libata: Support SATA attached via SAS
cover libata: Support SATA attached via SAS
Jeff,
Here is a refresh of my patchset to allow SAS HBAs to use libata to control attached SATA devices. It should apply cleanly to #upstream.
James,
After our discussion at the storage summit I think I have
a better idea what you are looking for with a SATA transport class. Unfortunately, the problem I am facing is that I am dealing with a firmware stack (ipr) which does not expose the physical transport to the host. The ipr firmware does all the device discovery and reports a configuration table describing the attached devices, but does not export any physical topology information. At some point in the future I hope to be able to extract this information from the ipr firmware stack and convert ipr to be able to utilize the sas/sata transport class, but, unfortunately, the firmware interfaces to accomplish this aren't available at this time.
Brian
Signature · 3 lines
Brian King eServer Storage I/O IBM Linux Technology Center
Quoted 7 lines · Brian King
Jeff,
Here is a refresh of my patchset to allow SAS HBAs to use libata to control attached SATA devices. It should apply cleanly to #upstream.
James,
Quoted 11 lines
After our discussion at the storage summit I think I have
a better idea what you are looking for with a SATA transport class. Unfortunately, the problem I am facing is that I am dealing with a firmware stack (ipr) which does not expose the physical transport to the host. The ipr firmware does all the device discovery and reports a configuration table describing the attached devices, but does not export any physical topology information. At some point in the future I hope to be able to extract this information from the ipr firmware stack and convert ipr to be able to utilize the sas/sata transport class, but, unfortunately, the firmware interfaces to accomplish this aren't available at this time.
Brian,
Does that mean that it doesn't have an SMP pass through? SMP and the SAS addresses attached to the phys on the HBA is enough to do discovery in the user space.
Doug Gilbert
Quoted 20 lines · Douglas Gilbert
Quoted 7 lines · Brian King
Jeff,
Here is a refresh of my patchset to allow SAS HBAs to use libata to control attached SATA devices. It should apply cleanly to #upstream.
James,
Quoted 11 lines
After our discussion at the storage summit I think I have
a better idea what you are looking for with a SATA transport class. Unfortunately, the problem I am facing is that I am dealing with a firmware stack (ipr) which does not expose the physical transport to the host. The ipr firmware does all the device discovery and reports a configuration table describing the attached devices, but does not export any physical topology information. At some point in the future I hope to be able to extract this information from the ipr firmware stack and convert ipr to be able to utilize the sas/sata transport class, but, unfortunately, the firmware interfaces to accomplish this aren't available at this time.
Quoted 4 lines
Brian,
Does that mean that it doesn't have an SMP pass through? SMP and the SAS addresses attached to the phys on the HBA is enough to do discovery in the user space.
Doug,
That is correct. There is no SMP passthru interface. The interface I am working with basically gives me some very basic information regarding all attached end devices (which does not include SMP devices). The information I get for each device includes:
1. The LUN's SAS address
2. The type of device to aid in HLDD attachment. This could be either a SAS device, a SATA device, or a RAID logical device.
3. A bus/target/lun tuple which can be used to map into SPI if the host dd wants to.
If you look in drivers/scsi/ipr.h at struct ipr_config_table_entry, that might give you a better idea as to what I get back for each device.
In a future firmware release I should have the firmware interfaces I need to be able to extract both adapter SAS/SATA phy information and SAS expander information such that I can move ipr to fit into the sas transport model. Unfortunately, I don't have this today.
Brian
Signature · 3 lines
Brian King eServer Storage I/O IBM Linux Technology Center
Quoted 4 lines · Brian King
Jeff,
Here is a refresh of my patchset to allow SAS HBAs to use libata to control attached SATA devices. It should apply cleanly to #upstream.
Brian,
I hope that libata's ATA PASS THROUGH (16) SCSI command is wired up as I just checked a new device type '-d sat' into smartmontools cvs.
Doug Gilbert
Quoted 10 lines · Douglas Gilbert
Quoted 4 lines · Brian King
Jeff,
Here is a refresh of my patchset to allow SAS HBAs to use libata to control attached SATA devices. It should apply cleanly to #upstream.
Brian,
I hope that libata's ATA PASS THROUGH (16) SCSI command is wired up as I just checked a new device type '-d sat' into smartmontools cvs.
Yes. Any command supported by libata today should also be supported with this patchset.
Brian
Signature · 3 lines
Brian King eServer Storage I/O IBM Linux Technology Center