Messages in this thread | | | Subject | Re: [PATCH v4 2/7] mtrr, x86: Fix MTRR lookup to handle inclusive entry | From | Toshi Kani <> | Date | Tue, 05 May 2015 13:31:32 -0600 |
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On Tue, 2015-05-05 at 20:39 +0200, Borislav Petkov wrote: > On Tue, May 05, 2015 at 11:32:08AM -0600, Toshi Kani wrote: > > > Ok, I'm confused. Shouldn't the inclusive:1 case be > > > > > > (start:mtrr_start) (mtrr_start:mtrr_end) (mtrr_end:end) > > > > > > ? > > > > > > If so, this function would need more changes... > > > > Yes, that's how it gets separated eventually. Since *repeat is set in > > this case, the code only needs to separate the first part at a time. > > The 2nd part gets separated in the next call with the *repeat. > > Aah, right, the caller is supposed to adjust the interval limits on > subsequent calls. Please reflect this in the comment because: > > * (start:mtrr_start) (mtrr_start:end) > > is misleading for inclusive:1.
Well, the comment kinda says it already, but I will try to clarify it.
/* * We have start:end spanning across an MTRR. * We split the region into either * - start_state:1 * (start:mtrr_end) (mtrr_end:end) * - end_state:1 or inclusive:1 * (start:mtrr_start) (mtrr_start:end) * depending on kind of overlap. * Return the type for first region and a pointer to * the start of second region so that caller will * lookup again on the second region. * Note: This way we handle multiple overlaps as well. */
Thanks, -Toshi
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