As the number of io-pgtable implementations grows beyond 1, it's time to rationalise the quirks mechanism before things have a chance to start getting really ugly and out-of-hand.
To that end: - Indicate exactly which quirks each format can/does support. - Fail creating a table if a caller wants unsupported quirks. - Properly document where each quirk applies and why. Signed-off-by: Robin Murphy <[email protected]> --- drivers/iommu/io-pgtable-arm-v7s.c | 3 +++ drivers/iommu/io-pgtable-arm.c | 2 ++ drivers/iommu/io-pgtable.c | 3 +++ drivers/iommu/io-pgtable.h | 24 ++++++++++++++++++++---- 4 files changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9bc607a 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -690,6 +690,9 @@ out_free_data: struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = { .alloc = arm_v7s_alloc_pgtable, .free = arm_v7s_free_pgtable, + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS | + IO_PGTABLE_QUIRK_NO_PERMS | + IO_PGTABLE_QUIRK_TLBI_ON_MAP, }; #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 4095af2..32f94f1 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -863,6 +863,7 @@ arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = { .alloc = arm_64_lpae_alloc_pgtable_s1, .free = arm_lpae_free_pgtable, + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, }; struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { @@ -873,6 +874,7 @@ struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = { struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = { .alloc = arm_32_lpae_alloc_pgtable_s1, .free = arm_lpae_free_pgtable, + .supported_quirks = IO_PGTABLE_QUIRK_ARM_NS, }; struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = { diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c index 876f6a7..0f57a45 100644 --- a/drivers/iommu/io-pgtable.c +++ b/drivers/iommu/io-pgtable.c @@ -52,6 +52,9 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, if (!fns) return NULL; + if (cfg->quirks & ~fns->supported_quirks) + return NULL; + iop = fns->alloc(cfg, cookie); if (!iop) return NULL; diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h index 4faee7d..6e7f11e 100644 --- a/drivers/iommu/io-pgtable.h +++ b/drivers/iommu/io-pgtable.h @@ -47,10 +47,24 @@ struct iommu_gather_ops { * page table walker. */ struct io_pgtable_cfg { - #define IO_PGTABLE_QUIRK_ARM_NS BIT(0) /* Set NS bit in PTEs */ - #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1) /* No AP/XN bits */ - #define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2) /* TLB Inv. on map */ - int quirks; + /* + * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in + * stage 1 PTEs, for hardware which insists on validating them + * even in non-secure state where they should normally be ignored. + * + * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and + * IOMMU_NOEXEC flags and map everything with full access, for + * hardware which does not implement the permissions of a given + * format, and/or requires some format-specific default value. + * + * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid + * (unmapped) entries but the hardware might do so anyway, perform + * TLB maintenance when mapping as well as when unmapping. + */ + #define IO_PGTABLE_QUIRK_ARM_NS BIT(0) + #define IO_PGTABLE_QUIRK_NO_PERMS BIT(1) + #define IO_PGTABLE_QUIRK_TLBI_ON_MAP BIT(2) + unsigned int quirks; unsigned long pgsize_bitmap; unsigned int ias; unsigned int oas; @@ -173,10 +187,12 @@ static inline void io_pgtable_tlb_sync(struct io_pgtable *iop) * * @alloc: Allocate a set of page tables described by cfg. * @free: Free the page tables associated with iop. + * @supported_quirks: Bitmap of quirks supported by the format. */ struct io_pgtable_init_fns { struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie); void (*free)(struct io_pgtable *iop); + unsigned int supported_quirks; }; extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns; -- 2.7.0.25.gfc10eb5.dirty _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
