With the users fully converted to DMA API operations, it's dead, Jim.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
With all current users now opted in to DMA API operations, make the
iommu_dev pointer mandatory, rendering the flush_pgtable callback
redundant for cache maintenance. However, since the DMA calls could be
nops in the case of a coherent IOMMU, we still need to ensure the page
table updates are fully synchronised against a subsequent page table
walk. In the unmap path, the TLB sync will usually need to do this
anyway, so just cement that requirement; in the map path which may
consist solely of cacheable memory writes (in the coherent case),
insert an appropriate barrier at the end of the operation, and obviate
the need to call flush_pgtable on every individual update for
synchronisation.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: slight clarification to tlb_sync comment]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, users of the LPAE page table code are (ab)using dma_map_page()
as a means to flush page table updates for non-coherent IOMMUs. Since
from the CPU's point of view, creating IOMMU page tables *is* passing
DMA buffers to a device (the IOMMU's page table walker), there's little
reason not to use the DMA API correctly.
Allow IOMMU drivers to opt into DMA API operations for page table
allocation and updates by providing their appropriate device pointer.
The expectation is that an LPAE IOMMU should have a full view of system
memory, so use streaming mappings to avoid unnecessary pressure on
ZONE_DMA, and treat any DMA translation as a warning sign.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The quirk causes the Non-Secure bit to be set in all page table entries.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
A number of IOMMUs found in ARM SoCs can walk architecture-compatible
page tables.
This patch adds a generic allocator for Stage-1 and Stage-2 v7/v8
long-descriptor page tables. 4k, 16k and 64k pages are supported, with
up to 4-levels of walk to cover a 48-bit address space.
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch introduces a generic framework for allocating page tables for
an IOMMU. There are a number of reasons we want to do this:
- It avoids duplication of complex table management code in IOMMU
drivers that use the same page table format
- It removes any coupling with the CPU table format (and even the
architecture!)
- It defines an API for IOMMU TLB maintenance
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
