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authorDavid Hildenbrand <dahi@linux.vnet.ibm.com>2015-05-11 18:52:10 +0300
committerIngo Molnar <mingo@kernel.org>2015-05-19 09:39:15 +0300
commitce01948eb85da733558fa77c2a554144a57ab0fb (patch)
tree4fecfe4c672e05fb36afc1813fd8dded81dee4d9
parent2cb7c9cb426660b5ed58b643d9e7dd5d50ba901f (diff)
downloadlinux-ce01948eb85da733558fa77c2a554144a57ab0fb.tar.xz
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>
-rw-r--r--arch/mips/mm/init.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index faa5c9822ecc..198a3147dd7d 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,