From fdb1d7be7c4d452e9735aeb2b60ae8a2fcf0a514 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 14 Nov 2014 17:16:49 +0000 Subject: [PATCH] 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/Kconfig | 8 +++ drivers/iommu/Makefile | 1 + drivers/iommu/io-pgtable.c | 71 ++++++++++++++++++++ drivers/iommu/io-pgtable.h | 128 +++++++++++++++++++++++++++++++++++++ 4 files changed, 208 insertions(+) create mode 100644 drivers/iommu/io-pgtable.c create mode 100644 drivers/iommu/io-pgtable.h diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 325188eef1c1..3faaa41db8ff 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -13,6 +13,14 @@ menuconfig IOMMU_SUPPORT if IOMMU_SUPPORT +menu "Generic IOMMU Pagetable Support" + +# Selected by the actual pagetable implementations +config IOMMU_IO_PGTABLE + bool + +endmenu + config OF_IOMMU def_bool y depends on OF && IOMMU_API diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 7b976f294a69..701c9516e2ae 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -1,6 +1,7 @@ obj-$(CONFIG_IOMMU_API) += iommu.o obj-$(CONFIG_IOMMU_API) += iommu-traces.o obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o +obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o obj-$(CONFIG_OF_IOMMU) += of_iommu.o obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o 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); +} diff --git a/drivers/iommu/io-pgtable.h b/drivers/iommu/io-pgtable.h new file mode 100644 index 000000000000..fdd792c37698 --- /dev/null +++ b/drivers/iommu/io-pgtable.h @@ -0,0 +1,128 @@ +#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 */ -- 2.20.1