Merge dma-contiguous.h into dma-map-ops.h, after removing the comment
describing the contiguous allocator into kernel/dma/contigous.c.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

dma_contiguous_set_default contains a trivial assignment, and has a
single caller that is compiled if CONFIG_CMA_DMA is enabled.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

dev_set_cma_area contains a trivial assignment.  It has just three
callers that all have a non-NULL device and depend on CONFIG_DMA_CMA,
so remove the wrapper.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

dma_declare_contiguous is a trivial wrapper around
dma_contiguous_reserve_area and just has a single caller.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Split out all the bits that are purely for dma_map_ops implementations
and related code into a new <linux/dma-map-ops.h> header so that they
don't get pulled into all the drivers.  That also means the architecture
specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h>
any more, which leads to a missing includes that were pulled in by the
x86 or arm versions in a few not overly portable drivers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

On an embedded system with a tiny (1 MiB) CMA area for video memory, and
a simple enough video pipeline, we can decrease the CMA_ALIGNMENT by a
factor of 2 to avoid wasting memory, as all the allocations for video
buffers will be of the exact same size (dictated by the size of the
screen).
Signed-off-by: NPaul Cercueil <paul@crapouillou.net>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Use dma_alloc_pages to allocate DMAable pages instead of hoping that
the architecture either has GFP_DMA32 or not more than 4G of memory.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Implement the alloc_noncoherent method to provide memory that is neither
coherent not contiguous.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This will allow IOMMU drivers to allocate non-contigous memory and
return a vmapped virtual address.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This API is the equivalent of alloc_pages, except that the returned memory
is guaranteed to be DMA addressable by the passed in device.  The
implementation will also be used to provide a more sensible replacement
for DMA_ATTR_NON_CONSISTENT flag.

Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages
as its backend.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)

All users are gone now, remove the API.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)

Use the new non-coherent DMA API including proper ownership transfers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

Use the new non-coherent DMA API including proper ownership transfers.
This includes adding additional calls to dma_sync_desc_dev as the
old syncing was rather ad-hoc.

Thanks to Thomas Bogendoerfer for debugging the ownership transfer
issues.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

Use the new non-coherent DMA API including proper ownership transfers.
This includes moving the DMA helpers to lib82596 based of an ifdef to
avoid include order problems.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (SNI part)

Use the new non-coherent DMA API including proper ownership transfers.
This also means we can allocate the buffer memory with the proper
direction instead of bidirectional.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

Use the new non-coherent DMA API including proper ownership transfers.
This also means we can allocate the memory as DMA_TO_DEVICE instead
of bidirectional.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

Add a new API to allocate and free memory that is guaranteed to be
addressable by a device, but which potentially is not cache coherent
for DMA.

To transfer ownership to and from the device, the existing streaming
DMA API calls dma_sync_single_for_device and dma_sync_single_for_cpu
must be used.

For now the new calls are implemented on top of dma_alloc_attrs just
like the old-noncoherent API, but once all drivers are switched to
the new API it will be replaced with a better working implementation
that is available on all architectures.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Switch the 53c700 driver to only use non-coherent descriptor memory if it
really has to because dma_alloc_coherent fails.  This doesn't matter for
any of the platforms it runs on currently, but that will change soon.

To help with this two new helpers to transfer ownership to and from the
device are added that abstract the syncing of the non-coherent memory.
The two current bidirectional cases are mapped to transfers to the
device, as that appears to what they are used for.  Note that for parisc,
which is the only architecture this driver needs to use non-coherent
memory on, the direction argument of dma_cache_sync is ignored, so this
will not change behavior in any way.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

This allows us to get rid of the LIB82596_DMA_ATTR defined and prepare
for untangling the coherent vs non-coherent DMA allocation API.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (SNI part)

The au1000-eth driver contains none of the manual cache synchronization
required for using DMA_ATTR_NON_CONSISTENT.  From what I can tell it
can be used on both dma coherent and non-coherent DMA platforms, but
I suspect it has been buggy on the non-coherent platforms all along.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

DMA_ATTR_NON_CONSISTENT is a no-op except on PA-RISC and a few MIPS
configs, so don't set it in this ARM specific driver part.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

DMA_ATTR_NON_CONSISTENT is a no-op except on PA-RISC and a few MIPS
configs, so don't set it in this ARM specific driver.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

To prevent a compiler error when a method call alloc_pages is
added (which I plan to for the dma_map_ops).
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Merge branch 'master' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into dma-mapping-for-next

Pull in the latest 5.9 tree for the commit to revert the
V4L2_FLAG_MEMORY_NON_CONSISTENT uapi addition.

