Commit-ID: ce01948eb85da733558fa77c2a554144a57ab0fb
Gitweb: http://git.kernel.org/tip/ce01948eb85da733558fa77c2a554144a57ab0fb
Author: David Hildenbrand <d...@linux.vnet.ibm.com>
AuthorDate: Mon, 11 May 2015 17:52:10 +0200
Committer: Ingo Molnar <mi...@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 <t...@linutronix.de>
Signed-off-by: David Hildenbrand <d...@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: david.lai...@aculab.com
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: airl...@linux.ie
Cc: a...@linux-foundation.org
Cc: b...@kernel.crashing.org
Cc: bige...@linutronix.de
Cc: borntrae...@de.ibm.com
Cc: daniel.vet...@intel.com
Cc: heiko.carst...@de.ibm.com
Cc: herb...@gondor.apana.org.au
Cc: ho...@suse.cz
Cc: hu...@google.com
Cc: m...@redhat.com
Cc: pau...@samba.org
Cc: r...@linux-mips.org
Cc: schwidef...@de.ibm.com
Cc: yang....@windriver.com
Link:
http://lkml.kernel.org/r/1431359540-32227-6-git-send-email-d...@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mi...@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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