drivers/iommu/io-pgtable.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Generic page table allocator for IOMMUs.
   4  *
   5  * Copyright (C) 2014 ARM Limited
   6  *
   7  * Author: Will Deacon <will.deacon@arm.com>
   8  */
   9
  10 #include <linux/bug.h>
  11 #include <linux/io-pgtable.h>
  12 #include <linux/kernel.h>
  13 #include <linux/types.h>
  14
  15 static const struct io_pgtable_init_fns *
  16 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
  17 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
  18         [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
  19         [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
  20         [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
  21         [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
  22         [ARM_MALI_LPAE] = &io_pgtable_arm_mali_lpae_init_fns,
  23 #endif
  24 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
  25         [ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
  26 #endif
  27 };
  28
  29 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
  30                                             struct io_pgtable_cfg *cfg,
  31                                             void *cookie)
  32 {
  33         struct io_pgtable *iop;
  34         const struct io_pgtable_init_fns *fns;
  35
  36         if (fmt >= IO_PGTABLE_NUM_FMTS)
  37                 return NULL;
  38
  39         fns = io_pgtable_init_table[fmt];
  40         if (!fns)
  41                 return NULL;
  42
  43         iop = fns->alloc(cfg, cookie);
  44         if (!iop)
  45                 return NULL;
  46
  47         iop->fmt        = fmt;
  48         iop->cookie     = cookie;
  49         iop->cfg        = *cfg;
  50
  51         return &iop->ops;
  52 }
  53 EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
  54
  55 /*
  56  * It is the IOMMU driver's responsibility to ensure that the page table
  57  * is no longer accessible to the walker by this point.
  58  */
  59 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
  60 {
  61         struct io_pgtable *iop;
  62
  63         if (!ops)
  64                 return;
  65
  66         iop = io_pgtable_ops_to_pgtable(ops);
  67         io_pgtable_tlb_flush_all(iop);
  68         io_pgtable_init_table[iop->fmt]->free(iop);
  69 }
  70 EXPORT_SYMBOL_GPL(free_io_pgtable_ops);