Some time ago, Sam pointed out a certain degree of overwrap between
generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121

)

I tweaked the meaning of mandatory-y a little bit; now it defines the
minimum set of ASM headers that all architectures must have.

If arch does not have specific implementation of a mandatory header,
Kbuild will let it fallback to the asm-generic one by automatically
generating a wrapper. This will allow to drop lots of redundant
generic-y defines.

Previously, "mandatory" was used in the context of UAPI, but I guess
this can be extended to kernel space ASM headers.

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

These comments are leftovers of commit fcc8487d

 ("uapi: export all
headers under uapi directories").

Prior to that commit, exported headers must be explicitly added to
header-y. Now, all headers under the uapi/ directories are exported.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This commit removes redundant generic-y defines in
arch/riscv/include/asm/Kbuild.

[1] It is redundant to define the same generic-y in both
    arch/$(ARCH)/include/asm/Kbuild and
    arch/$(ARCH)/include/uapi/asm/Kbuild.

    Remove the following generic-y:

      errno.h
      fcntl.h
      ioctl.h
      ioctls.h
      ipcbuf.h
      mman.h
      msgbuf.h
      param.h
      poll.h
      posix_types.h
      resource.h
      sembuf.h
      setup.h
      shmbuf.h
      signal.h
      socket.h
      sockios.h
      stat.h
      statfs.h
      swab.h
      termbits.h
      termios.h
      types.h

[2] It is redundant to define generic-y when arch-specific
    implementation exists in arch/$(ARCH)/include/asm/*.h

    Remove the following generic-y:

      cacheflush.h
      module.h

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

filechk_* rules often consist of multiple 'echo' lines. They must be
surrounded with { } or ( ) to work correctly. Otherwise, only the
string from the last 'echo' would be written into the target.

Let's take care of that in the 'filechk' in scripts/Kbuild.include
to clean up filechk_* rules.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Since commit 9c2af1c7

 ("kbuild: add .DELETE_ON_ERROR special
target"), the target file is automatically deleted on failure.

The boilerplate code

  ... || { rm -f $@; false; }

is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Commit 3a2429e1 ("kbuild: change if_changed_rule for multi-line
recipe") and commit 4f0e3a57

 ("kbuild: Add support for DT binding
schema checks") came in via different sub-systems.

This is a follow-up cleanup.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

The only/last user of UIMAGE_IN/OUT was removed by commit 4722a3e6


("microblaze: fix multiple bugs in arch/microblaze/boot/Makefile").

The input and output should always be $< and $@.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>

As mentioned in the info pages of gas, the '.align' pseudo op's
interpretation of the alignment value is architecture specific.
It might either be a byte value or taken to the power of two.

On ARM it's actually the latter which leads to unnecessary large
alignments of 16 bytes for 32 bit builds or 256 bytes for 64 bit
builds.

Fix this by switching to '.balign' instead which is consistent
across all architectures.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Coccinelle doesn't always have access to the values of named
(#define) constants, and they may likely often be bound to true
and false values anyway, resulting in false positives.  So stop
warning about them.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Avoid reporting on the use of an iterator index variable when
the variable is redeclared.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This has never been used.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This commit removes redundant generic-y defines in
arch/nds32/include/asm/Kbuild.

[1] It is redundant to define the same generic-y in both
    arch/$(ARCH)/include/asm/Kbuild and
    arch/$(ARCH)/include/uapi/asm/Kbuild.

    Remove the following generic-y:

      bitsperlong.h
      bpf_perf_event.h
      errno.h
      fcntl.h
      ioctl.h
      ioctls.h
      mman.h
      shmbuf.h
      stat.h

[2] It is redundant to define generic-y when arch-specific
    implementation exists in arch/$(ARCH)/include/asm/*.h

    Remove the following generic-y:

      ftrace.h

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

kernel/dma/Kconfig globally defines HAS_DMA as follows:

  config HAS_DMA
          bool
          depends on !NO_DMA
          default y

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Pull thermal management updates from Zhang Rui:

 - Add locking for cooling device sysfs attribute in case the cooling
   device state is changed by userspace and thermal framework
   simultaneously. (Thara Gopinath)

 - Fix a problem that passive cooling is reset improperly after system
   suspend/resume. (Wei Wang)

