Commit 4e14176a authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommu/sva: Stop using ioasid_set for SVA 



Instead SVA drivers can use a simple global IDA to allocate PASIDs for
each mm_struct.

Future work would be to allow drivers using the SVA APIs to reserve global
PASIDs from this IDA for their internal use, eg with the DMA API PASID
support.

Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20230322200803.869130-5-jacob.jun.pan@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 2bef9ba8

drivers/iommu/iommu-sva.c

+14 −27
Original line number Diff line number Diff line
@@ -9,47 +9,34 @@ 
#include "iommu-sva.h"



static DEFINE_MUTEX(iommu_sva_lock);

static DECLARE_IOASID_SET(iommu_sva_pasid);

static DEFINE_IDA(iommu_global_pasid_ida);



/**

 * 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 will be available for the lifetime of the mm.

 *

 * Returns 0 on success and < 0 on error.

 */

int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)

/* Allocate a PASID for the mm within range (inclusive) */

static 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 ||

	if (!pasid_valid(min) || !pasid_valid(max) ||

	    min == 0 || max < min)

		return -EINVAL;



	mutex_lock(&iommu_sva_lock);

	/* Is a PASID already associated with this mm? */

	if (pasid_valid(mm->pasid)) {

		if (mm->pasid < min || mm->pasid >= max)

		if (mm->pasid < min || mm->pasid > max)

			ret = -EOVERFLOW;

		goto out;

	}



	pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);

	if (!pasid_valid(pasid))

		ret = -ENOMEM;

	else

		mm->pasid = pasid;

	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_ATOMIC);

	if (ret < 0)

		goto out;

	mm->pasid = ret;

	ret = 0;

out:

	mutex_unlock(&iommu_sva_lock);

	return ret;

}

EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);



/**

 * iommu_sva_bind_device() - Bind a process address space to a device
@@ -221,8 +208,8 @@ iommu_sva_handle_iopf(struct iommu_fault *fault, void *data) 


void mm_pasid_drop(struct mm_struct *mm)

{

	if (pasid_valid(mm->pasid)) {

		ioasid_free(mm->pasid);

		mm->pasid = INVALID_IOASID;

	}

	if (likely(!pasid_valid(mm->pasid)))

		return;



	ida_free(&iommu_global_pasid_ida, mm->pasid);

}

drivers/iommu/iommu-sva.h

+0 −2
Original line number Diff line number Diff line
@@ -8,8 +8,6 @@ 
#include <linux/ioasid.h>

#include <linux/mm_types.h>



int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);



/* I/O Page fault */

struct device;

struct iommu_fault;