drivers/iommu/io-pgtable.h

   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  */
   8 enum 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  */
  29 struct 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  */
  49 struct 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  */
 106 struct 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  */
 125 struct 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  */
 136 void 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  */
 153 struct 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
 163 static 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
 169 static 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
 176 static 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  */
 191 struct 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
 196 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
 197 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
 198 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
 199 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
 200 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
 201
 202 #endif /* __IO_PGTABLE_H */