From: Sven Peter <s...@svenpeter.dev>
DART allows to only expose a subpage to the device. While this is an
optional feature on the M1 DARTs the new ones present on the Pro/Max
models require this field in every PTE.
Signed-off-by: Sven Peter <s...@svenpeter.dev>
Signed-off-by: Janne Grunau <j...@jannau.net>
---
Changes in v3:
- apply change to io-pgtable-dart.c
drivers/iommu/io-pgtable-dart.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/iommu/io-pgtable-dart.c b/drivers/iommu/io-pgtable-dart.c
index 0c5222942c65..fa8025c03bb5 100644
--- a/drivers/iommu/io-pgtable-dart.c
+++ b/drivers/iommu/io-pgtable-dart.c
@@ -14,6 +14,7 @@
#define pr_fmt(fmt) "dart io-pgtable: " fmt
#include <linux/atomic.h>
+#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/io-pgtable.h>
#include <linux/kernel.h>
@@ -63,6 +64,9 @@
/* Calculate the block/page mapping size at level l for pagetable in d. */
#define DART_BLOCK_SIZE(l, d) (1ULL << DART_LVL_SHIFT(l, d))
+#define APPLE_DART_PTE_SUBPAGE_START GENMASK_ULL(63, 52)
+#define APPLE_DART_PTE_SUBPAGE_END GENMASK_ULL(51, 40)
+
#define APPLE_DART1_PADDR_MASK GENMASK_ULL(35, 12)
/* Apple DART1 protection bits */
@@ -140,6 +144,10 @@ static void __dart_init_pte(struct dart_io_pgtable *data,
pte |= APPLE_DART_PTE_VALID;
+ /* subpage protection: always allow access to the entire page */
+ pte |= FIELD_PREP(APPLE_DART_PTE_SUBPAGE_START, 0);
+ pte |= FIELD_PREP(APPLE_DART_PTE_SUBPAGE_END, 0xfff);
+
for (i = 0; i < num_entries; i++)
ptep[i] = pte | paddr_to_iopte(paddr + i * sz, data);
}
--
2.35.1
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
