| Message ID | 159062136234.2192412.7285856919306307817.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Renovate memcpy_mcsafe with copy_mc_to_{user, kernel} | expand |
On Wed, May 27, 2020 at 4:32 PM Dan Williams <dan.j.williams@intel.com> 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@dwillia2-desk3.amr.corp.intel.com > > --- > > 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
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@dwillia2-desk3.amr.corp.intel.com --- 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. --- 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