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>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Replace efx_nic::rx_buffer_len with efx_nic::rx_dma_len, the maximum
RX DMA length.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The Linux side of EEH is triggered by MMIO reads, but this
driver's data path does not issue any MMIO reads (except in
legacy interrupt mode).  Therefore add a monitor function
to poll EEH periodically.

When preparing to reset the device based on our own error
detection, also poll EEH and defer to its recovery mechanism
if appropriate.

[bwh: Use a separate condition for the initial link poll; fix some
 style errors]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

On Siena, VFs share RSS configuration with the PF.  We attempted to
support configurations where the PF only uses 1 RX queue and VFs use
multiple RX queues, by (1) setting up RSS for the number of RX queues
per VF (2) disabling RSS in the PF's RX default filters.

Unfortunately commit cd2d5b52 ('sfc: Add SR-IOV back-end support
for SFC9000 family') only included (1).  This is (2).
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

efx_filter_insert_filter() uses the first table entry in the hash chain
that either has the same match values or is empty.  This means that
replacement doesn't always work correctly:

1. Insert filter F1 with match values M1, hashing to H1, at first
   possible entry E1.
2. Insert filter F2 with match values M2, hashing to H1, at second
   possible entry E2.
3. Remove filter F1.
4. Insert filter F3 with match values M2, hashing to H1, at first
   possible entry E1.

F3 should have either replaced F2 or been rejected (depending on
priority and the replace_equal parameter).

Instead, search for both a matching filter that the inserted filter
would replace, and an available insertion point, up to the applicable
maximum search depths.  If we insert at lower depth than a replaced
filter, clear the replaced filter.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

efx_filter_search() is only called from efx_filter_insert(), and
neither function is very long.  The following bug fix requires a more
sophisticated search with a third result, which is going to be easier
to implement as part of the same function.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

These functions happen to work for default MAC filters: they generate
an initial index of 1/0 for unicast/multicast respectively and an
increment of 1 for either, so a search succeeds at depth 2.  But this
is a matter of luck rather than design, and it really won't work well
with the bug fix we're about to do.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The 'for_insert' parameter is redundant since there are no longer
any other operations that need to search based on a filter spec.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The 'replace' flag to efx_filter_insert_filter() controls whether the
new filter may replace *any* filter, and is checked even before
priority comparison.  But lower-priority filters should never
block insertion of higher-priority filters.

Change the priority checking so that lower-priority filters are
replaced regardless of the value of the flag, and rename the
flag to 'replace_equal'.
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>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

There is a long-standing problem with the packet-timestamp matching in
the driver. When a PTP packet is received by the MC, the FPGA
timestamps the packet and the MC sends the timestamp and 6 bytes of
the UUID to the driver. The driver then matches the timestamp against
received packets using the same 6 bytes of UUID.

The problem comes from the choice of which 6 bytes to use. The PTP
spec is slightly contradictory and misleading in one of the two places
where the UUIDs are discussed. From section 7.2.2.2 of the spec, a
PTPD2 UUID can be either a EUI-64 or a EUI-64 constructed from a
EUI-48. The typical ethernet based implementation uses a EUI-64
constructed from a EUI-48. This works by taking the first 3 bytes of
the MAC address of the NIC being used for PTP (the OUI), then
inserting 0xFF, 0xFE, then taking the last 3 bytes of the MAC address
giving
          MAC[0], MAC[1], MAC[2], 0xFF, 0xFE, MAC[3], MAC[4], MAC[5]
The current MC firmware and driver discard the first two bytes of this
UUID and packets are matched against timestamps using bytes 2 to 7 so
there is a small risk that in a deployment of Solarflare PTP NICs used
with other vendors NICs, that a PTP packet could be matched against
the wrong timestamp. This applies to all other organisations whose
third byte of the OUI is 0x53. It's a long list but I notice that it
includes Cisco.

The necessary modifications to use bytes 0-2 and 5-7 of the UUID to
match against are quite small but introduce incompatibility between
older version of the firmware and driver.

When PTP is enabled via SO_TIMESTAMPING specifying PTP V2, the driver
will try to enable PTP in the firmware using the enhanced mode
(above). If the firmware returns an error, the driver will enable PTP
in the firmware using the old mode.

