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/kernel.h>
  23 #include <linux/types.h>
  24
  25 #include "io-pgtable.h"
  26
  27 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns;
  28 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
  29 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
  30 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
  31
  32 static const struct io_pgtable_init_fns *
  33 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] =
  34 {
  35 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
  36         [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
  37         [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
  38         [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
  39         [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
  40 #endif
  41 };
  42
  43 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
  44                                             struct io_pgtable_cfg *cfg,
  45                                             void *cookie)
  46 {
  47         struct io_pgtable *iop;
  48         const struct io_pgtable_init_fns *fns;
  49
  50         if (fmt >= IO_PGTABLE_NUM_FMTS)
  51                 return NULL;
  52
  53         fns = io_pgtable_init_table[fmt];
  54         if (!fns)
  55                 return NULL;
  56
  57         iop = fns->alloc(cfg, cookie);
  58         if (!iop)
  59                 return NULL;
  60
  61         iop->fmt        = fmt;
  62         iop->cookie     = cookie;
  63         iop->cfg        = *cfg;
  64
  65         return &iop->ops;
  66 }
  67
  68 /*
  69  * It is the IOMMU driver's responsibility to ensure that the page table
  70  * is no longer accessible to the walker by this point.
  71  */
  72 void free_io_pgtable_ops(struct io_pgtable_ops *ops)
  73 {
  74         struct io_pgtable *iop;
  75
  76         if (!ops)
  77                 return;
  78
  79         iop = container_of(ops, struct io_pgtable, ops);
  80         iop->cfg.tlb->tlb_flush_all(iop->cookie);
  81         io_pgtable_init_table[iop->fmt]->free(iop);
  82 }