On Wed, May 27, 2020 at 4:32 PM Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > Changes since v4 [1]: > - Fix up .gitignore for PowerPC test artifacts (Michael) > > - Collect Michael's Ack. > > [1]: http://lore.kernel.org/r/159010126119.975921.6614194205409771984.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx > > --- > > The primary motivation to go touch memcpy_mcsafe() is that the existing > benefit of doing slow "handle with care" copies is obviated on newer > CPUs. With that concern lifted it also obviates the need to continue to > update the MCA-recovery capability detection code currently gated by > "mcsafe_key". Now the old "mcsafe_key" opt-in to perform the copy with > concerns for recovery fragility can instead be made an opt-out from the > default fast copy implementation (enable_copy_mc_fragile()). > > The discussion with Linus on the first iteration of this patch > identified that memcpy_mcsafe() was misnamed relative to its usage. The > new names copy_mc_to_user() and copy_mc_to_kernel() clearly indicate the > intended use case and lets the architecture organize the implementation > accordingly. > > For both powerpc and x86 a copy_mc_generic() implementation is added as > the backend for these interfaces. > > Patches are relative to tip/master. I have not heard any additional feedback, or seen tip-bot traffic. Is this still under consideration for v5.8? The kernel's behavior on new platforms regresses without this, recoverable #MC escalates to panic. > > --- > > Dan Williams (2): > x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user,kernel}() > x86/copy_mc: Introduce copy_mc_generic() > > > arch/powerpc/Kconfig | 2 > arch/powerpc/include/asm/string.h | 2 > arch/powerpc/include/asm/uaccess.h | 40 +++-- > arch/powerpc/lib/Makefile | 2 > arch/powerpc/lib/copy_mc_64.S | 4 > arch/x86/Kconfig | 2 > arch/x86/Kconfig.debug | 2 > arch/x86/include/asm/copy_mc_test.h | 75 +++++++++ > arch/x86/include/asm/mcsafe_test.h | 75 --------- > arch/x86/include/asm/string_64.h | 32 ---- > arch/x86/include/asm/uaccess.h | 21 +++ > arch/x86/include/asm/uaccess_64.h | 20 -- > arch/x86/kernel/cpu/mce/core.c | 8 - > arch/x86/kernel/quirks.c | 9 - > arch/x86/lib/Makefile | 1 > arch/x86/lib/copy_mc.c | 64 ++++++++ > arch/x86/lib/copy_mc_64.S | 165 ++++++++++++++++++++ > arch/x86/lib/memcpy_64.S | 115 -------------- > arch/x86/lib/usercopy_64.c | 21 --- > drivers/md/dm-writecache.c | 15 +- > drivers/nvdimm/claim.c | 2 > drivers/nvdimm/pmem.c | 6 - > include/linux/string.h | 9 - > include/linux/uaccess.h | 9 + > include/linux/uio.h | 10 + > lib/Kconfig | 7 + > lib/iov_iter.c | 43 +++-- > tools/arch/x86/include/asm/mcsafe_test.h | 13 -- > tools/arch/x86/lib/memcpy_64.S | 115 -------------- > tools/objtool/check.c | 5 - > tools/perf/bench/Build | 1 > tools/perf/bench/mem-memcpy-x86-64-lib.c | 24 --- > tools/testing/nvdimm/test/nfit.c | 48 +++--- > .../testing/selftests/powerpc/copyloops/.gitignore | 2 > tools/testing/selftests/powerpc/copyloops/Makefile | 6 - > .../selftests/powerpc/copyloops/copy_mc_64.S | 1 > .../selftests/powerpc/copyloops/memcpy_mcsafe_64.S | 1 > 37 files changed, 451 insertions(+), 526 deletions(-) > rename arch/powerpc/lib/{memcpy_mcsafe_64.S => copy_mc_64.S} (98%) > create mode 100644 arch/x86/include/asm/copy_mc_test.h > delete mode 100644 arch/x86/include/asm/mcsafe_test.h > create mode 100644 arch/x86/lib/copy_mc.c > create mode 100644 arch/x86/lib/copy_mc_64.S > delete mode 100644 tools/arch/x86/include/asm/mcsafe_test.h > delete mode 100644 tools/perf/bench/mem-memcpy-x86-64-lib.c > create mode 120000 tools/testing/selftests/powerpc/copyloops/copy_mc_64.S > delete mode 120000 tools/testing/selftests/powerpc/copyloops/memcpy_mcsafe_64.S > > base-commit: 229aaa8c059f2c908e0561453509f996f2b2d5c4
