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parisc: use spin_lock_irqsave/spin_unlock_irqrestore for PTE updates

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User applications running on SMP kernels have long suffered from instability
and random segmentation faults.  This patch improves the situation although
there is more work to be done.

One of the problems is the various routines in pgtable.h that update page table
entries use different locking mechanisms, or no lock at all (set_pte_at).  This
change modifies the routines to all use the same lock pa_dbit_lock.  This lock
is used for dirty bit updates in the interruption code. The patch also purges
the TLB entries associated with the PTE to ensure that inconsistent values are
not used after the page table entry is updated.  The UP and SMP code are now
identical.

The change also includes a minor update to the purge_tlb_entries function in
cache.c to improve its efficiency.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
John David Anglin
2013-04-23 22:42:07 +02:00
committed by Helge Deller
parent cf71130d63
commit bda079d336
2 changed files with 28 additions and 28 deletions
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5
arch/parisc/kernel/cache.c
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@@ -421,14 +421,11 @@ void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
/* Note: purge_tlb_entries can be called at startup with
no context. */
/* Disable preemption while we play with %sr1. */
preempt_disable();
mtsp(mm->context, 1);
purge_tlb_start(flags);
mtsp(mm->context, 1);
pdtlb(addr);
pitlb(addr);
purge_tlb_end(flags);
preempt_enable();
}
EXPORT_SYMBOL(purge_tlb_entries);