include/linux/io-pgtable.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __IO_PGTABLE_H
   3 #define __IO_PGTABLE_H
   4 #include <linux/bitops.h>
   5
   6 /*
   7  * Public API for use by IOMMU drivers
   8  */
   9 enum io_pgtable_fmt {
  10         ARM_32_LPAE_S1,
  11         ARM_32_LPAE_S2,
  12         ARM_64_LPAE_S1,
  13         ARM_64_LPAE_S2,
  14         ARM_V7S,
  15         ARM_MALI_LPAE,
  16         IO_PGTABLE_NUM_FMTS,
  17 };
  18
  19 /**
  20  * struct iommu_gather_ops - IOMMU callbacks for TLB and page table management.
  21  *
  22  * @tlb_flush_all: Synchronously invalidate the entire TLB context.
  23  * @tlb_add_flush: Queue up a TLB invalidation for a virtual address range.
  24  * @tlb_sync:      Ensure any queued TLB invalidation has taken effect, and
  25  *                 any corresponding page table updates are visible to the
  26  *                 IOMMU.
  27  *
  28  * Note that these can all be called in atomic context and must therefore
  29  * not block.
  30  */
  31 struct iommu_gather_ops {
  32         void (*tlb_flush_all)(void *cookie);
  33         void (*tlb_add_flush)(unsigned long iova, size_t size, size_t granule,
  34                               bool leaf, void *cookie);
  35         void (*tlb_sync)(void *cookie);
  36 };
  37
  38 /**
  39  * struct io_pgtable_cfg - Configuration data for a set of page tables.
  40  *
  41  * @quirks:        A bitmap of hardware quirks that require some special
  42  *                 action by the low-level page table allocator.
  43  * @pgsize_bitmap: A bitmap of page sizes supported by this set of page
  44  *                 tables.
  45  * @ias:           Input address (iova) size, in bits.
  46  * @oas:           Output address (paddr) size, in bits.
  47  * @tlb:           TLB management callbacks for this set of tables.
  48  * @iommu_dev:     The device representing the DMA configuration for the
  49  *                 page table walker.
  50  */
  51 struct io_pgtable_cfg {
  52         /*
  53          * IO_PGTABLE_QUIRK_ARM_NS: (ARM formats) Set NS and NSTABLE bits in
  54          *      stage 1 PTEs, for hardware which insists on validating them
  55          *      even in non-secure state where they should normally be ignored.
  56          *
  57          * IO_PGTABLE_QUIRK_NO_PERMS: Ignore the IOMMU_READ, IOMMU_WRITE and
  58          *      IOMMU_NOEXEC flags and map everything with full access, for
  59          *      hardware which does not implement the permissions of a given
  60          *      format, and/or requires some format-specific default value.
  61          *
  62          * IO_PGTABLE_QUIRK_TLBI_ON_MAP: If the format forbids caching invalid
  63          *      (unmapped) entries but the hardware might do so anyway, perform
  64          *      TLB maintenance when mapping as well as when unmapping.
  65          *
  66          * IO_PGTABLE_QUIRK_ARM_MTK_4GB: (ARM v7s format) Set bit 9 in all
  67          *      PTEs, for Mediatek IOMMUs which treat it as a 33rd address bit
  68          *      when the SoC is in "4GB mode" and they can only access the high
  69          *      remap of DRAM (0x1_00000000 to 0x1_ffffffff).
  70          *
  71          * IO_PGTABLE_QUIRK_NO_DMA: Guarantees that the tables will only ever
  72          *      be accessed by a fully cache-coherent IOMMU or CPU (e.g. for a
  73          *      software-emulated IOMMU), such that pagetable updates need not
  74          *      be treated as explicit DMA data.
  75          *
  76          * IO_PGTABLE_QUIRK_NON_STRICT: Skip issuing synchronous leaf TLBIs
  77          *      on unmap, for DMA domains using the flush queue mechanism for
  78          *      delayed invalidation.
