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Diffstat (limited to 'include/linux/io-pgtable.h')
| -rw-r--r-- | include/linux/io-pgtable.h | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h new file mode 100644 index 000000000000..47d5ae559329 --- /dev/null +++ b/include/linux/io-pgtable.h @@ -0,0 +1,213 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __IO_PGTABLE_H +#define __IO_PGTABLE_H +#include <linux/bitops.h> + +/* + * Public API for use by IOMMU drivers + */ +enum io_pgtable_fmt { + ARM_32_LPAE_S1, + ARM_32_LPAE_S2, + ARM_64_LPAE_S1, + ARM_64_LPAE_S2, + ARM_V7S, + IO_PGTABLE_NUM_FMTS, +}; + +/** + * struct iommu_gather_ops - IOMMU callbacks for TLB and page table management. + * + * @tlb_flush_all: Synchronously invalidate the entire TLB context. + * @tlb_add_flush: Queue up a TLB invalidation for a virtual address range. + * @tlb_sync: Ensure any queued TLB invalidation has taken effect, and + * any corresponding page table updates are visible to the + * IOMMU. + * + * Note that these can all be called in atomic context and must therefore + * not block. + */ +struct iommu_gather_ops { + void (*tlb_flush_all)(void *cookie); + void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule, + bool leaf, void *cookie); + void (*tlb_sync)(void *cookie); +}; + +/** + * struct io_pgtable_cfg - Configuration data for a set of page tables. + * + * @quirks: A bitmap of hardware quirks that require some special + * action by the low-level page table allocator. + * @pgsize_bitmap: A bitmap of page sizes supported by this set of page + * tables. + * @ias: Input address (iova) size, in bits. + * @oas: Output address (paddr) size, in bits. + * @tlb: TLB management callbacks for this set of tables. + * @iommu_dev: The device representing the DMA configuration for the + * page table walker. + */ +struct io_pgtable_cfg { + /* + * 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. + * + * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all + * PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit + * when the SoC is in "4GB mode" and they can only access the high + * remap of DRAM (0x1_00000000 to 0x1_ffffffff). + * + * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever + * be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a + * software-emulated IOMMU), such that pagetable updates need not + * be treated as explicit DMA data. + * + * IO_PGTABLE_QUIRK_NON_STRICT: Skip issuing synchronous leaf TLBIs + * on unmap, for DMA domains using the flush queue mechanism for + * delayed invalidation. + */ + #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) + #define IO_PGTABLE_QUIRK_ARM_MTK_4GB BIT(3) + #define IO_PGTABLE_QUIRK_NO_DMA BIT(4) + #define IO_PGTABLE_QUIRK_NON_STRICT BIT(5) + unsigned long quirks; + unsigned long pgsize_bitmap; + unsigned int ias; + unsigned int oas; + const struct iommu_gather_ops *tlb; + struct device *iommu_dev; + + /* Low-level data specific to the table format */ + union { + struct { + u64 ttbr[2]; + u64 tcr; + u64 mair[2]; + } arm_lpae_s1_cfg; + + struct { + u64 vttbr; + u64 vtcr; + } arm_lpae_s2_cfg; + + struct { + u32 ttbr[2]; + u32 tcr; + u32 nmrr; + u32 prrr; + } arm_v7s_cfg; + }; +}; + +/** + * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers. + * + * @map: Map a physically contiguous memory region. + * @unmap: Unmap a physically contiguous memory region. + * @iova_to_phys: Translate iova to physical address. + * + * These functions map directly onto the iommu_ops member functions with + * the same names. + */ +struct io_pgtable_ops { + int (*map)(struct io_pgtable_ops *ops, unsigned long iova, + phys_addr_t paddr, size_t size, int prot); + size_t (*unmap)(struct io_pgtable_ops *ops, unsigned long iova, + size_t size); + phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops, + unsigned long iova); +}; + +/** + * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU. + * + * @fmt: The page table format. + * @cfg: The page table configuration. This will be modified to represent + * the configuration actually provided by the allocator (e.g. the + * pgsize_bitmap may be restricted). + * @cookie: An opaque token provided by the IOMMU driver and passed back to + * the callback routines in cfg->tlb. + */ +struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, + struct io_pgtable_cfg *cfg, + void *cookie); + +/** + * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller + * *must* ensure that the page table is no longer + * live, but the TLB can be dirty. + * + * @ops: The ops returned from alloc_io_pgtable_ops. + */ +void free_io_pgtable_ops(struct io_pgtable_ops *ops); + + +/* + * Internal structures for page table allocator implementations. + */ + +/** + * struct io_pgtable - Internal structure describing a set of page tables. + * + * @fmt: The page table format. + * @cookie: An opaque token provided by the IOMMU driver and passed back to + * any callback routines. + * @cfg: A copy of the page table configuration. + * @ops: The page table operations in use for this set of page tables. + */ +struct io_pgtable { + enum io_pgtable_fmt fmt; + void *cookie; + struct io_pgtable_cfg cfg; + struct io_pgtable_ops ops; +}; + +#define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops) + +static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop) +{ + iop->cfg.tlb->tlb_flush_all(iop->cookie); +} + +static inline void io_pgtable_tlb_add_flush(struct io_pgtable *iop, + unsigned long iova, size_t size, size_t granule, bool leaf) +{ + iop->cfg.tlb->tlb_add_flush(iova, size, granule, leaf, iop->cookie); +} + +static inline void io_pgtable_tlb_sync(struct io_pgtable *iop) +{ + iop->cfg.tlb->tlb_sync(iop->cookie); +} + +/** + * struct io_pgtable_init_fns - Alloc/free a set of page tables for a + * particular format. + * + * @alloc: Allocate a set of page tables described by cfg. + * @free: Free the page tables associated with iop. + */ +struct io_pgtable_init_fns { + struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie); + void (*free)(struct io_pgtable *iop); +}; + +extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns; +extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns; +extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns; +extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns; +extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns; + +#endif /* __IO_PGTABLE_H */ |