Switch the omap1510 platform ohci device to use dma_direct_set_offset
to set the DMA offset instead of using direct hooks into the DMA
mapping code and remove the now unused hooks.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NJanusz Krzysztofik <jmkrzyszt@gmail.com>
Acked-by: NTony Lindgren <tony@atomide.com>

Move the comment documenting dma_addr_t away from the dma_map_ops
definition which isn't very related to it, and toward DMA_MAPPING_ERROR,
which is somewhat related.  Add a little blurb about DMA_MAPPING_ERROR
as well.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Move the valid_dma_direction helper to a more suitable header, and
clean it up to use the proper enum as well as removing pointless braces.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This value is only used by a PCMCIA driver and not very useful.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NDominik Brodowski <linux@dominikbrodwski.net>

Pull MMC fix from Ulf Hansson:
 "Fix build warning in mmc_spi when CONFIG_HAS_DMA is unset"

* tag 'mmc-v5.9-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: mmc_spi: Fix mmc_spi_dma_alloc() return type for !HAS_DMA

Pull media fixes from Mauro Carvalho Chehab:

 - fix a regression at the CEC adapter core

 - two uAPI patches (one revert) for changes in this development cycle

* tag 'media/v5.9-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: dt-bindings: media: imx274: Convert to json-schema
  media: media/v4l2: remove V4L2_FLAG_MEMORY_NON_CONSISTENT flag
  media: cec-adap.c: don't use flush_scheduled_work()

Pull sound fixes from Takashi Iwai:
 "Just a handful small device-specific fixes including a couple of
  reverts"

* tag 'sound-5.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  Revert "ALSA: usb-audio: Disable Lenovo P620 Rear line-in volume control"
  Revert "ALSA: hda - Fix silent audio output and corrupted input on MSI X570-A PRO"
  ALSA: usb-audio: Add delay quirk for H570e USB headsets
  ALSA: hda/realtek: Enable front panel headset LED on Lenovo ThinkStation P520
  ALSA: hda/realtek - Couldn't detect Mic if booting with headset plugged
  ALSA: asihpi: fix iounmap in error handler

Commit 09854ba9 ("mm: do_wp_page() simplification") reorganized all
the code around the page re-use vs copy, but in the process also moved
the final unlock_page() around to after the wp_page_reuse() call.

That normally doesn't matter - but it means that the unlock_page() is
now done after releasing the page table lock.  Again, not a big deal,
you'd think.

But it turns out that it's very wrong indeed, because once we've
released the page table lock, we've basically lost our only reference to
the page - the page tables - and it could now be free'd at any time.  We
do hold the mmap_sem, so no actual unmap() can happen, but madvise can
come in and a MADV_DONTNEED will zap the page range - and free the page.

So now the page may be free'd just as we're unlocking it, which in turn
will usually trigger a "Bad page state" error in the freeing path.  To
make matters more confusing, by the time the debug code prints out the
page state, the unlock has typically completed and everything looks fine
again.

This all doesn't happen in any normal situations, but it does trigger
with the dirtyc0w_child LTP test.  And it seems to trigger much more
easily (but not expclusively) on s390 than elsewhere, probably because
s390 doesn't do the "batch pages up for freeing after the TLB flush"
that gives the unlock_page() more time to complete and makes the race
harder to hit.

Fixes: 09854ba9 ("mm: do_wp_page() simplification")
Link: https://lore.kernel.org/lkml/a46e9bbef2ed4e17778f5615e818526ef848d791.camel@redhat.com/
Link: https://lore.kernel.org/linux-mm/c41149a8-211e-390b-af1d-d5eee690fecb@linux.alibaba.com/Reported-by: NQian Cai <cai@redhat.com>
Reported-by: NAlex Shi <alex.shi@linux.alibaba.com>
Bisected-and-analyzed-by: NGerald Schaefer <gerald.schaefer@linux.ibm.com>
Tested-by: NGerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull bootconfig fixes from Steven Rostedt:
 "A couple of fixes for bootconfig.

  Masami discovered two bugs which this fixes and he added tests to
  cover these issues.

   - Fix a bug that breaks bootconfig tree nodes

   - Fix a bug that does not truncate whitespace properly

   - Add tests to cover the above two cases"

* tag 'trace-v5.9-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tools/bootconfig: Add testcase for tailing space
  tools/bootconfig: Add testcases for repeated key with brace
  lib/bootconfig: Fix to remove tailing spaces after value
  lib/bootconfig: Fix a bug of breaking existing tree nodes

Merge tag 'for-5.9/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - DM core fix for incorrect double bio splitting. Keep "fixing" this
   because past attempts didn't fully appreciate the liability relative
   to recursive bio splitting. This fix limits DM's bio splitting to a
   single method and does _not_ use blk_queue_split() for normal IO.

 - DM crypt Documentation updates for features added during 5.9 merge.

* tag 'for-5.9/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm crypt: document encrypted keyring key option
  dm crypt: document new no_workqueue flags
  dm: fix comment in dm_process_bio()
  dm: fix bio splitting and its bio completion order for regular IO

Pull btrfs fixes from David Sterba:
 "syzkaller started to hit us with reports, here's a fix for one type
  (stack overflow when printing checksums on read error).

  The other patch is a fix for sysfs object, we have a test for that and
  it leads to a crash."

* tag 'for-5.9-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix put of uninitialized kobject after seed device delete
  btrfs: fix overflow when copying corrupt csums for a message

This completes the split of the non-present and present pte cases by
moving the check for the source pte being present into the single
caller, which also means that we clearly separate out the very different
return value case for a non-present pte.

