On 2022/5/19 15:20, Lu Baolu wrote:
The iommu_sva_domain represents a hardware pagetable that the IOMMU
hardware could use for SVA translation. This adds some infrastructure
to support SVA domain in the iommu common layer. It includes:
- Add a new struct iommu_sva_domain and new IOMMU_DOMAIN_SVA domain
type.
- Add a new domain ops pointer in iommu_ops. The IOMMU drivers that
support SVA should provide the callbacks.
- Add helpers to allocate and free an SVA domain.
- Add helpers to set an SVA domain to a device and the reverse
operation.
Some buses, like PCI, route packets without considering the PASID value.
Thus a DMA target address with PASID might be treated as P2P if the
address falls into the MMIO BAR of other devices in the group. To make
things simple, the attach/detach interfaces only apply to devices
belonging to the singleton groups, and the singleton is immutable in
fabric i.e. not affected by hotplug.
The iommu_set/block_device_pasid() can be used for other purposes,
such as kernel DMA with pasid, mediation device, etc. Hence, it is put
in the iommu.c.
Suggested-by: Jean-Philippe Brucker<jean-phili...@linaro.org>
Suggested-by: Jason Gunthorpe<j...@nvidia.com>
Signed-off-by: Lu Baolu<baolu...@linux.intel.com>
---
include/linux/iommu.h | 51 +++++++++++++++++++++++++
drivers/iommu/iommu-sva-lib.h | 15 ++++++++
drivers/iommu/iommu-sva-lib.c | 48 +++++++++++++++++++++++
drivers/iommu/iommu.c | 71 +++++++++++++++++++++++++++++++++++
4 files changed, 185 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0c358b7c583b..e8cf82d46ce1 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -64,6 +64,9 @@ struct iommu_domain_geometry {
#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
#define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */
+#define __IOMMU_DOMAIN_SHARED (1U << 4) /* Page table shared from CPU */
+#define __IOMMU_DOMAIN_HOST_VA (1U << 5) /* Host CPU virtual address */
+
/*
* This are the possible domain-types
*
@@ -86,6 +89,8 @@ struct iommu_domain_geometry {
#define IOMMU_DOMAIN_DMA_FQ (__IOMMU_DOMAIN_PAGING | \
__IOMMU_DOMAIN_DMA_API | \
__IOMMU_DOMAIN_DMA_FQ)
+#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SHARED | \
+ __IOMMU_DOMAIN_HOST_VA)
struct iommu_domain {
unsigned type;
@@ -254,6 +259,7 @@ struct iommu_ops {
int (*def_domain_type)(struct device *dev);
const struct iommu_domain_ops *default_domain_ops;
+ const struct iommu_domain_ops *sva_domain_ops;
Per Joerg's comment in anther thread,
https://lore.kernel.org/linux-iommu/yodvj7ervpidw...@8bytes.org/
adding a sva_domain_ops here is not the right way to go.
If no objection, I will make the sva domain go through the
generic domain_alloc/free() callbacks in the next version.
Best regards,
baolu
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