[RFC v4 03/16] iommu: Add a new type field in iommu_resv_region

From: Eric Auger
Date: Tue Dec 13 2016 - 15:38:32 EST


We introduce a new field to differentiate the reserved region
types and specialize the apply_resv_region implementation.

Legacy direct mapped regions have IOMMU_RESV_DIRECT type.
We introduce 2 new reserved memory types:
- IOMMU_RESV_MSI will characterize MSI regions
- IOMMU_RESV_NOMAP characterize regions that cannot by mapped.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
---
drivers/iommu/amd_iommu.c | 1 +
include/linux/iommu.h | 7 +++++++
2 files changed, 8 insertions(+)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index a6c351d..3186c05 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3184,6 +3184,7 @@ static void amd_iommu_get_resv_regions(struct device *dev,

region->start = entry->address_start;
region->length = entry->address_end - entry->address_start;
+ region->type = IOMMU_RESV_DIRECT;
if (entry->prot & IOMMU_PROT_IR)
region->prot |= IOMMU_READ;
if (entry->prot & IOMMU_PROT_IW)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 7f6ebd0..ec87bac 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -117,18 +117,25 @@ enum iommu_attr {
DOMAIN_ATTR_MAX,
};

+/* These are the possible reserved region types */
+#define IOMMU_RESV_DIRECT (1 << 0)
+#define IOMMU_RESV_NOMAP (1 << 1)
+#define IOMMU_RESV_MSI (1 << 2)
+
/**
* struct iommu_resv_region - descriptor for a reserved memory region
* @list: Linked list pointers
* @start: System physical start address of the region
* @length: Length of the region in bytes
* @prot: IOMMU Protection flags (READ/WRITE/...)
+ * @type: Type of the reserved region
*/
struct iommu_resv_region {
struct list_head list;
phys_addr_t start;
size_t length;
int prot;
+ int type;
};

#ifdef CONFIG_IOMMU_API
--
1.9.1