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]> --- Just to allay any confusion, I intend this as a followup to the short-descriptor[1] and Mediatek IOMMU[2] patches, rather than a crucial addition, so it can either get picked up along with those or wait 'til later. v2: - Use unsigned long for the bitmap. - Do format-specific checks inline. - Enough of a difference that I don't feel comfortable putting Laurent's reviewed-by from v1 on it... Robin. [1]:http://thread.gmane.org/gmane.linux.kernel.iommu/12007 [2]:http://thread.gmane.org/gmane.linux.kernel.iommu/11974 drivers/iommu/io-pgtable-arm-v7s.c | 5 +++++ drivers/iommu/io-pgtable-arm.c | 13 +++++++++++-- drivers/iommu/io-pgtable.h | 22 ++++++++++++++++++---- 3 files changed, 34 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index d39a021..9fcceb1 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -623,6 +623,11 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > ARM_V7S_ADDR_BITS) return NULL; + if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS | + IO_PGTABLE_QUIRK_NO_PERMS | + IO_PGTABLE_QUIRK_TLBI_ON_MAP)) + return NULL; + data = kmalloc(sizeof(*data), GFP_KERNEL); if (!data) return NULL; diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 4095af2..debdf04 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -658,8 +658,12 @@ static struct io_pgtable * arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie) { u64 reg; - struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg); + struct arm_lpae_io_pgtable *data; + if (cfg->quirks & ~IO_PGTABLE_QUIRK_ARM_NS) + return NULL; + + data = arm_lpae_alloc_pgtable(cfg); if (!data) return NULL; @@ -742,8 +746,13 @@ static struct io_pgtable * arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) { u64 reg, sl; - struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg); + struct arm_lpae_io_pgtable *data; + /* The NS quirk doesn't apply at stage 2 */ + if (cfg->quirks) + return NULL; + + data = arm_lpae_alloc_pgtable(cfg); if (!data) return NULL; diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h index 4faee7d..d4f5027 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 long quirks; unsigned long pgsize_bitmap; unsigned int ias; unsigned int oas; -- 2.7.0.25.gfc10eb5.dirty _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