 - Cleanup the driver/thermal/ directory by moving intel and qcom
   platform specific drivers to platform specific sub-directories. (Amit
   Kucheria)

 - Some trivial cleanups. (Lukasz Luba, Wolfram Sang)

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal/intel: fixup for Kconfig string parsing tightening up
  drivers: thermal: Move QCOM_SPMI_TEMP_ALARM into the qcom subdir
  drivers: thermal: Move various drivers for intel platforms into a subdir
  thermal: Fix locking in cooling device sysfs update cur_state
  Thermal: do not clear passive state during system sleep
  thermal: zx2967_thermal: simplify getting .driver_data
  thermal: st: st_thermal: simplify getting .driver_data
  thermal: spear_thermal: simplify getting .driver_data
  thermal: rockchip_thermal: simplify getting .driver_data
  thermal: int340x_thermal: int3400_thermal: simplify getting .driver_data
  thermal: remove unused function parameter

Pull thermal SoC updates from Eduardo Valentin:

 - Tegra DT binding documentation for Tegra194

 - Armada now supports ap806 and cp110

 - RCAR thermal now supports R8A774C0 and R8A77990

 - Fixes on thermal_hwmon, IMX, generic-ADC, ST, RCAR, Broadcom,
   Uniphier, QCOM, Tegra, PowerClamp, and Armada thermal drivers.

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal: (22 commits)
  thermal: generic-adc: Fix adc to temp interpolation
  thermal: rcar_thermal: add R8A77990 support
  dt-bindings: thermal: rcar-thermal: add R8A77990 support
  thermal: rcar_thermal: add R8A774C0 support
  dt-bindings: thermal: rcar-thermal: add R8A774C0 support
  dt-bindings: cp110: document the thermal interrupt capabilities
  dt-bindings: ap806: document the thermal interrupt capabilities
  MAINTAINERS: thermal: add entry for Marvell MVEBU thermal driver
  thermal: armada: add overheat interrupt support
  thermal: st: fix Makefile typo
  thermal: uniphier: Convert to SPDX identifier
  thermal/intel_powerclamp: Change to use DEFINE_SHOW_ATTRIBUTE macro
  thermal: tegra: soctherm: Change to use DEFINE_SHOW_ATTRIBUTE macro
  dt-bindings: thermal: tegra-bpmp: Add Tegra194 support
  thermal: imx: save one condition block for normal case of nvmem initialization
  thermal: imx: fix for dependency on cpu-freq
  thermal: tsens: qcom: do not create duplicate regmap debugfs entries
  thermal: armada: Use PTR_ERR_OR_ZERO in armada_thermal_probe_legacy()
  dt-bindings: thermal: rcar-gen3-thermal: All variants use 3 interrupts
  thermal: broadcom: use devm_thermal_zone_of_sensor_register
  ...

Pull ftrace sh build fix from Steven Rostedt:
 "It appears that the zero-day bot did find a bug in my sh build.

  And that I didn't have the bad code in my config file when I cross
  compiled it, although there are a few other errors in sh that makes it
  not build for me, I missed that I added one more"

* tag 'trace-v4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  sh: ftrace: Fix missing parenthesis in WARN_ON()

Pull smb3 fixes from Steve French:
 "Three fixes, one for stable, one adds the (most secure) SMB3.1.1
  dialect to default list requested"

* tag '4.21-smb3-small-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: add smb3.1.1 to default dialect list
  cifs: fix confusing warning message on reconnect
  smb3: fix large reads on encrypted connections

Pull iomap maintainer update from Darrick Wong:
 "Christoph Hellwig and I have decided to take responsibility for the fs
  iomap code rather than let it languish further"

* tag 'iomap-4.21-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: take responsibility for the filesystem iomap code

Pull xfs fixlets from Darrick Wong:
 "Remove a couple of unnecessary local variables"

* tag 'xfs-4.21-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: xfs_fsops: drop useless LIST_HEAD
  xfs: xfs_buf: drop useless LIST_HEAD

Pull ceph updates from Ilya Dryomov:
 "A fairly quiet round: a couple of messenger performance improvements
  from myself and a few cap handling fixes from Zheng"

