MIPS: c-r4k: Sync icache when it fills from dcache
It is still necessary to handle icache coherency in flush_cache_range() and copy_to_user_page() when the icache fills from the dcache, even though the dcache does not need to be written back. However when this handling was added in commit 2eaa7ec2 ("[MIPS] Handle I-cache coherency in flush_cache_range()"), it did not do any icache flushing when it fills from dcache. Therefore fix r4k_flush_cache_range() to run local_r4k_flush_cache_range() without taking into account whether icache fills from dcache, so that the icache coherency gets handled. Checks are also added in local_r4k_flush_cache_range() so that the dcache blast doesn't take place when icache fills from dcache. A test to mmap a page PROT_READ|PROT_WRITE, modify code in it, and mprotect it to VM_READ|VM_EXEC (similar to case described in above commit) can hit this case quite easily to verify the fix. A similar check was added in commit f8829cae ("[MIPS] Fix aliasing bug in copy_to_user_page / copy_from_user_page"), so also fix copy_to_user_page() similarly, to call flush_cache_page() without taking into account whether icache fills from dcache, since flush_cache_page() already takes that into account to avoid performing a dcache flush. Signed-off-by: NJames Hogan <james.hogan@imgtec.com> Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Cc: Manuel Lauss <manuel.lauss@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12179/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
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