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| author | Dan Williams <dan.j.williams@intel.com> | 2022-04-25 11:43:44 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2022-07-25 12:18:06 -0700 |
| commit | 23a22cd1c98be518774fe7f7e8a5203af050525a (patch) | |
| tree | 023f45987cce6345b543ac60ecdb32654735a1db /Documentation/ABI | |
| parent | 80d10a6cee05029cae9d9d6e8ddb799ea6d01e0c (diff) | |
| download | linux-23a22cd1c98be518774fe7f7e8a5203af050525a.tar.bz2 | |
cxl/region: Allocate HPA capacity to regions
After a region's interleave parameters (ways and granularity) are set,
add a way for regions to allocate HPA (host physical address space) from
the free capacity in their parent root-decoder. The allocator for this
capacity reuses the 'struct resource' based allocator used for
CONFIG_DEVICE_PRIVATE.
Once the tuple of "ways, granularity, [uuid], and size" is set the
region configuration transitions to the CXL_CONFIG_INTERLEAVE_ACTIVE
state which is a precursor to allowing endpoint decoders to be added to
a region.
Co-developed-by: Ben Widawsky <bwidawsk@kernel.org>
Signed-off-by: Ben Widawsky <bwidawsk@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165784335630.1758207.420216490941955417.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-cxl | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index df347174fb37..52764c172338 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -324,3 +324,32 @@ Description: (RW) Configures the number of devices participating in the region is set by writing this value. Each device will provide 1/interleave_ways of storage for the region. + + +What: /sys/bus/cxl/devices/regionZ/size +Date: May, 2022 +KernelVersion: v5.20 +Contact: linux-cxl@vger.kernel.org +Description: + (RW) System physical address space to be consumed by the region. + When written trigger the driver to allocate space out of the + parent root decoder's address space. When read the size of the + address space is reported and should match the span of the + region's resource attribute. Size shall be set after the + interleave configuration parameters. Once set it cannot be + changed, only freed by writing 0. The kernel makes no guarantees + that data is maintained over an address space freeing event, and + there is no guarantee that a free followed by an allocate + results in the same address being allocated. + + +What: /sys/bus/cxl/devices/regionZ/resource +Date: May, 2022 +KernelVersion: v5.20 +Contact: linux-cxl@vger.kernel.org +Description: + (RO) A region is a contiguous partition of a CXL root decoder + address space. Region capacity is allocated by writing to the + size attribute, the resulting physical address space determined + by the driver is reflected here. It is therefore not useful to + read this before writing a value to the size attribute. |