linux/drivers/iommu/io-pgtable.h
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   1#ifndef __IO_PGTABLE_H
   2#define __IO_PGTABLE_H
   3#include <linux/bitops.h>
   4
   5/*
   6 * Public API for use by IOMMU drivers
   7 */
   8enum io_pgtable_fmt {
   9        ARM_32_LPAE_S1,
  10        ARM_32_LPAE_S2,
  11        ARM_64_LPAE_S1,
  12        ARM_64_LPAE_S2,
  13        ARM_V7S,
  14        IO_PGTABLE_NUM_FMTS,
  15};
  16
  17/**
  18 * struct iommu_gather_ops - IOMMU callbacks for TLB and page table management.
  19 *
  20 * @tlb_flush_all: Synchronously invalidate the entire TLB context.
  21 * @tlb_add_flush: Queue up a TLB invalidation for a virtual address range.
  22 * @tlb_sync:      Ensure any queued TLB invalidation has taken effect, and
  23 *                 any corresponding page table updates are visible to the
  24 *                 IOMMU.
  25 *
  26 * Note that these can all be called in atomic context and must therefore
  27 * not block.
  28 */
  29struct iommu_gather_ops {
  30        void (*tlb_flush_all)(void *cookie);
  31        void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
  32                              bool leaf, void *cookie);
  33        void (*tlb_sync)(void *cookie);
  34};
  35
  36/**
  37 * struct io_pgtable_cfg - Configuration data for a set of page tables.
  38 *
  39 * @quirks:        A bitmap of hardware quirks that require some special
  40 *                 action by the low-level page table allocator.
  41 * @pgsize_bitmap: A bitmap of page sizes supported by this set of page
  42 *                 tables.
  43 * @ias:           Input address (iova) size, in bits.
  44 * @oas:           Output address (paddr) size, in bits.
  45 * @tlb:           TLB management callbacks for this set of tables.
  46 * @iommu_dev:     The device representing the DMA configuration for the
  47 *                 page table walker.
  48 */
  49struct io_pgtable_cfg {
  50        /*
  51         * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
  52         *      stage 1 PTEs, for hardware which insists on validating them
  53         *      even in non-secure state where they should normally be ignored.
  54         *
  55         * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
  56         *      IOMMU_NOEXEC flags and map everything with full access, for
  57         *      hardware which does not implement the permissions of a given
  58         *      format, and/or requires some format-specific default value.
  59         *
  60         * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
  61         *      (unmapped) entries but the hardware might do so anyway, perform
  62         *      TLB maintenance when mapping as well as when unmapping.
  63         */
  64        #define IO_PGTABLE_QUIRK_ARM_NS         BIT(0)
  65        #define IO_PGTABLE_QUIRK_NO_PERMS       BIT(1)
  66        #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
  67        unsigned long                   quirks;
  68        unsigned long                   pgsize_bitmap;
  69        unsigned int                    ias;
  70        unsigned int                    oas;
  71        const struct iommu_gather_ops   *tlb;
  72        struct device                   *iommu_dev;
  73
  74        /* Low-level data specific to the table format */
  75        union {
  76                struct {
  77                        u64     ttbr[2];
  78                        u64     tcr;
  79                        u64     mair[2];
  80                } arm_lpae_s1_cfg;
  81
  82                struct {
  83                        u64     vttbr;
  84                        u64     vtcr;
  85                } arm_lpae_s2_cfg;
  86
  87                struct {
  88                        u32     ttbr[2];
  89                        u32     tcr;
  90                        u32     nmrr;
  91                        u32     prrr;
  92                } arm_v7s_cfg;
  93        };
  94};
  95
  96/**
  97 * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
  98 *
  99 * @map:          Map a physically contiguous memory region.
 100 * @unmap:        Unmap a physically contiguous memory region.
 101 * @iova_to_phys: Translate iova to physical address.
 102 *
 103 * These functions map directly onto the iommu_ops member functions with
 104 * the same names.
 105 */
 106struct io_pgtable_ops {
 107        int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
 108                   phys_addr_t paddr, size_t size, int prot);
 109        int (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
 110                     size_t size);
 111        phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
 112                                    unsigned long iova);
 113};
 114
 115/**
 116 * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
 117 *
 118 * @fmt:    The page table format.
 119 * @cfg:    The page table configuration. This will be modified to represent
 120 *          the configuration actually provided by the allocator (e.g. the
 121 *          pgsize_bitmap may be restricted).
 122 * @cookie: An opaque token provided by the IOMMU driver and passed back to
 123 *          the callback routines in cfg->tlb.
 124 */
 125struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
 126                                            struct io_pgtable_cfg *cfg,
 127                                            void *cookie);
 128
 129/**
 130 * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
 131 *                         *must* ensure that the page table is no longer
 132 *                         live, but the TLB can be dirty.
 133 *
 134 * @ops: The ops returned from alloc_io_pgtable_ops.
 135 */
 136void free_io_pgtable_ops(struct io_pgtable_ops *ops);
 137
 138
 139/*
 140 * Internal structures for page table allocator implementations.
 141 */
 142
 143/**
 144 * struct io_pgtable - Internal structure describing a set of page tables.
 145 *
 146 * @fmt:    The page table format.
 147 * @cookie: An opaque token provided by the IOMMU driver and passed back to
 148 *          any callback routines.
 149 * @tlb_sync_pending: Private flag for optimising out redundant syncs.
 150 * @cfg:    A copy of the page table configuration.
 151 * @ops:    The page table operations in use for this set of page tables.
 152 */
 153struct io_pgtable {
 154        enum io_pgtable_fmt     fmt;
 155        void                    *cookie;
 156        bool                    tlb_sync_pending;
 157        struct io_pgtable_cfg   cfg;
 158        struct io_pgtable_ops   ops;
 159};
 160
 161#define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
 162
 163static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
 164{
 165        iop->cfg.tlb->tlb_flush_all(iop->cookie);
 166        iop->tlb_sync_pending = true;
 167}
 168
 169static inline void io_pgtable_tlb_add_flush(struct io_pgtable *iop,
 170                unsigned long iova, size_t size, size_t granule, bool leaf)
 171{
 172        iop->cfg.tlb->tlb_add_flush(iova, size, granule, leaf, iop->cookie);
 173        iop->tlb_sync_pending = true;
 174}
 175
 176static inline void io_pgtable_tlb_sync(struct io_pgtable *iop)
 177{
 178        if (iop->tlb_sync_pending) {
 179                iop->cfg.tlb->tlb_sync(iop->cookie);
 180                iop->tlb_sync_pending = false;
 181        }
 182}
 183
 184/**
 185 * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
 186 *                              particular format.
 187 *
 188 * @alloc: Allocate a set of page tables described by cfg.
 189 * @free:  Free the page tables associated with iop.
 190 */
 191struct io_pgtable_init_fns {
 192        struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
 193        void (*free)(struct io_pgtable *iop);
 194};
 195
 196extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
 197extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
 198extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
 199extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
 200extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
 201
 202#endif /* __IO_PGTABLE_H */
 203