Add a quirk to flag AHCI attachment to the controller. This is for any
of the strategies for attaching nvme devices as children of the AHCI
device for Intel's RAID devices. This also has a side effect of cleaning
up resource allocation from failed nvme_attach calls now.
Sponsored by: Netflix
Reviewed by: mav
Differential Revision: https://reviews.freebsd.org/D33285
If we can't allocate more MSI-X vectors, accept using single shared.
If we can't allocate any MSI-X, try to allocate 2 MSI vectors, but
accept single shared. If still no luck, fall back to shared INTx.
This provides maximal flexibility in some limited scenarios. For
example, vmd(4) does not support INTx and can handle only limited
number of MSI/MSI-X vectors without sharing.
MFC after: 1 week
- For each queue pair precalculate CPU and domain it is bound to.
If queue pairs are not per-CPU, then use the domain of the device.
- Allocate most of queue pair memory from the domain it is bound to.
- Bind callouts to the same CPUs as queue pair to avoid migrations.
- Do not assign queue pairs to each SMT thread. It just wasted
resources and increased lock congestions.
- Remove fixed multiplier of CPUs per queue pair, spread them even.
This allows to use more queue pairs in some hardware configurations.
- If queue pair serves multiple CPUs, bind different NVMe devices to
different CPUs.
MFC after: 1 month
Sponsored by: iXsystems, Inc.
While it worked with the kenrel, it wasn't working with the loader.
It failed to handle dependencies correctly. The reason for that is
that we never created a nvme module with the DRIVER_MODULE, but
instead a nvme_pci and nvme_ahci module. Create a real nvme module
that nvd can be dependent on so it can import the nvme symbols it
needs from there.
Arguably, nvd should just be a simple child of nvme, but transitioning
to that (and winning that argument given why it was done this way) is
beyond the scope of this change.
Reviewed by: jhb@
Differential Revision: https://reviews.freebsd.org/D21382
load and people who pull in nvme/nvd from modules can't load nvd.ko
since it depends on nvme, not nvme_foo. The duplicate doesn't matter
since kldxref properly handles that case.
Intel has created RST and many laptops from vendors like Lenovo and Asus. It's a
mechanism for creating multiple boot devices under windows. It effectively hides
the nvme drive inside of the ahci controller. The details are supposed to be a
trade secret. However, there's a reverse engineered Linux driver, and this
implements similar operations to allow nvme drives to attach. The ahci driver
attaches nvme children that proxy the remapped resources to the child. nvme_ahci
is just like nvme_pci, except it doesn't do the PCI specific things. That's
moved into ahci where appropriate.
When the nvme drive is remapped, MSI-x interrupts aren't forwarded (the linux
driver doesn't know how to use this either). INTx interrupts are used
instead. This is suboptimal, but usually sufficient for the laptops these parts
are in.
This is based loosely on https://www.spinics.net/lists/linux-ide/msg53364.html
submitted, but not accepted by, Linux. It was written by Dan Williams. These
changes were written from scratch by Olivier Houchard.
Submitted by: cognet@ (Olivier Houchard)
