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Commit 8e35961b authored by Hideo Saito's avatar Hideo Saito Committed by Benjamin Herrenschmidt
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powerpc/mm: Fix broken MMU PID stealing on !SMP 



The recent rework of the MMU PID handling for non-hash CPUs has a
subtle bug in the !SMP "optimized" variant of the PID stealing
function.  It clears the PID in the mm context before it calls
local_flush_tlb_mm(). However, the later will not flush anything
if the PID in the context is clear...

Signed-off-by: default avatarHideo Saito <hsaito.ppc@gmail.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 59a3759d

arch/powerpc/mm/mmu_context_nohash.c

+3 −3
Original line number Diff line number Diff line
@@ -127,12 +127,12 @@ static unsigned int steal_context_up(unsigned int id) 


	pr_debug("[%d] steal context %d from mm @%p\n", cpu, id, mm);



	/* Mark this mm has having no context anymore */

	mm->context.id = MMU_NO_CONTEXT;



	/* Flush the TLB for that context */

	local_flush_tlb_mm(mm);



	/* Mark this mm has having no context anymore */

	mm->context.id = MMU_NO_CONTEXT;



	/* XXX This clear should ultimately be part of local_flush_tlb_mm */

	__clear_bit(id, stale_map[cpu]);