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 <laurent.pinchart@ideasonboard.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Will Deacon 2014-11-14 17:16:49 +00:00
Родитель eaa27f34e9
Коммит fdb1d7be7c
4 изменённых файлов: 208 добавлений и 0 удалений

Просмотреть файл

@ -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

Просмотреть файл

@ -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

Просмотреть файл

@ -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 <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);
}

128
drivers/iommu/io-pgtable.h Normal file
Просмотреть файл

@ -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 */