From b7fe54f6c2d437082dcbecfbd832f38edd9caaf4 Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Fri, 8 Jan 2021 23:10:56 +1100 Subject: Documentation: Add L1D flushing Documentation Add documentation of l1d flushing, explain the need for the feature and how it can be used. Signed-off-by: Balbir Singh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210108121056.21940-6-sblbir@amazon.com --- Documentation/userspace-api/spec_ctrl.rst | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation/userspace-api') diff --git a/Documentation/userspace-api/spec_ctrl.rst b/Documentation/userspace-api/spec_ctrl.rst index 7ddd8f667459..5e8ed9eef9aa 100644 --- a/Documentation/userspace-api/spec_ctrl.rst +++ b/Documentation/userspace-api/spec_ctrl.rst @@ -106,3 +106,11 @@ Speculation misfeature controls * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_ENABLE, 0, 0); * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_DISABLE, 0, 0); * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_FORCE_DISABLE, 0, 0); + +- PR_SPEC_L1D_FLUSH: Flush L1D Cache on context switch out of the task + (works only when tasks run on non SMT cores) + + Invocations: + * prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_L1D_FLUSH, 0, 0, 0); + * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_L1D_FLUSH, PR_SPEC_ENABLE, 0, 0); + * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_L1D_FLUSH, PR_SPEC_DISABLE, 0, 0); -- cgit v1.2.3