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Commit bc7d12b9 authored by Eric Auger's avatar Eric Auger Committed by Will Deacon
Browse files

iommu: Implement reserved_regions iommu-group sysfs file 



A new iommu-group sysfs attribute file is introduced. It contains
the list of reserved regions for the iommu-group. Each reserved
region is described on a separate line:
- first field is the start IOVA address,
- second is the end IOVA address,
- third is the type.

Signed-off-by: default avatarEric Auger <eric.auger@redhat.com>
Tested-by: default avatarTomasz Nowicki <tomasz.nowicki@caviumnetworks.com>
Tested-by: default avatarBharat Bhushan <bharat.bhushan@nxp.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 6c65fb31

Documentation/ABI/testing/sysfs-kernel-iommu_groups

+12 −0
Original line number Diff line number Diff line
@@ -12,3 +12,15 @@ Description: /sys/kernel/iommu_groups/ contains a number of sub- 
		file if the IOMMU driver has chosen to register a more

		common name for the group.

Users:



What:		/sys/kernel/iommu_groups/reserved_regions

Date: 		January 2017

KernelVersion:  v4.11

Contact: 	Eric Auger <eric.auger@redhat.com>

Description:    /sys/kernel/iommu_groups/reserved_regions list IOVA

		regions that are reserved. Not necessarily all

		reserved regions are listed. This is typically used to

		output direct-mapped, MSI, non mappable regions. Each

		region is described on a single line: the 1st field is

		the base IOVA, the second is the end IOVA and the third

		field describes the type of the region.

drivers/iommu/iommu.c

+36 −0
Original line number Diff line number Diff line
@@ -68,6 +68,12 @@ struct iommu_group_attribute { 
			 const char *buf, size_t count);

};



static const char * const iommu_group_resv_type_string[] = {

	[IOMMU_RESV_DIRECT]	= "direct",

	[IOMMU_RESV_RESERVED]	= "reserved",

	[IOMMU_RESV_MSI]	= "msi",

};



#define IOMMU_GROUP_ATTR(_name, _mode, _show, _store)		\

struct iommu_group_attribute iommu_group_attr_##_name =		\

	__ATTR(_name, _mode, _show, _store)
@@ -231,8 +237,33 @@ int iommu_get_group_resv_regions(struct iommu_group *group, 
}

EXPORT_SYMBOL_GPL(iommu_get_group_resv_regions);



static ssize_t iommu_group_show_resv_regions(struct iommu_group *group,

					     char *buf)

{

	struct iommu_resv_region *region, *next;

	struct list_head group_resv_regions;

	char *str = buf;



	INIT_LIST_HEAD(&group_resv_regions);

	iommu_get_group_resv_regions(group, &group_resv_regions);



	list_for_each_entry_safe(region, next, &group_resv_regions, list) {

		str += sprintf(str, "0x%016llx 0x%016llx %s\n",

			       (long long int)region->start,

			       (long long int)(region->start +

						region->length - 1),

			       iommu_group_resv_type_string[region->type]);

		kfree(region);

	}



	return (str - buf);

}



static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL);



static IOMMU_GROUP_ATTR(reserved_regions, 0444,

			iommu_group_show_resv_regions, NULL);



static void iommu_group_release(struct kobject *kobj)

{

	struct iommu_group *group = to_iommu_group(kobj);
@@ -310,6 +341,11 @@ struct iommu_group *iommu_group_alloc(void) 
	 */

	kobject_put(&group->kobj);



	ret = iommu_group_create_file(group,

				      &iommu_group_attr_reserved_regions);

	if (ret)

		return ERR_PTR(ret);



	pr_debug("Allocated group %d\n", group->id);



	return group;