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commit 9f048fa487409e364cf866c957cf0b0d782ca5a3 upstream. Depending on the particular CPU implementation a TLB shutdown may occur if multiple matching entries are detected upon the execution of a TLBP or the TLBWI/TLBWR instructions. Given that we don't know what entries we have been handed we need to be very careful with the initial TLB setup and avoid all these instructions. Therefore read all the TLB entries one by one with the TLBR instruction, bypassing the content addressing logic, and truncate any large pages in place so as to avoid a case in the second step where an incoming entry for a large page at a lower address overlaps with a replacement entry chosen at another index. Then preinitialize the TLB using addresses outside our usual unique range and avoiding clashes with any entries received, before making the usual call to local_flush_tlb_all(). This fixes (at least) R4x00 cores if TLBP hits multiple matching TLB entries (SGI IP22 PROM for examples sets up all TLBs to the same virtual address). Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 35ad7e181541 ("MIPS: mm: tlb-r4k: Uniquify TLB entries on init") Cc: stable@vger.kernel.org Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com> # Boston I6400, M5150 sim Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.