  79          */
  80         #define IO_PGTABLE_QUIRK_ARM_NS         BIT(0)
  81         #define IO_PGTABLE_QUIRK_NO_PERMS       BIT(1)
  82         #define IO_PGTABLE_QUIRK_TLBI_ON_MAP    BIT(2)
  83         #define IO_PGTABLE_QUIRK_ARM_MTK_4GB    BIT(3)
  84         #define IO_PGTABLE_QUIRK_NO_DMA         BIT(4)
  85         #define IO_PGTABLE_QUIRK_NON_STRICT     BIT(5)
  86         unsigned long                   quirks;
  87         unsigned long                   pgsize_bitmap;
  88         unsigned int                    ias;
  89         unsigned int                    oas;
  90         const struct iommu_gather_ops   *tlb;
  91         struct device                   *iommu_dev;
  92
  93         /* Low-level data specific to the table format */
  94         union {
  95                 struct {
  96                         u64     ttbr[2];
  97                         u64     tcr;
  98                         u64     mair[2];
  99                 } arm_lpae_s1_cfg;
 100
 101                 struct {
 102                         u64     vttbr;
 103                         u64     vtcr;
 104                 } arm_lpae_s2_cfg;
 105
 106                 struct {
 107                         u32     ttbr[2];
 108                         u32     tcr;
 109                         u32     nmrr;
 110                         u32     prrr;
 111                 } arm_v7s_cfg;
 112
 113                 struct {
 114                         u64     transtab;
 115                         u64     memattr;
 116                 } arm_mali_lpae_cfg;
 117         };
 118 };
 119
 120 /**
 121  * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
 122  *
 123  * @map:          Map a physically contiguous memory region.
 124  * @unmap:        Unmap a physically contiguous memory region.
 125  * @iova_to_phys: Translate iova to physical address.
 126  *
 127  * These functions map directly onto the iommu_ops member functions with
 128  * the same names.
 129  */
 130 struct io_pgtable_ops {
 131         int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
 132                    phys_addr_t paddr, size_t size, int prot);
 133         size_t (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
 134                         size_t size);
 135         phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
 136                                     unsigned long iova);
 137 };
 138
 139 /**
 140  * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
 141  *
 142  * @fmt:    The page table format.
 143  * @cfg:    The page table configuration. This will be modified to represent
 144  *          the configuration actually provided by the allocator (e.g. the
 145  *          pgsize_bitmap may be restricted).
 146  * @cookie: An opaque token provided by the IOMMU driver and passed back to
 147  *          the callback routines in cfg->tlb.
 148  */
 149 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
 150                                             struct io_pgtable_cfg *cfg,
 151                                             void *cookie);
 152
 153 /**
 154  * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
 155  *                         *must* ensure that the page table is no longer
 156  *                         live, but the TLB can be dirty.
 157  *
 158  * @ops: The ops returned from alloc_io_pgtable_ops.
 159  */
 160 void free_io_pgtable_ops(struct io_pgtable_ops *ops);
 161
 162
 163 /*
 164  * Internal structures for page table allocator implementations.
 165  */
 166
 167 /**
 168  * struct io_pgtable - Internal structure describing a set of page tables.
 169  *
 170  * @fmt:    The page table format.
 171  * @cookie: An opaque token provided by the IOMMU driver and passed back to
 172  *          any callback routines.
 173  * @cfg:    A copy of the page table configuration.
 174  * @ops:    The page table operations in use for this set of page tables.
 175  */
 176 struct io_pgtable {
 177         enum io_pgtable_fmt     fmt;
 178         void                    *cookie;
 179         struct io_pgtable_cfg   cfg;
 180         struct io_pgtable_ops   ops;
 181 };
 182
 183 #define io_pgtable_ops_to_pgtable(x) container_of((x), struct io_pgtable, ops)
 184
 185 static inline void io_pgtable_tlb_flush_all(struct io_pgtable *iop)
 186 {
 187         iop->cfg.tlb->tlb_flush_all(iop->cookie);
 188 }
 189
 190 static inline void io_pgtable_tlb_add_flush(struct io_pgtable *iop,
 191                 unsigned long iova, size_t size, size_t granule, bool leaf)
 192 {
 193         iop->cfg.tlb->tlb_add_flush(iova, size, granule, leaf, iop->cookie);
 194 }
 195
 196 static inline void io_pgtable_tlb_sync(struct io_pgtable *iop)
 197 {
 198         iop->cfg.tlb->tlb_sync(iop->cookie);
 199 }
 200
 201 /**
 202  * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
 203  *                              particular format.
 204  *
 205  * @alloc: Allocate a set of page tables described by cfg.
 206  * @free:  Free the page tables associated with iop.
 207  */
 208 struct io_pgtable_init_fns {
 209         struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
 210         void (*free)(struct io_pgtable *iop);
 211 };
 212
 213 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
 214 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
 215 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
 216 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
 217 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
 218 extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
 219
 220 #endif /* __IO_PGTABLE_H */