[00/37] MIPS: barriers & atomics cleanups

Message

Paul Burton Sept. 30, 2019, 11:08 p.m. UTC

This series consists of a bunch of cleanups to the way we handle memory
barriers (though no changes to the sync instructions we use to implement
them) & atomic memory accesses. One major goal was to ensure the
Loongson3 LL/SC errata workarounds are applied in a safe manner from
within inline-asm & that we can automatically verify the resulting
kernel binary looks reasonable. Many patches are cleanups found along
the way.

Applies atop v5.4-rc1.

Paul Burton (37):
  MIPS: Unify sc beqz definition
  MIPS: Use compact branch for LL/SC loops on MIPSr6+
  MIPS: barrier: Add __SYNC() infrastructure
  MIPS: barrier: Clean up rmb() & wmb() definitions
  MIPS: barrier: Clean up __smp_mb() definition
  MIPS: barrier: Remove fast_mb() Octeon #ifdef'ery
  MIPS: barrier: Clean up __sync() definition
  MIPS: barrier: Clean up sync_ginv()
  MIPS: atomic: Fix whitespace in ATOMIC_OP macros
  MIPS: atomic: Handle !kernel_uses_llsc first
  MIPS: atomic: Use one macro to generate 32b & 64b functions
  MIPS: atomic: Emit Loongson3 sync workarounds within asm
  MIPS: atomic: Use _atomic barriers in atomic_sub_if_positive()
  MIPS: atomic: Unify 32b & 64b sub_if_positive
  MIPS: atomic: Deduplicate 32b & 64b read, set, xchg, cmpxchg
  MIPS: bitops: Use generic builtin ffs/fls; drop cpu_has_clo_clz
  MIPS: bitops: Handle !kernel_uses_llsc first
  MIPS: bitops: Only use ins for bit 16 or higher
  MIPS: bitops: Use MIPS_ISA_REV, not #ifdefs
  MIPS: bitops: ins start position is always an immediate
  MIPS: bitops: Implement test_and_set_bit() in terms of _lock variant
  MIPS: bitops: Allow immediates in test_and_{set,clear,change}_bit
  MIPS: bitops: Use the BIT() macro
  MIPS: bitops: Avoid redundant zero-comparison for non-LLSC
  MIPS: bitops: Abstract LL/SC loops
  MIPS: bitops: Use BIT_WORD() & BITS_PER_LONG
  MIPS: bitops: Emit Loongson3 sync workarounds within asm
  MIPS: bitops: Use smp_mb__before_atomic in test_* ops
  MIPS: cmpxchg: Emit Loongson3 sync workarounds within asm
  MIPS: cmpxchg: Omit redundant barriers for Loongson3
  MIPS: futex: Emit Loongson3 sync workarounds within asm
  MIPS: syscall: Emit Loongson3 sync workarounds within asm
  MIPS: barrier: Remove loongson_llsc_mb()
  MIPS: barrier: Make __smp_mb__before_atomic() a no-op for Loongson3
  MIPS: genex: Add Loongson3 LL/SC workaround to ejtag_debug_handler
  MIPS: genex: Don't reload address unnecessarily
  MIPS: Check Loongson3 LL/SC errata workaround correctness

 arch/mips/Makefile                            |   2 +-
 arch/mips/Makefile.postlink                   |  10 +-
 arch/mips/include/asm/atomic.h                | 571 ++++++-----------
 arch/mips/include/asm/barrier.h               | 215 +------
 arch/mips/include/asm/bitops.h                | 593 ++++--------------
 arch/mips/include/asm/cmpxchg.h               |  59 +-
 arch/mips/include/asm/cpu-features.h          |  10 -
 arch/mips/include/asm/futex.h                 |   9 +-
 arch/mips/include/asm/llsc.h                  |  19 +-
 .../asm/mach-malta/cpu-feature-overrides.h    |   2 -
 arch/mips/include/asm/sync.h                  | 207 ++++++
 arch/mips/kernel/genex.S                      |   6 +-
 arch/mips/kernel/pm-cps.c                     |  20 +-
 arch/mips/kernel/syscall.c                    |   3 +-
 arch/mips/lib/bitops.c                        |  57 +-
 arch/mips/loongson64/Platform                 |   2 +-
 arch/mips/tools/.gitignore                    |   1 +
 arch/mips/tools/Makefile                      |   5 +
 arch/mips/tools/loongson3-llsc-check.c        | 307 +++++++++
 19 files changed, 975 insertions(+), 1123 deletions(-)
 create mode 100644 arch/mips/include/asm/sync.h
 create mode 100644 arch/mips/tools/loongson3-llsc-check.c