On 2024/10/10 0:23, Jason Gunthorpe wrote:
From: Nicolin Chen <nicolinc@xxxxxxxxxx>
ACPICA commit c4f5c083d24df9ddd71d5782c0988408cf0fc1ab
The IORT spec, Issue E.f (April 2024), adds a new CANWBS bit to the Memory
Access Flag field in the Memory Access Properties table, mainly for a PCI
Root Complex.
This CANWBS defines the coherency of memory accesses to be not marked IOWB
cacheable/shareable. Its value further implies the coherency impact from a
pair of mismatched memory attributes (e.g. in a nested translation case):
0x0: Use of mismatched memory attributes for accesses made by this
device may lead to a loss of coherency.
0x1: Coherency of accesses made by this device to locations in
Conventional memory are ensured as follows, even if the memory
attributes for the accesses presented by the device or provided by
the SMMU are different from Inner and Outer Write-back cacheable,
Shareable.
Acked-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
Thanks
Hanjun
