LXR linux/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
  27static const struct io_pgtable_init_fns *
  28io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
  29#ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
  30        [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
  31        [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
  32        [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
  33        [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
  34#endif
  35#ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
  36        [ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
  37#endif
  38};
  39
  40struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
  41                                            struct io_pgtable_cfg *cfg,
  42                                            void *cookie)
  43{
  44        struct io_pgtable *iop;
  45        const struct io_pgtable_init_fns *fns;
  46
  47        if (fmt >= IO_PGTABLE_NUM_FMTS)
  48                return NULL;
  49
  50        fns = io_pgtable_init_table[fmt];
  51        if (!fns)
  52                return NULL;
  53
  54        iop = fns->alloc(cfg, cookie);
  55        if (!iop)
  56                return NULL;
  57
  58        iop->fmt        = fmt;
  59        iop->cookie     = cookie;
  60        iop->cfg        = *cfg;
  61
  62        return &iop->ops;
  63}
  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 */
  69void 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