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linux-next/include/linux/iommu.h
Ohad Ben-Cohen 77ca233235 iommu/core: pass a user-provided token to fault handlers
Sometimes a single IOMMU user may have to deal with several
different IOMMU devices (e.g. remoteproc).

When an IOMMU fault happens, such users have to regain their
context in order to deal with the fault.

Users can't use the private fields of neither the iommu_domain nor
the IOMMU device, because those are already used by the IOMMU core
and low level driver (respectively).

This patch just simply allows users to pass a private token (most
notably their own context pointer) to iommu_set_fault_handler(),
and then makes sure it is provided back to the users whenever
an IOMMU fault happens.

The patch also adopts remoteproc to the new fault handling
interface, but the real functionality using this (recovery of
remote processors) will only be added later in a subsequent patch
set.

Cc: Fernando Guzman Lugo <fernando.lugo@ti.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2012-05-22 18:08:08 +02:00

208 lines
6.3 KiB
C

/*
* Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
* Author: Joerg Roedel <joerg.roedel@amd.com>
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __LINUX_IOMMU_H
#define __LINUX_IOMMU_H
#include <linux/errno.h>
#define IOMMU_READ (1)
#define IOMMU_WRITE (2)
#define IOMMU_CACHE (4) /* DMA cache coherency */
struct iommu_ops;
struct bus_type;
struct device;
struct iommu_domain;
/* iommu fault flags */
#define IOMMU_FAULT_READ 0x0
#define IOMMU_FAULT_WRITE 0x1
typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
struct device *, unsigned long, int, void *);
struct iommu_domain {
struct iommu_ops *ops;
void *priv;
iommu_fault_handler_t handler;
void *handler_token;
};
#define IOMMU_CAP_CACHE_COHERENCY 0x1
#define IOMMU_CAP_INTR_REMAP 0x2 /* isolates device intrs */
#ifdef CONFIG_IOMMU_API
/**
* struct iommu_ops - iommu ops and capabilities
* @domain_init: init iommu domain
* @domain_destroy: destroy iommu domain
* @attach_dev: attach device to an iommu domain
* @detach_dev: detach device from an iommu domain
* @map: map a physically contiguous memory region to an iommu domain
* @unmap: unmap a physically contiguous memory region from an iommu domain
* @iova_to_phys: translate iova to physical address
* @domain_has_cap: domain capabilities query
* @commit: commit iommu domain
* @pgsize_bitmap: bitmap of supported page sizes
*/
struct iommu_ops {
int (*domain_init)(struct iommu_domain *domain);
void (*domain_destroy)(struct iommu_domain *domain);
int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
int (*map)(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot);
size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
size_t size);
phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
unsigned long iova);
int (*domain_has_cap)(struct iommu_domain *domain,
unsigned long cap);
int (*device_group)(struct device *dev, unsigned int *groupid);
unsigned long pgsize_bitmap;
};
extern int bus_set_iommu(struct bus_type *bus, struct iommu_ops *ops);
extern bool iommu_present(struct bus_type *bus);
extern struct iommu_domain *iommu_domain_alloc(struct bus_type *bus);
extern void iommu_domain_free(struct iommu_domain *domain);
extern int iommu_attach_device(struct iommu_domain *domain,
struct device *dev);
extern void iommu_detach_device(struct iommu_domain *domain,
struct device *dev);
extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot);
extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
size_t size);
extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
unsigned long iova);
extern int iommu_domain_has_cap(struct iommu_domain *domain,
unsigned long cap);
extern void iommu_set_fault_handler(struct iommu_domain *domain,
iommu_fault_handler_t handler, void *token);
extern int iommu_device_group(struct device *dev, unsigned int *groupid);
/**
* report_iommu_fault() - report about an IOMMU fault to the IOMMU framework
* @domain: the iommu domain where the fault has happened
* @dev: the device where the fault has happened
* @iova: the faulting address
* @flags: mmu fault flags (e.g. IOMMU_FAULT_READ/IOMMU_FAULT_WRITE/...)
*
* This function should be called by the low-level IOMMU implementations
* whenever IOMMU faults happen, to allow high-level users, that are
* interested in such events, to know about them.
*
* This event may be useful for several possible use cases:
* - mere logging of the event
* - dynamic TLB/PTE loading
* - if restarting of the faulting device is required
*
* Returns 0 on success and an appropriate error code otherwise (if dynamic
* PTE/TLB loading will one day be supported, implementations will be able
* to tell whether it succeeded or not according to this return value).
*
* Specifically, -ENOSYS is returned if a fault handler isn't installed
* (though fault handlers can also return -ENOSYS, in case they want to
* elicit the default behavior of the IOMMU drivers).
*/
static inline int report_iommu_fault(struct iommu_domain *domain,
struct device *dev, unsigned long iova, int flags)
{
int ret = -ENOSYS;
/*
* if upper layers showed interest and installed a fault handler,
* invoke it.
*/
if (domain->handler)
ret = domain->handler(domain, dev, iova, flags,
domain->handler_token);
return ret;
}
#else /* CONFIG_IOMMU_API */
struct iommu_ops {};
static inline bool iommu_present(struct bus_type *bus)
{
return false;
}
static inline struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
{
return NULL;
}
static inline void iommu_domain_free(struct iommu_domain *domain)
{
}
static inline int iommu_attach_device(struct iommu_domain *domain,
struct device *dev)
{
return -ENODEV;
}
static inline void iommu_detach_device(struct iommu_domain *domain,
struct device *dev)
{
}
static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, int gfp_order, int prot)
{
return -ENODEV;
}
static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
int gfp_order)
{
return -ENODEV;
}
static inline phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain,
unsigned long iova)
{
return 0;
}
static inline int domain_has_cap(struct iommu_domain *domain,
unsigned long cap)
{
return 0;
}
static inline void iommu_set_fault_handler(struct iommu_domain *domain,
iommu_fault_handler_t handler, void *token)
{
}
static inline int iommu_device_group(struct device *dev, unsigned int *groupid)
{
return -ENODEV;
}
#endif /* CONFIG_IOMMU_API */
#endif /* __LINUX_IOMMU_H */