This allows to dip into zones for lower memory if they are available.
If one of the zones is not available the corresponding GFP_* flag
will evaluate to 0 so they won't change anything.  We provide an
arch tunable for those architectures that do not use GFP_DMA for
the lowest 24-bits, given that there are a few.

Roughly based on the x86 code.
Signed-off-by: Christoph Hellwig <hch@lst.de>

To preserve the x86 behavior.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

Try the CMA allocator for coherent allocations if supported.

Roughly modelled after the x86 code.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Roughly based on the x86 pci-nommu implementation.
Signed-off-by: Christoph Hellwig <hch@lst.de>

This means it uses whatever linear remapping scheme that the architecture
provides is used in the generic dma_direct ops.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>

The trivial direct mapping implementation already does a virtual to
physical translation which isn't strictly a noop, and will soon learn
to do non-direct but linear physical to dma translations through the
device offset and a few small tricks.  Rename it to a better fitting
name.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>

For architectures that just use the generic dma_noop_ops we can provide
a generic version of dma-mapping.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>

To implement the x86 forbid_dac and iommu_sac_force we want an arch hook
so that it can apply the global options across all dma_map_ops
implementations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Lift the code from x86 so that we behave consistently.  In the future we
should probably warn if any of these is set.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]

These days all devices should have a DMA coherent mask, and most dma_ops
implementations rely on that fact.  But just to be sure add an assert to
ring the warning bell if that is not the case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This is not needed in drivers, so move it to a private header.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Always returning 1 is the same behavior as not supplying a method at all.
Signed-off-by: Christoph Hellwig <hch@lst.de>

This frees the dma_direct_* namespace for a generic implementation.
Signed-off-by: Christoph Hellwig <hch@lst.de>

We want to use the dma_direct_ namespace for a generic implementation,
so rename powerpc to the second best choice: dma_nommu_.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Richard Kuo <rkuo@codeaurora.org>

And unlike the other helpers we don't require a <asm/dma-direct.h> as
this helper is a special case for ia64 only, and this keeps it as
simple as possible.
Signed-off-by: Christoph Hellwig <hch@lst.de>

phys_to_dma, dma_to_phys and dma_capable are helpers published by
architecture code for use of swiotlb and xen-swiotlb only.  Drivers are
not supposed to use these directly, but use the DMA API instead.

Move these to a new asm/dma-direct.h helper, included by a
linux/dma-direct.h wrapper that provides the default linear mapping
unless the architecture wants to override it.

In the MIPS case the existing dma-coherent.h is reused for now as
untangling it will take a bit of work.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>

This makes it match the generic version.
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The generic version now takes dma_pfn_offset into account, so there is no
more need for an architecture override.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

This makes sure the generic version can be used with architectures /
devices that have a DMA offset in the direct mapping.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

We always use the stub definitions, so remove the unused other code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Vineet Gupta <vgupta@synopsys.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

CONFIG_ALPHA_JENSEN has failed to compile since commit 6aca0503
("alpha/dma: use common noop dma ops"), so mark it as broken.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Pull parisc fixes from Helge Deller:

 - Many small fixes to show the real physical addresses of devices
   instead of hashed addresses.

 - One important fix to unbreak 32-bit SMP support: We forgot to 16-byte
   align the spinlocks in the assembler code.

 - Qemu support: The host will get a chance to sleep when the parisc
   guest is idle. We use the same mechanism as the power architecture by
   overlaying the "or %r10,%r10,%r10" instruction which is simply a nop
   on real hardware.

