efx_writed_table() uses a step of 16 bytes but efx_readd_table() uses
a step of 4 bytes. Why are they different?
Firstly, register access is asymmetric:
- The EVQ_RPTR table and RX_INDIRECTION_TBL can (or must?) be written
as dwords even though they have a step size of 16 bytes, unlike
most other CSRs.
- In general, a read of any width is valid for registers, so long as
it does not cross register boundaries. There is also no latching
behaviour in the BIU, contrary to rumour.
We write to the EVQ_RPTR table with efx_writed_table() but never read
it back as it's write-only. We write to the RX_INDIRECTION_TBL with
efx_writed_table(), but only read it back for the register dump, where
we use efx_reado_table() as for any other table with step size of 16.
We read MC_TREG_SMEM with efx_readd_table() for the register dump, but
normally read and write it with efx_readd() and efx_writed() using
offsets calculated in bytes.
Since these functions are trivial and have few callers, it's clearer
to open-code them at the call sites. While we're at it, update the
comments on the BIU behaviour again.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Receiving pause frames can block TX queue flushes. Earlier changes
work around this by reconfiguring the MAC during flushes for VFs, but
during flushes for the PF we would only change the fc_disable counter.
Unless the MAC is reconfigured for some other reason during the flush
(which I would not expect to happen) this had no effect at all.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Commit c31e5f9 ('sfc: Add channel specific receive_skb handler and
post_remove callback') added the function pointer field
efx_channel_type::post_remove and an unconditional call through it.
This field should have been initialised to efx_channel_dummy_op_void
in the existing instances of efx_channel_type, but this was only done
in efx_default_channel_type. Consequently, if a device has SR-IOV
enabled then removing the driver or device will result in an oops.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
MCDI supports requests up to 252 bytes long, which is only enough to
pass 63 RX queue IDs to MC_CMD_FLUSH_RX_QUEUES. However a VF may have
up to 64 RX queues, and if we try to flush them all we will generate
an over-length request and BUG() in efx_mcdi_copyin(). Currently
all VF drivers limit themselves to 32 RX queues, so reducing the
limit to 63 does no harm.
Also add a BUILD_BUG_ON in efx_mcdi_flush_rxqs() so we remember to
deal with the same problem there if EFX_MAX_CHANNELS is increased.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
efx_vfdi_set_status_page() validates the peer page count by
calculating the size of a request containing that many addresses and
comparing that with the maximum valid request size (4KB). The
calculation involves a multiplication that may overflow on a 32-bit
system.
We use kcalloc() to allocate memory to store the addresses; that also
does a multiplication and it does check for integer overflow, so any
values larger than 0x1fffffff will be rejected. However, values in
the range [0x1fffffffc, 0x1fffffff] pass boh tests and result in an
attempt to allocate nearly 4GB on the heap. This should be rejected
rather quickly as it's obviously impossible on a 32-bit system, and
indeed the maximum possible heap allocation is 32MB. Still, let's
make absolutely sure by fixing the initial validation.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
On the SFC9000 family, each port has 1024 Virtual Interfaces (VIs),
each with an RX queue, a TX queue, an event queue and a mailbox
register. These may be assigned to up to 127 SR-IOV virtual functions
per port, with up to 64 VIs per VF.
We allocate an extra channel (IRQ and event queue only) to receive
requests from VF drivers.
There is a per-port limit of 4 concurrent RX queue flushes, and queue
flushes may be initiated by the MC in response to a Function Level
Reset (FLR) of a VF. Therefore, when SR-IOV is in use, we submit all
flush requests via the MC.
The RSS indirection table is shared with VFs, so the number of RX
queues used in the PF is limited to the number of VIs per VF.
This is almost entirely the work of Steve Hodgson, formerly
shodgson@solarflare.com.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
