Messages in this thread Patch in this message | | | From | Kohei Tarumizu <> | Subject | [RFC PATCH 4/4] docs: ABI: Add sysfs documentation interface of hardware prefetch driver | Date | Mon, 11 Oct 2021 13:39:52 +0900 |
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This descrives the sysfs interface implemented on the hardware prefetch driver.
Signed-off-by: Kohei Tarumizu <tarumizu.kohei@fujitsu.com> --- .../ABI/testing/sysfs-devices-system-cpu | 58 +++++++++++++++++++ 1 file changed, 58 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index b46ef1476..caeefd320 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -666,3 +666,61 @@ Description: Preferred MTE tag checking mode ================ ============================================== See also: Documentation/arm64/memory-tagging-extension.rst + +What: /sys/devices/system/cpu/cpu*/hwpf/l*/enable + /sys/devices/system/cpu/cpu*/hwpf/l*/available_dist + /sys/devices/system/cpu/cpu*/hwpf/l*/dist + /sys/devices/system/cpu/cpu*/hwpf/l*/reliable +Date: October 2021 +Contact: Kohei Tarumizu <tarumizu.kohei@fujitsu.com> + Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: Parameters for the hardware prefetch driver + + This sysfs interface provides Hardware Prefetch (HWPF) tunable + attribute files by using implementation defined registers. + These attribute files are corresponding to the cache level of + the parent directory. + + enable: + Read/write interface to change hardware prefetch + enablement. + Read returns hardware prefetch enablement status: + 0: hardware prefetch is enabled + 1: hardware prefetch is disabled + + Write '0' to enable Hardware Prefetch. + Write '1' to disable Hardware Prefetch. + + available_dist: + Read only interface to get a list of values that can be + written to dist. + + dist: + Read/write interface to specify the hardware prefetch + distance. + Read return the current hardware prefetch distance value + in bytes or the string "auto". + + Write either a value in byte read from available_dist, + or the string "auto" to this attribuite. If you write + a value less than these, the value is rounded up. + + The value 0 and the string "auto" are the same and have + a special meaning. This means that instead of setting + dist to a user-specified value, it operates using + hardware-specific values. + + strong: + Read/write interface to change hardware prefetch + strongness. + Strong prefetch operation is surely executed, if there + is no corresponding data in cache. + Weak prefetch operation allows the hardware not to + execute operation depending on hardware state. + + Read returns hardware prefetch strongness status: + 0: hardware prefetch is generated strong + 1: hardware prefetch is generated weak + + Write '0' to hardware prefetch generate strong. + Write '1' to hardware prefetch generate weak. -- 2.27.0
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