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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-10 08:49:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-10 08:49:37 -0800
commit9b9e211360044c12d7738973c944d6f300134881 (patch)
treef994a379135e70397df3c653e6578ad7e5d295fe /include/asm-generic
parenta7ac314061375c7805e0d3a26aad6eb0c41100df (diff)
parent945409a6ef442cfe5f2f14e5626d4306d53100f0 (diff)
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas: - KCSAN enabled for arm64. - Additional kselftests to exercise the syscall ABI w.r.t. SVE/FPSIMD. - Some more SVE clean-ups and refactoring in preparation for SME support (scalable matrix extensions). - BTI clean-ups (SYM_FUNC macros etc.) - arm64 atomics clean-up and codegen improvements. - HWCAPs for FEAT_AFP (alternate floating point behaviour) and FEAT_RPRESS (increased precision of reciprocal estimate and reciprocal square root estimate). - Use SHA3 instructions to speed-up XOR. - arm64 unwind code refactoring/unification. - Avoid DC (data cache maintenance) instructions when DCZID_EL0.DZP == 1 (potentially set by a hypervisor; user-space already does this). - Perf updates for arm64: support for CI-700, HiSilicon PCIe PMU, Marvell CN10K LLC-TAD PMU, miscellaneous clean-ups. - Other fixes and clean-ups; highlights: fix the handling of erratum 1418040, correct the calculation of the nomap region boundaries, introduce io_stop_wc() mapped to the new DGH instruction (data gathering hint). * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits) arm64: Use correct method to calculate nomap region boundaries arm64: Drop outdated links in comments arm64: perf: Don't register user access sysctl handler multiple times drivers: perf: marvell_cn10k: fix an IS_ERR() vs NULL check perf/smmuv3: Fix unused variable warning when CONFIG_OF=n arm64: errata: Fix exec handling in erratum 1418040 workaround arm64: Unhash early pointer print plus improve comment asm-generic: introduce io_stop_wc() and add implementation for ARM64 arm64: Ensure that the 'bti' macro is defined where linkage.h is included arm64: remove __dma_*_area() aliases docs/arm64: delete a space from tagged-address-abi arm64: Enable KCSAN kselftest/arm64: Add pidbench for floating point syscall cases arm64/fp: Add comments documenting the usage of state restore functions kselftest/arm64: Add a test program to exercise the syscall ABI kselftest/arm64: Allow signal tests to trigger from a function kselftest/arm64: Parameterise ptrace vector length information arm64/sve: Minor clarification of ABI documentation arm64/sve: Generalise vector length configuration prctl() for SME arm64/sve: Make sysctl interface for SVE reusable by SME ...
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/barrier.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index 640f09479bdf..4c2c1b830344 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -251,5 +251,16 @@ do { \
#define pmem_wmb() wmb()
#endif
+/*
+ * ioremap_wc() maps I/O memory as memory with write-combining attributes. For
+ * this kind of memory accesses, the CPU may wait for prior accesses to be
+ * merged with subsequent ones. In some situation, such wait is bad for the
+ * performance. io_stop_wc() can be used to prevent the merging of
+ * write-combining memory accesses before this macro with those after it.
+ */
+#ifndef io_stop_wc
+#define io_stop_wc do { } while (0)
+#endif
+
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_GENERIC_BARRIER_H */