[GIT PULL] RISC-V changes for 4.16

[Palmer Dabbelt]

The following changes since commit d8a5b80568a9cb66810e75b182018e9edb68e8ff:

  Linux 4.15 (2018-01-28 13:20:33 -0800)

are available in the git repository at:

  ssh://git@gitolite.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux.git tags/riscv-for-linus-4.16-merge_window
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gpg:                 aka "Palmer Dabbelt <palmer at sifive.com>" [ultimate]

for you to fetch changes up to 4889dec6c87d90619cc1e8436327b91f4bb0e467:

  riscv: inline set_pgdir into its only caller (2018-01-30 19:16:17 -0800)

----------------------------------------------------------------
RISC-V changes for 4.16

This tag contains the fixes we'd like to target for the 4.16 merge
window.  It's not as much as I was originally hoping to do but between
glibc, the chip, and FOSDEM there just wasn't enough time to get
everything put together.  As such, this merge window is essentially just
going to be small changes.  This includes mostly cleanups:

* A build fix failure to the audit test cases.  RISC-V doesn't have
  renameat because the generic syscall ABI moved to renameat2 by the
  time of our port.  The syscall audit test cases don't understand this,
  so I added a trivial fix.  This went through mailing list review
  during the 4.15 merge window, but nobody has picked it up so I think
  it's best to just do this here.
* The removal of our command-line argument processing code.  The
  "mem_end" stuff was broken and the rest duplicated generic device tree
  code.  The generic code was already being called.
* Some unused/redundant code has been removed, including
  __ARCH_HAVE_MMU, current_pgdir, and the initialization of init_mm.pgd.
* SUM is disabled upon taking a trap, which means that user memory is
  protected during traps taking inside copy_{to,from}_user().
* The sptbr CSR has been renamed to satp in C code.  We haven't changed
  the assembly code in order to maintain compatibility with binutils
  2.29, which doesn't understand the new name.

Additionally, we're adding some new features:

* Basic ftrace support, thanks to Alan Kao!
* Support for ZONE_DMA32.  This is necessary for all the normal reasons,
  but also to deal with a deficiency in the Xilinx PCIe controller we're
  using on our FPGA-based systems.  While the ZONE_DMA32 addition should
  be sufficient for most uses, it doesn't complete the fix for the
  Xilinx controller.
* TLB shootdowns now only target the harts where they're necessary,
  instead of applying to all harts in the system.

These patches have all been sitting on our linux-next branch for a while
now.  Due to time constraints this is all I feel comfortable submitting
during the 4.16 merge window, hopefully we'll do better next time!

----------------------------------------------------------------
Alan Kao (1):
      riscv/ftrace: Add basic support

Andrew Waterman (1):
      RISC-V: Limit the scope of TLB shootdowns

Christoph Hellwig (6):
      riscv: disable SUM in the exception handler
      riscv: add ZONE_DMA32
      riscv: remove the unused current_pgdir function
      riscv: don't read back satp in paging_init
      riscv: rename sptbr to satp
      riscv: inline set_pgdir into its only caller

Michael Clark (1):
      RISC-V: Remove duplicate command-line parsing logic

Palmer Dabbelt (2):
      audit: Avoid build failures on systems without renameat
      RISC-V: Remove mem_end command line processing

Tobias Klauser (2):
      riscv: remove unused __ARCH_HAVE_MMU define
      riscv: remove redundant unlikely()

 arch/riscv/Kconfig                    |  10 +++
 arch/riscv/include/asm/Kbuild         |   1 -
 arch/riscv/include/asm/csr.h          |  14 ++--
 arch/riscv/include/asm/ftrace.h       |  10 +++
 arch/riscv/include/asm/mmu_context.h  |  17 ++---
 arch/riscv/include/asm/tlbflush.h     |  20 +++---
 arch/riscv/include/asm/unistd.h       |   1 -
 arch/riscv/kernel/Makefile            |   7 ++
 arch/riscv/kernel/entry.S             |   9 ++-
 arch/riscv/kernel/ftrace.c            |  41 +++++++++++
 arch/riscv/kernel/head.S              |   6 +-
 arch/riscv/kernel/mcount.S            | 126 ++++++++++++++++++++++++++++++++++
 arch/riscv/kernel/setup.c             |  44 +++---------
 arch/riscv/kernel/vdso.c              |   2 +-
 arch/riscv/mm/fault.c                 |   4 ++
 arch/riscv/mm/init.c                  |  12 ++--
 include/asm-generic/audit_dir_write.h |   2 +
 17 files changed, 250 insertions(+), 76 deletions(-)
 create mode 100644 arch/riscv/include/asm/ftrace.h
 create mode 100644 arch/riscv/kernel/ftrace.c
 create mode 100644 arch/riscv/kernel/mcount.S