On Wed, 2019-08-21 at 16:24 +0100, Will Deacon wrote:
> On Wed, Aug 21, 2019 at 09:53:12PM +0800, Yong Wu wrote:
> > MediaTek extend the arm v7s descriptor to support up to 34 bits PA where
> > the bit32 and bit33 are encoded in the bit9 and bit4 of the PTE
> > respectively. Meanwhile the iova still is 32bits.
> >
> > Regarding whether the pagetable address could be over 4GB, the mt8183
> > support it while the previous mt8173 don't, thus keep it as is.
> >
> > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> > ---
> > drivers/iommu/io-pgtable-arm-v7s.c | 32 +++++++++++++++++++++++++-------
> > include/linux/io-pgtable.h | 7 +++----
> > 2 files changed, 28 insertions(+), 11 deletions(-)
>
> [...]
>
> > @@ -731,7 +747,9 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
> > {
> > struct arm_v7s_io_pgtable *data;
> >
> > - if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > ARM_V7S_ADDR_BITS)
> > + if (cfg->ias > ARM_V7S_ADDR_BITS ||
> > + (cfg->oas > ARM_V7S_ADDR_BITS &&
> > + !(cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT)))
>
> Please can you instead change arm_v7s_alloc_pgtable() so that it allows an
> ias of up to 34 when the IO_PGTABLE_QUIRK_ARM_MTK_EXT is set?
Here I only simply skip the oas checking for our case. then which way do
your prefer? something like you commented before:?
if (cfg->ias > ARM_V7S_ADDR_BITS)
return NULL;
if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT) {
if (!IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
cfg->oas = min(cfg->oas, ARM_V7S_ADDR_BITS);
else if (cfg->oas > 34)
return NULL;
} else if (cfg->oas > ARM_V7S_ADDR_BITS) {
return NULL;
}
>
> With that change:
>
> Acked-by: Will Deacon <will@xxxxxxxxxx>
>
> Will
>
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