fdbe574eb6
IOMMU domain users such as VFIO face a similar problem to DMA API ops with regard to mapping MSI messages in systems where the MSI write is subject to IOMMU translation. With the relevant infrastructure now in place for managed DMA domains, it's actually really simple for other users to piggyback off that and reap the benefits without giving up their own IOVA management, and without having to reinvent their own wheel in the MSI layer. Allow such users to opt into automatic MSI remapping by dedicating a region of their IOVA space to a managed cookie, and extend the mapping routine to implement a trivial linear allocator in such cases, to avoid the needless overhead of a full-blown IOVA domain. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
106 lines
3.4 KiB
C
106 lines
3.4 KiB
C
/*
|
|
* Copyright (C) 2014-2015 ARM Ltd.
|
|
*
|
|
* 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/>.
|
|
*/
|
|
#ifndef __DMA_IOMMU_H
|
|
#define __DMA_IOMMU_H
|
|
|
|
#ifdef __KERNEL__
|
|
#include <asm/errno.h>
|
|
|
|
#ifdef CONFIG_IOMMU_DMA
|
|
#include <linux/iommu.h>
|
|
#include <linux/msi.h>
|
|
|
|
int iommu_dma_init(void);
|
|
|
|
/* Domain management interface for IOMMU drivers */
|
|
int iommu_get_dma_cookie(struct iommu_domain *domain);
|
|
int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
|
|
void iommu_put_dma_cookie(struct iommu_domain *domain);
|
|
|
|
/* Setup call for arch DMA mapping code */
|
|
int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
|
|
u64 size, struct device *dev);
|
|
|
|
/* General helpers for DMA-API <-> IOMMU-API interaction */
|
|
int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
|
|
|
|
/*
|
|
* These implement the bulk of the relevant DMA mapping callbacks, but require
|
|
* the arch code to take care of attributes and cache maintenance
|
|
*/
|
|
struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
|
|
unsigned long attrs, int prot, dma_addr_t *handle,
|
|
void (*flush_page)(struct device *, const void *, phys_addr_t));
|
|
void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
|
|
dma_addr_t *handle);
|
|
|
|
int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
|
|
|
|
dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
|
|
unsigned long offset, size_t size, int prot);
|
|
int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
|
|
int nents, int prot);
|
|
|
|
/*
|
|
* Arch code with no special attribute handling may use these
|
|
* directly as DMA mapping callbacks for simplicity
|
|
*/
|
|
void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
|
|
enum dma_data_direction dir, unsigned long attrs);
|
|
void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
|
|
enum dma_data_direction dir, unsigned long attrs);
|
|
dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
|
|
size_t size, enum dma_data_direction dir, unsigned long attrs);
|
|
void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
|
|
size_t size, enum dma_data_direction dir, unsigned long attrs);
|
|
int iommu_dma_supported(struct device *dev, u64 mask);
|
|
int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
|
|
|
|
/* The DMA API isn't _quite_ the whole story, though... */
|
|
void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
|
|
|
|
#else
|
|
|
|
struct iommu_domain;
|
|
struct msi_msg;
|
|
|
|
static inline int iommu_dma_init(void)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
|
|
{
|
|
return -ENODEV;
|
|
}
|
|
|
|
static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
|
|
{
|
|
return -ENODEV;
|
|
}
|
|
|
|
static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
|
|
{
|
|
}
|
|
|
|
static inline void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_IOMMU_DMA */
|
|
#endif /* __KERNEL__ */
|
|
#endif /* __DMA_IOMMU_H */
|