From 3850db49da87121b54c3ba43c82cdbe5a7c76be5 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Fri, 12 Feb 2016 17:09:46 +0000 Subject: [PATCH] iommu/io-pgtable: Rationalise quirk handling 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. Reviewed-by: Laurent Pinchart Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- 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 d39a021a4f6d..9fcceb135f51 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 b2bbc8427579..f433b516098a 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -659,8 +659,12 @@ 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; @@ -743,8 +747,13 @@ 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 4faee7d23ee9..d4f502742e3b 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; -- GitLab