iommu/sva: Add PASID helpers
Let IOMMU drivers allocate a single PASID per mm. Store the mm in the IOASID set to allow refcounting and searching mm by PASID, when handling an I/O page fault. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20201106155048.997886-3-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
parent
cb4789b0d1
commit
cfc78dfd9b
@ -103,6 +103,11 @@ config IOMMU_DMA
|
|||||||
select IRQ_MSI_IOMMU
|
select IRQ_MSI_IOMMU
|
||||||
select NEED_SG_DMA_LENGTH
|
select NEED_SG_DMA_LENGTH
|
||||||
|
|
||||||
|
# Shared Virtual Addressing library
|
||||||
|
config IOMMU_SVA_LIB
|
||||||
|
bool
|
||||||
|
select IOASID
|
||||||
|
|
||||||
config FSL_PAMU
|
config FSL_PAMU
|
||||||
bool "Freescale IOMMU support"
|
bool "Freescale IOMMU support"
|
||||||
depends on PCI
|
depends on PCI
|
||||||
|
@ -27,3 +27,4 @@ obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o
|
|||||||
obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
|
obj-$(CONFIG_S390_IOMMU) += s390-iommu.o
|
||||||
obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o
|
obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o
|
||||||
obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
|
obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
|
||||||
|
obj-$(CONFIG_IOMMU_SVA_LIB) += iommu-sva-lib.o
|
||||||
|
86
drivers/iommu/iommu-sva-lib.c
Normal file
86
drivers/iommu/iommu-sva-lib.c
Normal file
@ -0,0 +1,86 @@
|
|||||||
|
// SPDX-License-Identifier: GPL-2.0
|
||||||
|
/*
|
||||||
|
* Helpers for IOMMU drivers implementing SVA
|
||||||
|
*/
|
||||||
|
#include <linux/mutex.h>
|
||||||
|
#include <linux/sched/mm.h>
|
||||||
|
|
||||||
|
#include "iommu-sva-lib.h"
|
||||||
|
|
||||||
|
static DEFINE_MUTEX(iommu_sva_lock);
|
||||||
|
static DECLARE_IOASID_SET(iommu_sva_pasid);
|
||||||
|
|
||||||
|
/**
|
||||||
|
* iommu_sva_alloc_pasid - Allocate a PASID for the mm
|
||||||
|
* @mm: the mm
|
||||||
|
* @min: minimum PASID value (inclusive)
|
||||||
|
* @max: maximum PASID value (inclusive)
|
||||||
|
*
|
||||||
|
* Try to allocate a PASID for this mm, or take a reference to the existing one
|
||||||
|
* provided it fits within the [@min, @max] range. On success the PASID is
|
||||||
|
* available in mm->pasid, and must be released with iommu_sva_free_pasid().
|
||||||
|
* @min must be greater than 0, because 0 indicates an unused mm->pasid.
|
||||||
|
*
|
||||||
|
* Returns 0 on success and < 0 on error.
|
||||||
|
*/
|
||||||
|
int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
|
||||||
|
{
|
||||||
|
int ret = 0;
|
||||||
|
ioasid_t pasid;
|
||||||
|
|
||||||
|
if (min == INVALID_IOASID || max == INVALID_IOASID ||
|
||||||
|
min == 0 || max < min)
|
||||||
|
return -EINVAL;
|
||||||
|
|
||||||
|
mutex_lock(&iommu_sva_lock);
|
||||||
|
if (mm->pasid) {
|
||||||
|
if (mm->pasid >= min && mm->pasid <= max)
|
||||||
|
ioasid_get(mm->pasid);
|
||||||
|
else
|
||||||
|
ret = -EOVERFLOW;
|
||||||
|
} else {
|
||||||
|
pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
|
||||||
|
if (pasid == INVALID_IOASID)
|
||||||
|
ret = -ENOMEM;
|
||||||
|
else
|
||||||
|
mm->pasid = pasid;
|
||||||
|
}
|
||||||
|
mutex_unlock(&iommu_sva_lock);
|
||||||
|
return ret;
|
||||||
|
}
|
||||||
|
EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
|
||||||
|
|
||||||
|
/**
|
||||||
|
* iommu_sva_free_pasid - Release the mm's PASID
|
||||||
|
* @mm: the mm
|
||||||
|
*
|
||||||
|
* Drop one reference to a PASID allocated with iommu_sva_alloc_pasid()
|
||||||
|
*/
|
||||||
|
void iommu_sva_free_pasid(struct mm_struct *mm)
|
||||||
|
{
|
||||||
|
mutex_lock(&iommu_sva_lock);
|
||||||
|
if (ioasid_put(mm->pasid))
|
||||||
|
mm->pasid = 0;
|
||||||
|
mutex_unlock(&iommu_sva_lock);
|
||||||
|
}
|
||||||
|
EXPORT_SYMBOL_GPL(iommu_sva_free_pasid);
|
||||||
|
|
||||||
|
/* ioasid_find getter() requires a void * argument */
|
||||||
|
static bool __mmget_not_zero(void *mm)
|
||||||
|
{
|
||||||
|
return mmget_not_zero(mm);
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* iommu_sva_find() - Find mm associated to the given PASID
|
||||||
|
* @pasid: Process Address Space ID assigned to the mm
|
||||||
|
*
|
||||||
|
* On success a reference to the mm is taken, and must be released with mmput().
|
||||||
|
*
|
||||||
|
* Returns the mm corresponding to this PASID, or an error if not found.
|
||||||
|
*/
|
||||||
|
struct mm_struct *iommu_sva_find(ioasid_t pasid)
|
||||||
|
{
|
||||||
|
return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
|
||||||
|
}
|
||||||
|
EXPORT_SYMBOL_GPL(iommu_sva_find);
|
15
drivers/iommu/iommu-sva-lib.h
Normal file
15
drivers/iommu/iommu-sva-lib.h
Normal file
@ -0,0 +1,15 @@
|
|||||||
|
/* SPDX-License-Identifier: GPL-2.0 */
|
||||||
|
/*
|
||||||
|
* SVA library for IOMMU drivers
|
||||||
|
*/
|
||||||
|
#ifndef _IOMMU_SVA_LIB_H
|
||||||
|
#define _IOMMU_SVA_LIB_H
|
||||||
|
|
||||||
|
#include <linux/ioasid.h>
|
||||||
|
#include <linux/mm_types.h>
|
||||||
|
|
||||||
|
int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
|
||||||
|
void iommu_sva_free_pasid(struct mm_struct *mm);
|
||||||
|
struct mm_struct *iommu_sva_find(ioasid_t pasid);
|
||||||
|
|
||||||
|
#endif /* _IOMMU_SVA_LIB_H */
|
Loading…
Reference in New Issue
Block a user