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authorBarry Song <song.bao.hua@hisilicon.com>2021-02-23 03:32:30 +0300
committerJonathan Corbet <corbet@lwn.net>2021-03-15 22:17:40 +0300
commit6bfef171d0d74cb050112e0e49feb20bfddf7f42 (patch)
tree698bc8ec8a31a6a345c8ec75dc0d5ba902162573 /Documentation/features
parentd0c4c07e7b38113796aeb7ec57c9f0bb4c3503b0 (diff)
downloadlinux-6bfef171d0d74cb050112e0e49feb20bfddf7f42.tar.xz
Documentation/features: mark BATCHED_UNMAP_TLB_FLUSH doesn't apply to ARM64
BATCHED_UNMAP_TLB_FLUSH is used on x86 to do batched tlb shootdown by sending one IPI to TLB flush all entries after unmapping pages rather than sending an IPI to flush each individual entry. On arm64, tlb shootdown is done by hardware. Flush instructions are innershareable. The local flushes are limited to the boot (1 per CPU) and when a task is getting a new ASID. So marking this feature as "TODO" is not proper. ".." isn't good as well. So this patch adds a "N/A" for this kind of features which are not needed on some architectures. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Acked-by: Will Deacon <will@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210223003230.11976-1-song.bao.hua@hisilicon.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/features')
-rw-r--r--Documentation/features/arch-support.txt1
-rw-r--r--Documentation/features/vm/TLB/arch-support.txt2
2 files changed, 2 insertions, 1 deletions
diff --git a/Documentation/features/arch-support.txt b/Documentation/features/arch-support.txt
index d22a1095e661..118ae031840b 100644
--- a/Documentation/features/arch-support.txt
+++ b/Documentation/features/arch-support.txt
@@ -8,4 +8,5 @@ The meaning of entries in the tables is:
| ok | # feature supported by the architecture
|TODO| # feature not yet supported by the architecture
| .. | # feature cannot be supported by the hardware
+ | N/A| # feature doesn't apply to the architecture
diff --git a/Documentation/features/vm/TLB/arch-support.txt b/Documentation/features/vm/TLB/arch-support.txt
index 48a5ca548399..e1c3a4c4d107 100644
--- a/Documentation/features/vm/TLB/arch-support.txt
+++ b/Documentation/features/vm/TLB/arch-support.txt
@@ -9,7 +9,7 @@
| alpha: | TODO |
| arc: | TODO |
| arm: | TODO |
- | arm64: | TODO |
+ | arm64: | N/A |
| csky: | TODO |
| h8300: | .. |
| hexagon: | TODO |