--- /dev/null
+/*
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (C) 2014 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/bug.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+#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);
+}
--- /dev/null
+#ifndef __IO_PGTABLE_H
+#define __IO_PGTABLE_H
+
+/*
+ * Public API for use by IOMMU drivers
+ */
+enum io_pgtable_fmt {
+ IO_PGTABLE_NUM_FMTS,
+};
+
+/**
+ * struct iommu_gather_ops - IOMMU callbacks for TLB and page table management.
+ *
+ * @tlb_flush_all: Synchronously invalidate the entire TLB context.
+ * @tlb_add_flush: Queue up a TLB invalidation for a virtual address range.
+ * @tlb_sync: Ensure any queue TLB invalidation has taken effect.
+ * @flush_pgtable: Ensure page table updates are visible to the IOMMU.
+ *
+ * Note that these can all be called in atomic context and must therefore
+ * not block.
+ */
+struct iommu_gather_ops {
+ void (*tlb_flush_all)(void *cookie);
+ void (*tlb_add_flush)(unsigned long iova, size_t size, bool leaf,
+ void *cookie);
+ void (*tlb_sync)(void *cookie);
+ void (*flush_pgtable)(void *ptr, size_t size, void *cookie);
+};
+
+/**
+ * struct io_pgtable_cfg - Configuration data for a set of page tables.
+ *
+ * @quirks: A bitmap of hardware quirks that require some special
+ * action by the low-level page table allocator.
+ * @pgsize_bitmap: A bitmap of page sizes supported by this set of page
+ * tables.
+ * @ias: Input address (iova) size, in bits.
+ * @oas: Output address (paddr) size, in bits.
+ * @tlb: TLB management callbacks for this set of tables.
+ */
+struct io_pgtable_cfg {
+ int quirks; /* IO_PGTABLE_QUIRK_* */
+ unsigned long pgsize_bitmap;
+ unsigned int ias;
+ unsigned int oas;
+ const struct iommu_gather_ops *tlb;
+
+ /* Low-level data specific to the table format */
+ union {
+ };
+};
+
+/**
+ * struct io_pgtable_ops - Page table manipulation API for IOMMU drivers.
+ *
+ * @map: Map a physically contiguous memory region.
+ * @unmap: Unmap a physically contiguous memory region.
+ * @iova_to_phys: Translate iova to physical address.
+ *
+ * These functions map directly onto the iommu_ops member functions with
+ * the same names.
+ */
+struct io_pgtable_ops {
+ int (*map)(struct io_pgtable_ops *ops, unsigned long iova,
+ phys_addr_t paddr, size_t size, int prot);
+ int (*unmap)(struct io_pgtable_ops *ops, unsigned long iova,
+ size_t size);
+ phys_addr_t (*iova_to_phys)(struct io_pgtable_ops *ops,
+ unsigned long iova);
+};
+
+/**
+ * alloc_io_pgtable_ops() - Allocate a page table allocator for use by an IOMMU.
+ *
+ * @fmt: The page table format.
+ * @cfg: The page table configuration. This will be modified to represent
+ * the configuration actually provided by the allocator (e.g. the
+ * pgsize_bitmap may be restricted).
+ * @cookie: An opaque token provided by the IOMMU driver and passed back to
+ * the callback routines in cfg->tlb.
+ */
+struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
+ struct io_pgtable_cfg *cfg,
+ void *cookie);
+
+/**
+ * free_io_pgtable_ops() - Free an io_pgtable_ops structure. The caller
+ * *must* ensure that the page table is no longer
+ * live, but the TLB can be dirty.
+ *
+ * @ops: The ops returned from alloc_io_pgtable_ops.
+ */
+void free_io_pgtable_ops(struct io_pgtable_ops *ops);
+
+
+/*
+ * Internal structures for page table allocator implementations.
+ */
+
+/**
+ * struct io_pgtable - Internal structure describing a set of page tables.
+ *
+ * @fmt: The page table format.
+ * @cookie: An opaque token provided by the IOMMU driver and passed back to
+ * any callback routines.
+ * @cfg: A copy of the page table configuration.
+ * @ops: The page table operations in use for this set of page tables.
+ */
+struct io_pgtable {
+ enum io_pgtable_fmt fmt;
+ void *cookie;
+ struct io_pgtable_cfg cfg;
+ struct io_pgtable_ops ops;
+};
+
+/**
+ * struct io_pgtable_init_fns - Alloc/free a set of page tables for a
+ * particular format.
+ *
+ * @alloc: Allocate a set of page tables described by cfg.
+ * @free: Free the page tables associated with iop.
+ */
+struct io_pgtable_init_fns {
+ struct io_pgtable *(*alloc)(struct io_pgtable_cfg *cfg, void *cookie);
+ void (*free)(struct io_pgtable *iop);
+};
+
+#endif /* __IO_PGTABLE_H */
projects / linux-2.6-block.git / commitdiff