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sched/preempt, powerpc: Disable preemption in enable_kernel_altivec() explicitly

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enable_kernel_altivec() has to be called with disabled preemption.
Let's make this explicit, to prepare for pagefault_disable() not
touching preemption anymore.

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>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.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: 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/1431359540-32227-14-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
David Hildenbrand
2015-05-11 17:52:18 +02:00
committed by Ingo Molnar
parent 2f09b227ee
commit 5f76eea88d
4 changed files with 27 additions and 6 deletions
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11
arch/powerpc/lib/vmx-helper.c
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@@ -27,11 +27,11 @@ int enter_vmx_usercopy(void)
if (in_interrupt())
return 0;
/* This acts as preempt_disable() as well and will make
* enable_kernel_altivec(). We need to disable page faults
* as they can call schedule and thus make us lose the VMX
* context. So on page faults, we just fail which will cause
* a fallback to the normal non-vmx copy.
preempt_disable();
/*
* We need to disable page faults as they can call schedule and
* thus make us lose the VMX context. So on page faults, we just
* fail which will cause a fallback to the normal non-vmx copy.
*/
pagefault_disable();
@@ -47,6 +47,7 @@ int enter_vmx_usercopy(void)
int exit_vmx_usercopy(void)
{
pagefault_enable();
preempt_enable();
return 0;
}