Merge: Provide a new two step DMA mapping API

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1227

# Merge Request Required Information
JIRA: https://issues.redhat.com/browse/RHEL-73606

Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

Depends: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/866

## Summary of Changes
```
Upstream in v6.16:
a25e796 ("PCI/P2PDMA: Refactor the p2pdma mapping helpers")
ca2c2e4 ("dma-mapping: move the PCI P2PDMA mapping helpers to pci-p2pdma.h")
5c87cff ("iommu: generalize the batched sync after map interface")
dc2e692 ("iommu: add kernel-doc for iommu_unmap_fast")
393cf70 ("dma-mapping: Provide an interface to allow allocate IOVA")
ed18a46 ("iommu/dma: Factor out a iommu_dma_map_swiotlb helper")
433a762 ("dma-mapping: Implement link/unlink ranges API")
5f3b133 ("dma-mapping: add a dma_need_unmap helper")
3ee7d94 ("docs: core-api: document the IOVA-based API")
```

## Approved Development Ticket(s)
All submissions to CentOS Stream must reference a ticket in [Red Hat Jira](https://issues.redhat.com/).

<details><summary>Click for formatting instructions</summary>
Please follow the CentOS Stream [contribution documentation](https://docs.centos.org/en-US/stream-contrib/quickstart/) for how to file this ticket and have it approved.

List tickets each on their own line of this description using the format "Resolves: RHEL-76229", "Related: RHEL-76229" or "Reverts: RHEL-76229", as appropriate.
</details>

Signed-off-by: Eder Zulian <ezulian@redhat.com>

Approved-by: John W. Linville <linville@redhat.com>
Approved-by: Jerry Snitselaar <jsnitsel@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Scott Weaver <scweaver@redhat.com>

Author: swvrrh

Documentation/core-api/dma-api.rst

@@ -530,6 +530,77 @@ routines, e.g.:::
 		....
 	}
 
+Part Ie - IOVA-based DMA mappings
+---------------------------------
+
+These APIs allow a very efficient mapping when using an IOMMU.  They are an
+optional path that requires extra code and are only recommended for drivers
+where DMA mapping performance, or the space usage for storing the DMA addresses
+matter.  All the considerations from the previous section apply here as well.
+
+::
+
+    bool dma_iova_try_alloc(struct device *dev, struct dma_iova_state *state,
+		phys_addr_t phys, size_t size);
+
+Is used to try to allocate IOVA space for mapping operation.  If it returns
+false this API can't be used for the given device and the normal streaming
+DMA mapping API should be used.  The ``struct dma_iova_state`` is allocated
+by the driver and must be kept around until unmap time.
+
+::
+
+    static inline bool dma_use_iova(struct dma_iova_state *state)
+
+Can be used by the driver to check if the IOVA-based API is used after a
+call to dma_iova_try_alloc.  This can be useful in the unmap path.
+
+::
+
+    int dma_iova_link(struct device *dev, struct dma_iova_state *state,
+		phys_addr_t phys, size_t offset, size_t size,
+		enum dma_data_direction dir, unsigned long attrs);
+
+Is used to link ranges to the IOVA previously allocated.  The start of all
+but the first call to dma_iova_link for a given state must be aligned
+to the DMA merge boundary returned by ``dma_get_merge_boundary())``, and
+the size of all but the last range must be aligned to the DMA merge boundary
+as well.
+
+::
+
+    int dma_iova_sync(struct device *dev, struct dma_iova_state *state,
+		size_t offset, size_t size);
+
+Must be called to sync the IOMMU page tables for IOVA-range mapped by one or
+more calls to ``dma_iova_link()``.
+
+For drivers that use a one-shot mapping, all ranges can be unmapped and the
+IOVA freed by calling:
+
+::
+
+   void dma_iova_destroy(struct device *dev, struct dma_iova_state *state,
+		size_t mapped_len, enum dma_data_direction dir,
+                unsigned long attrs);
+
+Alternatively drivers can dynamically manage the IOVA space by unmapping
+and mapping individual regions.  In that case
+
+::
+
+    void dma_iova_unlink(struct device *dev, struct dma_iova_state *state,
+		size_t offset, size_t size, enum dma_data_direction dir,
+		unsigned long attrs);
+
+is used to unmap a range previously mapped, and
+
+::
+
+   void dma_iova_free(struct device *dev, struct dma_iova_state *state);
+
+is used to free the IOVA space.  All regions must have been unmapped using
+``dma_iova_unlink()`` before calling ``dma_iova_free()``.
 
 Part II - Non-coherent DMA allocations
 --------------------------------------