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authorBalbir Singh <sblbir@amazon.com>2021-01-08 15:10:56 +0300
committerThomas Gleixner <tglx@linutronix.de>2021-07-28 12:42:25 +0300
commitb7fe54f6c2d437082dcbecfbd832f38edd9caaf4 (patch)
treef0483d05dd7cc20f613c45568b74a4399073863d /Documentation/userspace-api
parente893bb1bb4d2eb635eba61e5d9c5135d96855773 (diff)
downloadlinux-b7fe54f6c2d437082dcbecfbd832f38edd9caaf4.tar.xz
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 <sblbir@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210108121056.21940-6-sblbir@amazon.com
Diffstat (limited to 'Documentation/userspace-api')
-rw-r--r--Documentation/userspace-api/spec_ctrl.rst8
1 files changed, 8 insertions, 0 deletions
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);