Messages in this thread | | | Date | Tue, 03 Apr 2012 09:37:24 +0400 | From | Konstantin Khlebnikov <> | Subject | Re: [x86 PAT PATCH 1/2] x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines |
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Suresh Siddha wrote: > 'pfn' argument for track_pfn_vma_new() can be used for reserving the attribute > for the pfn range. No need to depend on 'vm_pgoff' > > Similarly, untrack_pfn_vma() can depend on the 'pfn' argument if it > is non-zero or can use follow_phys() to get the starting value of the pfn > range. > > Also the non zero 'size' argument can be used instead of recomputing > it from vma. > > This cleanup also prepares the ground for the track/untrack pfn vma routines > to take over the ownership of setting PAT specific vm_flag in the 'vma'. > > Signed-off-by: Suresh Siddha<suresh.b.siddha@intel.com> > Cc: Venkatesh Pallipadi<venki@google.com> > Cc: Konstantin Khlebnikov<khlebnikov@openvz.org> > --- > arch/x86/mm/pat.c | 30 +++++++++++++++++------------- > 1 files changed, 17 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c > index f6ff57b..617f42b 100644 > --- a/arch/x86/mm/pat.c > +++ b/arch/x86/mm/pat.c > @@ -693,14 +693,10 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, > unsigned long pfn, unsigned long size) > { > unsigned long flags; > - resource_size_t paddr; > - unsigned long vma_size = vma->vm_end - vma->vm_start; > > - if (is_linear_pfn_mapping(vma)) { > - /* reserve the whole chunk starting from vm_pgoff */ > - paddr = (resource_size_t)vma->vm_pgoff<< PAGE_SHIFT; > - return reserve_pfn_range(paddr, vma_size, prot, 0); > - } > + /* reserve the whole chunk starting from pfn */ > + if (is_linear_pfn_mapping(vma)) > + return reserve_pfn_range(pfn, size, prot, 0);
you mix here pfn and paddr: old code passes paddr as first argument of reserve_pfn_range().
> > if (!pat_enabled) > return 0; > @@ -716,20 +712,28 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, > /* > * untrack_pfn_vma is called while unmapping a pfnmap for a region. > * untrack can be called for a specific region indicated by pfn and size or > - * can be for the entire vma (in which case size can be zero). > + * can be for the entire vma (in which case pfn, size are zero). > */ > void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, > unsigned long size) > { > resource_size_t paddr; > - unsigned long vma_size = vma->vm_end - vma->vm_start; > + unsigned long prot; > > - if (is_linear_pfn_mapping(vma)) { > - /* free the whole chunk starting from vm_pgoff */ > - paddr = (resource_size_t)vma->vm_pgoff<< PAGE_SHIFT; > - free_pfn_range(paddr, vma_size); > + if (!is_linear_pfn_mapping(vma)) > return; > + > + /* free the chunk starting from pfn or the whole chunk */ > + paddr = (resource_size_t)pfn; > + if (!paddr&& !size) { > + if (follow_phys(vma, vma->vm_start, 0,&prot,&paddr)) { > + WARN_ON_ONCE(1); > + return; > + } > + > + size = vma->vm_end - vma->vm_start; > } > + free_pfn_range(paddr, size); > } > > pgprot_t pgprot_writecombine(pgprot_t prot)
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