[RFC v2 4/8] iommu: Add a list of iommu_reserved_region in iommu_domain

From: Eric Auger
Date: Fri Nov 04 2016 - 07:24:43 EST


Introduce a new iommu_reserved_region struct. This embodies
an IOVA reserved region that cannot be used along with the IOMMU
API. The list is protected by a dedicated mutex.

An iommu domain now owns a list of those.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>

---
---
drivers/iommu/iommu.c | 2 ++
include/linux/iommu.h | 17 +++++++++++++++++
2 files changed, 19 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 9a2f196..0af07492 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1061,6 +1061,8 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,

domain->ops = bus->iommu_ops;
domain->type = type;
+ INIT_LIST_HEAD(&domain->reserved_regions);
+ mutex_init(&domain->resv_mutex);
/* Assume all sizes by default; the driver may override this later */
domain->pgsize_bitmap = bus->iommu_ops->pgsize_bitmap;

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 436dc21..0f2eb64 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -84,6 +84,8 @@ struct iommu_domain {
void *handler_token;
struct iommu_domain_geometry geometry;
void *iova_cookie;
+ struct list_head reserved_regions;
+ struct mutex resv_mutex; /* protects the reserved region list */
};

enum iommu_cap {
@@ -131,6 +133,21 @@ struct iommu_dm_region {
int prot;
};

+/**
+ * struct iommu_reserved_region - descriptor for a reserved iova region
+ * @list: Linked list pointers
+ * @start: IOVA base address of the region
+ * @length: Length of the region in bytes
+ */
+struct iommu_reserved_region {
+ struct list_head list;
+ dma_addr_t start;
+ size_t length;
+};
+
+#define iommu_reserved_region_for_each(resv, d) \
+ list_for_each_entry(resv, &(d)->reserved_regions, list)
+
#ifdef CONFIG_IOMMU_API

/**
--
1.9.1