Markos Chandras ed4cbc81ad MIPS: HTW: Prevent accidental HTW start due to nested htw_{start, stop} ... activate_mm() and switch_mm() call get_new_mmu_context() which in turn can enable the HTW before the entryhi is changed with the new ASID. Since the latter will enable the HTW in local_flush_tlb_all(), then there is a small timing window where the HTW is running with the new ASID but with an old pgd since the TLBMISS_HANDLER_SETUP_PGD hasn't assigned a new one yet. In order to prevent that, we introduce a simple htw counter to avoid starting HTW accidentally due to nested htw_{start,stop}() sequences. Moreover, since various IPI calls can enforce TLB flushing operations on a different core, such an operation may interrupt another htw_{stop,start} in progress leading inconsistent updates of the htw_seq variable. In order to avoid that, we disable the interrupts whenever we update that variable. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: <stable@vger.kernel.org> # 3.17+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9118/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>		2015-02-16 10:55:26 +01:00
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asm	MIPS: HTW: Prevent accidental HTW start due to nested htw_{start, stop}	2015-02-16 10:55:26 +01:00
uapi/asm	Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus	2014-12-11 17:56:37 -08:00