18dd2bc0fSBen WidawskyWhat: /sys/bus/cxl/flush 28dd2bc0fSBen WidawskyDate: Januarry, 2022 38dd2bc0fSBen WidawskyKernelVersion: v5.18 48dd2bc0fSBen WidawskyContact: linux-cxl@vger.kernel.org 58dd2bc0fSBen WidawskyDescription: 68dd2bc0fSBen Widawsky (WO) If userspace manually unbinds a port the kernel schedules 78dd2bc0fSBen Widawsky all descendant memdevs for unbind. Writing '1' to this attribute 88dd2bc0fSBen Widawsky flushes that work. 98dd2bc0fSBen Widawsky 106b625b2bSDan Williams 11b39cb105SDan WilliamsWhat: /sys/bus/cxl/devices/memX/firmware_version 12b39cb105SDan WilliamsDate: December, 2020 13b39cb105SDan WilliamsKernelVersion: v5.12 14b39cb105SDan WilliamsContact: linux-cxl@vger.kernel.org 15b39cb105SDan WilliamsDescription: 16b39cb105SDan Williams (RO) "FW Revision" string as reported by the Identify 17b39cb105SDan Williams Memory Device Output Payload in the CXL-2.0 18b39cb105SDan Williams specification. 19b39cb105SDan Williams 206b625b2bSDan Williams 21b39cb105SDan WilliamsWhat: /sys/bus/cxl/devices/memX/ram/size 22b39cb105SDan WilliamsDate: December, 2020 23b39cb105SDan WilliamsKernelVersion: v5.12 24b39cb105SDan WilliamsContact: linux-cxl@vger.kernel.org 25b39cb105SDan WilliamsDescription: 26b39cb105SDan Williams (RO) "Volatile Only Capacity" as bytes. Represents the 27b39cb105SDan Williams identically named field in the Identify Memory Device Output 28b39cb105SDan Williams Payload in the CXL-2.0 specification. 29b39cb105SDan Williams 306b625b2bSDan Williams 31b39cb105SDan WilliamsWhat: /sys/bus/cxl/devices/memX/pmem/size 32b39cb105SDan WilliamsDate: December, 2020 33b39cb105SDan WilliamsKernelVersion: v5.12 34b39cb105SDan WilliamsContact: linux-cxl@vger.kernel.org 35b39cb105SDan WilliamsDescription: 36b39cb105SDan Williams (RO) "Persistent Only Capacity" as bytes. Represents the 37b39cb105SDan Williams identically named field in the Identify Memory Device Output 38b39cb105SDan Williams Payload in the CXL-2.0 specification. 394812be97SDan Williams 406b625b2bSDan Williams 41bcc79ea3SDan WilliamsWhat: /sys/bus/cxl/devices/memX/serial 42bcc79ea3SDan WilliamsDate: January, 2022 43bcc79ea3SDan WilliamsKernelVersion: v5.18 44bcc79ea3SDan WilliamsContact: linux-cxl@vger.kernel.org 45bcc79ea3SDan WilliamsDescription: 46bcc79ea3SDan Williams (RO) 64-bit serial number per the PCIe Device Serial Number 47bcc79ea3SDan Williams capability. Mandatory for CXL devices, see CXL 2.0 8.1.12.2 48bcc79ea3SDan Williams Memory Device PCIe Capabilities and Extended Capabilities. 49bcc79ea3SDan Williams 506b625b2bSDan Williams 51cf1f6877SDan WilliamsWhat: /sys/bus/cxl/devices/memX/numa_node 52cf1f6877SDan WilliamsDate: January, 2022 53cf1f6877SDan WilliamsKernelVersion: v5.18 54cf1f6877SDan WilliamsContact: linux-cxl@vger.kernel.org 55cf1f6877SDan WilliamsDescription: 56cf1f6877SDan Williams (RO) If NUMA is enabled and the platform has affinitized the 57cf1f6877SDan Williams host PCI device for this memory device, emit the CPU node 58cf1f6877SDan Williams affinity for this device. 59cf1f6877SDan Williams 606b625b2bSDan Williams 619968c9ddSDavidlohr BuesoWhat: /sys/bus/cxl/devices/memX/security/state 629968c9ddSDavidlohr BuesoDate: June, 2023 639968c9ddSDavidlohr BuesoKernelVersion: v6.5 649968c9ddSDavidlohr BuesoContact: linux-cxl@vger.kernel.org 659968c9ddSDavidlohr BuesoDescription: 669968c9ddSDavidlohr Bueso (RO) Reading this file will display the CXL security state for 6748dcdbb1SDavidlohr Bueso that device. Such states can be: 'disabled', 'sanitize', when 6848dcdbb1SDavidlohr Bueso a sanitization is currently underway; or those available only 6948dcdbb1SDavidlohr Bueso for persistent memory: 'locked', 'unlocked' or 'frozen'. This 7048dcdbb1SDavidlohr Bueso sysfs entry is select/poll capable from userspace to notify 7148dcdbb1SDavidlohr Bueso upon completion of a sanitize operation. 