Messages in this thread | | | From | Ira Weiny <> | Subject | [PATCH RFC v2 00/18] DCD: Add support for Dynamic Capacity Devices (DCD) | Date | Mon, 28 Aug 2023 22:20:51 -0700 |
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A Dynamic Capacity Device (DCD) (CXL 3.0 spec 9.13.3) is a CXL memory device that implements dynamic capacity. Dynamic capacity feature allows memory capacity to change dynamically, without the need for resetting the device.
Even though this is marked v2 by b4, this is effectively a whole new series for DCD support. Quite a bit of the core support was completed by Navneet in [4]. However, the architecture through the CXL region, DAX region, and DAX Device layers is completely different. Particular attention was paid to:
1) managing skip resources in the hardware device 2) ensuring the host OS only sent a release memory mailbox response when all DAX devices are done using an extent 3) allowing dax devices to span extents 4) allowing dax devices to use parts of extents
I could say all of the review comments from v1 are addressed but frankly the series has changed so much that I can't guarantee anything.
The series continues to be based on the type-2 work posted from Dan.[2] However, my branch with that work is a bit dated. Therefore I have posted this series on github here.[5]
Testing was sped up with cxl-test and ndctl dcd support. A preview of that work is on github.[6] In addition Fan Ni's Qemu DCD series was used part of the time.[3]
The major parts of this series are:
- Get the dynamic capacity (DC) region information from cxl device - Configure device DC regions reported by hardware - Enhance CXL and DAX regions for DC a. maintain separation between the hardware extents and the CXL region extents to provide for the addition of interleaving in the future. - Get and maintain the hardware extent lists for each device via an initial extent list and DC event records a. Add capacity Events b. Add capacity response b. Release capacity events d. Release capacity response - Notify region layers of extent changes - Allow for DAX devices to be created on extents which are surfaced - Maintain references on extents which are in use a. Send Release capacity Response only when DAX devices are not using memory - Allow DAX region extent labels to change to allow for flexibility in DAX device creation in the future (further enhancements are required to ndctl for this) - Trace Dynamic Capacity events - Add cxl-test infrastructure to allow for faster unit testing
To: Dan Williams <dan.j.williams@intel.com> Cc: Navneet Singh <navneet.singh@intel.com> Cc: Fan Ni <fan.ni@samsung.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: linux-cxl@vger.kernel.org Cc: linux-kernel@vger.kernel.org
[1] https://lore.kernel.org/all/64326437c1496_934b2949f@dwillia2-mobl3.amr.corp.intel.com.notmuch/ [2] https://lore.kernel.org/all/168592149709.1948938.8663425987110396027.stgit@dwillia2-xfh.jf.intel.com/ [3] https://lore.kernel.org/all/6483946e8152f_f1132294a2@iweiny-mobl.notmuch/ [4] https://lore.kernel.org/r/20230604-dcd-type2-upstream-v1-0-71b6341bae54@intel.com [5] https://github.com/weiny2/linux-kernel/commits/dcd-v2-2023-08-28 [6] https://github.com/weiny2/ndctl/tree/dcd-region2
--- Changes in v2: - iweiny: Complete rework of the entire series - Link to v1: https://lore.kernel.org/r/20230604-dcd-type2-upstream-v1-0-71b6341bae54@intel.com
--- Ira Weiny (15): cxl/hdm: Debug, use decoder name function cxl/mbox: Flag support for Dynamic Capacity Devices (DCD) cxl/region: Add Dynamic Capacity decoder and region modes cxl/port: Add Dynamic Capacity mode support to endpoint decoders cxl/port: Add Dynamic Capacity size support to endpoint decoders cxl/region: Add Dynamic Capacity CXL region support cxl/mem: Read extents on memory device discovery cxl/mem: Handle DCD add and release capacity events. cxl/region: Expose DC extents on region driver load cxl/region: Notify regions of DC changes dax/bus: Factor out dev dax resize logic dax/region: Support DAX device creation on dynamic DAX regions tools/testing/cxl: Make event logs dynamic tools/testing/cxl: Add DC Regions to mock mem data tools/testing/cxl: Add Dynamic Capacity events
Navneet Singh (3): cxl/mem: Read Dynamic capacity configuration from the device cxl/mem: Expose device dynamic capacity configuration cxl/mem: Trace Dynamic capacity Event Record
Documentation/ABI/testing/sysfs-bus-cxl | 56 ++- drivers/cxl/core/core.h | 1 + drivers/cxl/core/hdm.c | 215 ++++++++- drivers/cxl/core/mbox.c | 646 +++++++++++++++++++++++++- drivers/cxl/core/memdev.c | 77 ++++ drivers/cxl/core/port.c | 19 + drivers/cxl/core/region.c | 418 +++++++++++++++-- drivers/cxl/core/trace.h | 65 +++ drivers/cxl/cxl.h | 99 +++- drivers/cxl/cxlmem.h | 138 +++++- drivers/cxl/mem.c | 50 ++ drivers/cxl/pci.c | 8 + drivers/dax/Makefile | 1 + drivers/dax/bus.c | 263 ++++++++--- drivers/dax/bus.h | 1 + drivers/dax/cxl.c | 213 ++++++++- drivers/dax/dax-private.h | 61 +++ drivers/dax/extent.c | 133 ++++++ tools/testing/cxl/test/mem.c | 782 +++++++++++++++++++++++++++----- 19 files changed, 3005 insertions(+), 241 deletions(-) --- base-commit: c76cce37fb6f3796e8e146677ba98d3cca30a488 change-id: 20230604-dcd-type2-upstream-0cd15f6216fd
Best regards, -- Ira Weiny <ira.weiny@intel.com>
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