* tag 'ceph-for-4.21-rc1' of git://github.com/ceph/ceph-client:
  ceph: don't encode inode pathes into reconnect message
  ceph: update wanted caps after resuming stale session
  ceph: skip updating 'wanted' caps if caps are already issued
  ceph: don't request excl caps when mount is readonly
  ceph: don't update importing cap's mseq when handing cap export
  libceph: switch more to bool in ceph_tcp_sendmsg()
  libceph: use MSG_SENDPAGE_NOTLAST with ceph_tcp_sendpage()
  libceph: use sock_no_sendpage() as a fallback in ceph_tcp_sendpage()
  libceph: drop last_piece logic from write_partial_message_data()
  ceph: remove redundant assignment
  ceph: cleanup splice_dentry()

Fixes build break on most ARM/ARM64 defconfigs:

  lib/genalloc.c: In function 'gen_pool_add_virt':
  lib/genalloc.c:190:10: error: implicit declaration of function 'vzalloc_node'; did you mean 'kzalloc_node'?
  lib/genalloc.c:190:8: warning: assignment to 'struct gen_pool_chunk *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
  lib/genalloc.c: In function 'gen_pool_destroy':
  lib/genalloc.c:254:3: error: implicit declaration of function 'vfree'; did you mean 'kfree'?

Fixes: 6862d2fc

 ('lib/genalloc.c: use vzalloc_node() to allocate the bitmap')
Cc: Huang Shijie <sjhuang@iluvatar.ai>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Skidanov <alexey.skidanov@intel.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: ->sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_ge...

Pull trivial vfs updates from Al Viro:
 "A few cleanups + Neil's namespace_unlock() optimization"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  exec: make prepare_bprm_creds static
  genheaders: %-<width>s had been there since v6; %-*s - since v7
  VFS: use synchronize_rcu_expedited() in namespace_unlock()
  iov_iter: reduce code duplication

Pull MIPS fixes from Paul Burton:
 "A few early MIPS fixes for 4.21:

   - The Broadcom BCM63xx platform sees a fix for resetting the BCM6368
     ethernet switch, and the removal of a platform device we've never
     had a driver for.

   - The Alchemy platform sees a few fixes for bitrot that occurred
     within the past few cycles.

   - We now enable vectored interrupt support for the MediaTek MT7620
     SoC, which makes sense since they're supported by the SoC but in
     this case also works around a bug relating to the location of
     exception vectors when using a recent version of U-Boot.

   - The atomic64_fetch_*_relaxed() family of functions see a fix for a
     regression in MIPS64 kernels since v4.19.

   - Cavium Octeon III CN7xxx systems will now disable their RGMII
     interfaces rather than attempt to enable them & warn about the lack
     of support for doing so, as they did since initial CN7xx...

Pull powerpc fixes from Michael Ellerman:
 "A fix for the recent access_ok() change, which broke the build. We
  recently added a use of type in order to squash a warning elsewhere
  about type being unused.

  A handful of other minor build fixes, and one defconfig update.

  Thanks to: Christian Lamparter, Christophe Leroy, Diana Craciun,
  Mathieu Malaterre"

* tag 'powerpc-4.21-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Drop use of 'type' from access_ok()
  KVM: PPC: Book3S HV: radix: Fix uninitialized var build error
  powerpc/configs: Add PPC4xx_OCM to ppc40x_defconfig
  powerpc/4xx/ocm: Fix phys_addr_t printf warnings
  powerpc/4xx/ocm: Fix compilation error due to PAGE_KERNEL usage
  powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup'

Pull parisc fix from Helge Deller:
 "Fix boot issues with a series of parisc servers since kernel 4.20.

  Remapping kernel text with set_kernel_text_rw() missed to remap from
  lowest up until the highest huge-page aligned kernel text addresss"

* 'parisc-4.21-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Remap hugepage-aligned pages in set_kernel_text_rw()

Pull h8300 fix from Yoshinori Sato:
 "Build problem fix"

* tag 'for-4.21' of git://git.sourceforge.jp/gitroot/uclinux-h8/linux:
  h8300: pci: Remove local declaration of pcibios_penalize_isa_irq

Pull more ARM SoC updates from Olof Johansson:
 "A few updates that we merged late but are low risk for regressions for
  other platforms (and a few other straggling patches):

   - I mis-tagged the 'drivers' branch, and missed 3 patches. Merged in
     here. They're for a driver for the PL353 SRAM controller and a
     build fix for the qualcomm scm driver.

