This adds initial support for the Maintenance command, specifically
the soft and hard PPR operations on a dpa. The implementation allows
to be executed at runtime, therefore semantically, data is retained
and CXL.mem requests are correctly processed.
Keep track of the requests upon a general media or DRAM event.
Post Package Repair (PPR) maintenance operations may be supported by CXL
devices that implement CXL.mem protocol. A PPR maintenance operation
requests the CXL device to perform a repair operation on its media.
For example, a CXL device with DRAM components that support PPR features
may implement PPR Maintenance operations. DRAM components may support two
types of PPR, hard PPR (hPPR), for a permanent row repair, and Soft PPR
(sPPR), for a temporary row repair. Soft PPR is much faster than hPPR,
but the repair is lost with a power cycle.
CXL spec 3.2 section 8.2.10.7.1.2 describes the device's sPPR (soft PPR)
maintenance operation and section 8.2.10.7.1.3 describes the device's
hPPR (hard PPR) maintenance operation feature.
CXL spec 3.2 section 8.2.10.7.2.1 describes the sPPR feature discovery and
configuration.
CXL spec 3.2 section 8.2.10.7.2.2 describes the hPPR feature discovery and
configuration.
CXL spec 3.2 section 8.2.10.2.1.4 Table 8-60 describes the Memory Sparing
Event Record.
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Co-developed-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20250917143330.294698-3-Jonathan.Cameron@huawei.com>
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