreeBSD.org> — thank you king, we love you for this one 🫶

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and that's the whole page, bestie!! you're now officially fluent in mvs 💅 this was the Debian build of the manual, dated March 23, 2015 — yes, she's an older icon but she still slays. now go forth and configure your SATA ports, you've got this fr fr. ✨🦋🌸