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-rw-r--r--include/linux/io-pgtable.h213
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diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
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+++ b/include/linux/io-pgtable.h
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+/* 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 */