Commit 2768935a46 ('sfc: reuse pages to avoid DMA mapping/unmapping
costs') did not fully take account of DMA scattering which was
introduced immediately before. If a received packet is invalid and
must be discarded, we only drop a reference to the first buffer's
page, but we need to drop a reference for each buffer the packet
used.
I think this bug was missed partly because efx_recycle_rx_buffers()
was not renamed and so no longer does what its name says. It does not
change the state of buffers, but only prepares the underlying pages
for recycling. Rename it accordingly.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The device::iommu_group field may be set even if no IOMMU is in use.
iommu_present() is still a better indicator, although it doesn't tell
us whether *our* device is affected.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
GRO can handle non-TCP packets and pass them up without coalescing,
but it has to do some extra work to parse the packet which we can
bypass using the hardware parse result. (This condition yields a
false negative for TCP/IPv6 packets received by Falcon, but its
performance is already poor in that case due to lack of checksum
offload.)
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
efx_start_datapath() asserts that we can fit 2 RX scatter buffers plus
a software structure, each appropriately aligned, into a single page.
Where L1_CACHE_BYTES == 256 and PAGE_SIZE == 4096, which is the case
on s390, this assertion fails.
The current scatter buffer size is also not a multiple of 64 or 128,
which are more common cache line sizes. If we can make both the start
and end of a scatter buffer cache-aligned, this will reduce the need
for read-modify-write operations on inter- processor links.
Fix the alignment by reducing EFX_RX_USR_BUF_SIZE to 2048 - 256 ==
1792. (We could use 2048 - L1_CACHE_BYTES, but EFX_RX_USR_BUF_SIZE
also affects user-level networking where a larger amount of
housekeeping data may be needed. Although this version of the driver
does not support user-level networking, I prefer to keep scattering
behaviour consistent with the out-of-tree version.)
This still doesn't fix the s390 build because like most architectures
it has NET_IP_ALIGN == 2. When NET_IP_ALIGN != 0 we cannot achieve
cache line alignment at either the start or end of a scatter buffer,
so there is actually no point in padding the buffers to a multiple of
the cache line size. All we need is 4-byte alignment of the network
header, so do that.
Adjust the assertions accordingly.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The two architectures that define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
(powerpc and x86) now both define NET_IP_ALIGN as 0, so there is no
need for this optimisation any more.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trivial sparse detected functions that should be static.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allocating 2 buffers per page is insanely inefficient when MTU is 1500
and PAGE_SIZE is 64K (as it usually is on POWER). Allocate as many as
we can fit, and choose the refill batch size at run-time so that we
still always use a whole page at once.
[bwh: Fix loop condition to allow for compound pages; rebase]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
On POWER systems, DMA mapping/unmapping operations are very expensive.
These changes reduce these costs by trying to reuse DMA mapped pages.
After all the buffers associated with a page have been processed and
passed up, the page is placed into a ring (if there is room). For
each page that is required for a refill operation, a page in the ring
is examined to determine if its page count has fallen to 1, ie. the
kernel has released its reference to these packets. If this is the
case, the page can be immediately added back into the RX descriptor
ring, without having to re-map it for DMA.
If the kernel is still holding a reference to this page, it is removed
from the ring and unmapped for DMA. Then a new page, which can
immediately be used by RX buffers in the descriptor ring, is allocated
and DMA mapped.
The time a page needs to spend in the recycle ring before the kernel
has released its page references is based on the number of buffers
that use this page. As large pages can hold more RX buffers, the RX
recycle ring can be shorter. This reduces memory usage on POWER
systems, while maintaining the performance gain achieved by recycling
pages, following the driver change to pack more than two RX buffers
into large pages.
When an IOMMU is not present, the recycle ring can be small to reduce
memory usage, since DMA mapping operations are inexpensive.
With a small recycle ring, attempting to refill the descriptor queue
with more buffers than the equivalent size of the recycle ring could
ultimately lead to memory leaks if page entries in the recycle ring
were overwritten. To prevent this, the check to see if the recycle
ring is full is changed to check if the next entry to be written is
NULL.
[bwh: Combine and rebase several commits so this is complete
before the following buffer-packing changes. Remove module
parameter.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Enable RX DMA scattering iff an RX buffer large enough for the current
MTU will not fit into a single page and the NIC supports DMA
scattering for kernel-mode RX queues.
On Falcon and Siena, the RX_USR_BUF_SIZE field is used as the DMA
limit for both all RX queues with scatter enabled. Set it to 1824,
matching what Onload uses now.
Maintain a statistic for frames truncated due to lack of descriptors
(rx_nodesc_trunc). This is distinct from rx_frm_trunc which may be
incremented when scattering is disabled and implies an over-length
frame.
Whenever an MTU change causes scattering to be turned on or off,
update filters that point to the PF queues, but leave others
unchanged, as VF drivers assume scattering is off.
Add n_frags parameters to various functions, and make them iterate:
- efx_rx_packet()
- efx_recycle_rx_buffers()
- efx_rx_mk_skb()
- efx_rx_deliver()
Make efx_handle_rx_event() responsible for updating
efx_rx_queue::removed_count.
Change the RX pipeline state to a starting ring index and number of
fragments, and make __efx_rx_packet() responsible for clearing it.