7248dcdbb1SDavidlohr Bueso 7348dcdbb1SDavidlohr Bueso 7448dcdbb1SDavidlohr BuesoWhat: /sys/bus/cxl/devices/memX/security/sanitize 7548dcdbb1SDavidlohr BuesoDate: June, 2023 7648dcdbb1SDavidlohr BuesoKernelVersion: v6.5 7748dcdbb1SDavidlohr BuesoContact: linux-cxl@vger.kernel.org 7848dcdbb1SDavidlohr BuesoDescription: 7948dcdbb1SDavidlohr Bueso (WO) Write a boolean 'true' string value to this attribute to 8048dcdbb1SDavidlohr Bueso sanitize the device to securely re-purpose or decommission it. 8148dcdbb1SDavidlohr Bueso This is done by ensuring that all user data and meta-data, 8248dcdbb1SDavidlohr Bueso whether it resides in persistent capacity, volatile capacity, 8348dcdbb1SDavidlohr Bueso or the LSA, is made permanently unavailable by whatever means 8448dcdbb1SDavidlohr Bueso is appropriate for the media type. This functionality requires 85*0fcde598SDavidlohr Bueso the device to be disabled, that is, not actively decoding any 86*0fcde598SDavidlohr Bueso HPA ranges. This permits avoiding explicit global CPU cache 87*0fcde598SDavidlohr Bueso management, relying instead for it to be done when a region 88*0fcde598SDavidlohr Bueso transitions between software programmed and hardware committed 89*0fcde598SDavidlohr Bueso states. 909968c9ddSDavidlohr Bueso 919968c9ddSDavidlohr Bueso 92180ffd33SDavidlohr BuesoWhat /sys/bus/cxl/devices/memX/security/erase 93180ffd33SDavidlohr BuesoDate: June, 2023 94180ffd33SDavidlohr BuesoKernelVersion: v6.5 95180ffd33SDavidlohr BuesoContact: linux-cxl@vger.kernel.org 96180ffd33SDavidlohr BuesoDescription: 97180ffd33SDavidlohr Bueso (WO) Write a boolean 'true' string value to this attribute to 98180ffd33SDavidlohr Bueso secure erase user data by changing the media encryption keys for 99*0fcde598SDavidlohr Bueso all user data areas of the device. This functionality requires 100*0fcde598SDavidlohr Bueso the device to be disabled, that is, not actively decoding any 101*0fcde598SDavidlohr Bueso HPA ranges. This permits avoiding explicit global CPU cache 102*0fcde598SDavidlohr Bueso management, relying instead for it to be done when a region 103*0fcde598SDavidlohr Bueso transitions between software programmed and hardware committed 104*0fcde598SDavidlohr Bueso states. 105180ffd33SDavidlohr Bueso 106180ffd33SDavidlohr Bueso 1079521875bSVishal VermaWhat: /sys/bus/cxl/devices/memX/firmware/ 1089521875bSVishal VermaDate: April, 2023 1099521875bSVishal VermaKernelVersion: v6.5 1109521875bSVishal VermaContact: linux-cxl@vger.kernel.org 1119521875bSVishal VermaDescription: 1129521875bSVishal Verma (RW) Firmware uploader mechanism. The different files under 1139521875bSVishal Verma this directory can be used to upload and activate new 1149521875bSVishal Verma firmware for CXL devices. The interfaces under this are 1159521875bSVishal Verma documented in sysfs-class-firmware. 1169521875bSVishal Verma 1179521875bSVishal Verma 1184812be97SDan WilliamsWhat: /sys/bus/cxl/devices/*/devtype 1194812be97SDan WilliamsDate: June, 2021 1204812be97SDan WilliamsKernelVersion: v5.14 1214812be97SDan WilliamsContact: linux-cxl@vger.kernel.org 1224812be97SDan WilliamsDescription: 12386677a4eSDan Williams (RO) CXL device objects export the devtype attribute which 12486677a4eSDan Williams mirrors the same value communicated in the DEVTYPE environment 12586677a4eSDan Williams variable for uevents for devices on the "cxl" bus. 1264812be97SDan Williams 1276b625b2bSDan Williams 12883fbdbe4SDan WilliamsWhat: /sys/bus/cxl/devices/*/modalias 12983fbdbe4SDan WilliamsDate: December, 2021 13083fbdbe4SDan WilliamsKernelVersion: