mirror of https://github.com/acidanthera/audk.git
5ce29ae84d
The helper that updates live page table entries writes a zero entry, invalidates the covered address range from the TLBs, and finally writes the actual entry. This ensures that no TLB conflicts can occur. Writing the final entry needs to complete before any translations can be performed, as otherwise, the zero entry, which describes an invalid translation, may be observed by the page table walker, resulting in a translation fault. For this reason, the final write is followed by a DSB barrier instruction. However, this barrier will not stall the pipeline, and instruction fetches may still hit this invalid translation, as has been observed and reported by Oliver. To ensure that the new translation is fully active before returning from this helper, we have to insert an ISB barrier as well. Reported-by: Oliver Steffen <osteffen@redhat.com> Tested-by: Oliver Steffen <osteffen@redhat.com> Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com> Acked-by: Michael D Kinney <michael.d.kinney@intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> |
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| .. | ||
| AArch64 | ||
| Arm | ||
| ArmMmuBaseLib.inf | ||
| ArmMmuPeiLib.inf | ||