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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-02-24 11:47:32 +0100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-03-02 04:56:48 +0100 |
| commit | f342552b917a18a7a1fa2c10625df85fac828c36 (patch) | |
| tree | 236fc598d5c4342bd69c0098547ad6df51557990 /arch/powerpc/mm | |
| parent | Linux 2.6.38-rc7 (diff) | |
| download | linux-f342552b917a18a7a1fa2c10625df85fac828c36.tar.xz linux-f342552b917a18a7a1fa2c10625df85fac828c36.zip | |
powerpc/mm: Make hpte_need_flush() safe for preemption
hpte_need_flush() might be called outside of a preempt section
when manipulating the kernel page tables, so we need to use the
appopriate variants of per-cpu variable accesses. There should
be no risk of being in the middle of a batch and a context
switch will flush any pending batch.
[Patch extracted from a larger patch in Peter's preemptible
mmu_gather series]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/tlb_hash64.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c index 1ec06576f619..c14d09f614f3 100644 --- a/arch/powerpc/mm/tlb_hash64.c +++ b/arch/powerpc/mm/tlb_hash64.c @@ -38,13 +38,11 @@ DEFINE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch); * neesd to be flushed. This function will either perform the flush * immediately or will batch it up if the current CPU has an active * batch on it. - * - * Must be called from within some kind of spinlock/non-preempt region... */ void hpte_need_flush(struct mm_struct *mm, unsigned long addr, pte_t *ptep, unsigned long pte, int huge) { - struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch); + struct ppc64_tlb_batch *batch = &get_cpu_var(ppc64_tlb_batch); unsigned long vsid, vaddr; unsigned int psize; int ssize; @@ -99,6 +97,7 @@ void hpte_need_flush(struct mm_struct *mm, unsigned long addr, */ if (!batch->active) { flush_hash_page(vaddr, rpte, psize, ssize, 0); + put_cpu_var(ppc64_tlb_batch); return; } @@ -127,6 +126,7 @@ void hpte_need_flush(struct mm_struct *mm, unsigned long addr, batch->index = ++i; if (i >= PPC64_TLB_BATCH_NR) __flush_tlb_pending(batch); + put_cpu_var(ppc64_tlb_batch); } /* |