From fdb1d7be7c4d452e9735aeb2b60ae8a2fcf0a514 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 14 Nov 2014 17:16:49 +0000 Subject: iommu: introduce generic page table allocation framework This patch introduces a generic framework for allocating page tables for an IOMMU. There are a number of reasons we want to do this: - It avoids duplication of complex table management code in IOMMU drivers that use the same page table format - It removes any coupling with the CPU table format (and even the architecture!) - It defines an API for IOMMU TLB maintenance Tested-by: Laurent Pinchart Signed-off-by: Will Deacon --- drivers/iommu/io-pgtable.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 drivers/iommu/io-pgtable.c (limited to 'drivers/iommu/io-pgtable.c') diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c new file mode 100644 index 000000000000..f664a1ca49cf --- /dev/null +++ b/drivers/iommu/io-pgtable.c @@ -0,0 +1,71 @@ +/* + * Generic page table allocator for IOMMUs. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + * + * Copyright (C) 2014 ARM Limited + * + * Author: Will Deacon + */ + +#include +#include +#include + +#include "io-pgtable.h" + +static const struct io_pgtable_init_fns * +io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = +{ +}; + +struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, + struct io_pgtable_cfg *cfg, + void *cookie) +{ + struct io_pgtable *iop; + const struct io_pgtable_init_fns *fns; + + if (fmt >= IO_PGTABLE_NUM_FMTS) + return NULL; + + fns = io_pgtable_init_table[fmt]; + if (!fns) + return NULL; + + iop = fns->alloc(cfg, cookie); + if (!iop) + return NULL; + + iop->fmt = fmt; + iop->cookie = cookie; + iop->cfg = *cfg; + + return &iop->ops; +} + +/* + * It is the IOMMU driver's responsibility to ensure that the page table + * is no longer accessible to the walker by this point. + */ +void free_io_pgtable_ops(struct io_pgtable_ops *ops) +{ + struct io_pgtable *iop; + + if (!ops) + return; + + iop = container_of(ops, struct io_pgtable, ops); + iop->cfg.tlb->tlb_flush_all(iop->cookie); + io_pgtable_init_table[iop->fmt]->free(iop); +} -- cgit v1.2.3