* 'parisc-4.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: qemu idle sleep support
  parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
  parisc: Show unhashed EISA EEPROM address
  parisc: Show unhashed HPA of Dino chip
  parisc: Show initial kernel memory layout unhashed
  parisc: Show unhashed hardware inventory

Merge tag 'apparmor-pr-2018-01-07' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor fix from John Johansen:
 "This fixes a regression when the kernel feature set is reported as
  supporting mount and policy is pinned to a feature set that does not
  support mount mediation"

* tag 'apparmor-pr-2018-01-07' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: fix regression in mount mediation when feature set is pinned

Merge tag 'led_fixes_for_4.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fix from Jacek Anaszewski:
 "The commit 2b83ff96 for 4.15-rc6, which was fixing LED brightness
  setting after clearing delay_off broke the behavior on any alteration
  of delay_on{off} properties, due to use of a LED core helper that does
  too much for this particular case"

* tag 'led_fixes_for_4.15-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: core: Fix regression caused by commit 2b83ff96

Pull MTD bugfix from Richard Weinberger:
 "A single fix for the pxa3xx NAND driver"

* tag 'for-linus-20180107' of git://git.infradead.org/linux-mtd:
  mtd: nand: pxa3xx: Fix READOOB implementation

Commit 2b83ff96 ("led: core: Fix brightness setting when setting delay_off=0")
replaced del_timer_sync(&led_cdev->blink_timer) with led_stop_software_blink()
in led_blink_set(), which additionally clears LED_BLINK_SW flag as well as
zeroes blink_delay_on and blink_delay_off properties of the struct led_classdev.

Cleansing of the latter ones wasn't required to fix the original issue but
wasn't considered harmful. It nonetheless turned out to be so in case when
pointer to one or both props is passed to led_blink_set() like in the
ledtrig-timer.c. In such cases zeroes are passed later in delay_on and/or
delay_off arguments to led_blink_setup(), which results either in stopping
the software blinking or setting blinking frequency always to 1Hz.

Avoid using led_stop_software_blink() and add a single call required
to clear LED_BLINK_SW flag, which was the only needed modification to
fix the original issue.

Fixes 2b83ff96 ("led: core: Fix brightness setting when setting delay_off=0")
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

Pull vfs fixes from Al Viro:

 - untangle sys_close() abuses in xt_bpf

 - deal with register_shrinker() failures in sget()

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'"
  sget(): handle failures of register_shrinker()
  mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.

Pull KVM fixes from Radim Krčmář:
 "s390:
   - Two fixes for potential bitmap overruns in the cmma migration code

  x86:
   - Clear guest provided GPRs to defeat the Project Zero PoC for CVE
     2017-5715"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: vmx: Scrub hardware GPRs at VM-exit
  KVM: s390: prevent buffer overrun on memory hotplug during migration
  KVM: s390: fix cmma migration for multiple memory slots

In the current driver, OOB bytes are accessed in raw mode, and when a
page access is done with NDCR_SPARE_EN set and NDCR_ECC_EN cleared, the
driver must read the whole spare area (64 bytes in case of a 2k page,
16 bytes for a 512 page). The driver was only reading the free OOB
bytes, which was leaving some unread data in the FIFO and was somehow
leading to a timeout.

We could patch the driver to read ->spare_size + ->ecc_size instead of
just ->spare_size when READOOB is requested, but we'd better make
in-band and OOB accesses consistent.
Since the driver is always accessing in-band data in non-raw mode (with
the ECC engine enabled), we should also access OOB data in this mode.
That's particularly useful when using the BCH engine because in this
mode the free OOB bytes are also ECC protected.

Fixes: 43bcfd2b ("mtd: nand: pxa3xx: Add driver-specific ECC BCH support")
Cc: stable@vger.kernel.org
Reported-by: Sean Nyekjær <sean.nyekjaer@prevas.dk>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Tested-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Richard Weinberger <richard@nod.at>

Pull powerpc fix from Michael Ellerman:
 "Just one fix to correctly return SEGV_ACCERR when we take a SEGV on a
  mapped region. The bug was introduced in the refactoring of the page
  fault handler we did in the previous release.

  Thanks to John Sperbeck"

* tag 'powerpc-4.15-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Fix SEGV on mapped region to return SEGV_ACCERR

KVM: s390: fixes for cmma migration

Two fixes for potential bitmap overruns in the cmma migration
code.