v5.18 13183fbdbe4SDan WilliamsContact: linux-cxl@vger.kernel.org 13283fbdbe4SDan WilliamsDescription: 13386677a4eSDan Williams (RO) CXL device objects export the modalias attribute which 13486677a4eSDan Williams mirrors the same value communicated in the MODALIAS environment 13586677a4eSDan Williams variable for uevents for devices on the "cxl" bus. 13683fbdbe4SDan Williams 1376b625b2bSDan Williams 1384812be97SDan WilliamsWhat: /sys/bus/cxl/devices/portX/uport 1394812be97SDan WilliamsDate: June, 2021 1404812be97SDan WilliamsKernelVersion: v5.14 1414812be97SDan WilliamsContact: linux-cxl@vger.kernel.org 1424812be97SDan WilliamsDescription: 14386677a4eSDan Williams (RO) CXL port objects are enumerated from either a platform 14486677a4eSDan Williams firmware device (ACPI0017 and ACPI0016) or PCIe switch upstream 14586677a4eSDan Williams port with CXL component registers. The 'uport' symlink connects 14686677a4eSDan Williams the CXL portX object to the device that published the CXL port 1474812be97SDan Williams capability. 1487d4b5ca2SDan Williams 1496b625b2bSDan Williams 150172738bbSDan WilliamsWhat: /sys/bus/cxl/devices/{port,endpoint}X/parent_dport 151172738bbSDan WilliamsDate: January, 2023 152172738bbSDan WilliamsKernelVersion: v6.3 153172738bbSDan WilliamsContact: linux-cxl@vger.kernel.org 154172738bbSDan WilliamsDescription: 155172738bbSDan Williams (RO) CXL port objects are instantiated for each upstream port in 156172738bbSDan Williams a CXL/PCIe switch, and for each endpoint to map the 157172738bbSDan Williams corresponding memory device into the CXL port hierarchy. When a 158172738bbSDan Williams descendant CXL port (switch or endpoint) is enumerated it is 159172738bbSDan Williams useful to know which 'dport' object in the parent CXL port 160172738bbSDan Williams routes to this descendant. The 'parent_dport' symlink points to 161172738bbSDan Williams the device representing the downstream port of a CXL switch that 162172738bbSDan Williams routes to {port,endpoint}X. 163172738bbSDan Williams 164172738bbSDan Williams 1657d4b5ca2SDan WilliamsWhat: /sys/bus/cxl/devices/portX/dportY 1667d4b5ca2SDan WilliamsDate: June, 2021 1677d4b5ca2SDan WilliamsKernelVersion: v5.14 1687d4b5ca2SDan WilliamsContact: linux-cxl@vger.kernel.org 1697d4b5ca2SDan WilliamsDescription: 17086677a4eSDan Williams (RO) CXL port objects are enumerated from either a platform 17186677a4eSDan Williams firmware device (ACPI0017 and ACPI0016) or PCIe switch upstream 17286677a4eSDan Williams port with CXL component registers. The 'dportY' symlink 17386677a4eSDan Williams identifies one or more downstream ports that the upstream port 17486677a4eSDan Williams may target in its decode of CXL memory resources. The 'Y' 17586677a4eSDan Williams integer reflects the hardware port unique-id used in the 17686677a4eSDan Williams hardware decoder target list. 17740ba17afSDan Williams 1786b625b2bSDan Williams 17940ba17afSDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y 18040ba17afSDan WilliamsDate: June, 2021 18140ba17afSDan WilliamsKernelVersion: v5.14 18240ba17afSDan WilliamsContact: linux-cxl@vger.kernel.org 18340ba17afSDan WilliamsDescription: 18486677a4eSDan Williams (RO) CXL decoder objects are enumerated from either a platform 18540ba17afSDan Williams firmware description, or a CXL HDM decoder register set in a 18640ba17afSDan Williams PCIe device (see CXL 2.0 section 8.2.5.12 CXL HDM Decoder 18740ba17afSDan Williams Capability Structure). The 'X' in decoderX.Y represents the 18840ba17afSDan Williams cxl_port container of this decoder, and 'Y' represents the 18940ba17afSDan Williams instance id of a given decoder resource. 