Based on earlier versions by David Riddoch and Jon Cooper.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Adjust rx_buf->page_offset when we eat the RX hash prefix. Remove
efx_rx_buf_offset(), which is now redundant.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Currently we prefetch from the Ethernet header, but we will also read
the hash prefix. In practice they should be in the same cache line
and this won't hurt, but it is still pointless to add on the hash
prefix size.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
efx_rx_buf_va() returns the virtual address of the current start of
the buffer. The callers must add the hash prefix size themselves.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
The pipeline mechanism will need to change a bit for scattered
packets. Add a wrapper to insulate efx_process_channel() from this.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
[bwh: Remove more dead code, and make efx_ptp_rx() pull the data it
needs into the header area.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Instead of having efx_ptp_rx() call netif_receive_skb() for an invalid
PTP packet, make it return false for rejected packets and have
efx_rx_deliver() pass them up.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
RX DMA buffers start at an offset of EFX_PAGE_IP_ALIGN bytes from the
start of a cache line. This offset obviously needs to be included in
the virtual address, but this was missed in commit b590ace09d
('sfc: Fix efx_rx_buf_offset() in the presence of swiotlb') since
EFX_PAGE_IP_ALIGN is equal to 0 on both x86 and powerpc.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
We assume that the mapping between DMA and virtual addresses is done
on whole pages, so we can find the page offset of an RX buffer using
the lower bits of the DMA address. However, swiotlb maps in units of
2K, breaking this assumption.
Add an explicit page_offset field to struct efx_rx_buffer.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
We may currently allocate two RX DMA buffers to a page, and only unmap
the page when the second is completed. We do not sync the first RX
buffer to be completed; this can result in packet loss or corruption
if the last RX buffer completed in a NAPI poll is the first in a page
and is not DMA-coherent. (In the middle of a NAPI poll, we will
handle the following RX completion and unmap the page *before* looking
at the content of the first buffer.)
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Allows an extra channel to override the standard receive_skb handler
and also for extra non generic operations to be performed on remove.
Also set default rx strategy so only skbs can be delivered to the
PTP receive function.
Signed-off-by: Stuart Hodgson <smhodgson@solarflare.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
The PTP channel will have its own RX queue even though it's not
a regular traffic channel.
Original work by Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Stuart Hodgson <smhodgson@solarflare.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Ben Hutchings says:
====================
1. Fix potential badness when running a self-test with SR-IOV enabled.
2. Fix calculation of some interface statistics that could run backward.
3. Miscellaneous cleanup.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches. Delete
a few that are content-free.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Previously we refilled with much larger batches, which caused large latency
spikes. We now have many more much much smaller spikes!
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
The in-tree driver has never supported Driverlink. The rest of the
comments are rather redundant, but we can usefully state what the
requirements are on the buffer state.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Conflicts:
drivers/net/ethernet/sfc/rx.c
Overlapping changes in drivers/net/ethernet/sfc/rx.c, one to change
the rx_buf->is_page boolean into a set of u16 flags, and another to
adjust how ->ip_summed is initialized.
Signed-off-by: David S. Miller <davem@davemloft.net>
When pre-allocating skbs for received packets, we set ip_summed =
CHECKSUM_UNNCESSARY. We used to change it back to CHECKSUM_NONE when
the received packet had an incorrect checksum or unhandled protocol.
Commit bc8acf2c8c ('drivers/net: avoid
some skb->ip_summed initializations') mistakenly replaced the latter
assignment with a DEBUG-only assertion that ip_summed ==
CHECKSUM_NONE. This assertion is always false, but it seems no-one
has exercised this code path in a DEBUG build.
Fix this by moving our assignment of CHECKSUM_UNNECESSARY into
efx_rx_packet_gro().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
When SR-IOV is enabled we may receive FLR (Function-Level Reset)
events, associated queue flush events and requests from VF drivers at
any time. Therefore we need to keep event queues and interrupts
enabled whenever possible.
Currently we stop interrupt-driven event processing before flushing RX
and TX queues; efx_nic_flush_queues() then polls event queues for
flush events and discards any others it finds. Change it to work with
the regular event handling functions.
Currently efx_start_channel() fills RX queues synchronously when a
device is brought up. This could now race with NAPI, so change it to
send fill events.
This was almost entirely written by Steve Hodgson, formerly
shodgson@solarflare.com.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
This function returns the page offset of the buffer, which can be
calculated based on either its DMA address or its virtual address. It
used to use the virtual address and we would cast that to unsigned
long, as anything smaller would result in a compiler warning. Now
that it's using the DMA address we should use unsigned int, matching
the return type. It is also unnecessary to use __force.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Replace checksummed and discard booleans from efx_handle_rx_event()
with a bitmask, added to the flags field.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
These files were using moduleparam infrastructure, but were not
including anything for it -- which is fine when module.h is being
implicitly included in all files, but that is going away.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
To ease skb->truesize sanitization, its better to be able to localize
all references to skb frags size.
Define accessors : skb_frag_size() to fetch frag size, and
skb_frag_size_{set|add|sub}() to manipulate it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
Cc: Steve Hodgson <shodgson@solarflare.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Moves the Solarflare drivers into drivers/net/ethernet/sfc/ and
make the necessary Kconfig and Makefile changes.
CC: Steve Hodgson <shodgson@solarflare.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
