Commit d8fe365a authored by Sven Peter's avatar Sven Peter Committed by Joerg Roedel
Browse files

iommu/io-pgtable: Add DART subpage protection support 



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: default avatarSven Peter <sven@svenpeter.dev>
Signed-off-by: default avatarJanne Grunau <j@jannau.net>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarHector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20220916094152.87137-4-j@jannau.net


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 745ef109

drivers/iommu/io-pgtable-dart.c

+8 −0
Original line number Diff line number Diff line
@@ -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 */
@@ -107,6 +111,10 @@ 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;