Messages in this thread | | | Date | Sun, 26 Apr 2020 00:26:42 -0700 | From | Christoph Hellwig <> | Subject | Re: [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code |
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> diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c > index 4db13a6b9f3b..1cae4b911a33 100644 > --- a/arch/arc/mm/highmem.c > +++ b/arch/arc/mm/highmem.c > @@ -53,11 +53,10 @@ void *kmap_atomic(struct page *page) > { > int idx, cpu_idx; > unsigned long vaddr; > + void *addr = kmap_atomic_fast(page); > > - preempt_disable(); > - pagefault_disable(); > - if (!PageHighMem(page)) > - return page_address(page); > + if (addr) > + return addr;
Wouldn't it make sense to just move kmap_atomic itelf to common code, and call out to a kmap_atomic_high for the highmem case, following the scheme in kmap? Same for the unmap side. That might require to support kmap_atomic_prot everywhere first, which sounds like a really good idea anyway, and would avoid the need for strange workaround in drm.
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