[bwh: Fix some style errors; remove private ioctl bits]
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>

HTB uses an internal pfifo queue, which limit is not reported
to userland tools (tc), and value inherited from device tx_queue_len
at setup time.

Introduce TCA_HTB_DIRECT_QLEN attribute to allow finer control.

Remove two obsolete pr_err() calls as well.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We are currently busy waiting for MDIO registers to complete their
operation but we did not propagate the result back to the caller.
Update r6040_phy_{read,write} to report the busy waiting result
accordingly.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

It's useful to be able to get the initial state of all entries. The patch adds
the support for IPv4 and IPv6.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As suggested by Eric Dumazet, allow user to select mode which chooses
TX port randomly. Functionality should be more of less similar to
round-robin mode with even lower overhead.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

No need to duplicate code for this.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

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 b590ace0
('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>

efx_device_detach_sync() locks all TX queues before marking the device
detached and thus disabling further TX scheduling.  But it can still
be interrupted by TX completions which then result in TX scheduling in
soft interrupt context.  This will deadlock when it tries to acquire
a TX queue lock that efx_device_detach_sync() already acquired.

To avoid deadlock, we must use netif_tx_{,un}lock_bh().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

BQL (Byte Queue Limits) proper operation needs TX completion
being serviced in a timely fashion.

bnx2x uses a non standard NAPI poll weight, and thats not fair to other
napi poll handlers, and even not reasonable.

Use the default value instead.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some drivers use a too big NAPI poll weight.

This patch adds a NAPI_POLL_WEIGHT default value
and issues an error message if a driver attempts
to use a bigger weight.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We must try harder to get unique (addr, port) pairs when
doing port autoselection for sockets with SO_REUSEADDR
option set.

This is a continuation of commit aacd9289
for IPv6.
Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch uses module_platform_driver_probe() macro which makes
the code smaller and simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch uses module_platform_driver_probe() macro which makes
the code smaller and simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch uses module_platform_driver_probe() macro which makes
the code smaller and simpler.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull powerpc fixes from Ben Herrenschmidt:
 "Here are a few powerpc bits & fixes for rc1.  A couple of str*cpy
  fixes, some fixes in handling the FSCR register on Power8 (controls
  the enabling of processor features), a 32-bit build fix and a couple
  more nits."

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Set DSCR bit in FSCR setup
  powerpc: Add DSCR FSCR register bit definition
  powerpc: Fix setting FSCR for HV=0 and on secondary CPUs
  powerpc: Wireup the kcmp syscall to sys_ni
  powerpc: Remove unused BITOP_LE_SWIZZLE macro
  powerpc: Avoid link stack corruption in MMU on syscall entry path
  drivers/tty/hvc: Use strlcpy instead of strncpy
  powerpc/pseries/hvcserver: Fix strncpy buffer limit in location code
  powerpc: Fix compile of sha1-powerpc-asm.S on 32-bit

Pull virtio hwrng fix from Rusty Russell:
 "Nasty side-effect of vmalloc'ing modules: their static vars cannot be
  put into scatterlists.  Jens has a check queued for this, so it
  shouldn't happen again.

  We could fix this in virtio_rng, but it's actually far easier to just
  do it in the core"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  hw_random: make buffer usable in scatterlist.

Pull networking fixes from David Miller:
 "A moderately sized pile of fixes, some specifically for merge window
  introduced regressions although others are for longer standing items
  and have been queued up for -stable.

  I'm kind of tired of all the RDS protocol bugs over the years, to be
  honest, it's way out of proportion to the number of people who
  actually use it.

   1) Fix missing range initialization in netfilter IPSET, from Jozsef
      Kadlecsik.

   2) ieee80211_local->tim_lock needs to use BH disabling, from Johannes
      Berg.

   3) Fix DMA syncing in SFC driver, from Ben Hutchings.

   4) Fix regression in BOND device MAC address setting, from Jiri
      Pirko.

   5) Missing usb_free_urb in ISDN Hisax driver, from Marina Makienko.

   6) Fix UDP checksumming in bnx2x driver for 57710 and 57711 chips,
      fix from Dmitry Kravkov.

   7) Missing cfgspace_lock initialization in BCMA driver.

