Pull Xtensa updates from Max Filippov:

 - add support for execute in place (XIP) kernels

 - improvements in inline assembly: use named arguments and "m"
   constraints where possible

 - improve stack dumping

 - clean up system_call code and syscall tracing

 - various small fixes and cleanups

* tag 'xtensa-20191201' of git://github.com/jcmvbkbc/linux-xtensa: (30 commits)
  xtensa: clean up system_call/xtensa_rt_sigreturn interaction
  xtensa: fix system_call interaction with ptrace
  xtensa: rearrange syscall tracing
  xtensa: fix syscall_set_return_value
  xtensa: drop unneeded headers from coprocessor.S
  xtensa: entry: Remove unneeded need_resched() loop
  xtensa: use MEMBLOCK_ALLOC_ANYWHERE for KASAN shadow map
  xtensa: fix TLB sanity checker
  xtensa: get rid of __ARCH_USE_5LEVEL_HACK
  xtensa: mm: fix PMD folding implementation
  xtensa: make stack dump size configurable
  xtensa: improve stack dumping
  xtensa: use "m" constraint instead of "r" in futex.h assembly
  xtensa: use "m" constraint instead of "a" in cmpxchg.h assembly
  xtensa: use named assembly arguments in cmpxchg.h
  xtensa: use "m" constraint instead of "a" in atomic.h assembly
  xtensa: use named assembly arguments in atomic.h
  xtensa: use "m" constraint instead of "a" in bitops.h assembly
  xtensa: use named assembly arguments in bitops.h
  xtensa: use macros to generate *_bit and test_and_*_bit functions
  ...

system_call assembly code always pushes pointer to struct pt_regs as the
last additional parameter for all system calls. The only user of this
feature is xtensa_rt_sigreturn.
Avoid this special case. Define xtensa_rt_sigreturn as accepting no
argiments. Use current_pt_regs to get pointer to struct pt_regs in
xtensa_rt_sigreturn. Don't pass additional parameter from system_call
code.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

system_call saves and restores syscall number across system call to make
clone and execv entry and exit tracing match. This complicates things
when syscall code may be changed by ptrace.
Preserve syscall code in copy_thread and start_thread directly instead of
doing tricks in system_call.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Pull dma-mapping updates from Christoph Hellwig:

 - improve dma-debug scalability (Eric Dumazet)

 - tiny dma-debug cleanup (Dan Carpenter)

 - check for vmap memory in dma_map_single (Kees Cook)

 - check for dma_addr_t overflows in dma-direct when using DMA offsets
   (Nicolas Saenz Julienne)

 - switch the x86 sta2x11 SOC to use more generic DMA code (Nicolas
   Saenz Julienne)

 - fix arm-nommu dma-ranges handling (Vladimir Murzin)

 - use __initdata in CMA (Shyam Saini)

 - replace the bus dma mask with a limit (Nicolas Saenz Julienne)

 - merge the remapping helpers into the main dma-direct flow (me)

 - switch xtensa to the generic dma remap handling (me)

 - various cleanups around dma_capable (me)

 - remove unused dev arguments to various dma-noncoherent helpers (me)

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux:

* tag 'dma-mapping-5.5' of git://git.infradead.org/users/hch/dma-mapping: (22 commits)
  dma-mapping: treat dev->bus_dma_mask as a DMA limit
  dma-direct: exclude dma_direct_map_resource from the min_low_pfn check
  dma-direct: don't check swiotlb=force in dma_direct_map_resource
  dma-debug: clean up put_hash_bucket()
  powerpc: remove support for NULL dev in __phys_to_dma / __dma_to_phys
  dma-direct: avoid a forward declaration for phys_to_dma
  dma-direct: unify the dma_capable definitions
  dma-mapping: drop the dev argument to arch_sync_dma_for_*
  x86/PCI: sta2x11: use default DMA address translation
  dma-direct: check for overflows on 32 bit DMA addresses
  dma-debug: increase HASH_SIZE
  dma-debug: reorder struct dma_debug_entry fields
  xtensa: use the generic uncached segment support
  dma-mapping: merge the generic remapping helpers into dma-direct
  dma-direct: provide mmap and get_sgtable method overrides
  dma-direct: remove the dma_handle argument to __dma_direct_alloc_pages
  dma-direct: remove __dma_direct_free_pages
  usb: core: Remove redundant vmap checks
  kernel: dma-contiguous: mark CMA parameters __initdata/__initconst
  dma-debug: add a schedule point in debug_dma_dump_mappings()
  ...

syscall return value is in the register a2, not a0.

Cc: stable@vger.kernel.org # v5.0+
Fixes: 9f24f3c1067c ("xtensa: implement tracehook functions and enable HAVE_ARCH_TRACEHOOK")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa has 2-level page tables and already uses pgtable-nopmd for page
table folding.

Add walks of p4d level where appropriate and drop usage of
__ARCH_USE_5LEVEL_HACK.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Message-Id: <1572964400-16542-3-git-send-email-rppt@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> [fix up
               arch/xtensa/include/asm/fixmap.h and
               arch/xtensa/mm/tlb.c]

There was a definition of pmd_offset() in arch/xtensa/include/asm/pgtable.h
that shadowed the generic implementation defined in
include/asm-generic/pgtable-nopmd.h.

As the result, xtensa had shortcuts in page table traversal in several
places instead of doing level unfolding.

Remove local override for pmd_offset() and add page table unfolding where
necessary.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Message-Id: <1572964400-16542-2-git-send-email-rppt@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Numeric assembly arguments are hard to understand and assembly code that
uses them is hard to modify. Use named arguments in __cmpxchg_u32 and
xchg_u32.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>