   - A new platform, RDA Micro RDA8810PL (Cortex-A5 w/ integrated
     Vivante GPU, 256MB RAM, Wifi). This includes some acked
     platform-specific drivers (serial, etc). This also include DTs for
     two boards with this SoC, OrangePi 2G and OrangePi i86.

   - i.MX8 is another new platform (NXP, 4x Cortex-A53 + Cortex-M4, 4K
     video playback offload). This is the first i.MX 64-bit SoC.

   - Some minor updates to Samsung boards (adding a few peripherals in
     DTs).

   - Small rework for SMP bootup on STi platforms.

   - A couple of TEE driver fixes.

   - A couple of new config options (bcm2835 thermal, Uniphier MDMAC)
     enabled in defconfigs"

* tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (27 commits)
  ARM: multi_v7_defconfig: enable CONFIG_UNIPHIER_MDMAC
  arm64: defconfig: Re-enable bcm2835-thermal driver
  MAINTAINERS: Add entry for RDA Micro SoC architecture
  tty: serial: Add RDA8810PL UART driver
  ARM: dts: rda8810pl: Add interrupt support for UART
  dt-bindings: serial: Document RDA Micro UART
  ARM: dts: rda8810pl: Add timer support
  ARM: dts: Add devicetree for OrangePi i96 board
  ARM: dts: Add devicetree for OrangePi 2G IoT board
  ARM: dts: Add devicetree for RDA8810PL SoC
  ARM: Prepare RDA8810PL SoC
  dt-bindings: arm: Document RDA8810PL and reference boards
  dt-bindings: Add RDA Micro vendor prefix
  ARM: sti: remove pen_release and boot_lock
  arm64: dts: exynos: Add Bluetooth chip to TM2(e) boards
  arm64: dts: imx8mq-evk: enable watchdog
  arm64: dts: imx8mq: add watchdog devices
  MAINTAINERS: add i.MX8 DT path to i.MX architecture
  arm64: add support for i.MX8M EVK board
  arm64: add basic DTS for i.MX8MQ
  ...

Pull arm64 fixes from Will Deacon:
 "I'm safely chained back up to my desk, so please pull these arm64
  fixes for -rc1 that address some issues that cropped up during the
  merge window:

   - Prevent KASLR from mapping the top page of the virtual address
     space

   - Fix device-tree probing of SDEI driver

   - Fix incorrect register offset definition in Hisilicon DDRC PMU
     driver

   - Fix compilation issue with older binutils not liking unsigned
     immediates

   - Fix uapi headers so that libc can provide its own sigcontext
     definition

   - Fix handling of private compat syscalls

   - Hook up compat io_pgetevents() syscall for 32-bit tasks

   - Cleanup to arm64 Makefile (including now to avoid silly conflicts)"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: compat: Hook up io_pgetevents() for 32-bit tasks
  arm64: compat: Don't pull syscall number from regs in arm_compat_syscall
  arm64: compat: Avoid sending SIGILL for unallocated syscall numbers
  arm64/sve: Disentangle <uapi/asm/ptrace.h> from <uapi/asm/sigcontext.h>
  arm64/sve: ptrace: Fix SVE_PT_REGS_OFFSET definition
  drivers/perf: hisi: Fixup one DDRC PMU register offset
  arm64: replace arm64-obj-* in Makefile with obj-*
  arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region
  firmware: arm_sdei: Fix DT platform device creation
  firmware: arm_sdei: fix wrong of_node_put() in init function
  arm64: entry: remove unused register aliases
  arm64: smp: Fix compilation error

Pull ARM updates from Russell King:
 "Included in this update:

   - Florian Fainelli noticed that userspace segfaults caused by the
     lack of kernel-userspace helpers was hard to diagnose; we now issue
     a warning when userspace tries to use the helpers but the kernel
     has them disabled.

   - Ben Dooks wants compatibility for the old ATAG serial number with
     DT systems.

   - Some cleanup of assembly by Nicolas Pitre.

   - User accessors optimisation from Vincent Whitchurch.

   - More robust kdump on SMP systems from Yufen Wang.

   - Sebastian Andrzej Siewior noticed problems with the SMP "boot_lock"
     on RT kernels, and so we convert the Versatile series of platforms
     to use a raw spinlock instead, consolidating the Versatile
     implementation. We entirely remove the boot_lock on OMAP systems,
     where it's unnecessary. Further patches for other systems will be
     submitted for the following merge window.

  ...

Pull arch/csky updates from Guo Ren:
 "Here are three main features (cpu_hotplug, basic ftrace, basic perf)
  and some bugfixes:

  Features:
   - Add CPU-hotplug support for SMP
   - Add ftrace with function trace and function graph trace
   - Add Perf support
   - Add EM_CSKY_OLD 39
   - optimize kernel panic print.
   - remove syscall_exit_work

  Bugfixes:
   - fix abiv2 mmap(... O_SYNC) failure
   - fix gdb coredump error
   - remove vdsp implement for kernel
   - fix qemu failure to bootup sometimes
   - fix ftrace call-graph panic
   - fix device tree node reference leak
   - remove meaningless header-y
   - fix save hi,lo,dspcr regs in switch_stack
   - remove unused members in processor.h"

* tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux:
  csky: Add perf support for C-SKY
  csky: Add EM_CSKY_OLD 39
  clocksource/drivers/c-sky: fixup ftrace call-graph panic
  csky: ftrace call graph supported.
  csky: basic ftrace supported
  csky: remove unused members in processor.h
  csky: optimize kernel panic print.
  csky: stacktrace supported.
  csky: CPU-hotplug supported for SMP
  clocksource/drivers/c-sky: fixup qemu fail to bootup sometimes.
  csky: fixup save hi,lo,dspcr regs in switch_stack.
  csky: remove syscall_exit_work
  csky: fixup remove vdsp implement for kernel.
  csky: bugfix gdb coredump error.
  csky: fixup abiv2 mmap(... O_SYNC) failed.
  csky: define syscall_get_arch()
  elf-em.h: add EM_CSKY
  csky: remove meaningless header-y
  csky: Don't leak device tree node reference

Merge more updates from Andrew Morton:

 - procfs updates

 - various misc bits

 - lib/ updates

 - epoll updates

 - autofs

 - fatfs

 - a few more MM bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
  mm/page_io.c: fix polled swap page in
  checkpatch: add Co-developed-by to signature tags
  docs: fix Co-Developed-by docs
  drivers/base/platform.c: kmemleak ignore a known leak
  fs: don't open code lru_to_page()
  fs/: remove caller signal_pending branch predictions
  mm/: remove caller signal_pending branch predictions
  arch/arc/mm/fault.c: remove caller signal_pending_branch predictions
  kernel/sched/: remove caller signal_pending branch predictions
  kernel/locking/mutex.c: remove caller signal_pending branch predictions
  mm: select HAVE_MOVE_PMD on x86 for faster mremap
  mm: speed up mremap by 20x on large regions
  mm: treewide: remove unused address argument from pte_alloc functions
  initramfs: cleanup incomplete ...

Some non-generic ia64 configs don't build swiotlb, and thus should not
pull in the generic non-coherent DMA infrastructure.

Fixes: 68c60834

 ("swiotlb: remove dma_mark_clean")
Reported-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This has been broken forever, and nobody ever really noticed because
it's purely a performance issue.

Long long ago, in commit 6175ddf0 ("x86: Clean up mem*io functions")
Brian Gerst simplified the memory copies to and from iomem, since on
x86, the instructions to access iomem are exactly the same as the
regular instructions.

That is technically true, and things worked, and nobody said anything.
Besides, back then the regular memcpy was pretty simple and worked fine.

Nobody noticed except for David Laight, that is.  David has a testing a
TLP monitor he was writing for an FPGA, and has been occasionally
complaining about how memcpy_toio() writes things one byte at a time.

Which is completely unacceptable from a performance standpoint, even if
it happens to technically work.

The reason it's writing one byte at a time is because while it's
technically true that accesses to iomem are the same as accesses to
regular memory on x86, the _granularity_ (and ordering) of accesses
matter to iomem in ways that they don't matter to regular cached memory.

In particular, when ERMS is set, we default to using "rep movsb" for
larger memory copies.  That is indeed perfectly fine for real memory,
since the whole point is that the CPU is going to do cacheline
optimizations and executes the memory copy efficiently for cached
memory.

With iomem? Not so much.  With iomem, "rep movsb" will indeed work, but
it will copy things one byte at a time. Slowly and ponderously.

Now, originally, back in 2010 when commit 6175ddf0

 was done, we
didn't use ERMS, and this was much less noticeable.

Our normal memcpy() was simpler in other ways too.

Because in fact, it's not just about using the string instructions.  Our
memcpy() these days does things like "read and write overlapping values"
to handle the last bytes of the copy.  Again, for normal memory,
overlapping accesses isn't an issue.  For iomem? It can be.

So this re-introduces the specialized memcpy_toio(), memcpy_fromio() and
memset_io() functions.  It doesn't particularly optimize them, but it
tries to at least not be horrid, or do overlapping accesses.  In fact,
this uses the existing __inline_memcpy() function that we still had
lying around that uses our very traditional "rep movsl" loop followed by
movsw/movsb for the final bytes.

Somebody may decide to try to improve on it, but if we've gone almost a
decade with only one person really ever noticing and complaining, maybe
it's not worth worrying about further, once it's not _completely_ broken?

Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This actually enables the __put_user_goto() functionality in
unsafe_put_user().

For an example of the effect of this, this is the code generated for the

        unsafe_put_user(signo, &infop->si_signo, Efault);

in the waitid() system call:

	movl %ecx,(%rbx)        # signo, MEM[(struct __large_struct *)_2]

It's just one single store instruction, along with generating an
exception table entry pointing to the Efault label case in case that
instruction faults.

Before, we would generate this:

	xorl    %edx, %edx
	movl %ecx,(%rbx)        # signo, MEM[(struct __large_struct *)_3]
        testl   %edx, %edx
        jne     .L309

with the exception table generated for that 'mov' instruction causing us
to jump to a stub that set %edx to -EFAULT and then jumped back to the
'testl' instruction.

So not only do we now get rid of the extra code in the normal sequence,
we also avoid unnecessarily keeping that extra error register live
across it all.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is finally the actual reason for the odd error handling in the
"unsafe_get/put_user()" functions, introduced over three years ago.

Using a "jump to error label" interface is somewhat odd, but very
convenient as a programming interface, and more importantly, it fits
very well with simply making the target be the exception handler address
directly from the inline asm.

The reason it took over three years to actually do this? We need "asm
goto" support for it, which only became the default on x86 last year.
It's now been a year that we've forced asm goto support (see commit
e501ce95

 "x86: Force asm-goto"), and so let's just do it here too.

[ Side note: this commit was originally done back in 2016. The above
  commentary about timing is obviously about it only now getting merged
  into my real upstream tree     - Linus ]

Sadly, gcc still only supports "asm goto" with asms that do not have any
outputs, so we are limited to only the put_user case for this.  Maybe in
several more years we can do the get_user case too.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The alternative coding patch for parisc in kernel 4.20 broke booting
machines with PA8500-PA8700 CPUs. The problem is, that for such machines
the parisc kernel automatically utilizes huge pages to access kernel
text code, but the set_kernel_text_rw() function, which is used shortly
before applying any alternative patches, didn't used the correctly
hugepage-aligned addresses to remap the kernel text read-writeable.

Fixes: 3847dab7

 ("parisc: Add alternative coding infrastructure")
Cc: <stable@vger.kernel.org>	[4.20]
Signed-off-by: Helge Deller <deller@gmx.de>

Merge in a few missing patches from the pull request (my copy of the
branch was behind the staged version in linux-next).

* next/drivers:
  memory: pl353: Add driver for arm pl353 static memory controller
  dt-bindings: memory: Add pl353 smc controller devicetree binding information
  firmware: qcom: scm: fix compilation error when disabled

Signed-off-by: Olof Johansson <olof@lixom.net>

Enable the UniPhier MIO DMAC driver. This is used as the DMA engine
for accelerating the SD/eMMC controller drivers.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Olof Johansson <olof@lixom.net>