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| author | Dan Williams <dan.j.williams@intel.com> | 2022-05-24 04:02:30 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2022-07-22 03:19:24 +0300 |
| commit | cf880423b6a0599499c1f83542cab0b75daa29ba (patch) | |
| tree | 96a5bff952a52b195ee1c3908cdeca59f9572f3a /Documentation/ABI/testing | |
| parent | 0c33b3935265cd5aafa18904363bab0c545adeee (diff) | |
| download | linux-cf880423b6a0599499c1f83542cab0b75daa29ba.tar.xz | |
cxl/hdm: Add support for allocating DPA to an endpoint decoder
The region provisioning flow will roughly follow a sequence of:
1/ Allocate DPA to a set of decoders
2/ Allocate HPA to a region
3/ Associate decoders with a region and validate that the DPA allocations
and topologies match the parameters of the region.
For now, this change (step 1) arranges for DPA capacity to be allocated
and deleted from non-committed decoders based on the decoder's mode /
partition selection. Capacity is allocated from the lowest DPA in the
partition and any 'pmem' allocation blocks out all remaining ram
capacity in its 'skip' setting. DPA allocations are enforced in decoder
instance order. I.e. decoder N + 1 always starts at a higher DPA than
instance N, and deleting allocations must proceed from the
highest-instance allocated decoder to the lowest.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165784329399.1758207.16732038126938632700.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'Documentation/ABI/testing')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 0b672248d126..1ab69aca6152 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -197,7 +197,7 @@ Date: May, 2022 KernelVersion: v5.20 Contact: linux-cxl@vger.kernel.org Description: - (RO) When a CXL decoder is of devtype "cxl_decoder_endpoint" it + (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it translates from a host physical address range, to a device local address range. Device-local address ranges are further split into a 'ram' (volatile memory) range and 'pmem' (persistent @@ -206,3 +206,38 @@ Description: when a decoder straddles the volatile/persistent partition boundary, and 'none' indicates the decoder is not actively decoding, or no DPA allocation policy has been set. + + 'mode' can be written, when the decoder is in the 'disabled' + state, with either 'ram' or 'pmem' to set the boundaries for the + next allocation. + + +What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource +Date: May, 2022 +KernelVersion: v5.20 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) When a CXL decoder is of devtype "cxl_decoder_endpoint", + and its 'dpa_size' attribute is non-zero, this attribute + indicates the device physical address (DPA) base address of the + allocation. + + +What: /sys/bus/cxl/devices/decoderX.Y/dpa_size +Date: May, 2022 +KernelVersion: v5.20 +Contact: linux-cxl@vger.kernel.org +Description: + (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it + translates from a host physical address range, to a device local + address range. The range, base address plus length in bytes, of + DPA allocated to this decoder is conveyed in these 2 attributes. + Allocations can be mutated as long as the decoder is in the + disabled state. A write to 'dpa_size' releases the previous DPA + allocation and then attempts to allocate from the free capacity + in the device partition referred to by 'decoderX.Y/mode'. + Allocate and free requests can only be performed on the highest + instance number disabled decoder with non-zero size. I.e. + allocations are enforced to occur in increasing 'decoderX.Y/id' + order and frees are enforced to occur in decreasing + 'decoderX.Y/id' order. |