Re: [PATCHv8 1/8] iommu/io-pgtable-arm: Add support to use system cache

On 2020-11-23 20:36, Will Deacon wrote:

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@codeaurora.org

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."

Sure, thanks.