[PATCHv9 1/8] iommu/io-pgtable-arm: Add support to use system cache

[Sai Prakash Ranjan]

Add a quirk IO_PGTABLE_QUIRK_ARM_OUTER_WBWA to override
the outer-cacheability attributes set in the TCR for a
non-coherent page table walker when using system cache.

Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan at 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..6b8bb4f4afef 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 outer-cacheability
+	 *	attributes set in the TCR for a non-coherent page-table walker.
 	 */
 	#define IO_PGTABLE_QUIRK_ARM_NS		BIT(0)
 	#define IO_PGTABLE_QUIRK_NO_PERMS	BIT(1)
@@ -93,6 +96,7 @@ struct io_pgtable_cfg {
 	#define IO_PGTABLE_QUIRK_ARM_MTK_EXT	BIT(3)
 	#define IO_PGTABLE_QUIRK_NON_STRICT	BIT(4)
 	#define IO_PGTABLE_QUIRK_ARM_TTBR1	BIT(5)
+	#define IO_PGTABLE_QUIRK_ARM_OUTER_WBWA	BIT(6)
 	unsigned long			quirks;
 	unsigned long			pgsize_bitmap;
 	unsigned int			ias;
-- 
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