On Tue, Nov 17, 2020 at 08:00:40PM +0530, Sai Prakash Ranjan wrote:
> Add a quirk IO_PGTABLE_QUIRK_ARM_OUTER_WBWA to override
> the attributes set in TCR for the page table walker when
> using system cache.
>
> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
> ---
> drivers/iommu/io-pgtable-arm.c | 10 ++++++++--
> include/linux/io-pgtable.h | 4 ++++
> 2 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
> index a7a9bc08dcd1..7c9ea9d7874a 100644
> --- a/drivers/iommu/io-pgtable-arm.c
> +++ b/drivers/iommu/io-pgtable-arm.c
> @@ -761,7 +761,8 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
>
> if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS |
> IO_PGTABLE_QUIRK_NON_STRICT |
> - IO_PGTABLE_QUIRK_ARM_TTBR1))
> + IO_PGTABLE_QUIRK_ARM_TTBR1 |
> + IO_PGTABLE_QUIRK_ARM_OUTER_WBWA))
> return NULL;
>
> data = arm_lpae_alloc_pgtable(cfg);
> @@ -773,10 +774,15 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
> tcr->sh = ARM_LPAE_TCR_SH_IS;
> tcr->irgn = ARM_LPAE_TCR_RGN_WBWA;
> tcr->orgn = ARM_LPAE_TCR_RGN_WBWA;
> + if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_OUTER_WBWA)
> + goto out_free_data;
> } else {
> tcr->sh = ARM_LPAE_TCR_SH_OS;
> tcr->irgn = ARM_LPAE_TCR_RGN_NC;
> - tcr->orgn = ARM_LPAE_TCR_RGN_NC;
> + if (!(cfg->quirks & IO_PGTABLE_QUIRK_ARM_OUTER_WBWA))
> + tcr->orgn = ARM_LPAE_TCR_RGN_NC;
> + else
> + tcr->orgn = ARM_LPAE_TCR_RGN_WBWA;
> }
>
> tg1 = cfg->quirks & IO_PGTABLE_QUIRK_ARM_TTBR1;
> diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
> index 4cde111e425b..a9a2c59fab37 100644
> --- a/include/linux/io-pgtable.h
> +++ b/include/linux/io-pgtable.h
> @@ -86,6 +86,9 @@ struct io_pgtable_cfg {
> *
> * IO_PGTABLE_QUIRK_ARM_TTBR1: (ARM LPAE format) Configure the table
> * for use in the upper half of a split address space.
> + *
> + * IO_PGTABLE_QUIRK_ARM_OUTER_WBWA: Override the attributes set in TCR for
> + * the page table walker when using system cache.
Please can you reword this to say:
"Override the outer-cacheability attributes set in the TCR for a non-coherent
page-table walker."
Will
