Messages in this thread Patch in this message | | | Date | Tue, 19 May 2015 00:19:30 -0700 | From | tip-bot for David Hildenbrand <> | Subject | [tip:sched/core] sched/preempt, mm/kmap, MIPS: Disable preemption in kmap_coherent() explicitly |
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Commit-ID: ce01948eb85da733558fa77c2a554144a57ab0fb Gitweb: http://git.kernel.org/tip/ce01948eb85da733558fa77c2a554144a57ab0fb Author: David Hildenbrand <dahi@linux.vnet.ibm.com> AuthorDate: Mon, 11 May 2015 17:52:10 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 19 May 2015 08:39:15 +0200
sched/preempt, mm/kmap, MIPS: Disable preemption in kmap_coherent() explicitly
k(un)map_coherent relies on pagefault_disable() to also disable preemption.
Let's make this explicit, to prepare for pagefault_disable() not touching preemption anymore.
This patch is based on a patch by Yang Shi on the -rt tree: "k{un}map_coherent are just called when cpu_has_dc_aliases == 1 with VIPT cache. However, actually, the most modern MIPS processors have PIPT dcache without dcache alias issue. In such case, k{un}map_atomic will be called with preempt enabled."
Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-6-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/mips/mm/init.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index faa5c98..198a314 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -90,6 +90,7 @@ static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot) BUG_ON(Page_dcache_dirty(page)); + preempt_disable(); pagefault_disable(); idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1); idx += in_interrupt() ? FIX_N_COLOURS : 0; @@ -152,6 +153,7 @@ void kunmap_coherent(void) write_c0_entryhi(old_ctx); local_irq_restore(flags); pagefault_enable(); + preempt_enable(); } void copy_user_highpage(struct page *to, struct page *from,
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