   8) Validate parameter size for SCTP assoc stats getsockopt(), from
      Guenter Roeck.

   9) Fix SCTP association hangs, from Lee A Roberts.

  10) Fix jumbo frame handling in r8169, from Francois Romieu.

  11) Fix phy_device memory leak, from Petr Malat.

  12) Omit trailing FCS from frames received in BGMAC driver, from Hauke
      Mehrtens.

  13) Missing socket refcount release in L2TP, from Guillaume Nault.

  14) sctp_endpoint_init should respect passed in gfp_t, rather than use
      GFP_KERNEL unconditionally.  From Dan Carpenter.

  15) Add AISX AX88179 USB driver, from Freddy Xin.

  16) Remove MAINTAINERS entries for drivers deleted during the merge
      window, from Cesar Eduardo Barros.

  17) RDS protocol can try to allocate huge amounts of memory, check
      that the user's request length makes sense, from Cong Wang.

  18) SCTP should use the provided KMALLOC_MAX_SIZE instead of it's own,
      bogus, definition.  From Cong Wang.

  19) Fix deadlocks in FEC driver by moving TX reclaim into NAPI poll,
      from Frank Li.  Also, fix a build error introduced in the merge
      window.

  20) Fix bogus purging of default routes in ipv6, from Lorenzo Colitti.

  21) Don't double count RTT measurements when we leave the TCP receive
      fast path, from Neal Cardwell."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (61 commits)
  tcp: fix double-counted receiver RTT when leaving receiver fast path
  CAIF: fix sparse warning for caif_usb
  rds: simplify a warning message
  net: fec: fix build error in no MXC platform
  net: ipv6: Don't purge default router if accept_ra=2
  net: fec: put tx to napi poll function to fix dead lock
  sctp: use KMALLOC_MAX_SIZE instead of its own MAX_KMALLOC_SIZE
  rds: limit the size allocated by rds_message_alloc()
  MAINTAINERS: remove eexpress
  MAINTAINERS: remove drivers/net/wan/cycx*
  MAINTAINERS: remove 3c505
  caif_dev: fix sparse warnings for caif_flow_cb
  ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to gigabit ethernet adapter driver
  sctp: use the passed in gfp flags instead GFP_KERNEL
  ipv[4|6]: correct dropwatch false positive in local_deliver_finish
  l2tp: Restore socket refcount when sendmsg succeeds
  net/phy: micrel: Disable asymmetric pause for KSZ9021
  bgmac: omit the fcs
  phy: Fix phy_device_free memory leak
  bnx2x: Fix KR2 work-around condition
  ...

Pull irq fixes and cleanups from Thomas Gleixner:
 "Commit e5ab012c ("nohz: Make tick_nohz_irq_exit() irq safe") is
  the first commit in the series and the minimal necessary bugfix, which
  needs to go back into stable.

  The remanining commits enforce irq disabling in irq_exit(), sanitize
  the hardirq/softirq preempt count transition and remove a bunch of no
  longer necessary conditionals."

I personally love getting rid of the very subtle and confusing
IRQ_EXIT_OFFSET thing.  Even apart from the whole "more lines removed
than added" thing.

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irq: Don't re-enable interrupts at the end of irq_exit
  irq: Remove IRQ_EXIT_OFFSET workaround
  Revert "nohz: Make tick_nohz_irq_exit() irq safe"
  irq: Sanitize invoke_softirq
  irq: Ensure irq_exit() code runs with interrupts disabled
  nohz: Make tick_nohz_irq_exit() irq safe

Pull smpboot bugfix from Thomas Gleixner:
 "A single bugfix for a regression introduced with the conversion of the
  stop machine threads to the generic smpboot thread management
  facility"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine: Mark per cpu stopper enabled early

Pull second round of GPIO changes from Grant Likely:
 "This branch contains a few bug fixes that I missed the first time
  around and updates to the gpio_desc series included in the first pull
  request.  This tag has been retagged to drop the 2 head commits
  because the one of them caused a build failure."

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux:
  gpio/gpio-ich: fix ichx_gpio_check_available() return what callers expect
  gpiolib: move comment to right function
  gpiolib: use const parameters when possible
  gpiolib: check descriptors validity before use