When using Blue-Flame, BF, the QPN overrides the VLAN, CV, and SV
fields in the WQE. Thus, BF may only be used for QPNs with bits 6,7
unset.
The current ethernet driver code reserves a TX QP range with 256b
alignment.
This is wrong because if there are more than 64 TX QPs in use, QPNs >=
base + 65 will have bits 6/7 set.
This problem is not specific for the Ethernet driver, any entity that
tries to reserve more than 64 BF-enabled QPs should fail. Also, using
ranges is not necessary here and is wasteful.
The new mechanism introduced here will support reservation for "Eth
QPs eligible for BF" for all drivers: bare-metal, multi-PF, and VFs
(when hypervisors support WC in VMs). The flow we use is:
1. In mlx4_en, allocate Tx QPs one by one instead of a range allocation,
and request "BF enabled QPs" if BF is supported for the function
2. In the ALLOC_RES FW command, change param1 to:
a. param1[23:0] - number of QPs
b. param1[31-24] - flags controlling QPs reservation
Bit 31 refers to Eth blueflame supported QPs. Those QPs must have bits
6 and 7 unset in order to be used in Ethernet.
Bits 24-30 of the flags are currently reserved.
When a function tries to allocate a QP, it states the required
attributes for this QP. Those attributes are considered "best-effort".
If an attribute, such as Ethernet BF enabled QP, is a must-have
attribute, the function has to check that attribute is supported
before trying to do the allocation.
In a lower layer of the code, mlx4_qp_reserve_range masks out the bits
which are unsupported. If SRIOV is used, the PF validates those
attributes and masks out unsupported attributes as well. In order to
notify VFs which attributes are supported, the VF uses QUERY_FUNC_CAP
command. This command's mailbox is filled by the PF, which notifies
which QP allocation attributes it supports.
Obtained from: Linux (dual BSD/GPLv2 licensed)
Submitted by: Dexuan Cui @ microsoft . com
Differential Revision: https://reviews.freebsd.org/D8868
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
Previously, the mlx4 driver queried the firmware in order to get the
number of supported EQs. Under SRIOV, since this was done before the
driver notified the firmware how many VFs it actually needs, the
firmware had to take into account a worst case scenario and always
allocated four EQs per VF, where one was used for events while the
others were used for completions. Now, when the firmware supports the
asymmetric allocation scheme, denoted by exposing num_sys_eqs > 0 (-->
MLX4_DEV_CAP_FLAG2_SYS_EQS), we use the QUERY_FUNC command to query
the firmware before enabling SRIOV. Thus we can get more EQs and MSI-X
vectors per function. Moreover, when running in the new
firmware/driver mode, the limitation that the number of EQs should be
a power of two is lifted.
Obtained from: Linux (dual BSD/GPLv2 licensed)
Submitted by: Dexuan Cui @ microsoft . com
Differential Revision: https://reviews.freebsd.org/D8867
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
like other PCI network drivers. The sys/ofed directory is now mainly
reserved for generic infiniband code, with exception of the mthca driver.
- Add new manual page, mlx4en(4), describing how to configure and load
mlx4en.
- All relevant driver C-files are now prefixed mlx4, mlx4_en and
mlx4_ib respectivly to avoid object filename collisions when compiling
the kernel. This also fixes an issue with proper dependency file
generation for the C-files in question.
- Device mlxen is now device mlx4en and depends on device mlx4, see
mlx4en(4). Only the network device name remains unchanged.
- The mlx4 and mlx4en modules are now built by default on i386 and
amd64 targets. Only building the mlx4ib module depends on
WITH_OFED=YES .
Sponsored by: Mellanox Technologies
