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