| Message ID | 20220112234749.1965960-1-ben.widawsky@intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | CXL Region driver | expand |
Dang. Responded to the wrong thread... v3 coming. Ignore this please. Thanks. Ben On 22-01-12 15:47:34, Ben Widawsky wrote: > Major changes since v1: > - bug fixes in certain calculations for region programming > - bug fix in for_each_cxl_decoder_target > - clarify ENIW and IG from ways and granularity > - wait_for_commit bug fix > - use devm management for region removal > - remove trace points > - add basic libnvdimm connection > > Original commit message follows with minor updates for correctness. > > --- > > This patch series introduces the CXL region driver as well as associated APIs in > CXL core. The region driver enables the creation of "regions" which is a concept > defined by the CXL 2.0 specification [1]. Region verification and programming > state are owned by the cxl_region driver (implemented in the cxl_region module). > It relies on cxl_mem to determine if devices are CXL routed, and cxl_port to > actually handle the programming of the HDM decoders. Much of the region driver > is an implementation of algorithms described in the CXL Type 3 Memory Device > Software Guide [2]. > > The region driver will be responsible for configuring regions found on > persistent capacities in the Label Storage Area (LSA), it will also enumerate > regions configured by BIOS, usually volatile capacities, and will allow for > dynamic region creation (which can then be stored in the LSA). It is the primary > consumer of the CXL Port [3] and CXL Mem drivers introduced previously [4]. Dan > has reworked those drivers which is a requirement for this branch. A cached copy > is included in the gitlab for this project [5]. Those patches will be posted > shortly. > > The patches for the region driver could be squashed. They're broken out to aid > review and because that's the order they were implemented in. My preference is > to keep those as they are. > > Some things are still missing and will be worked on while these are reviewed (in > priority order): > 1. Volatile regions/LSA regions (Have a plan) > 2. Switch ports (Have a plan) > 3. Decoder programming restrictions (No plan). The one know restriction I've > missed is to disallow programming HDM decoders that aren't in incremental > system physical address ranges. > 4. CXL region teardown -> nd_region teardown > 5. Stress testing > > Here is an example of output when programming a x2 interleave region > > # ./cxlctl create-region -n -a -s $((256<<20)) /sys/bus/cxl/devices/decoder0.0 > [ 57.564475][ T654] cxl_core:cxl_add_region:478: cxl region0.0:0: Added region0.0:0 to decoder0.0 > [ 57.608949][ T655] cxl_region:allocate_address_space:170: cxl_region region0.0:0: resource [mem 0x4c00000000-0x4c1fffffff] > [ 57.610056][ T655] cxl_core:cxl_commit_decoder:394: cxl_port port1: decoder1.0 > [ 57.610056][ T655] Base 0x0000004c00000000 > [ 57.610056][ T655] Size 512M > [ 57.610056][ T655] IG 0 (256b) > [ 57.610056][ T655] ENIW 1 (x2) > [ 57.610056][ T655] TargetList: 0 1 -1 -1 -1 -1 -1 -1 > [ 57.613584][ T655] cxl_core:cxl_commit_decoder:394: cxl_port endpoint2: decoder2.0 > [ 57.613584][ T655] Base 0x0000004c00000000 > [ 57.613584][ T655] Size 512M > [ 57.613584][ T655] IG 0 (256b) > [ 57.613584][ T655] ENIW 1 (x2) > [ 57.613584][ T655] TargetList: -1 -1 -1 -1 -1 -1 -1 -1 > [ 57.617051][ T655] cxl_core:cxl_commit_decoder:394: cxl_port endpoint3: decoder3.0 > [ 57.617051][ T655] Base 0x0000004c00000000 > [ 57.617051][ T655] Size 512M > [ 57.617051][ T655] IG 0 (256b) > [ 57.617051][ T655] ENIW 1 (x2) > [ 57.617051][ T655] TargetList: -1 -1 -1 -1 -1 -1 -1 -1 > [ 57.619433][ T655] cxl_region region0.0:0: Bound > [ 57.621435][ T655] cxl_core:cxl_bus_probe:1384: cxl_region region0.0:0: probe: 0 > > If you're wondering how I tested this, I've baked it into my cxlctl app [6] and > lib [7]. Eventually this will get absorbed by ndctl/cxl-cli/libcxl. > > > Branch can be found at gitlab [8]. > > --- > > [1]: https://www.computeexpresslink.org/download-the-specification > [2]: https://cdrdv2.intel.com/v1/dl/getContent/643805?wapkw=CXL%20memory%20device%20sw%20guide > [3]: https://lore.kernel.org/linux-cxl/20211022183709.1199701-9-ben.widawsky@intel.com/ > [4]: https://lore.kernel.org/linux-cxl/20211022183709.1199701-17-ben.widawsky@intel.com/ > [5]: https://gitlab.com/bwidawsk/linux/-/commit/126793e22427f7975a8f2fca373764be78012e88 > [6]: https://gitlab.com/bwidawsk-cxl/cxlctl > [7]: https://gitlab.com/bwidawsk-cxl/cxl_rs > [8]: https://gitlab.com/bwidawsk/linux/-/tree/cxl_region-v2 > > Ben Widawsky (15): > cxl/core: Rename find_cxl_port > cxl/core: Track port depth > cxl/region: Add region creation ABI > cxl/region: Introduce concept of region configuration > cxl/mem: Cache port created by the mem dev > cxl/region: Introduce a cxl_region driver > cxl/acpi: Handle address space allocation > cxl/region: Address space allocation > cxl/region: Implement XHB verification > cxl/region: HB port config verification > cxl/region: Add infrastructure for decoder programming > cxl/region: Collect host bridge decoders > cxl: Program decoders for regions > cxl/pmem: Convert nvdimm bridge API to use memdev > cxl/region: Create an nd_region > > .clang-format | 3 + > Documentation/ABI/testing/sysfs-bus-cxl | 63 ++ > .../driver-api/cxl/memory-devices.rst | 14 + > drivers/cxl/Makefile | 2 + > drivers/cxl/acpi.c | 30 + > drivers/cxl/core/Makefile | 1 + > drivers/cxl/core/core.h | 4 + > drivers/cxl/core/hdm.c | 199 +++++ > drivers/cxl/core/pmem.c | 19 +- > drivers/cxl/core/port.c | 132 ++- > drivers/cxl/core/region.c | 525 ++++++++++++ > drivers/cxl/cxl.h | 48 +- > drivers/cxl/cxlmem.h | 9 + > drivers/cxl/mem.c | 16 +- > drivers/cxl/pmem.c | 2 +- > drivers/cxl/port.c | 42 +- > drivers/cxl/region.c | 769 ++++++++++++++++++ > drivers/cxl/region.h | 47 ++ > tools/testing/cxl/Kbuild | 1 + > 19 files changed, 1903 insertions(+), 23 deletions(-) > create mode 100644 drivers/cxl/core/region.c > create mode 100644 drivers/cxl/region.c > create mode 100644 drivers/cxl/region.h > > -- > 2.34.1 >