19040ba17afSDan Williams 1916b625b2bSDan Williams 19240ba17afSDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/{start,size} 19340ba17afSDan WilliamsDate: June, 2021 19440ba17afSDan WilliamsKernelVersion: v5.14 19540ba17afSDan WilliamsContact: linux-cxl@vger.kernel.org 19640ba17afSDan WilliamsDescription: 19786677a4eSDan Williams (RO) The 'start' and 'size' attributes together convey the 19886677a4eSDan Williams physical address base and number of bytes mapped in the 19986677a4eSDan Williams decoder's decode window. For decoders of devtype 20086677a4eSDan Williams "cxl_decoder_root" the address range is fixed. For decoders of 20186677a4eSDan Williams devtype "cxl_decoder_switch" the address is bounded by the 20286677a4eSDan Williams decode range of the cxl_port ancestor of the decoder's cxl_port, 20386677a4eSDan Williams and dynamically updates based on the active memory regions in 20486677a4eSDan Williams that address space. 20540ba17afSDan Williams 2066b625b2bSDan Williams 20740ba17afSDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/locked 20840ba17afSDan WilliamsDate: June, 2021 20940ba17afSDan WilliamsKernelVersion: v5.14 21040ba17afSDan WilliamsContact: linux-cxl@vger.kernel.org 21140ba17afSDan WilliamsDescription: 21286677a4eSDan Williams (RO) CXL HDM decoders have the capability to lock the 21386677a4eSDan Williams configuration until the next device reset. For decoders of 21486677a4eSDan Williams devtype "cxl_decoder_root" there is no standard facility to 21586677a4eSDan Williams unlock them. For decoders of devtype "cxl_decoder_switch" a 21686677a4eSDan Williams secondary bus reset, of the PCIe bridge that provides the bus 21786677a4eSDan Williams for this decoders uport, unlocks / resets the decoder. 21840ba17afSDan Williams 2196b625b2bSDan Williams 22040ba17afSDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/target_list 22140ba17afSDan WilliamsDate: June, 2021 22240ba17afSDan WilliamsKernelVersion: v5.14 22340ba17afSDan WilliamsContact: linux-cxl@vger.kernel.org 22440ba17afSDan WilliamsDescription: 22586677a4eSDan Williams (RO) Display a comma separated list of the current decoder 22686677a4eSDan Williams target configuration. The list is ordered by the current 22786677a4eSDan Williams configured interleave order of the decoder's dport instances. 22886677a4eSDan Williams Each entry in the list is a dport id. 22940ba17afSDan Williams 2306b625b2bSDan Williams 23140ba17afSDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/cap_{pmem,ram,type2,type3} 23240ba17afSDan WilliamsDate: June, 2021 23340ba17afSDan WilliamsKernelVersion: v5.14 23440ba17afSDan WilliamsContact: linux-cxl@vger.kernel.org 23540ba17afSDan WilliamsDescription: 23686677a4eSDan Williams (RO) When a CXL decoder is of devtype "cxl_decoder_root", it 23740ba17afSDan Williams represents a fixed memory window identified by platform 23840ba17afSDan Williams firmware. A fixed window may only support a subset of memory 23940ba17afSDan Williams types. The 'cap_*' attributes indicate whether persistent 24040ba17afSDan Williams memory, volatile memory, accelerator memory, and / or expander 24140ba17afSDan Williams memory may be mapped behind this decoder's memory window. 24240ba17afSDan Williams 2436b625b2bSDan Williams 24440ba17afSDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/target_type 24540ba17afSDan WilliamsDate: June, 2021 24640ba17afSDan WilliamsKernelVersion: v5.14 24740ba17afSDan WilliamsContact: linux-cxl@vger.kernel.org 24840ba17afSDan WilliamsDescription: 24986677a4eSDan Williams (RO) When a CXL decoder is of devtype "cxl_decoder_switch", it 25086677a4eSDan Williams can optionally decode either accelerator memory (type-2) or 25186677a4eSDan Williams expander memory (type-3). The 'target_type' attribute indicates 25286677a4eSDan Williams the current setting which may dynamically change based on what 25340ba17afSDan Williams memory regions are activated in this decode hierarchy. 