The present pte case currently always succeeds.

This is a pure code re-organization with no semantic change: the intent
is to make it much easier to add a new return case to the present pte
case for when we do early COW at page table copy time.

This was split out from the previous commit simply to make it easy to
visually see that there were no semantic changes from this code
re-organization.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a purely mechanical split of the copy_one_pte() function.  It's
not immediately obvious when looking at the diff because of the
indentation change, but the way to see what is going on in this commit
is to use the "-w" flag to not show pure whitespace changes, and you see
how the first part of copy_one_pte() is simply lifted out into a
separate function.

And since the non-present case is marked unlikely, don't make the new
function be inlined.  Not that gcc really seems to care, since it looks
like it will inline it anyway due to the whole "single callsite for
static function" logic.  In fact, code generation with the function
split is almost identical to before.  But not marking it inline is the
right thing to do.

This is pure prep-work and cleanup for subsequent changes.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull vfs fixes from Al Viro:
 "No common topic, just assorted fixes"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fuse: fix the ->direct_IO() treatment of iov_iter
  fs: fix cast in fsparam_u32hex() macro
  vboxsf: Fix the check for the old binary mount-arguments struct

Pull networking fixes from Jakub Kicinski:

 - fix failure to add bond interfaces to a bridge, the offload-handling
   code was too defensive there and recent refactoring unearthed that.
   Users complained (Ido)

 - fix unnecessarily reflecting ECN bits within TOS values / QoS marking
   in TCP ACK and reset packets (Wei)

 - fix a deadlock with bpf iterator. Hopefully we're in the clear on
   this front now... (Yonghong)

 - BPF fix for clobbering r2 in bpf_gen_ld_abs (Daniel)

 - fix AQL on mt76 devices with FW rate control and add a couple of AQL
   issues in mac80211 code (Felix)

 - fix authentication issue with mwifiex (Maximilian)

 - WiFi connectivity fix: revert IGTK support in ti/wlcore (Mauro)

 - fix exception handling for multipath routes via same device (David
   Ahern)

 - revert back to a BH spin lock flavor for nsid_lock: there are paths
   which do require the BH context protection (Taehee)

 - fix interrupt / queue / NAPI handling in the lantiq driver (Hauke)

 - fix ife module load deadlock (Cong)

 - make an adjustment to netlink reply message type for code added in
   this release (the sole change touching uAPI here) (Michal)

 - a number of fixes for small NXP and Microchip switches (Vladimir)

[ Pull request acked by David: "you can expect more of this in the
  future as I try to delegate more things to Jakub" ]

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (167 commits)
  net: mscc: ocelot: fix some key offsets for IP4_TCP_UDP VCAP IS2 entries
  net: dsa: seville: fix some key offsets for IP4_TCP_UDP VCAP IS2 entries
  net: dsa: felix: fix some key offsets for IP4_TCP_UDP VCAP IS2 entries
  inet_diag: validate INET_DIAG_REQ_PROTOCOL attribute
  net: bridge: br_vlan_get_pvid_rcu() should dereference the VLAN group under RCU
  net: Update MAINTAINERS for MediaTek switch driver
  net/mlx5e: mlx5e_fec_in_caps() returns a boolean
  net/mlx5e: kTLS, Avoid kzalloc(GFP_KERNEL) under spinlock
  net/mlx5e: kTLS, Fix leak on resync error flow
  net/mlx5e: kTLS, Add missing dma_unmap in RX resync
  net/mlx5e: kTLS, Fix napi sync and possible use-after-free
  net/mlx5e: TLS, Do not expose FPGA TLS counter if not supported
  net/mlx5e: Fix using wrong stats_grps in mlx5e_update_ndo_stats()
  net/mlx5e: Fix multicast counter not up-to-date in "ip -s"
  net/mlx5e: Fix endianness when calculating pedit mask first bit
  net/mlx5e: Enable adding peer miss rules only if merged eswitch is supported
  net/mlx5e: CT: Fix freeing ct_label mapping
  net/mlx5e: Fix memory leak of tunnel info when rule under multipath not ready
  net/mlx5e: Use synchronize_rcu to sync with NAPI
  net/mlx5e: Use RCU to protect rq->xdp_prog
  ...

Pull io_uring fixes from Jens Axboe:
 "A few fixes - most of them regression fixes from this cycle, but also
  a few stable heading fixes, and a build fix for the included demo tool
  since some systems now actually have gettid() available"

* tag 'io_uring-5.9-2020-09-22' of git://git.kernel.dk/linux-block:
  io_uring: fix openat/openat2 unified prep handling
  io_uring: mark statx/files_update/epoll_ctl as non-SQPOLL
  tools/io_uring: fix compile breakage
  io_uring: don't use retry based buffered reads for non-async bdev
  io_uring: don't re-setup vecs/iter in io_resumit_prep() is already there
  io_uring: don't run task work on an exiting task
  io_uring: drop 'ctx' ref on task work cancelation
  io_uring: grab any needed state during defer prep