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