254c9700604SIra Weiny 2556b625b2bSDan Williams 256c9700604SIra WeinyWhat: /sys/bus/cxl/devices/endpointX/CDAT 257c9700604SIra WeinyDate: July, 2022 2588752efd2SDan WilliamsKernelVersion: v6.0 259c9700604SIra WeinyContact: linux-cxl@vger.kernel.org 260c9700604SIra WeinyDescription: 261c9700604SIra Weiny (RO) If this sysfs entry is not present no DOE mailbox was 262c9700604SIra Weiny found to support CDAT data. If it is present and the length of 263c9700604SIra Weiny the data is 0 reading the CDAT data failed. Otherwise the CDAT 264c9700604SIra Weiny data is reported. 2652c866903SDan Williams 2662c866903SDan Williams 2672c866903SDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/mode 2682c866903SDan WilliamsDate: May, 2022 2698752efd2SDan WilliamsKernelVersion: v6.0 2702c866903SDan WilliamsContact: linux-cxl@vger.kernel.org 2712c866903SDan WilliamsDescription: 272cf880423SDan Williams (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it 2732c866903SDan Williams translates from a host physical address range, to a device local 2742c866903SDan Williams address range. Device-local address ranges are further split 2752c866903SDan Williams into a 'ram' (volatile memory) range and 'pmem' (persistent 2762c866903SDan Williams memory) range. The 'mode' attribute emits one of 'ram', 'pmem', 2772c866903SDan Williams 'mixed', or 'none'. The 'mixed' indication is for error cases 2782c866903SDan Williams when a decoder straddles the volatile/persistent partition 2792c866903SDan Williams boundary, and 'none' indicates the decoder is not actively 2802c866903SDan Williams decoding, or no DPA allocation policy has been set. 281cf880423SDan Williams 282cf880423SDan Williams 'mode' can be written, when the decoder is in the 'disabled' 283cf880423SDan Williams state, with either 'ram' or 'pmem' to set the boundaries for the 284cf880423SDan Williams next allocation. 285cf880423SDan Williams 286cf880423SDan Williams 287cf880423SDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/dpa_resource 288cf880423SDan WilliamsDate: May, 2022 2898752efd2SDan WilliamsKernelVersion: v6.0 290cf880423SDan WilliamsContact: linux-cxl@vger.kernel.org 291cf880423SDan WilliamsDescription: 292cf880423SDan Williams (RO) When a CXL decoder is of devtype "cxl_decoder_endpoint", 293cf880423SDan Williams and its 'dpa_size' attribute is non-zero, this attribute 294cf880423SDan Williams indicates the device physical address (DPA) base address of the 295cf880423SDan Williams allocation. 296cf880423SDan Williams 297cf880423SDan Williams 298cf880423SDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/dpa_size 299cf880423SDan WilliamsDate: May, 2022 3008752efd2SDan WilliamsKernelVersion: v6.0 301cf880423SDan WilliamsContact: linux-cxl@vger.kernel.org 302cf880423SDan WilliamsDescription: 303cf880423SDan Williams (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it 304cf880423SDan Williams translates from a host physical address range, to a device local 305cf880423SDan Williams address range. The range, base address plus length in bytes, of 306cf880423SDan Williams DPA allocated to this decoder is conveyed in these 2 attributes. 307cf880423SDan Williams Allocations can be mutated as long as the decoder is in the 308cf880423SDan Williams disabled state. A write to 'dpa_size' releases the previous DPA 309cf880423SDan Williams allocation and then attempts to allocate from the free capacity 310cf880423SDan Williams in the device partition referred to by 'decoderX.Y/mode'. 311cf880423SDan Williams Allocate and free requests can only be performed on the highest 312cf880423SDan Williams instance number disabled decoder with non-zero size. I.e. 313cf880423SDan Williams allocations are enforced to occur in increasing 'decoderX.Y/id' 314cf880423SDan Williams order and frees are enforced to occur in decreasing 315cf880423SDan Williams 'decoderX.Y/id' order. 316538831f1SBen Widawsky 317538831f1SBen Widawsky 318538831f1SBen WidawskyWhat: /sys/bus/cxl/devices/decoderX.Y/interleave_ways 319538831f1SBen WidawskyDate: May, 2022 3208752efd2SDan WilliamsKernelVersion: v6.0 321538831f1SBen WidawskyContact: linux-cxl@vger.kernel.org 322538831f1SBen WidawskyDescription: 323538831f1SBen Widawsky (RO) The number of targets across which this decoder's host 324538831f1SBen Widawsky physical address (HPA) memory range is interleaved. The device 325538831f1SBen Widawsky maps every Nth block of HPA (of size == 326538831f1SBen Widawsky 'interleave_granularity') to consecutive DPA addresses. The 327538831f1SBen Widawsky decoder's position in the interleave is determined by the 328538831f1SBen Widawsky device's (endpoint or switch) switch ancestry. For root 329538831f1SBen Widawsky decoders their interleave is specified by platform firmware and 330538831f1SBen Widawsky they only specify a downstream target order for host bridges. 331538831f1SBen Widawsky 332538831f1SBen Widawsky 333538831f1SBen WidawskyWhat: /sys/bus/cxl/devices/decoderX.Y/interleave_granularity 334538831f1SBen WidawskyDate: May, 2022 3358752efd2SDan WilliamsKernelVersion: v6.0 336538831f1SBen WidawskyContact: linux-cxl@vger.kernel.org 337538831f1SBen WidawskyDescription: 338538831f1SBen Widawsky (RO) The number of consecutive bytes of host physical address 339538831f1SBen Widawsky space this decoder claims at address N before the decode rotates 340538831f1SBen Widawsky to the next target in the interleave at address N + 341538831f1SBen Widawsky interleave_granularity (assuming N is aligned to 342538831f1SBen Widawsky interleave_granularity). 343779dd20cSBen Widawsky 344779dd20cSBen Widawsky 3456e099264SDan WilliamsWhat: /sys/bus/cxl/devices/decoderX.Y/create_{pmem,ram}_region 3466e099264SDan WilliamsDate: May, 2022, January, 2023 3476e099264SDan WilliamsKernelVersion: v6.0 (pmem), v6.3 (ram) 348779dd20cSBen WidawskyContact: linux-cxl@vger.kernel.org 349779dd20cSBen WidawskyDescription: 350779dd20cSBen Widawsky (RW) Write a string in the form 'regionZ' to start the process 3516e099264SDan Williams of defining a new persistent, or volatile memory region 3526e099264SDan Williams (interleave-set) within the decode range bounded by root decoder 3536e099264SDan Williams 'decoderX.Y'. The value written must match the current value 3546e099264SDan Williams returned from reading this attribute. An atomic compare exchange 3556e099264SDan Williams operation is done on write to assign the requested id to a 3566e099264SDan Williams region and allocate the region-id for the next creation attempt. 3576e099264SDan Williams EBUSY is returned if the region name written does not match the 3586e099264SDan Williams current cached value. 359779dd20cSBen Widawsky 360779dd20cSBen Widawsky 361779dd20cSBen WidawskyWhat: /sys/bus/cxl/devices/decoderX.Y/delete_region 362779dd20cSBen WidawskyDate: May, 2022 3638752efd2SDan WilliamsKernelVersion: v6.0 364779dd20cSBen WidawskyContact: linux-cxl@vger.kernel.org 365779dd20cSBen WidawskyDescription: 366779dd20cSBen Widawsky (WO) Write a string in the form 'regionZ' to delete that region, 367779dd20cSBen Widawsky provided it is currently idle / not bound to a driver. 368dd5ba0ebSBen Widawsky 369dd5ba0ebSBen Widawsky 370dd5ba0ebSBen WidawskyWhat: /sys/bus/cxl/devices/regionZ/uuid 371dd5ba0ebSBen WidawskyDate: May, 2022 3728752efd2SDan WilliamsKernelVersion: v6.0 373dd5ba0ebSBen WidawskyContact: linux-cxl@vger.kernel.org 374dd5ba0ebSBen WidawskyDescription: 375dd5ba0ebSBen Widawsky (RW) Write a unique identifier for the region. This field must 376dd5ba0ebSBen Widawsky be set for persistent regions and it must not conflict with the 377a8e7d558SDan Williams UUID of another region. For volatile ram regions this 378a8e7d558SDan Williams attribute is a read-only empty string. 37980d10a6cSBen Widawsky 38080d10a6cSBen Widawsky 38180d10a6cSBen WidawskyWhat: /sys/bus/cxl/devices/regionZ/interleave_granularity 38280d10a6cSBen WidawskyDate: May, 2022 3838752efd2SDan WilliamsKernelVersion: v6.0 38480d10a6cSBen WidawskyContact: linux-cxl@vger.kernel.org 38580d10a6cSBen WidawskyDescription: 38680d10a6cSBen Widawsky (RW) Set the number of consecutive bytes each device in the 38780d10a6cSBen Widawsky interleave set will claim. The possible interleave granularity 38880d10a6cSBen Widawsky values are determined by the CXL spec and the participating 38980d10a6cSBen Widawsky devices. 39080d10a6cSBen Widawsky 39180d10a6cSBen Widawsky 39280d10a6cSBen WidawskyWhat: /sys/bus/cxl/devices/regionZ/interleave_ways 39380d10a6cSBen WidawskyDate: May, 2022 3948752efd2SDan WilliamsKernelVersion: v6.0 39580d10a6cSBen WidawskyContact: linux-cxl@vger.kernel.org 39680d10a6cSBen WidawskyDescription: 39780d10a6cSBen Widawsky (RW) Configures the number of devices participating in the 39880d10a6cSBen Widawsky region is set by writing this value. Each device will provide 39980d10a6cSBen Widawsky 1/interleave_ways of storage for the region. 40023a22cd1SDan Williams 40123a22cd1SDan Williams 40223a22cd1SDan WilliamsWhat: /sys/bus/cxl/devices/regionZ/size 40323a22cd1SDan WilliamsDate: May, 2022 4048752efd2SDan WilliamsKernelVersion: v6.0 40523a22cd1SDan WilliamsContact: linux-cxl@vger.kernel.org 40623a22cd1SDan WilliamsDescription: 40723a22cd1SDan Williams (RW) System physical address space to be consumed by the region. 40823a22cd1SDan Williams When written trigger the driver to allocate space out of the 40923a22cd1SDan Williams parent root decoder's address space. When read the size of the 41023a22cd1SDan Williams address space is reported and should match the span of the 41123a22cd1SDan Williams region's resource attribute. Size shall be set after the 41223a22cd1SDan Williams interleave configuration parameters. Once set it cannot be 41323a22cd1SDan Williams changed, only freed by writing 0. The kernel makes no guarantees 41423a22cd1SDan Williams that data is maintained over an address space freeing event, and 41523a22cd1SDan Williams there is no guarantee that a free followed by an allocate 41623a22cd1SDan Williams results in the same address being allocated. 41723a22cd1SDan Williams 41823a22cd1SDan Williams 4197d505f98SDan WilliamsWhat: /sys/bus/cxl/devices/regionZ/mode 4207d505f98SDan WilliamsDate: January, 2023 4217d505f98SDan WilliamsKernelVersion: v6.3 4227d505f98SDan WilliamsContact: linux-cxl@vger.kernel.org 4237d505f98SDan WilliamsDescription: 4247d505f98SDan Williams (RO) The mode of a region is established at region creation time 4257d505f98SDan Williams and dictates the mode of the endpoint decoder that comprise the 4267d505f98SDan Williams region. For more details on the possible modes see 4277d505f98SDan Williams /sys/bus/cxl/devices/decoderX.Y/mode 4287d505f98SDan Williams 4297d505f98SDan Williams 43023a22cd1SDan WilliamsWhat: /sys/bus/cxl/devices/regionZ/resource 43123a22cd1SDan WilliamsDate: May, 2022 4328752efd2SDan WilliamsKernelVersion: v6.0 43323a22cd1SDan WilliamsContact: linux-cxl@vger.kernel.org 43423a22cd1SDan WilliamsDescription: 43523a22cd1SDan Williams (RO) A region is a contiguous partition of a CXL root decoder 43623a22cd1SDan Williams address space. Region capacity is allocated by writing to the 43723a22cd1SDan Williams size attribute, the resulting physical address space determined 43823a22cd1SDan Williams by the driver is reflected here. It is therefore not useful to 43923a22cd1SDan Williams read this before writing a value to the size attribute. 