The CREATE_CQ command is permitted to return a size smaller than
requested, which could leave us in a situation where the completion
queue could overflow.
Avoid overflow by limiting the submission queue fill level to the
actual size of the completion queue.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The Linux and FreeBSD drivers for the (totally undocumented) ENA
adapters use a two-phase reset mechanism: first set ENA_CTRL.RESET and
wait for this to be reflected in ENA_STAT.RESET, then clear
ENA_CTRL.RESET and again wait for it to be reflected in
ENA_STAT.RESET.
The iPXE driver currently assumes a self-clearing reset mechanism,
which appeared to work at the time that the driver was created but
seems no longer to function, at least on the t3.nano and t3a.nano
instance types found in eu-west-1.
Switch to a simplified version of the two-phase reset mechanism as
used by Linux and FreeBSD.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The malloc_dma() function allocates memory with specified physical
alignment, and is typically (though not exclusively) used to allocate
memory for DMA.
Rename to malloc_phys() to more closely match the functionality, and
to create name space for functions that specifically allocate and map
DMA-capable buffers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Devices that support jumbo frames will currently default to the
largest possible MTU. This assumption is valid for virtual adapters
such as virtio-net, where the MTU must have been configured by a
system administrator, but is unsafe in the general case of a physical
adapter.
Default to the standard Ethernet MTU, unless explicitly overridden
either by the driver or via the ${netX/mtu} setting.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some older versions of gcc (observed with gcc 4.7.2) report a spurious
uninitialised variable warning in ena_get_device_attributes(). Work
around this warning by manually inlining the relevant code (which has
only a single call site).
Reported-by: xbgmsharp <xbgmsharp@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown