Pull RISC-V updates from Paul Walmsley:
 "A few minor RISC-V updates for v5.3-rc4:

   - Remove __udivdi3() from the 32-bit Linux port, converting the only
     upstream user to use do_div(), per Linux policy

   - Convert the RISC-V standard clocksource away from per-cpu data
     structures, since only one is used by Linux, even on a multi-CPU
     system

   - A set of DT binding updates that remove an obsolete text binding in
     favor of a YAML binding, fix a bogus compatible string in the
     schema (thus fixing a "make dtbs_check" warning), and clarifies the
     future values expected in one of the RISC-V CPU properties"

* tag 'riscv/for-v5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  dt-bindings: riscv: fix the schema compatible string for the HiFive Unleashed board
  dt-bindings: riscv: remove obsolete cpus.txt
  RISC-V: Remove udivdi3
  riscv: delay: use do_div() instead of __udivdi3()
  dt-bindings: Update the riscv,isa string description
  RISC-V: Remove per cpu clocksource

Pull x86 fixes from Thomas Gleixner:
 "A few fixes for x86:

   - Don't reset the carefully adjusted build flags for the purgatory
     and remove the unwanted flags instead. The 'reset all' approach led
     to build fails under certain circumstances.

   - Unbreak CLANG build of the purgatory by avoiding the builtin
     memcpy/memset implementations.

   - Address missing prototype warnings by including the proper header

   - Fix yet more fall-through issues"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/lib/cpu: Address missing prototypes warning
  x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
  x86/purgatory: Do not use __builtin_memcpy and __builtin_memset
  x86: mtrr: cyrix: Mark expected switch fall-through
  x86/ptrace: Mark expected switch fall-through

A compilation -Wimplicit-fallthrough warning was enabled by commit
a035d552a93b ("Makefile: Globally enable fall-through warning")

Even though clang 10.0.0 does not currently support this warning without
a patch, clang currently does not support a value for this option.

  Link: https://bugs.llvm.org/show_bug.cgi?id=39382

The gcc default for this warning is 3 so removing the =3 has no effect
for gcc and enables the warning for patched versions of clang.

Also remove the =3 from an existing use in a parisc Makefile:
arch/parisc/math-emu/Makefile

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull powerpc fix from Michael Ellerman:
 "Just one fix, a revert of a commit that was meant to be a minor
  improvement to some inline asm, but ended up having no real benefit
  with GCC and broke booting 32-bit machines when using Clang.

  Thanks to: Arnd Bergmann, Christophe Leroy, Nathan Chancellor, Nick
  Desaulniers, Segher Boessenkool"

* tag 'powerpc-5.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  Revert "powerpc: slightly improve cache helpers"

Pull fall-through fixes from Gustavo A. R. Silva:
 "Mark more switch cases where we are expecting to fall through, fixing
  fall-through warnings in arm, sparc64, mips, i386 and s390"

* tag 'Wimplicit-fallthrough-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  ARM: ep93xx: Mark expected switch fall-through
  scsi: fas216: Mark expected switch fall-throughs
  pcmcia: db1xxx_ss: Mark expected switch fall-throughs
  video: fbdev: omapfb_main: Mark expected switch fall-throughs
  watchdog: riowd: Mark expected switch fall-through
  s390/net: Mark expected switch fall-throughs
  crypto: ux500/crypt: Mark expected switch fall-throughs
  watchdog: wdt977: Mark expected switch fall-through
  watchdog: scx200_wdt: Mark expected switch fall-through
  watchdog: Mark expected switch fall-throughs
  ARM: signal: Mark expected switch fall-through
  mfd: omap-usb-host: Mark expected switch fall-throughs
  mfd: db8500-prcmu: Mark expected switch fall-throughs
  ARM: OMAP: dma: Mark expected switch fall-throughs
  ARM: alignment: Mark expected switch fall-throughs
  ARM: tegra: Mark expected switch fall-through
  ARM/hw_breakpoint: Mark expected switch fall-throughs

Mark switch cases where we are expecting to fall through.

Fix the following warnings (Building: arm-ep93xx_defconfig arm):

arch/arm/mach-ep93xx/crunch.c: In function 'crunch_do':
arch/arm/mach-ep93xx/crunch.c:46:3: warning: this statement may
fall through [-Wimplicit-fallthrough=]
      memset(crunch_state, 0, sizeof(*crunch_state));
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/arm/mach-ep93xx/crunch.c:53:2: note: here
     case THREAD_NOTIFY_EXIT:
     ^~~~

Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warning:

arch/arm/kernel/signal.c: In function 'do_signal':
arch/arm/kernel/signal.c:598:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
    restart -= 2;
    ~~~~~~~~^~~~
arch/arm/kernel/signal.c:599:3: note: here
   case -ERESTARTNOHAND:
   ^~~~

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warnings:

arch/arm/plat-omap/dma.c: In function 'omap_set_dma_src_burst_mode':
arch/arm/plat-omap/dma.c:384:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (dma_omap2plus()) {
      ^
arch/arm/plat-omap/dma.c:393:2: note: here
  case OMAP_DMA_DATA_BURST_16:
  ^~~~
arch/arm/plat-omap/dma.c:394:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (dma_omap2plus()) {
      ^
arch/arm/plat-omap/dma.c:402:2: note: here
  default:
  ^~~~~~~
arch/arm/plat-omap/dma.c: In function 'omap_set_dma_dest_burst_mode':
arch/arm/plat-omap/dma.c:473:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (dma_omap2plus()) {
      ^
arch/arm/plat-omap/dma.c:481:2: note: here
  default:
  ^~~~~~~

Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warnings:

arch/arm/mm/alignment.c: In function 'thumb2arm':
arch/arm/mm/alignment.c:688:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if ((tinstr & (3 << 9)) == 0x0400) {
      ^
arch/arm/mm/alignment.c:700:2: note: here
  default:
  ^~~~~~~
arch/arm/mm/alignment.c: In function 'do_alignment_t32_to_handler':
arch/arm/mm/alignment.c:753:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
   poffset->un = (tinst2 & 0xff) << 2;
   ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
arch/arm/mm/alignment.c:754:2: note: here
  case 0xe940:
  ^~~~

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warning:

arch/arm/mach-tegra/reset.c: In function 'tegra_cpu_reset_handler_enable':
arch/arm/mach-tegra/reset.c:72:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
   tegra_cpu_reset_handler_set(reset_address);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm/mach-tegra/reset.c:74:2: note: here
  case 0:
  ^~~~

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>