440b9686e8cSDan Williams 441b9686e8cSDan Williams 442b9686e8cSDan WilliamsWhat: /sys/bus/cxl/devices/regionZ/target[0..N] 443b9686e8cSDan WilliamsDate: May, 2022 4448752efd2SDan WilliamsKernelVersion: v6.0 445b9686e8cSDan WilliamsContact: linux-cxl@vger.kernel.org 446b9686e8cSDan WilliamsDescription: 447b9686e8cSDan Williams (RW) Write an endpoint decoder object name to 'targetX' where X 448b9686e8cSDan Williams is the intended position of the endpoint device in the region 449b9686e8cSDan Williams interleave and N is the 'interleave_ways' setting for the 450b9686e8cSDan Williams region. ENXIO is returned if the write results in an impossible 451b9686e8cSDan Williams to map decode scenario, like the endpoint is unreachable at that 452b9686e8cSDan Williams position relative to the root decoder interleave. EBUSY is 453b9686e8cSDan Williams returned if the position in the region is already occupied, or 454b9686e8cSDan Williams if the region is not in a state to accept interleave 455b9686e8cSDan Williams configuration changes. EINVAL is returned if the object name is 456b9686e8cSDan Williams not an endpoint decoder. Once all positions have been 457b9686e8cSDan Williams successfully written a final validation for decode conflicts is 458b9686e8cSDan Williams performed before activating the region. 459176baefbSDan Williams 460176baefbSDan Williams 461176baefbSDan WilliamsWhat: /sys/bus/cxl/devices/regionZ/commit 462176baefbSDan WilliamsDate: May, 2022 4638752efd2SDan WilliamsKernelVersion: v6.0 464176baefbSDan WilliamsContact: linux-cxl@vger.kernel.org 465176baefbSDan WilliamsDescription: 466176baefbSDan Williams (RW) Write a boolean 'true' string value to this attribute to 467176baefbSDan Williams trigger the region to transition from the software programmed 468176baefbSDan Williams state to the actively decoding in hardware state. The commit 469176baefbSDan Williams operation in addition to validating that the region is in proper 470176baefbSDan Williams configured state, validates that the decoders are being 471176baefbSDan Williams committed in spec mandated order (last committed decoder id + 472176baefbSDan Williams 1), and checks that the hardware accepts the commit request. 473176baefbSDan Williams Reading this value indicates whether the region is committed or 474176baefbSDan Williams not. 4757ff6ad10SAlison Schofield 4767ff6ad10SAlison Schofield 4777ff6ad10SAlison SchofieldWhat: /sys/bus/cxl/devices/memX/trigger_poison_list 4787ff6ad10SAlison SchofieldDate: April, 2023 4797ff6ad10SAlison SchofieldKernelVersion: v6.4 4807ff6ad10SAlison SchofieldContact: linux-cxl@vger.kernel.org 4817ff6ad10SAlison SchofieldDescription: 4827ff6ad10SAlison Schofield (WO) When a boolean 'true' is written to this attribute the 4837ff6ad10SAlison Schofield memdev driver retrieves the poison list from the device. The 4847ff6ad10SAlison Schofield list consists of addresses that are poisoned, or would result 4857ff6ad10SAlison Schofield in poison if accessed, and the source of the poison. This 4867ff6ad10SAlison Schofield attribute is only visible for devices supporting the 4877ff6ad10SAlison Schofield capability. The retrieved errors are logged as kernel 4887ff6ad10SAlison Schofield events when cxl_poison event tracing is enabled. 489