[PATCHv5 1/6] iommu/io-pgtable-arm: Add support to use system cache

Sai Prakash Ranjan
2020-09-22T06:18:43Z

Add a quirk IO_PGTABLE_QUIRK_SYS_CACHE 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 | 7 ++++++-
include/linux/io-pgtable.h | 4 ++++
2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index dc7bcf858b6d..828426c16fa9 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -789,7 +789,8 @@ 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_SYS_CACHE))
return NULL;

data = arm_lpae_alloc_pgtable(cfg);
@@ -801,6 +802,10 @@ 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;
+ } else if (cfg->quirks & IO_PGTABLE_QUIRK_SYS_CACHE) {
+ tcr->sh = ARM_LPAE_TCR_SH_OS;
+ tcr->irgn = ARM_LPAE_TCR_RGN_NC;
+ tcr->orgn = ARM_LPAE_TCR_RGN_WBWA;
} else {
tcr->sh = ARM_LPAE_TCR_SH_OS;
tcr->irgn = ARM_LPAE_TCR_RGN_NC;
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index 23285ba645db..ecc9d2248b84 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_SYS_CACHE: Override the attributes set in TCR for
+ * the page table walker when using system cache.
*/
#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_SYS_CACHE BIT(6)
unsigned long quirks;
unsigned long pgsize_bitmap;
unsigned int ias;