drivers/iommu/io-pgtable.c

   1 /*
   2  * Generic page table allocator for IOMMUs.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  *
  16  * Copyright (C) 2014 ARM Limited
  17  *
  18  * Author: Will Deacon <will.deacon@arm.com>
  19  */
  20
  21 #include <linux/bug.h>
  22 #include <linux/io-pgtable.h>
  23 #include <linux/kernel.h>
  24 #include <linux/types.h>
  25
  26 static const struct io_pgtable_init_fns *
  27 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
  28 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
  29         [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
  30         [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
  31         [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
  32         [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
  33 #endif
  34 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
  35         [ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
  36 #endif
  37 };
  38
  39 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
  40                                             struct io_pgtable_cfg *cfg,
  41                                             void *cookie)
  42 {
  43         struct io_pgtable *iop;
  44         const struct io_pgtable_init_fns *fns;
  45
  46         if (fmt >= IO_PGTABLE_NUM_FMTS)
  47                 return NULL;
  48
  49         fns = io_pgtable_init_table[fmt];
  50         if (!fns)
  51                 return NULL;
  52
  53         iop = fns->alloc(cfg, cookie);
  54         if (!iop)
  55                 return NULL;
  56
  57         iop->fmt        = fmt;
  58         iop->cookie     = cookie;
  59         iop->cfg        = *cfg;
  60
  61         return &iop->ops;
  62 }
  63 EXPORT_SYMBOL_GPL(alloc_io_pgtable_ops);
  64
  65 /*
  66  * It is the IOMMU driver's responsibility to ensure that the page table
  67  * is no longer accessible to the walker by this point.
  68  */
  69 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
  70 {
  71         struct io_pgtable *iop;
  72
  73         if (!ops)
  74                 return;
  75
  76         iop = container_of(ops, struct io_pgtable, ops);
  77         io_pgtable_tlb_flush_all(iop);
  78         io_pgtable_init_table[iop->fmt]->free(iop);
  79 }
  80 EXPORT_SYMBOL_GPL(free_io_pgtable_ops);