Messages in this thread Patch in this message | | | From | Janne Grunau <> | Subject | [PATCH v4 3/5] iommu/io-pgtable: Add DART subpage protection support | Date | Thu, 1 Sep 2022 03:25:17 +0200 |
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From: Sven Peter <sven@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 <sven@svenpeter.dev> Signed-off-by: Janne Grunau <j@jannau.net>
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(no changes since v3)
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 43ef375812e6..659dd9e83d2c 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> @@ -40,6 +41,9 @@ #define DART_PTES_PER_TABLE(d) \ (DART_GRANULE(d) >> ilog2(sizeof(dart_iopte))) +#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 */ @@ -109,6 +113,10 @@ static int dart_init_pte(struct dart_io_pgtable *data, return -EEXIST; } + /* 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); + pte |= APPLE_DART1_PTE_PROT_SP_DIS; pte |= APPLE_DART_PTE_VALID; -- 2.35.1
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