Messages in this thread Patch in this message | | | From | Janne Grunau <> | Subject | [PATCH v2 2/4] iommu/io-pgtable: Add DART subpage protection support | Date | Tue, 3 May 2022 08:22:59 +0200 |
| |
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> --- drivers/iommu/io-pgtable-arm.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 94ff319ae8ac..71570bbc9096 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -10,6 +10,7 @@ #define pr_fmt(fmt) "arm-lpae io-pgtable: " fmt #include <linux/atomic.h> +#include <linux/bitfield.h> #include <linux/bitops.h> #include <linux/io-pgtable.h> #include <linux/kernel.h> @@ -133,6 +134,9 @@ #define APPLE_DART_PTE_PROT_NO_WRITE (1<<7) #define APPLE_DART_PTE_PROT_NO_READ (1<<8) +#define APPLE_DART_PTE_SUBPAGE_START GENMASK_ULL(63, 52) +#define APPLE_DART_PTE_SUBPAGE_END GENMASK_ULL(51, 40) + /* IOPTE accessors */ #define iopte_deref(pte,d) __va(iopte_to_paddr(pte, d)) @@ -273,6 +277,12 @@ static void __arm_lpae_init_pte(struct arm_lpae_io_pgtable *data, else pte |= ARM_LPAE_PTE_TYPE_BLOCK; + if (data->iop.fmt == APPLE_DART) { + /* 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
| |