Messages in this thread | | | Subject | Re: [PATCH v4 09/24] iommu/io-pgtable-arm-v7s: Clear LVL_SHIFT/BITS macro instead of the formula | From | Robin Murphy <> | Date | Thu, 26 Nov 2020 16:03:49 +0000 |
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On 2020-11-11 12:38, Yong Wu wrote: > The current _ARM_V7S_LVL_BITS/ARM_V7S_LVL_SHIFT use a formula to calculate > the corresponding value for level1 and level2 to pretend the code sane. > Actually their level1 and level2 values are different from each other. > This patch only clear the two macro. No functional change.
Grammar nit: to "clear" the macro sounds like you're making it empty or removing it entirely; I think you mean to say "clarify" here. English is the worst language sometimes... :)
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> Suggested-by: Robin Murphy <robin.murphy@arm.com> > Signed-off-by: Yong Wu <yong.wu@mediatek.com> > --- > drivers/iommu/io-pgtable-arm-v7s.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c > index 4d0aa079470f..58cc201c10a3 100644 > --- a/drivers/iommu/io-pgtable-arm-v7s.c > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > @@ -44,13 +44,11 @@ > > /* > * We have 32 bits total; 12 bits resolved at level 1, 8 bits at level 2, > - * and 12 bits in a page. With some carefully-chosen coefficients we can > - * hide the ugly inconsistencies behind these macros and at least let the > - * rest of the code pretend to be somewhat sane. > + * and 12 bits in a page. > */ > #define ARM_V7S_ADDR_BITS 32 > -#define _ARM_V7S_LVL_BITS(lvl) (16 - (lvl) * 4) > -#define ARM_V7S_LVL_SHIFT(lvl) (ARM_V7S_ADDR_BITS - (4 + 8 * (lvl))) > +#define _ARM_V7S_LVL_BITS(lvl) ((lvl) == 1 ? 12 : 8) > +#define ARM_V7S_LVL_SHIFT(lvl) ((lvl) == 1 ? 20 : 12) > #define ARM_V7S_TABLE_SHIFT 10 > > #define ARM_V7S_PTES_PER_LVL(lvl) (1 << _ARM_V7S_LVL_BITS(lvl)) >
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