From 992ebcf14f3cf029b8d0da4f479d752c19d8c726 Mon Sep 17 00:00:00 2001 From: "Stephen M. Cameron" Date: Thu, 27 May 2010 15:14:29 -0500 Subject: [PATCH] [SCSI] hpsa: Add hpsa.txt to Documentation/scsi Signed-off-by: Stephen M. Cameron Signed-off-by: James Bottomley --- Documentation/scsi/hpsa.txt | 100 ++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 Documentation/scsi/hpsa.txt diff --git a/Documentation/scsi/hpsa.txt b/Documentation/scsi/hpsa.txt new file mode 100644 index 000000000000..4055657340a2 --- /dev/null +++ b/Documentation/scsi/hpsa.txt @@ -0,0 +1,100 @@ + +HPSA - Hewlett Packard Smart Array driver +----------------------------------------- + +This file describes the hpsa SCSI driver for HP Smart Array controllers. +The hpsa driver is intended to supplant the cciss driver for newer +Smart Array controllers. The hpsa driver is a SCSI driver, while the +cciss driver is a "block" driver. Actually cciss is both a block +driver (for logical drives) AND a SCSI driver (for tape drives). This +"split-brained" design of the cciss driver is a source of excess +complexity and eliminating that complexity is one of the reasons +for hpsa to exist. + +Supported devices: +------------------ + +Smart Array P212 +Smart Array P410 +Smart Array P410i +Smart Array P411 +Smart Array P812 +Smart Array P712m +Smart Array P711m +StorageWorks P1210m + +Additionally, older Smart Arrays may work with the hpsa driver if the kernel +boot parameter "hpsa_allow_any=1" is specified, however these are not tested +nor supported by HP with this driver. For older Smart Arrays, the cciss +driver should still be used. + +HPSA specific entries in /sys +----------------------------- + + In addition to the generic SCSI attributes available in /sys, hpsa supports + the following attributes: + + HPSA specific host attributes: + ------------------------------ + + /sys/class/scsi_host/host*/rescan + + the host "rescan" attribute is a write only attribute. Writing to this + attribute will cause the driver to scan for new, changed, or removed devices + (e.g. hot-plugged tape drives, or newly configured or deleted logical drives, + etc.) and notify the SCSI midlayer of any changes detected. Normally this is + triggered automatically by HP's Array Configuration Utility (either the GUI or + command line variety) so for logical drive changes, the user should not + normally have to use this. It may be useful when hot plugging devices like + tape drives, or entire storage boxes containing pre-configured logical drives. + + HPSA specific disk attributes: + ------------------------------ + + /sys/class/scsi_disk/c:b:t:l/device/unique_id + /sys/class/scsi_disk/c:b:t:l/device/raid_level + /sys/class/scsi_disk/c:b:t:l/device/lunid + + (where c:b:t:l are the controller, bus, target and lun of the device) + + For example: + + root@host:/sys/class/scsi_disk/4:0:0:0/device# cat unique_id + 600508B1001044395355323037570F77 + root@host:/sys/class/scsi_disk/4:0:0:0/device# cat lunid + 0x0000004000000000 + root@host:/sys/class/scsi_disk/4:0:0:0/device# cat raid_level + RAID 0 + +HPSA specific ioctls: +--------------------- + + For compatibility with applications written for the cciss driver, many, but + not all of the ioctls supported by the cciss driver are also supported by the + hpsa driver. The data structures used by these are described in + include/linux/cciss_ioctl.h + + CCISS_DEREGDISK + CCISS_REGNEWDISK + CCISS_REGNEWD + + The above three ioctls all do exactly the same thing, which is to cause the driver + to rescan for new devices. This does exactly the same thing as writing to the + hpsa specific host "rescan" attribute. + + CCISS_GETPCIINFO + + Returns PCI domain, bus, device and function and "board ID" (PCI subsystem ID). + + CCISS_GETDRIVVER + + Returns driver version in three bytes encoded as: + (major_version << 16) | (minor_version << 8) | (subminor_version) + + CCISS_PASSTHRU + CCISS_BIG_PASSTHRU + + Allows "BMIC" and "CISS" commands to be passed through to the Smart Array. + These are used extensively by the HP Array Configuration Utility, SNMP storage + agents, etc. See cciss_vol_status at http://cciss.sf.net for some examples. +