sfc: Stop using iommu_present()

Even if an IOMMU might be present for some PCI segment in the system,
that doesn't necessarily mean it provides translation for the device
we care about. It appears that what we care about here is specifically
whether DMA mapping ops involve any IOMMU overhead or not, so check for
translation actually being active for our device.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://lore.kernel.org/r/7350f957944ecfce6cce90f422e3992a1f428775.1649166055.git.robin.murphy@arm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sfc: The RX page_ring is optional

The RX page_ring is an optional feature that improves
performance. When allocation fails the driver can still
function, but possibly with a lower bandwidth.
Guard against dereferencing a NULL page_ring.

Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs")
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Reported-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/164111288276.5798.10330502993729113868.stgit@palantir17.mph.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sfc: falcon: Check null pointer of rx_queue->page_ring

Because of the possible failure of the kcalloc, it should be better to
set rx_queue->page_ptr_mask to 0 when it happens in order to maintain
the consistency.

Fixes: 5a6681e22c14 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Link: https://lore.kernel.org/r/20211220140344.978408-1-jiasheng@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet: clean up mis-targeted comments

As part of the W=1 cleanups for ethernet, a million [*] driver
comments had to be cleaned up to get the W=1 compilation to
succeed. This change finally makes the drivers/net/ethernet tree
compile with W=1 set on the command line. NOTE: The kernel uses
kdoc style (see Documentation/process/kernel-doc.rst) when
documenting code, not doxygen or other styles.

After this patch the x86_64 build has no warnings from W=1, however
scripts/kernel-doc says there are 1545 more warnings in source files, that
I need to develop a script to fix in a followup patch.

The errors fixed here are all kdoc of a few classes, with a few outliers:
In file included from drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c:10:
drivers/net/ethernet/qlogic/netxen/netxen_nic.h:1193:18: warning: ‘FW_DUMP_LEVELS’ defined but not used [-Wunused-const-variable=]
1193 | static const u32 FW_DUMP_LEVELS[] = { 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff };
| ^~~~~~~~~~~~~~
... repeats 4 times...
drivers/net/ethernet/sun/cassini.c:2084:24: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body]
2084 | RX_USED_ADD(page, i);
drivers/net/ethernet/natsemi/ns83820.c: In function ‘phy_intr’:
drivers/net/ethernet/natsemi/ns83820.c:603:6: warning: variable ‘tbisr’ set but not used [-Wunused-but-set-variable]
603 | u32 tbisr, tanar, tanlpar;
| ^~~~~
drivers/net/ethernet/natsemi/ns83820.c: In function ‘ns83820_get_link_ksettings’:
drivers/net/ethernet/natsemi/ns83820.c:1207:11: warning: variable ‘tanar’ set but not used [-Wunused-but-set-variable]
1207 | u32 cfg, tanar, tbicr;
| ^~~~~
drivers/net/ethernet/packetengines/yellowfin.c:1063:18: warning: variable ‘yf_size’ set but not used [-Wunused-but-set-variable]
1063 | int data_size, yf_size;
| ^~~~~~~

Normal kdoc fixes:
warning: Function parameter or member 'x' not described in 'y'
warning: Excess function parameter 'x' description in 'y'
warning: Cannot understand <string> on line <NNN> - I thought it was a doc line

[*] - ok it wasn't quite a million, but it felt like it.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: falcon: don't score irq moderation points for GRO

Same rationale as for sfc, except that this wasn't performance-tested.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mm: remove __GFP_COLD

As the page free path makes no distinction between cache hot and cold
pages, there is no real useful ordering of pages in the free list that
allocation requests can take advantage of. Juding from the users of
__GFP_COLD, it is likely that a number of them are the result of copying
other sites instead of actually measuring the impact. Remove the
__GFP_COLD parameter which simplifies a number of paths in the page
allocator.

This is potentially controversial but bear in mind that the size of the
per-cpu pagelists versus modern cache sizes means that the whole per-cpu
list can often fit in the L3 cache. Hence, there is only a potential
benefit for microbenchmarks that alloc/free pages in a tight loop. It's
even worse when THP is taken into account which has little or no chance
of getting a cache-hot page as the per-cpu list is bypassed and the
zeroing of multiple pages will thrash the cache anyway.

The truncate microbenchmarks are not shown as this patch affects the
allocation path and not the free path. A page fault microbenchmark was
tested but it showed no sigificant difference which is not surprising
given that the __GFP_COLD branches are a miniscule percentage of the
fault path.

Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net: ethernet/sfc: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
Cc: Edward Cree <ecree@solarflare.com>
Cc: Bert Kenward <bkenward@solarflare.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc-falcon: get rid of custom busy polling code

In linux-4.5, busy polling was implemented in core
NAPI stack, meaning that all custom implementation can
be removed from drivers.

Not only we remove lot's of tricky code, we also remove
one lock operation in fast path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Edward Cree <ecree@solarflare.com>
Cc: Bert Kenward <bkenward@solarflare.com>
Acked-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver

Rationale: The differences between Falcon and Siena are in many ways larger
than those between Siena and EF10 (despite Siena being nominally "Falcon-
architecture"); for instance, Falcon has no MCPU, so there is no MCDI.
Removing Falcon support from the sfc driver should simplify the latter,
and avoid the possibility of Falcon support being broken by changes to sfc
(which are rarely if ever tested on Falcon, it being end-of-lifed hardware).

The sfc-falcon driver created in this changeset is essentially a copy of the
sfc driver, but with Siena- and EF10-specific code, including MCDI, removed
and with the "efx_" identifier prefix changed to "ef4_" (for "EFX 4000-
series") to avoid collisions when both drivers are built-in.

This changeset removes Falcon from the sfc driver's PCI ID table; then in
sfc I've removed obvious Falcon-related code: I removed the Falcon NIC
functions, Falcon PHY code, and EFX_REV_FALCON_*, then fixed up everything
that referenced them.

Also, increment minor version of both drivers (to 4.1).

For now, CONFIG_SFC selects CONFIG_SFC_FALCON, so that updating old configs
doesn't cause Falcon support to disappear; but that should be undone at
some point in the future.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>